JP2645647B2 - Pre-stroke control device for pre-stroke control type fuel injection pump for diesel engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-stroke control device for a pre-stroke control type fuel injection pump for a diesel engine for injecting fuel into a combustion chamber of an internal combustion engine.

2. Description of the Related Art Conventionally, in a fuel injection pump for pumping fuel to a fuel injection nozzle of a diesel engine, control of a fuel injection amount is performed by rotating a plunger for pressurizing fuel in the pump, and control of fuel injection timing. Is performed by changing the coaxial rotation phase with respect to the crank angle phase of the engine by a centrifugal or electronic auto timer provided on a plunger drive cam shaft driven by the engine. I was However, in the case of injection timing control, since the inertial mass of the camshaft is relatively large, and the driving torque of the pump transmitted from the coaxial to the plunger is large, the above-described timer is also necessarily large.
As a result, there have been problems such as an increase in cost and an increase in the size of the entire pump.

For this purpose, the present applicant has a control sleeve slidably fitted to the outside of the plunger for pressurizing the fuel, and by moving the control sleeve in the axial direction of the plunger by the actuator, the pre-stroke of the plunger is performed. A pre-stroke control type fuel injection pump configured to control the fuel injection timing and the fuel oil supply rate by changing the fuel injection timing has already been proposed.

Problems to be Solved by the Invention It is an object of the present invention to adjust the prestroke of the plunger of the prestroke control type fuel injection pump, that is, the fuel injection timing and the fuel feed rate, to optimal values according to the operating state of the vehicle. An object of the present invention is to control an actuator for moving a control sleeve so as to control the fuel injection pump, prevent the fuel injection pump from being damaged, improve running feeling and fuel efficiency of the vehicle, and reduce exhaust gas.

Means for Solving the Problems The pre-stroke control device for a diesel engine pre-stroke control type fuel injection pump according to the present invention responds to various operation state information from an operation state information source, and performs steady operation, acceleration operation, Determining means for determining an operation mode corresponding to an operation state of a deceleration operation, a start-up operation and a warm-up operation, and selecting one of a plurality of pre-stroke maps corresponding to the operation mode; And a limit pre-stroke value calculation circuit that calculates a target pre-stroke value based on the engine speed and the fuel injection amount from a usage limit map. And the lower one of the calculated target pre-stroke value and the limit pre-stroke value is selected and output. A low value selection circuit for controlling the electric actuator to control the pre-stroke of the plunger according to the selected lower value.

According to the above configuration, the target pre-stroke value is calculated from the pre-stroke map corresponding to the operation mode determined according to the predetermined operation state, and based on the engine speed and the fuel injection amount from the usage limit map. A limit pre-stroke value is calculated, and the control sleeve is moved via the actuator to adjust the fuel injection timing and fuel delivery rate such that the plunger pre-stroke matches the lower of the pre-stroke values. The use limit map controls the fuel injection timing so that the fuel injection pump can be used below the pump withstand pressure limit even in a high engine speed range, thereby preventing damage to the fuel injection pump. This makes it possible to increase the pump discharge pressure in the middle and low rotation range, improve the running feeling and fuel efficiency of the vehicle by improving the engine output, and reduce black smoke and white smoke in exhaust gas.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment of Fuel Injection Pump] A first embodiment of a prestroke control type fuel injection pump for a diesel engine applied to the present invention shown in FIGS.
In the embodiment, reference numeral 2 denotes a housing of a row type fuel injection pump of a diesel engine, and 4 denotes one of a plurality of barrels held in the housing. They are located side by side on a plane. Reference numeral 6 denotes a discharge valve holder connected to each cylinder of the engine mounted on the upper part of each barrel 4, 7a denotes a discharge valve, 8 denotes a plunger slidably fitted in each barrel 4, and 10 denotes a plunger. , A cam for raising the plunger 8 in conjunction with a drive shaft of an engine (not shown), a control sleeve 14 slidably fitted around the outer periphery of the plunger 8, and 16 fixed to each barrel 4. A guide pin 18 which engages with the guide groove 17 of the control sleeve 14 to restrict its rotation is a sleeve rotatably supported by the barrel 4 and non-rotatably engaged with the plunger 8. The plunger 8 has an oil passage 8a communicating the upper end surface and the peripheral side surface, a peripheral side opening 8b formed in the peripheral side surface communicating with the oil passage 8a, and a peripheral side surface continuous with the opening 8b and along the plunger 8 axis. A vertical groove 8c engraved in the groove, and an inclined groove 8d that intersects the vertical groove 8c and is inclined with respect to the plunger axis. The two grooves 8c and 8d and the oil supply hole 8b (hereinafter, referred to as an opening) are provided. A control groove is formed. On the other hand, the control sleeve 14 is provided with a control hole 14a for defining the end of the injection. here,
When the plunger 8 makes a predetermined effective stroke as shown in FIG. 6, the conditions for injecting fuel are as follows: the upper and lower width and length of the control sleeve 14 are 10 and the length including the vertical groove 8c and the opening 8b. Is assumed to be l1, it is required that the relationship l0> l1 be established. As shown in FIG. 7, when the plunger 8 injects fuel with the minimum effective stroke, the condition for preventing the two-stage blowing at the end of the injection is determined by the condition between the upper edge of the control hole 14a and the upper end of the control sleeve 14. The length between them is l4, the control hole 14
aWhen the length between the upper edge and the upper end of the vertical groove 8c is l3, l3 ≧ l
Four relationships are required to be established. Further, as shown in FIG. 8, when the plunger 8 moves up and down at a position where the control hole 14a faces the vertical groove 8c, that is, the condition for determining no fuel injection is determined by the lower edge of the control hole 14a and the control sleeve. When the length between the lower end and the lower end is 14, it is required that the relationship of l1> l2 is established. Further, in FIG.
Even if the control hole 14a is closed by the plunger 8 at the lower edge of the opening 8b in the state of the non-injection operation, the condition for reliably realizing the non-injection is required to satisfy the relationship of l1 ≧ l4. In FIG. 3, reference numeral 15 denotes a fuel chamber for storing fuel supplied from a feed pump (not shown). Since the fuel is fitted to the barrel 4 while the plunger 8 is kept oil-tight, the cam shaft Room 13 does not leak. Also 21
Is a lubrication port for supplying lubricating oil into the camshaft chamber 13, and 23 is a guide pin protruding from the tapet 25, and slidably engages with a guide groove 27 formed in the housing 2.
Further, although not shown in FIG. 4, reference numerals shown in FIG.
Reference numeral 29 denotes an adjustment screw (not shown in FIGS. 4 and 11) for fine adjustment of a pre-stroke screwed into a screw hole of an operation shaft 26 to be described later. By rotating the plunger 8, the pre-stroke of the plunger 8 can be finely adjusted.

Further, in the above configuration, when the cam 12 makes one rotation by the cam shaft 12a which is interlocked by receiving the rotational force from the drive shaft of the engine, the roller 25a of the tapet 25 lifts the plunger 8 upward by a constant amount every time the cam 12 is pressed. The amount reciprocates up and down one stroke.

Here, the plunger 8 is moved from the state shown in FIG.
Fig. 10 (a) ~
To explain (e) (assume that the control sleeve 14 is at a fixed position), the relative position between the plunger 8 and the control sleeve 14 is as shown in FIG. When it is not yet completely closed, the pressurizing chamber 20 and the fuel chamber 15 are in communication with each other, so that no fuel is pumped. Next, when the opening 8b is closed by the control sleeve 14 as shown in FIG. 3C via the state of FIG. 2B, the pressurizing chamber 20 is shut off from the fuel chamber 15 and pressurized by the plunger 8. . The stroke of the plunger 8 between (a) and (c) is called pre-stroke.
When the plunger 8 continues to rise as shown in FIGS. (C) to (d), the discharge pressure in the pressurizing chamber 20 overcomes the spring force of the spring 7b of the discharge valve holder 6, and the discharge valve 7a opens, The high-pressure fuel is supplied to the injection nozzle V via the injection pipe 6a. Then, the inclined groove 8d of the plunger is moved to the control hole 14a as shown in FIG.
The fuel is fed under pressure until it communicates with the control chamber 14a, but when the inclined groove 8d comes to face the control hole 14a as shown in FIG.
“0” communicates with the fuel chamber 15 via the oil passage 8a, the opening 8b, and the groove 8c, and the pressure feeding ends. As is apparent from FIG. 5, the inclined groove 8d extends on the outer periphery of the plunger 8 so as to be inclined with respect to the axis thereof. The corresponding time between the inclined groove 8b and the opening 14a of the control sleeve 14 can be changed in the stroke, whereby the injection amount of the plunger 8 per stroke can be adjusted. The displacement of the sleeve 18 in the rotation direction is performed by displacing the rack 24 engaging with the ball 22 fixed on the sleeve 18 in the longitudinal direction thereof.

Next, the control mechanism of the injection timing will be described. The control of the injection timing is performed by sliding the control sleeve 14 along the plunger 8.
An operating shaft 26 which is supported by the housing 2 and has an axis on a side of the control sleeve 14 which is parallel to a plane on which the above-mentioned barrels 4 are arranged in parallel and which is perpendicular to the axis of the plunger 8; A lever 28 which is fixed and extends from the operation shaft toward the plunger 8; and a rotational displacement about the operation shaft 26 of the lever, which is formed on the outer peripheral surface of the control sleeve 14 and is engaged with the distal end of the lever 28. This is performed by the notch groove 14b for interlocking the sliding displacement of the control sleeve 14. In addition,
The outer peripheral surface of the distal end of the lever 28 has a curvature that is always in contact with the inner peripheral surface of the cutout groove 14b so as to prevent play. As shown in FIG. 11, the support portions 26a at both ends of the operating shaft 26 are provided via bearings 30 having an outer diameter larger than the diametric outer size of the operating shaft including the operating shaft and the lever 28. And a plate 32 is interposed between one end of the bearing 30 and the housing 2. 34 is a snap ring which is fitted to the housing 2 to prevent the bearing 30 from coming off.
Reference numeral 36 denotes a positioning pin which is implanted in the bearing 30 and penetrates through the plate 32 to engage with the housing 2. The operation shaft 26 is attached by mounting the barrel 4, the plunger 8 and the control sleeve 14 on the housing 2 and then connecting the operation shaft 26 to the housing 2.
This is done by inserting from the end.

The rotational displacement of the operating shaft 26 is controlled by an operating lever fixed to one end of the operating shaft 26 as shown in FIGS.
And a pre-stroke actuator 44, such as a linear solenoid, which is supported by a bracket 41 on the housing 2 and rotates the operation lever 40 via a slider 42, in order to operate the actuator accurately. A pre-stroke sensor 46 such as a potentiometer or a differential transformer sensor for measuring the rotational displacement of the operation lever 40.
Are supported by the bracket 41. A control unit, which will be described later, integrates various operating state information and information on the rotational displacement of the operating shaft 26 from the pre-stroke sensor 46 to calculate and obtain accurate pre-stroke control of the plunger 8. Have been.

According to the above-described configuration of the first embodiment, the inclined groove 8d which rotates the plunger 8 around its axis to form a part of the control groove.
By changing the relative position of the control hole 14a with respect to the effective stroke of the plunger, the fuel injection amount can be adjusted. When the vertical groove 8c is aligned with the control hole 14a, a non-injection state can be obtained as shown in FIG. When the operation shaft 26 having the lever 28 is rotated, the control sleeve 14 is displaced in the axial direction of the plunger. For this reason, when the pre-stroke of the plunger changes, the injection timing can be adjusted. And
The dimensions of each part between the plunger and the control sleeve are 6th to 6th.
As shown in FIG. 9, l0> l1 (formula (1)), l1> l2
(Equation (2)), l1 ≧ l4 (Equation (3)), and l3 ≧ l4
Since the relationship of (Equation (4)) is set to be satisfied, the condition for enabling injection according to Expression (1) is the condition for ensuring no injection according to Expression (2), and the condition for ensuring no injection is according to Expression (3). In the non-injection operation state, when the condition for reliably preventing the injection of the fuel is that the injection is performed with the minimum effective stroke according to the equation (4), the plunger 8 is displaced to the top dead center as shown in FIG. At this time, even if the control hole 14a does not communicate with the control groove, the condition that the upper end of the vertical groove 8c faces the fuel chamber 15 from the upper end of the control sleeve 14 to prevent the fuel from being blown in two stages is defined. You. For this reason, reliable fuel injection amount control and injection timing control can be realized, and the injection timing can be controlled with a small operating force, so that the injection timing control can be electronically controlled. That makes the structure simple. Further, since the plunger 8 is oil-tightly fitted in the lower cylindrical portion of the barrel 4, the fuel in the fuel chamber 15 can be prevented from flowing into the camshaft chamber 13. Further, the profile of the cam 12 was changed while maintaining the plunger diameter shown in FIG. 3 to increase the cam lift amount, or the plunger diameter alone was increased while the cam lift amount was unchanged, and the discharge pressure, that is, the pump pressure was increased. In the case of a pump having a structure, when the pump pressure reaches the vicinity of the pump withstand pressure, that is, in the high engine speed range, it is easy to perform an advancing operation (moving the control sleeve 14 downward) by the injection timing control. Since the pump can be used at a pressure lower than the pump withstand pressure, it is possible to increase the pump discharge pressure in a medium to low load region, and to improve the engine output in the same region.

In the first embodiment, the control groove is provided on the plunger 8 and the control hole 14a is provided on the control sleeve 14. However, the control groove may be provided on the control sleeve side, and the control hole may be provided on the plunger side. Although it is engraved on only one peripheral surface of the plunger 8, it may be provided on the opposite peripheral surface. The opening 8b penetrates the plunger and the control hole 14a of the control sleeve.
Are provided two each, but both are located at corresponding positions.
It may be individual. As a modified example of the control groove of the above embodiment, as shown in FIG. 13, a control groove having a vertical groove 8c, an inclined groove 8d, and an opening 8b communicating with an oil passage 8a in a plunger may be used. In this case, the inner diameter d1 of the control hole is set so as to be at least equal to or larger than the distance d0 between the two grooves 8c and 8d in order to ensure a state of no injection. 14 and 15
The control groove shown in the figure may be used. Further, in the first embodiment, if the notch is provided over the inner and outer peripheral surfaces of the upper end of the control sleeve 14 or the notch is provided at the lower end of the first barrel portion 4a, the control sleeve becomes the first barrel. Even if the lower end of the portion 4a comes into contact with the lower end and becomes oil-tight, fuel is discharged from the notch into the fuel chamber, so that two-stage blowing can be prevented.

Next, as shown at point P in FIG.
The operation and effect will be described by taking as an example a case where the height of the cam 12 is 14 mm (having a cam profile shown in FIG. 19) and the cam 12 has a configuration shown in a cam diagram shown in FIG.

As shown in FIG. 18, the relationship between the camshaft rotation speed and the pump discharge pressure is represented by a graph M. At this time, assuming that the working pressure limit of the pump is 800 kg / cm ² , in the so-called middle and low engine speed range of the engine in which the number of rotations of the cam is from 500 to about 900 rpm, the cam angle shown in the cam diagram of FIG. , The discharge pressure of the fuel is increased by the plunger 8 as the engine speed increases. When the camshaft reaches about 900 rpm, the working pressure of the pump is reached. About 90
0 rpm, that is, when the point M is reached, the control sleeve 14
Is moved downward along the plunger 8 by a predetermined amount. Then, the pre-stroke of the plunger 8 is shortened, and fuel is injected when the speed constant is in the direction of the arrow, ie, the cam angle is in the range of 2θ, as shown in FIG. Therefore, as shown in Fig. 18, in the high engine speed range, the fuel is sent from the fuel injection pump to the engine at a constant and maximum discharge pressure M "regardless of the engine speed. The angle is controlled, and the fuel is injected into the combustion chamber at an appropriate time, mixed with the air in the same chamber, and burned.

Now, the main specifications of the fuel injection pump (injection pump having a structure in which the injection timing is adjusted by a centrifugal auto timer) used in each type of diesel engine already known on the market are described as follows. It looks like a table.

From this, plotting the average oil feed rate (mm ³ / deg) on the horizontal axis and (plunger diameter) ² × cam lift on the vertical axis for models A to J gives the graph of FIG. From this graph, the geometric average oil transfer rate V _p (mm ³ / deg), the plunger diameter D (mm) and the cam lift h (mm) are V = 2.47.
It can be seen that the relational expression of × 10 ⁻² × D ² × h holds. This relational expression means that the average oil transfer rate can be almost calculated from the plunger diameter and the cam lift.

Incidentally relates model A-J, looking at the relationship between the stroke volume per single cylinder of the engine V _s (l) and the geometric mean oil feed rate V _p, is shown as the graph of FIG. 17, each fuel It can be seen that the pump is included in the area below the straight line K. In other words, it can be said that there is no injection pump in a region above the straight line K that increases the average oil supply rate, that is, the discharge pressure, to increase the fuel injection amount per unit angle of the cam. The reason for this is related to the fact that the injection timing of each of the conventional injection pumps A to J was adjusted using a centrifugal auto timer. That is, as shown by the dashed line in the graph of FIG. 18, each of the injection pumps A to J is designed so that the discharge pressure of the pump reaches a state almost close to the pressure resistance limit of the pump itself when the engine is in the maximum rotation range. This is because the injection timing control is performed by sequentially changing the rotation phase of the camshaft with respect to the crank angle phase of the engine in the intermediate range. For this reason, the engine's low-to-medium
(Corresponding to the number of rotations of the camshaft 00).
It cannot be used at all in the area indicated by N to improve the engine output performance.

Therefore, when the injection timing control is performed in the fuel injection pump of the present embodiment, the fuel is injected within the range of the cam angle θ2 as apparent from FIG. At this time, the cam lift is lower than in the range of the cam angle θ1, which is a normal injection timing. Accordingly, the pump discharge pressure can be prevented from decreasing or increasing when the injection timing is advanced.

Hereinafter, the relationship between the injection timing control and the pump discharge pressure will be described in detail.

For example, the profile of the cam 12 is formed in a cam shape having the dimensions shown in FIG. 19, the lift amount is set to 14 mm, and the resulting cam diagram is shown in FIG. Here sets the diameter of the plunger 8 to 12 mm, when determining the geometric average oil feed rate V _p obtained at this ^{time, = 2.47 × 10 -2 × D} 2 × h = 2.47
× 10 ^-2 × 12 ² × 14 ≒ 49.8 mm ³ / deg. When this is plotted in the graph of FIG. 17, the point P is obtained. Similarly, when D = 12 and h = 15, V _p ≒ 55 and the point Q in the graph is D = 12 and h = 1.
When 2.5, the point R is at V _p ≒ 45, and when D = 9.5 and h = 12, V _p ≒
Point S 26.5 is, D = 9.5, the point at V _p ≒ 24.5 when h = 11 T
When D = 9.5 and h = 9.6, the point U is obtained when V _p ≒ 21.5,
Each is depicted in Figure 17. Table 2 is obtained by rearranging the points P to U.

Thus as shown in Figure 17. If brought into increased cam lift against plunger diameter as compared to Table 1, it can be seen that the average oil feed rate V _p is plotted in the upper portion of the straight line K.

By the way, in the row type injection pump, there is a certain limit in increasing the diameter of the plunger due to the restriction of the arrangement interval of the barrel fitted to the plunger. It is not preferable that the height of the pump housing mounted on the engine greatly exceeds the upper end because of the engine mountability.Therefore, there is a limit to increasing the cam lift. Since the position of the mounting bolt hole at the time of mounting on the engine is restricted, there is a limit in increasing the base circle of the cam 12 and the cam lift.

To determine the plunger diameter and cam lift to be applicable in consideration of these design conditions of each pump, the average oil feed rate V _p as shown in FIG. 17 is a straight line V connecting the point Q and the point S
_p1 = a 22.8V _s +10.8, linear V _p2 = 18 bear the point R and point U.
It is within the range that satisfies the relational expression between the two relations of 8V _s +10.2 (the shaded portion in FIG. 17) and is within this range.
Based on V _p , a plunger diameter D and a cam lift h that satisfy the relational expression of V _p = 2.47 × 10 ⁻² × D ² × h can be selected and adopted. Here, V _s represents the stroke volume per single cylinder of the engine (l).

As described above, the engine operates as a fuel injection pump having a high discharge pressure in the middle and low rotational speed range of the engine, so that the engine output can be improved. In a high rotational speed range of the engine, the injection timing is advanced at the maximum discharge pressure. Therefore, the engine can be operated under optimum control, and the pump (solid line) of the present embodiment has a higher engine speed than the conventional injection pump (dashed line) as shown in the graph of FIG. Since the injection time is configured to be short in the entire rotation range, fuel efficiency is improved accordingly, and smoke emission performance is also improved.

In FIG. 18, the straight line L indicates each case of D = 12.5 and h = 14, and the straight line N indicates each case of D = 12 and h = 13. In the above description, the pump withstand pressure is 800 kg / cm ² , but the present invention is not limited to this.
Although the interval between −M ″ is almost equal to the pump withstand pressure, the pre-stroke may be controlled to be equal to or less than the pump withstand pressure.

Further, in this embodiment, the cam having the profile shown in FIG. 19 was used. However, when the radius R1 of the profile was increased, the velocity constant line as shown by the two-dot chain line abcd in FIG. A trapezoidal figure is obtained. In this profile, the velocity constant between b and c becomes substantially constant (the lift curve also changes, although not shown). When fuel is injected in this cam angle range, the average pressure of the injection is large, so the fuel chamber The fuel particles injected into the combustion chamber are small and sufficiently diffuse into the combustion chamber to burn effectively. Further, since the average injection pressure is large, the range of selection of the injection timing (particularly, the advance timing) is widened.

[Second Embodiment of Fuel Injection Pump] Next, a second embodiment of the prestroke control type fuel injection pump for a diesel engine shown in FIGS. 22 to 26 will be described. Note that components that are the same as or similar to those of the first embodiment will be described with the same reference numerals. A control sleeve 14 is externally fitted to the plunger 8, and an outer peripheral surface 141 of the control sleeve is fitted.
The ball portion 281 at the tip of the operation lever 28 extending from the operation shaft 26 fits into the hole 142 formed at the bottom. As shown in FIG. 24 (a), the plunger 8 has an oil passage 8a communicating the upper end surface 811 and the peripheral side surface 812 and a peripheral side opening 8b formed in the peripheral side surface 812. One end communicates with the inclined groove 8d in which the position of the plunger 8 in the longitudinal direction gradually changes. On the other hand, the control sleeve 14 has a downward surface as an injection start surface 143, and further has a control hole 14a for communicating between the inner peripheral side surface and the outer peripheral side surface. Therefore, in the process of ascending plunger 8 from home position P0 shown by a solid line in FIG.
Make an empty movement (pre-stroke) only. Further, from the position (indicated by a dashed line in FIG. 24 (a)) P1 at which the lower end of the peripheral side opening 8b of the oil passage 8a and the lower end of the inclined groove 8d have reached a position above the injection start surface 143 of the control sleeve. The effective stroke b of the plunger extends to a position where the groove 8d faces the control hole 14a of the control sleeve, during which the plunger 8 can pressurize the fuel in the pressurizing chamber 20 above the plunger.

The operating shaft 26 extends along the direction in which other pressurizing units (not shown) in the injection pump are arranged, and is slidably and rotatably mounted on the housing 2 via a bearing (not shown). . As shown in FIG. 23, at one end of the operation shaft 26, a spline portion 261 and a pair of flange portions 262 subsequent thereto,
263 are each formed. The spline portion 261 is provided with a lever for adjusting the injection timing in which the movement of the operation shaft 26 in the axial direction B is restricted by the lever restricting piece 2a on the housing 2 side, and the operation shaft 26 is movably locked in the axial direction B. A first lever (hereinafter, simply referred to as a first lever) 40 is attached, and can be operated to rotate the operation shaft 26 in the shaft rotation direction A. On the other hand, in the gap between the pair of flanges 262 and 263, an injection amount adjusting lever (hereinafter simply referred to as the second lever) which is pivotally supported by the pin 51 on the housing 2 and locks the operation shaft 26 so as to be rotatable about the shaft. 24) is attached, which allows the operating shaft 26
Can be operated to move in the axial direction B. A pre-stroke actuator 44 such as a linear solenoid is connected to a pivot end of the first lever 40 via a slider 42.
However, a well-known governor 54 is connected to the rotating end of the second lever 24. The pre-stroke actuator 44 is controlled by a control unit 52, and a pre-stroke sensor 46 such as a position meter for measuring the rotational displacement of the first lever 40 is provided for accurately operating the pre-stroke actuator 44. Have been. The control unit 52 has engine speed, accelerator pedal position,
Various operating state information sources 50 such as engine coolant temperature, intake air temperature, intake system boost pressure, and fuel injection amount are connected,
The operation state information and the information from the pre-stroke sensor 46 are integrated and calculated to more accurately control the pre-stroke of the plunger 8.

The operation of the injection pump shown in FIG. 22 will be described. When a diesel engine (not shown) is driven, the camshaft 12a rotates in conjunction therewith to move the plunger 8 up and down. At the same time, the governor 54 and the control unit 52 operate to support the control sleeve 14 via the operation shaft 26 in a predetermined state. Here, the control sleeve 14 is connected to the home position (No.
(See FIG. 24 (a)) Assuming that it is in S0, first, the control unit 52 supplies an output current to the actuator 44, and the first
It is assumed that the lever 40 rotates the operation shaft 26 and the control sleeve 14 moves down to the position S1 shown in FIG. 24 (b). In this state, when the plunger 8 rises from its home position P0, the lowermost end of the inclined groove 8d and the peripheral side opening 8b of the oil passage 8a move to a position P1 reaching above the injection start surface 143,
The pre-stroke a1 becomes relatively small, and the injection timing is advanced. Conversely, the control sleeve 14 has its home position
If it moves to a position above S0, the injection timing will be delayed. Note that the effective stroke b does not change during the injection timing adjustment. On the other hand, when the governor 54 operates, the operation shaft 26 is moved in the axial direction B by the second lever 24.
That is, the operation shaft 26 reaches the position L1 which is separated from the home position L0 (see FIG. 25) by the sliding amount C (see FIG. 26).
14a is rotated by a predetermined amount. When the plunger 8 rises above the home position P0 in this state (see FIG. 24 (c)), the pre-stroke a of the plunger does not change compared to the case shown in FIG. 24 (a). However, the facing portion of the inclined groove 8d facing the control hole 14a is a portion where the position in the longitudinal direction of the plunger is lower (compared to the case of FIG. 24 (a)), and the effective stroke b1 is large. Conversely, when the control sleeve 14 rotates in the opposite direction to the case shown in FIG. 26, the effective stroke becomes smaller. By displacing the control hole 14a of the control sleeve in this manner, the plunger 8
The injection amount per one stroke can be adjusted.

The injection pump shown in FIG.
The injection timing can be adjusted by rotating the lever 40 in the axial rotation direction A, and the injection amount can be adjusted by moving the lever in the axial direction B by the second lever 24.

In the above-described process, the operating shaft 26 was slidably engaged with the first lever 40 via the spline portion 261. Instead, as shown in FIG. 27, the implantation key 60 was mounted on the operating shaft 26, On the other hand, a configuration in which the slidable first lever 40 is fitted outside may be adopted. Further, although the electromagnetic solenoid 44 is connected to the first lever 40, a hydraulic cylinder (not shown) may be used instead.

[Prestroke control device according to the present invention]

Next, a pre-stroke control device for controlling the fuel injection timing and the fuel transfer rate by the control sleeve of the above-described diesel engine pre-stroke control type fuel injection pump will be described.

In FIG. 28, as described above, the pre-stroke control device includes the operation state information source 50 and the control unit 5.
2. It is composed of a pre-stroke actuator 44 and a pre-stroke sensor 46. Operating state information sources 50, an engine rotational speed sensor 70 for detecting the engine rotational speed N _E, vehicle speed sensor 71 for detecting the speed of the vehicle, start switch 72 to be ON when starting the engine, when the depressed brake pedal Niyu Tsentralnyi Sui Tutsi 75 brake switch 73 becomes oN, Kuratsuchisuitsuchi 74 becomes oN when depressed the Kuratsuchipedaru, transmission is turned oN when in a Niyutoraru position, coolant temperature sensor 76 for detecting an engine coolant temperature T _W,
An intake air temperature sensor 77 for detecting the intake air temperature, an intake pressure sensor 78 for detecting the boost pressure of the intake system, a fuel temperature sensor 79 for detecting the temperature of the fuel supplied to the fuel injection pump, and a fuel injection for detecting the fuel injection amount Q the amount sensor (or the rack-and-pinion position sensor for detecting the position R _W of rack-and-pinion 24) 80, and an accelerator pedal position sensor 81 that detects an accelerator pedal position a _CC
Consists of

ON information from switches 72 to 75 is the control unit
The data is input to the microprocessor 87 via the buffer 84 in the 52. The engine speed and vehicle speed information, which are pulse signals from the sensors 70 and 71, are shaped by the waveform shaping circuit 83 and then input to the microprocessor 87. Other sensors 76 ~
Various information as analog signals from 81 are converted to digital signals by an A / D converter 86 via a multiplexer 85 and then input to a microprocessor 87. The microprocessor 87 includes a first mode, a second mode, and a third mode during a start mode, a warm-up mode, an acceleration mode, a deceleration mode, and a steady operation of the vehicle.
And an 8-bit read / write memory (hereinafter referred to as RAM) 91 having a flag for the fourth mode, and a fixed memory (hereinafter referred to as ROM) 92 having a pre-stroke map corresponding to each of the operation modes. The digital signal output from the microprocessor 87 corresponding to the pre-stroke value corresponding to the predetermined operation state is converted into an analog signal by the D / A converter 88, and then the servo circuit 89 and the amplifier circuit
It is input to the pre-stroke actuator 44 via 90, and operates the actuator to displace the control sleeve 14 to a predetermined position. The pre-stroke sensor 46 feeds back the rotational displacement information of the operation shaft 26 to the servo circuit 89 so that the actuator 44 can be operated accurately, and the pre-stroke sensor 46 sends the information to the microprocessor 87 via the multiplexer 85 and the A / D converter 86. input.

FIG. 29 shows the structure of the microprocessor 87 in more detail. The ROM 92 stores the first, second, third, and fourth mode pre-stroke maps 9 during different steady-state operations.
3, 94, 95 and 96, acceleration mode pre-stroke map 97,
Deceleration mode pre-stroke map 98, start mode pre-stroke map 99, warm-up mode pre-stroke map 10
It has 0 or more limit map 101. Matsupu 93-98 are three-dimensional Matsupu that predetermined optimum prestroke value for plunger 8 in accordance with the engine rotational speed N _E and the fuel injection amount Q (or rack-and-pinion position R _W), and Matsupu 99 Numeral 100 denotes a three-dimensional map in which an optimum pre-stroke value according to the engine speed _NE and the engine cooling water temperature T _W is determined in advance. The service limit map 101 is a three-dimensional map in which the maximum limit of the pre-stroke value according to the engine speed and the fuel injection amount is determined in advance, and is used to specify the service pressure limit of the pump.

Output terminals of the first to fourth mode pre-stroke maps 93 to 96 are connected to a first switching switch 106 which is switched by a steady operation mode determining circuit 102 in the microprocessor 87.
Connected to one fixed contact. The steady operation mode determination circuit 102 responds to the engine cooling water temperature information from the water temperature sensor 76, and in this embodiment, switches the operation mode based on three different cooling water temperatures of 60 ° C, 10 ° C, and -5 ° C. The movable contact of the switch 106 is selectively switched.

The output terminals of the acceleration and deceleration mode prestroke maps 97 and 98 are switched by an acceleration / deceleration mode determination circuit 103 in the microprocessor 87.
And the other fixed contacts of the same switch are connected to the output terminal of the switching switch 106. acceleration·
The deceleration mode determination circuit 103 is an accelerator pedal position sensor 81
In response to the pedal position (Acc) information from the CPU, the accelerator pedal depressing speed ΔA is differentiated. When the determination circuit 103 determines the acceleration mode based on the calculated accelerator pedal depression speed ΔA and the ON information from the brake switch 73, the determination circuit 103 sets the movable contact of the switching switch 107 to the contact to the acceleration mode pre-stroke map 97. If it is determined that the connection has been made, and if the "deceleration mode" is determined, the movable contact of the switching switch 107 is connected to the contact to the deceleration mode pre-stroke map 98. When the “acceleration mode” or the “deceleration mode” is released, the determination circuit 103 switches the switch to return to the steady operation mode.
The movable contact 107 is connected to the contact to the switching switch 106.

The output terminal of the starting mode pre-stroke map 99 is connected to the fixed contact of a third switching switch 108 which is switched by a starting mode determining circuit 104 in the microprocessor 87, and the other fixed contact of the switch is a switching switch 107. Output terminal. The start mode determination circuit 104 receives the ON information from the start switch 72 and the engine speed sensor 70.
Opening Acc which accords with the engine speed information from the engine and the pedal position information from the accelerator pedal position sensor 81
If the "engine start mode" is determined based on these information, the movable contact of the switching switch 108 is connected to the contact to the start mode pre-stroke map 99.
The determination circuit 104 connects the movable contact of the switching switch 108 at the time of canceling the “engine start mode” to the contact to the switching switch 107.

The output terminal of the warm-up mode pre-stroke map 100 is
The fixed contact of a fourth switching switch 109, which is switched by a warm-up mode determination circuit 105 in the microprocessor 87, is connected to the other fixed contact of the fourth switching switch 109.
Output terminal. The warm-up mode determination circuit 105
In response to the engine cooling water temperature information from the water temperature sensor 76 and the ON information from the neutral switch 75, if it is determined that the engine is in the "warm-up mode" based on these information, the movable contact of the switching switch 109 is moved to the warm-up mode pre-stroke map. 1
Connect to the contact to 00. The determination circuit 105 connects the movable contact of the switching switch 109 at the time of releasing the "engine warm-up mode" to the contact to the switching switch 108.

The target pre-stroke value calculation circuit 110 connected to the output terminal of the switching switch 109 converts a predetermined pre-stroke value area from any one of the pre-stroke maps selected by the determination circuits 102 to 105 according to a predetermined operation state. The target pre-stroke value L _ps is obtained by three-dimensionally interpolating the selected pre-stroke value L _{ps according} to the operating state parameters of the engine speed N _E , the fuel injection amount Q (or the rack position R _W ), and the engine cooling water temperature T _W. . That is, first to fourth, while performing an interpolation operation on the engine speed N _E and the fuel injection amount Q with respect to acceleration and deceleration modes prestroke Matsupu 93-98, with respect to start and warm-up mode prestroke Matsupu 99 and 100 is summer to perform an interpolation operation in the engine speed N _E and the cooling water temperature T _W. With such goals prestroke value L _ps obtained in is input to the low value selector circuit 112, is used for control of other system control, for example, a governor 54 for moving the rack-and-pinion 24.

Limit pre-stroke value calculation circuit 111, selects a predetermined prestroke value area from use limit Matsupu 101 in response to the engine speed N _E and the fuel injection amount Q in a predetermined operating state, which was further three-dimensional interpolation operation To obtain the limit pre-stroke value L _{ps LIMIT} . The limit pre-stroke value thus obtained is input to the low value selection circuit 112.
Lower value selector circuit 112 selects and outputs one of the lower value of the target prestroke value L _ps and limitations prestroke value L _{ps LIMIT,} and actuating the pre-stroke activator Yu eta 44 as described above Become.

The failure determination circuit 113 connected to the amplifier circuit 90 determines failure of the fuel injection pump from various parameters and can operate the pre-stroke actuator 44 so as to prevent damage to the pump. .

Each of the above-described prestroke maps 93 to 100 and the use limit map 101 are subjected to three-dimensional interpolation calculation based on two of operating state parameters such as an engine speed, a fuel injection amount, and a coolant temperature. Each map may be subjected to a three-dimensional interpolation calculation using other operating state parameters,
Two-dimensional or four-dimensional interpolation may be performed based on one or three operating state parameters. For example, in the case of the three-dimensional map in which the pre-stroke is a function of the engine speed and the coolant temperature in the start mode prestroke map 99, as shown in FIG. In the case of a three-dimensional map in which the pre-stroke is a function of the cooling water temperature and time, the pre-stroke characteristic curve shown in FIG. In the case of a four-dimensional map as a function of number, cooling water temperature and time, a prestroke characteristic curve as shown in FIG. 32 is obtained.

〔motion〕

Next, the operation of the microprocessor 87 will be described with reference to FIGS.
This will be described with reference to FIG.

When the key switch is turned on and the power is turned on at the time of starting the vehicle, the main routine shown in FIG. 33 is started, and the microprocessor 87 is initialized. Next, start switch 7
2. ON information from the brake switch 73, the clutch switch 74, and the neutral switch 75 through the buffer 84 is input to the microprocessor 87. Also, the microprocessor 87 has a multiplexer 85 and an A / D
The cooling water temperature, intake air temperature, boost pressure, fuel temperature, fuel injection amount, and accelerator pedal position information through the converter 86 are input, and the engine speed and vehicle speed information through the waveform shaping circuit 83 from the sensors 70 and 71. Is input, but the engine speed and the vehicle speed information are pulse signals and are subjected to arithmetic processing. These operating state information are stored in the microprocessor 87.
Put in RAM91. Thereafter, a start mode determination subroutine, a warm-up mode determination subroutine, a steady operation mode determination subroutine, and an acceleration / deceleration mode determination subroutine performed by the determination circuits 102 to 105 are sequentially called.

First, when the start mode determination subroutine is called,
As shown in FIG. 34, it is determined whether or not the start switch 72 is ON based on various operation state information read into the RAM 91. When the switch 72 is ON, it is next determined whether or not the accelerator opening degree is greater than 30% based on the accelerator pedal position information. Acc> In the case of 30%, further determines whether the engine speed is 0 ≦ N _E <300rpm, and when this condition is true, it is determined that the "engine start mode", in the RAM91 The start mode flag is set to 1.
If the above conditions do not apply, the start mode flag is cleared. When the setting or clearing of this flag is completed, the warm-up mode determination subroutine is called.

In the warm-up mode determination subroutine, as shown in FIG. 35, it is determined whether or not the neutral switch 75 is ON, that is, whether or not the transmission is in the neutral position. Switch
If 75 is ON, it is next determined whether or not the engine coolant temperature is T _W ≦ 5 ° C. If this condition is satisfied,
The "engine warm-up mode" is determined, and the warm-up mode flag in the RAM 91 is set to 1. If the above conditions do not apply, the warm-up mode flag is cleared. After the setting or resetting of this flag, the steady operation mode determination subroutine is called.

In the steady operation mode determination subroutine, as shown in FIG. 36, and summer as the cooling water temperature T _W is determined whether corresponds to any temperature range, the cooling water temperature T _W ≧ 60
If it is determined that the temperature is 0 ° C., the fourth mode flag in the RAM 91 is determined. If it is determined that 60 ° C.> T _W ≧ 10 ° C., the third mode flag is determined that 10 ° C.> T _W > -5 ° C. the second mode flag, and if it is determined that the -5 ° C. ≧ T _W to excisional respectively the first mode flag to 1 if. After clearing the other three mode flags after setting the corresponding one mode flag to 1, the acceleration / deceleration mode determination subroutine is called.

In the acceleration / deceleration mode determination subroutine, as shown in FIG. 37, it is determined whether or not the brake switch 73 is ON, that is, whether or not the brake pedal is depressed to brake the vehicle. If switch 73 is not ON, RAM91
The difference dA between the current accelerator opening Acc _NEW and the previous accelerator opening Acc _OLD from the accelerator pedal position information contained in
Differentiate cc with time dt to calculate accelerator pedal depression speed Δ
Ask for A. Accelerator pedal depression speed is a predetermined positive value
It is determined whether or not ΔA ≧ Ca with respect to Ca. If the acceleration condition is satisfied, it is determined that “acceleration mode” is set, the deceleration mode flag is cleared, and the acceleration mode flag is set to 1. . If the acceleration condition does not apply, or if the brake switch 73 is ON, it is determined whether the accelerator pedal depressing speed is ΔA ≦ −Cd with respect to another predetermined positive value Cd. If this deceleration condition that matches during engine braking or braking is applicable,
The deceleration mode is determined, and the acceleration mode flag is cleared and the deceleration mode flag is set. If the deceleration condition does not apply, both the acceleration and deceleration mode flags are cleared. When both flags are set and / or cleared, the subroutine ends.

When any one of the mode flags is set to 1 in this manner, a corresponding prestroke map in the ROM 92 outputs a prestroke value corresponding to the operating state. The pre-stroke actuator 44 is operated so as to be displaced. Thereafter, the main routine returns to the input of information from each switch, and repeats the mode determination.

Microprocessor every predetermined time, for example, every 0.01 second
When the interrupt signal is input to 87, the above-mentioned main routine is temporarily interrupted, and the interrupt routine shown in FIGS. 38 (a) and 38 (b) is started. First, the determination circuits 102 to 105 sequentially determine whether or not the start, warm-up, acceleration, deceleration, first, second, third, and fourth mode flags are set to 1. For example, if the start mode flag is 1
If it is determined that the switch is set to
Eight movable contacts are connected to the contacts to the starting mode pre-stroke map 99, and the head address of this map is entered in a register in the microprocessor 87, and the pre-stroke value area corresponding to the operation state is read. Similarly, when it is determined that any one of the other mode flags is set to 1, the movable contact of the switch 106, 107 or 109 is connected to the contact to the corresponding pre-stroke map 93 to 98 or 100. Then, the start address of the corresponding map is stored in a register, and the pre-stroke value area corresponding to the operation state is read. Next, by the target pre-stroke value calculation circuit 110, the read pre-stroke value region is used for the engine speed _NE and the cooling water T _W in the start mode and the warm-up mode, and for the other modes. In this case, a three-dimensional interpolation calculation is performed on the engine speed _NE and the fuel injection amount Q to obtain a target prestroke value _Lps corresponding to the operating state. At the same time, the start address of the usage limit map 101 is entered into a register in the microprocessor 87, and the limit pre-stroke value area corresponding to the operation state is read. The limit pre-stroke value calculation circuit 111 performs a three-dimensional interpolation calculation of the read limit pre-stroke value region with the engine speed _NE and the fuel injection amount Q to obtain a limit pre-stroke value L _{ps LIMIT} that matches the operating state. Ask. Low value selection circuit 1
According to 12, it is determined whether or not the limit pre-stroke value L _{ps LIMIT} > the target pre-stroke value L _ps . If it is determined that the value L _ps is smaller, the target pro-stroke value L _ps is output as it is, while if it is determined that the value L _{ps LIMIT} is smaller, this value is set to the target pre-stroke value. It is output as L _{ps and} entered into a register in the pre-stroke exit port of microprocessor 87. When this interrupt routine ends and the main routine returns, the target prestroke value _Lps stored in the register of the output port is output according to the main routine, and the prestroke actuator 44 is operated. It will be.

The various routines described above with reference to FIGS. 33 to 38 show an example of a program by a microprocessor. Although not shown in this program, the routine is issued by sensors 70 and 71. An engine speed calculation routine and a vehicle speed calculation routine using an external interrupt function of the microprocessor for calculating the engine speed and the vehicle speed from the pulse signal thus obtained are included.

Although the embodiments of the present invention have been described in detail, the present invention is not limited thereto, and those skilled in the art can make various changes and modifications without departing from the scope of the present invention. I can understand. For example, as a modification of the microprocessor program, part of the main routine in FIG. 33, for example, input of information from each sensor may be performed by a timer interrupt routine or an external interrupt routine, or
Part of the interrupt routine of FIG. 38, for example, the output of the target pre-stroke value _Lps can also be performed by the main routine.
Further, in the fuel injection pump, the pre-stroke control of the plunger 8 by the pre-stroke actuator 44 is used only to change the fuel oil supply rate, and another actuator changes the fuel injection timing via the camshaft phase changing mechanism. In this case as well, it is possible to control the fuel injection timing and the fuel feed rate to optimal values using the above-described pre-stroke control device.

As described above, in the prestroke control device for the diesel engine prestroke control type fuel injection pump according to the present invention, the engine speed, the engine cooling water temperature, the accelerator opening, the accelerator pedal depression speed, the start key, the The start mode, warm-up mode, first to fourth modes during normal operation, acceleration mode and deceleration mode are determined from various operation state information such as the ON state of the toral switch and brake switch, and the optimal mode is determined for each mode. A target pre-stroke value corresponding to a predetermined operating state is calculated from a pre-stroke map in which a predetermined pre-stroke value is predetermined, and a limit corresponding to a predetermined operating state is determined from an operating limit map in which a working pressure limit of the pump is determined. Calculates the pre-stroke value and calculates the pre-stroke value according to the lower value of both pre-stroke values. By preparative stroke activator Yu eta 44 is operated to move the control sleeve 14, it is possible to control the pre-stroke of the plunger 8 so as to control the fuel injection timing and fuel oil feed rate to the optimum value.

Therefore, in any operating state, the target pre-stroke value does not exceed the limit pre-stroke value that defines the operating pressure limit of the pump. In this case, the pump discharge pressure can be increased, and the maximum pump discharge pressure can be maintained in the high rotation range. For this reason, since the fuel injection pressure is increased, the fuel particles injected into the engine combustion chamber become minute and sufficiently diffused, so that the combustion efficiency is improved, and the output and fuel efficiency of the engine can be improved.

In addition, since the optimal pre-stroke value according to the operating state can be obtained, it is possible to improve the running feeling during steady operation, the acceleration feeling required during acceleration, and the deceleration feeling during deceleration, and the black smoke during deceleration. Generation and generation of white smoke at the time of starting and warming-up can be suppressed or prevented. Furthermore, the engine can be easily started and the warm-up time of the engine during warm-up can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of a pre-stroke control type fuel injection pump for a diesel engine applied to the present invention, FIG. 2 is a side view seen from an arrow II in FIG. 1, and FIG. Is a cross-sectional view taken along the line III-III in FIG. 1, FIG. 4 is an exploded perspective view showing main components, FIG. 5 is an enlarged perspective view of a main part of the plunger 8 and the control sleeve 14, and FIGS. FIGS. 10 (a) to 10 (e) are operation explanatory diagrams showing an operation at a relative position between the plunger 8 and the control sleeve 14, FIGS.
FIG. 12 is a sectional view taken along the line XI-XI, and FIG.
13 to 15 are front views showing modified examples of the control grooves cut on the outer peripheral surface of the plunger, and FIG. 16 is a diagram showing the average oil feed rate and (plunger diameter D) ² × cam reflote. FIG. 17 is a graph showing the relationship between the stroke volume per cylinder of the engine and the geometric average oil supply rate, and FIG.
FIG. 19 is a graph showing the relationship between the camshaft rotation speed and the pump side pipe internal pressure. FIG. 19 is a front view showing a cam profile. FIG. 20 is a cam diagram. FIG. 21 is a characteristic diagram of the pump shown in FIG. , FIG. 22 is a sectional view showing a second embodiment of the pump, FIG. 23 is a perspective view of a main part of the pump of FIG. 22, and FIGS. 24 (a) to (c) are explanatory diagrams of the operation of the plunger and the control sleeve. FIG. 25 is a cross-sectional view of a main part of FIG. 24 (a), FIG. 26 is a cross-sectional view of a main part of FIG. 24 (c), and FIG. 27 is used for another modification of the second embodiment. FIG. 28 is a circuit diagram of a pre-stroke control device according to the present invention, FIG. 29 is a circuit diagram showing the microprocessor 87 of FIG. 28 in detail, and FIGS. Graphs showing the characteristics of different starting prestroke maps, respectively, FIG. 33 is a flowchart showing a main routine by the microprocessor, and FIG. 34 is a starting mode shown in FIG. Flow chart illustrating a de determination subroutine, FIG. 35 flow chart showing a warming-up mode determination subroutine Figure 33, Figure 36 is a
33 is a flowchart showing a steady operation mode determination subroutine of FIG. 33, FIG. 37 is a flowchart showing an acceleration / deceleration mode determination subroutine of FIG. 33, and FIGS. 38 (a) and (b) are interrupt routines by a microprocessor. FIG. 2 ... housing, 7a ... discharge valve, 8 ... plunger,
8a ... oil passage, 8b ... opening, 8c ... vertical groove, 8d ... inclined groove,
12 ... Cam, 12a ... Cam shaft, 14 ... Control sleeve, 14a
... control hole, 20 ... pressurizing chamber, 26 ... operating shaft, 28 ... lever, 40 ... operating lever, 44 ... prestroke actuator, 46 ... prestroke sensor, 50 ... operating state Information source, 52: Control unit, 70: Engine speed sensor, 71: Vehicle speed sensor, 72: Start switch, 73: Brake switch, 74: Clutch switch, 75: Neutral switch, 76 ... … Water temperature sensor,
77 ... intake air temperature sensor, 78 ... intake air pressure sensor, 79 ... fuel temperature sensor, 80 ... fuel injection amount sensor, 81 ... accelerator pedal position sensor, 83 ... waveform shaping circuit, 84 buffer,
85 multiplexer, 86 A / D converter, 87 microprocessor, 88 D / A converter, 89 servo circuit, 90 amplifier circuit, 91 read / write memory, 92 …
... fixed memory, 93 ... first mode pre-stroke map, 94 ... second mode pre-stroke map, 95 ... third mode pre-stroke map, 96 ... fourth mode pre-stroke map, 97 ... acceleration mode pre Stroke map, 98 …… Deceleration mode pre-stroke map, 99 ……
Start mode pre-stroke map, 100 ... Warm-up mode pre-stroke map, 101 ... Use limit map, 102 ...
································································································
…… Target shake stroke value calculation circuit, 111 …… Limit pre-stroke value calculation circuit, 112 …… Low value selection circuit, 113 ……
Failure judgment circuit.

Continuation of front page (56) References JP-A-56-96132 (JP, A) JP-A-57-113930 (JP, A) JP-A-59-77046 (JP, A) JP-A-59-115441 (JP, A) , A) JP-A-60-13950 (JP, A) JP-A-60-35162 (JP, A) Fully open sho.59-186436 (JP, U) Really open sho 60-1958 (JP, U) Really open 60-125363 (JP, U)

Claims (11)

(57) [Claims] 1. A control sleeve (14) slidably fitted outside a plunger (8) for pressurizing a fuel, and said control sleeve (14) is moved by said actuator (44) to said plunger (8). By moving in the axial direction of
In the pre-stroke control type fuel injection pump configured to control the fuel injection timing and the fuel supply rate by changing the pre-stroke of the plunger, various operations from the operation state information source (50) are performed. In response to the state information, an operation mode corresponding to the operation state of the steady operation, the acceleration operation, the deceleration operation, the start and the warm-up operation is determined, and a plurality of prestroke maps (93 to 93) corresponding to the operation mode are determined.
Judging means for selecting one of 100) (102 to 105)
A target pre-stroke value calculating circuit (110) for calculating a target pre-stroke value (L _ps ) corresponding to a predetermined operating state from the selected pre-stroke map; and an engine speed ( N _E ) and the fuel injection quantity (Q) based on the limit pre-stroke value (L _{ps LIMIT} )
A limit pre-stroke value calculation circuit (111) for calculating
A low value selection circuit (112) for selecting and outputting the lower one of the calculated target pre-stroke value (L _ps) and the limit pre-stroke value (L _{ps LIMIT} ); The electric actuator (4) controls the pre-stroke of the plunger (8) according to the lower value.
4) A pre-stroke control device of a pre-stroke control type fuel injection pump for diesel engines, which is operated in 4). And a determining means for determining a first, second, third or fourth mode during steady operation, and a first, second, third or fourth mode corresponding to the determined mode. The pre-stroke control device according to claim 1, further comprising a steady operation mode determination circuit (102) for selecting a stroke map (93-96). 3. An acceleration / deceleration map for determining an acceleration mode and a deceleration mode and selecting an acceleration mode pre-stroke map (97) and a deceleration mode pre-stroke map (98).
3. The pre-stroke control device according to claim 1, further comprising a deceleration mode determination circuit. 4. A starting mode determining circuit (104) for determining an engine starting mode and selecting a starting mode pre-stroke map (99), wherein the determining means includes a starting mode determining circuit (104). 4. The pre-stroke control device according to claim 3. 5. A warm-up mode judging circuit (105) for judging an engine warm-up mode and selecting a warm-up mode pre-stroke map (100). The pre-stroke control device according to any one of the above items. 6. A target pre-stroke value calculation circuit (110).
But first, second, third, fourth, acceleration and deceleration prestroke map engine speed information from (93 to 98) the operating state information sources (50) (N _E) and the fuel injection amount information (Q ) And a three-dimensional interpolation calculation as a function, and a starting and warming-up mode pre-stroke map (99, 100) is obtained from the engine speed (N _E ) and the engine cooling water temperature (T _W ) from the operating state information source (50). By performing three-dimensional interpolation as a function,
The prestroke control device according to any one of claims 1 to 5, wherein a target prestroke value ( _Lps) is obtained. 7. A limit pre-stroke value calculation circuit (111).
The engine limit information (NE) and the fuel injection amount information (Q) from the operating state information source (50)
Pre-stroke of by three-dimensional interpolation operation as a function, which is to seek the limit prestroke value (L _{ps LIMIT),} according to any one of the claims paragraph 1 to paragraph 6 with Control device. 8. A steady-state operation mode determination circuit (102) determines a first, second, third, or fourth mode in response to an engine coolant temperature (T _W ) from an operation state information source (50). A pre-stroke control device according to claim 2. 9. An acceleration / deceleration mode determination circuit (103) detects accelerator pedal position information (Ac) from an operation state information source (50).
c), the accelerator pedal depressing speed (ΔA) is calculated, and the accelerator pedal depressing speed is set to a first predetermined value (C
4. The pre-stroke control according to claim 3, wherein if it is larger than a), the acceleration mode is determined, and if the accelerator pedal depressing speed is smaller than a second predetermined value (-Cd), the deceleration mode is determined. apparatus. 10. A start mode determination circuit (104) comprising: a start switch ON information from an operation state information source (50); an accelerator opening based on accelerator pedal position information (Acc); and an engine speed information source (N _E ). 5. The pre-stroke control device according to claim 4, wherein a start mode is determined in response to the control signal. 11. A warm-up mode judging circuit (105) judges a warm-up mode in response to neutral switch ON information and engine cooling water temperature information (T _W ) from an operating state information source (50). The pre-stroke control device according to claim 5, wherein