JPH0425427B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention controls the fuel injection amount of a prime mover and the discharge amount of a hydraulic pump based on a rotation speed deviation signal between a target rotation speed signal of the prime mover and an output rotation speed signal. The present invention relates to a control device for a system including a prime mover and a hydraulic pump.

[Background of the invention]

FIG. 4 is a block diagram showing a conventional control device for a system including a prime mover and a hydraulic pump as disclosed in detail in Japanese Patent Application Laid-open No. 57-65822.

In the figure, 1 indicates a prime mover such as a diesel engine, and 2 is a so-called electronic fuel injection pump that electrically controls the amount of fuel injected into the prime mover. 3
4 is a variable displacement hydraulic pump driven by the prime mover 1, and 4 is a so-called electronic pump regulator that controls the tilt angle of the inclined slope (or inclined shaft) of the hydraulic pump 3 by an electric signal. be. The target rotational speed signal No. to the prime mover 1 is set by the driver using the fuel throttle lever 5, while the output rotational speed signal N of the prime mover 1 is detected by the rotational speed detector.
The adder 7 calculates and outputs a rotation speed deviation signal ΔN between the target rotation speed signal No. and the output rotation speed N. Displacement of a rack (not shown) of the fuel injection pump 2 is detected by a rack position detector (not shown), and a rack position signal L is output. The adder 8 controls the rack position based on the deviation signal Lo between the rotation speed deviation signal ΔN given as the rack target position signal and the rack position signal L, and the fuel injection amount of the fuel injection pump 2 is determined.

Further, 9 is a pump control function generator which inputs the pressure signal P from the pressure detector 11 provided in the discharge pipe 10 of the hydraulic pump 3 and the rotation speed deviation signal ΔN from the adder 7. Pump tilting command signal Xq for controlling the discharge amount to regulator 4
Output.

Reference numeral 12 indicates an operation signal Xo to the regulator 4 for controlling the operating speed of an actuator (not shown) which is circuit-connected to the hydraulic pump 3 via the discharge pipe 10.
This is a pump tilting command operation lever that issues a command to control the discharge amount of the hydraulic pump 3.

The regulator 4 operates the hydraulic pump 3 according to the minimum value of the operation signal Xo from the operation lever 12 and the pump tilting signal Xq from the pump control function generator 9.
Controls the discharge amount.

The rotational speed deviation signal ΔN increases as the load on the hydraulic pump 3 increases and the output rotational speed N decreases, and conversely, as the load on the hydraulic pump 3 decreases,
As the output rotation speed N increases, it becomes smaller. Therefore, as ΔN increases, the electronic fuel pump 2 moves its rack position in the direction of increasing the fuel injection amount to increase the output of the prime mover 1, and the output rotation speed signal N
When ΔN becomes smaller, the amount of fuel injection is reduced to prevent the output rotational speed N of the prime mover 1 from becoming excessive.

The input torque of the hydraulic pump 3 is proportional to the product of the slope tilting amount and the discharge pressure. Therefore, when the load on the hydraulic pump 3 increases (discharge pressure P rises), the output rotational speed signal N of the prime mover 1 decreases, and the rotational speed deviation signal ΔN increases, the pump control function generator 9 changes the value of ΔN. As the pump tilting amount signal Xq increases, the product of the discharge pressure signal P becomes smaller, and the input torque of the hydraulic pump 3 follows the output torque line (not shown) of the prime mover 1 set by the slot lever 5 of the prime mover 1. The pump tilting signal Xq is output so as to decrease the discharge amount of the hydraulic pump 3. The pump control function generator 9 in FIG. 4 shows a hydraulic pump input torque line S ₁ →S ₀ →S ₂ that decreases as ΔN increases.

In the conventional control device for a system including a prime mover and a hydraulic pump configured as described above, when the pump tilt command operating lever 12 is operated to enter the working state from the non-working state, the fuel throttle lever 5 is simultaneously operated. It is necessary to increase the target rotational speed of the prime mover 1 by operating it, and when the operating signal Xo of the operating lever 12 increases rapidly, the discharge amount of the hydraulic pump 3 is controlled via the regulator 4 and increases. On the other hand, the throttle lever 5 rapidly increases the target rotational speed signal No. Since the prime mover 1 is a large inertial body with a flywheel, the output rotational speed signal N does not increase immediately, so the target rotational speed signal No. The rotation speed deviation signal ΔN, which is the difference from the output rotation speed signal N, becomes larger, and the input torque curve of the hydraulic pump 3 becomes, for example, S ₁ →S ₀ →
S ₂ and the output Xq of the pump control function generator 9 decreases, so immediately Xq<Xo,
The discharge amount of the hydraulic pump 3 decreases. After that, when the prime mover 1 is accelerated and the output rotation speed signal N approaches the target rotation speed signal No, the rotation speed deviation ΔN decreases, and the output of the pump control function generator 9 becomes S ₂ →S ₀ →S _1. The output Xq increases and the discharge amount of the hydraulic pump 3 increases.

In this work situation, when the load on the hydraulic pump 3 is increased, the load on the hydraulic pump 3 is first decreased,
Although it has the advantage of quickly increasing the output rotation speed of the prime mover 1, the operating signal Xo of the operating lever 12
Despite the operation to increase the speed of the actuator and accelerate the actuator, the discharge amount of the hydraulic pump 3 temporarily decreases and the speed of the actuator decreases. The drawback is that it can be uncomfortable due to the inability to do so.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks of the conventional control device, and the target rotational speed signal does not suddenly increase even when the target rotational speed of the prime mover is operated to rapidly increase the target rotational speed of the prime mover together with the operation of the operation lever for pump tilting command. It is an object of the present invention to provide a control device for a system including a prime mover and a hydraulic pump that can suppress rapid changes in rotational speed deviation and continuously and smoothly increase the discharge amount of a hydraulic pump 3.

[Summary of the invention]

In order to achieve this object, the present invention provides a first target rotation speed signal generated based on a control lever signal and a second target rotation speed signal based on the integration of a target rotation speed increment value set and outputted in response to an increase/decrease in a rotation speed deviation signal. By determining the deviation from the output rotation speed using the minimum value of the target rotation speed signals as the target rotation speed signal, and controlling the fuel injection amount and the discharge amount of the hydraulic pump based on this rotation speed deviation signal, the rotation speed is The rapid increase in the number deviation signal is controlled, and the discharge amount of the hydraulic pump 3 is continuously and smoothly increased or decreased.

[Embodiments of the invention]

An example of this invention will be described below with reference to FIG. In FIG. 1, the same reference numerals as in FIG. 4 indicate the same parts.

Reference numeral 13 denotes a target rotational speed increment value function generator, which inputs a rotational speed deviation signal ΔN between the target rotational speed signal No. and the output rotational speed N, and generates a target rotational speed increment value δ ₁ .
The target rotational speed increment value function generator 13 generates an increment value δ ₁ that is a constant maximum value e for the rotational speed deviation ΔN in a range where ΔN is smaller than the set value c, and c<
When ΔN<d, an increment value δ ₁ that decreases in proportion to the magnitude of ΔN is generated, and when ΔN is greater than a set value d, an increment value δ ₁ that is a constant minimum value f is generated. 14 is an integrator that successively adds up the increment value δ ₁ and outputs a target rotational speed signal N ₂ . 15 is a minimum value selector which selects the first target rotation speed signal output from the fuel throttle lever 5;
The minimum value of N ₁ and the second target rotation speed signal N ₂ outputted from the integrator 14 is determined as the target rotation speed No. of the prime mover 1. Further, the minimum value selector 15 selects the output _N1 of the throttle lever 5 from the integrator 1.
It works to apply a limiter to the output _N2 of 4.

By gradually operating the operating lever 12, the integrator 1
4 is started, and the second target rotational speed signal N ₂ increases, but the increment value δ ₁ is δ ₁ =e (maximum value) because the target rotational speed signal ΔN is small. The minimum value selector 15 works to limit the output _N2 of the integrator 14 with the output _N1 of the throttle lever 5, so the target rotational speed signal No. is gradually increased by the integrator 14. , throttle lever 5 output
When N ₁ is reached, the integrator 14 stops, and the target rotational speed signal No becomes equal to N ₁ after a predetermined time, and eventually the prime mover 1 receives the operation signal N ₁ of the throttle lever 5.
The output will be controlled by

Next, when the operating lever 12 and the throttle lever 5 are suddenly operated simultaneously, the target rotational speed signal _N1 from the throttle lever 5 increases rapidly, and when the rotational speed deviation signal ΔN is about to increase, the target rotational speed increment value function generator 13 reduces the increment value δ ₁ to, for example, δ ₁ = f,
Decrease the rate of increase of the second target rotational speed signal _N2 .
At this time, the minimum value selector 15 selects the minimum value of N ₁ and N _2.
Since N ₂ is selected and the rapid increase in target rotation speed signal No. is suppressed, the target rotation speed signal No. gradually increases until N ₂ reaches the value of N ₁ , and the target rotation speed signal ΔN is lowered, so the rotation speed deviation The signal ΔN does not increase too rapidly. Therefore, ΔN input to the pump control function generator 11 also does not increase, so the input torque of the hydraulic pump 3 follows the output torque line in the high output range of the prime mover 1 set by the throttle lever 5. As a result, the discharge amount of the hydraulic pump 3 can be smoothly increased in accordance with the operation signal Xo of the operation lever 12.

Therefore, when the driver simultaneously operates the operating lever 12 and the throttle lever 5 to control the speed of the actuator, the output rotation speed of the prime mover and the discharge of the hydraulic pump 3 will change in accordance with the increase in the operating signal Xo. The amount can be increased gradually and smoothly, providing a good operating feel.

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

16 converts the operation signal Xo into the first target rotational speed signal N ₁
With a function generator that converts the operation signal Xo into
In the range where the operation signal Xo is smaller than the set value a, a constant low-speed target rotation speed signal N _L is generated, and the operation signal Xo
increases in proportion to Xo between the set value a and the maximum target rotational speed signal _XH when the operation signal Xo exceeds the set value b. Furthermore, the fuel throttle lever 5 shown in FIG. 1 has been eliminated.

In this embodiment configured as described above, when the operating lever 12' is not operated or when the operating lever 12' is operated and the operating signal Xo is below the set value,
The function generator 16 generates a constant low-speed target rotational speed signal N _L
is generated as the first target rotational speed signal _N1 , so
The prime mover 1 is automatically driven at low speed and in a low output range, resulting in low fuel consumption.

In addition, by operating the operating lever 12', the operating signal Xo
When the operating signal Xo of the operating lever 12' is set above the set value b, the first target rotational speed signal _N1 automatically increases in proportion to the magnitude of the operating signal Xo. The maximum target rotational speed signal N _H is output from the function generator 16 as the first target rotational speed signal N ₁ .

According to the embodiment described above, in addition to the effects of the embodiment shown in FIG. 1, the target rotational speed of the prime mover and the slope tilting amount of the hydraulic pump can be controlled by operating only the pump tilting command control lever. This makes it possible to improve the fuel consumption rate under light loads and further improve operability.

FIG. 3 shows another embodiment of the present invention, in which the same reference numerals in FIG. 2 indicate the same parts.

17 is the output rotation speed signal N from the rotation speed detector 6
It is a differentiator that differentiates . 18 is a function generator that calculates the rotation speed deviation correction value, and is the output from the differentiator 17.
dN/dt is input, and in the range where dN/dt is smaller than the set value g, the correction value δ ₂ =O is output, and when it is larger than dN/dt, the correction value δ ₂ is increased in proportion to dN/dt,
When dN/dt exceeds the set value h, δ ₂ =i (maximum value) is output. Reference numeral 19 denotes an adder which inputs the rotational speed deviation signal ΔN and the correction value δ ₂ from the function generator 18 to obtain a second rotational speed deviation ΔN ₂ =ΔN−δ ₂ . ΔN ₂ output from the adder 19 is input to the pump control function generator 9, and the pump tilting signal Xq is controlled based on the increase in ΔN ₂ .

When the target rotation speed No. of the prime mover 1 increases by suddenly operating the operation lever 12', the output rotation speed signal N
also increases, and the differential value dN/dt increases. dN／dt
is larger than g, the function generator 18 generates a correction value δ ₂
is increased from zero, and the second rotational speed deviation ΔN ₂ = ΔN
−δ ₂ is decreased as the output rotational speed signal N increases. The function generator 9 changes the pump tilting signal Xq so as to increase the input torque (absorbed horsepower) of the hydraulic pump 3 by decreasing the input ΔN ₂ , so the load applied to the prime mover 1 increases, and the load on the prime mover 1 increases. Limit excessive increase in output rotational speed N.

According to the above embodiment, when the operating lever 12 is suddenly operated, the output rotational speed signal of the prime mover 1 increases;
That is, since the input torque of the hydraulic pump 3 is controlled to be increased while suppressing the acceleration of the prime mover 1 to a predetermined value or less, in addition to the effects of the embodiments shown in FIGS. 1 and 2, the acceleration of the prime mover 1 is It becomes possible to increase the output rotation speed and the discharge amount of the hydraulic pump 3 more smoothly, and the effect of improving the operational feeling is achieved.

Although all of the control devices according to the embodiments of the present invention have been explained above using calculation block diagrams, the present invention may also be configured with an analog circuit using an operational amplifier or a digital circuit using a microcomputer. This has similar effects.

〔Effect of the invention〕

According to the present invention described above, when the operating lever for pump tilt command is suddenly operated to increase the speed of the actuator, the output rotation speed of the prime mover and the hydraulic pump discharge amount are adjusted according to the increase in the operating signal of the operating lever. can be increased smoothly, which has the effect of improving the driver's operating sensation.

[Brief explanation of drawings]

FIG. 1 is a control block diagram of a system including a prime mover and a hydraulic pump according to an embodiment of the present invention, and FIG. 2 is a control block diagram of a system including a prime mover and a hydraulic pump according to another embodiment of the present invention. FIG. 3 is a control block diagram of a system including a prime mover and a hydraulic pump according to another embodiment of the present invention, and FIG. 4 is a control block diagram of a conventional system including a prime mover and a hydraulic pump. 1... Prime mover, 2... Fuel injection pump, 3...
Hydraulic pump, 4... Pump regulator, 7, 8
... Adder, 9 ... Pump control function generator, 12
..., 12'...operation lever for pump tilting command,
13...Target rotational speed increment value function generator, 14...
Integrator, 15...Minimum value selector, 17...Differentiator, 18...Function generator for calculating the rotation speed deviation correction value, N...Output rotation speed signal, No.....Target rotation speed signal, N ₁ ...First target rotation speed signal, N ₂ ...
Second target rotation speed signal, ΔN...Rotation speed deviation signal, _ΔN2 ...Second rotation speed deviation signal, _δ1 ...Target rotation speed, incremental value, _δ2 ...Rotation speed deviation correction value, e …
...The maximum value of the target rotation speed increment value, f...The minimum value of the target rotation speed increment value.

Claims (1)

[Scope of Claims] 1. The system includes a prime mover and a hydraulic pump driven by the prime mover, and calculates a difference between a target rotational speed signal and an output rotational speed signal of the prime mover, and based on this rotational speed deviation signal. The fuel injection amount of the prime mover is controlled, and the pump tilt signal from the pump control function generator, which decreases as the rotation speed deviation signal increases, and the operation signal from the pump tilt command control lever are set to the minimum value. Therefore, in a control device for a system including a prime mover and a hydraulic pump that controls the discharge amount of the hydraulic pump,
incremental value generating means for generating a target rotational speed increment value that becomes smaller as the value of the rotational speed deviation signal increases; an integrating means for determining a target rotational speed signal of the prime mover; and determining the minimum value of the first target rotational speed signal and the second target rotational speed signal generated based on the operation of the lever that commands the rotational speed of the prime mover. A control device for a system including a prime mover and a hydraulic pump, comprising minimum value selection means for outputting a target rotation speed signal for the prime mover. 2 The functional relationship between the target rotational speed increment value set by the incremental value generation means and the rotational speed deviation signal is that when the rotational speed deviation signal is below the first set value, the target rotational speed increment value takes a constant maximum value, and the rotational speed increases. In the range where the number deviation signal is greater than the first setting value and smaller than the second setting value, the target rotational speed increment value decreases in accordance with the increase in the value, and the rotational speed deviation signal is equal to or higher than the second setting value. 2. A control device for a system including a prime mover and a hydraulic pump according to claim 1, wherein the functional relationship is a constant minimum value. 3. Differentiating means for differentiating the output rotational speed signal to obtain a differential value, and correction value generating means for generating a rotational speed deviation correction value that increases as the differential value output from the differentiating means increases. , subtracting the rotation speed deviation correction value generated by the correction value generating means from the rotation speed deviation signal to obtain a second rotation speed deviation signal, and outputting the second rotation speed deviation signal to the pump control function generator. A control device for a system including a prime mover and a hydraulic pump according to claim 1, further comprising an adding means.