JP2567193B2 - Hydraulic pump discharge flow control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge flow rate control device for a hydraulic pump, such as a hydraulic excavator or a hydraulic crane, which is driven by the rotational force of a prime mover. For more details,
DISCLOSURE OF THE INVENTION The present invention relates to a hydraulic mechanical device provided with a hydraulic actuator that is operated according to the discharge flow rate of a hydraulic pump, so as to maximize the output of the prime mover without overloading the prime mover. And a discharge flow rate control device for a hydraulic pump that optimally controls the output flow rate of the pump according to an operation signal so that the operability of the driver is improved even in a high load region.

[0002]

2. Description of the Related Art Recently, in hydraulic machinery, in order to maximize the output of the prime mover of the hydraulic drive circuit to increase the work efficiency, the maximum work load is increased according to the type of work and the size of load. It is designed to preset the output, thereby maximizing the loss of unwanted energy. Generally, the discharge flow rate of the variable displacement hydraulic pump is determined by the product of the rotational speed of the prime mover and the tilting amount of the pump tilt plate, so the discharge flow rate increases with an increase in the tilting amount.

In such a conventional hydraulic machine device, since the hydraulic pump is driven by the prime mover, when the pressure torque from the hydraulic pump becomes larger than the output of the prime mover, that is, when the prime mover is overloaded. , The speed of the prime mover is reduced. Moreover, if a larger overload is continued and applied, the prime mover will stop.

Therefore, the following technique is adopted so that the maximum output can be utilized while limiting and adjusting the input torque of the hydraulic pump within the output range of the conventional prime mover. That is, a regulator for adjusting the tilt amount of the swash plate of the pump to limit the input torque is installed and used, and the pressures of its own pump and the relative pump (only the self pump when alone) are fed back. In this way, when the pressure increases, the discharge flow rate decreases, and when the pressure decreases, the flow rate decreases to maximize the output of the driving gear.

[0005]

However, since such a system achieves its purpose through a hydraulic circuit, its structure is very complicated, and it is often difficult to manufacture, and there are technical limitations. There is. In addition, there is also a problem that the degree of efficiency is slightly lowered. Therefore, a hydraulic circuit for limiting the magnitude of the pump output and a hydraulic circuit including a structure that forms a negative system in discharging a discharge amount proportional to the driver's operating means (lever or pedal) are configured. It has to be done and its composition is very complicated.

Further, the flow rate is discharged from the low load region in proportion to the operation amount of the driver's operating means, but in the high load region, the operation amount is changed when the operation angle of the swash plate tilt amount exceeds a certain value. Regardless of the maximum discharge amount, it was decided to discharge. Therefore, there are problems that the driver's operation area becomes small and the operability is limited.

The present invention has been made in view of the above circumstances, and an object of the present invention is to set a maximum discharge flow rate of a pump (hereinafter, referred to as "the flow rate required by a driver and a maximum output of a prime mover"). "Maximum pump dischargeable flow rate") is compared through the controller, and the required discharge amount (hereinafter,
By adopting the technique of simply calculating and outputting the "pump required discharge flow rate"), the regulator structure of the hydraulic pump is simplified and the operation is facilitated.

Another object is to detect the output pressure of the pump and back-calculate the maximum dischargeable flow rate of the pump to maximize the pump output and increase the energy efficiency under the output limit value of the prime mover to improve work performance. To improve.

Still another object is to make it easy to implement mechanically a pump characteristic curve required for work by a controller in a desired form, which is unnecessary. It is to prevent the waste of energy.

Still another object is to improve the operability flexibly and finely by proportionally adjusting the discharge flow rate according to the maximum operation angle of the driver even in the high load region.

[0011]

SUMMARY OF THE INVENTION A pump discharge flow rate control device of the present invention is a prime mover that obtains a rotational force from a fuel injection device of a fuel injection device, and at least one variable capacity that is driven by the rotational force of the prime mover. Type hydraulic pump, operating means for switching the driver's operation amount to a specific signal and outputting the signal,
A plurality of actuators that are operated according to the discharge flow rate of the hydraulic pump, and a plurality of flow rate control valves that adjust the flow direction and flow rate of the hydraulic pressure transmitted from the hydraulic pump to the actuator in accordance with operation signals from the operating means. In the hydraulic mechanical device provided with ,, the output selection means for selecting the magnitude of the output horsepower of the prime mover, and the role of changing the discharge amount by adjusting the swash plate tilt angle of the variable displacement hydraulic pump. A regulator, an electromagnetic proportional pressure-reducing valve that adjusts the regulator by generating pilot hydraulic pressure in proportion to the amount of input electricity, a first detection unit that detects the discharge force of the variable displacement hydraulic pump, the constituent elements, and the like. as an electromagnetic hydraulic control device constituted by an electromagnetic control that overall control, combine the operation signal accepted by said operation means First calculation means and a maximum ejectable flow of the hydraulic pump by a pressure value read from the selected value and the first detection means of the output selecting means for calculating a pump required flow rate
Second calculating means for calculating the amount , comparing means for comparing the pump required flow rate with the maximum dischargeable flow rate, and the maximum dischargeable flow rate when the pump required flow rate is larger than the maximum dischargeable flow rate And a means for controlling the discharge flow rate of the hydraulic pump by outputting the pump output flow rate value with the electromagnetic proportional pressure reducing valve .
1 calculating means is the pump negative detected by the first detecting means
The load pressure and the output diagram selected by the output selection means.
The operation amount is determined by the maximum value of the pump discharge flow rate determined by
And the required discharge flow rate of the pump,
Amount) = (required flow rate coefficient) x (required flow rate)
The coefficient is determined, and operation of the operating means is performed from this required flow coefficient.
The above object is achieved by calculating the pump required flow rate with respect to the volume .

The first computing means is a characteristic diagram of the operation amount of the operating means and the pump required flow rate according to the load pressure of the pump detected by the first detecting means and the output diagram selected from the output selecting means. Immediately, the required flow rate coefficient may be calculated and selected, and the required pump flow rate may be calculated from the required flow rate coefficient according to the operation amount of the operating means.

A second method for detecting the actual rotational speed of the prime mover
A detection means is provided, and the second calculation means calculates the deviation between the target rotation speed and the actual rotation speed to calculate the compensating flow rate from the horsepower selection value of the output selection and the pump pressure value read by the pressure sensor. The maximum dischargeable flow rate of the hydraulic pump may be calculated based on this compensation flow rate.

Further, instead of using the first detecting means, a plurality of third detecting means for detecting the operating speed or the position of the actuator or the like is provided instead, and the second calculating means is the third detecting means. The operating speed from the detecting means is detected, the operating flow rate of each actuator is calculated, the total discharge flow rate of the hydraulic pump is calculated based on the operating flow rate, and the target rotating speed of the prime mover is calculated from the second calculating means. It is also possible to calculate the compensating flow rate based on the horsepower selection value of the output selection by obtaining the deviation between the actual rotational speed and the maximum rotational speed of the hydraulic pump based on this compensating flow rate.

In the third selecting means for selecting the maximum dischargeable flow rate of the pump, the third selecting means operates according to the maximum discharge flow rate selected by the third selecting means. The required flow rate coefficient may be calculated and selected immediately from the characteristic diagram of the operation amount of the means and the pump required flow rate, and the pump required flow rate may be calculated from this required flow rate coefficient according to the operation amount of the operating means.

[0016]

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 is a schematic diagram of a pump discharge flow rate control device configured to embody the present invention.

The pump discharge flow rate control device of the present embodiment includes at least one variable displacement hydraulic pump 3 driven by the rotational force of the prime mover 2, and a plurality of hydraulic pumps 3 operated by the discharge flow rate of the hydraulic pump 3. Hydraulic actuator 9, 1
0 and the hydraulic pump 3 to the actuators 9 and 1
A hydraulic machine including a plurality of flow rate control valves 8 for adjusting the flow direction and flow amount of hydraulic oil transmitted to 0, and an operating means 11 for converting an operation amount of a driver into an electric signal (voltage or current) and outputting the electric signal. It is a pump discharge flow rate control device used in the apparatus.

This device further has an electric adjusting device for limiting the magnitude of the horsepower of the prime mover 2, the output selecting means 12 for selecting the maximum magnitude, and the variable capacity. Regulator 5 for adjusting the tilting angle of the swash plate of the hydraulic pump 3 to change the discharge flow rate, and the regulator 5 described above.
A proportional hydraulic pressure reducing valve 6a, 6b for adjusting the regulator 5 by receiving a pressure from the third pump 4 for generating a control signal at a constant hydraulic pressure to generate a pilot pressure according to an input electric signal amount, The displacement type hydraulic pump 3 is provided with first detecting means 14a and 14b for detecting the discharge pressure, and an electromagnetic controller for controlling input / output signals of the above-mentioned components and the like.

The operation and effect of the apparatus of this embodiment constructed as described above will be described below.

First, when the driver performs an operation through the operation means 11 in order to perform a desired work, each actuator operation required flow rate is calculated according to the operation signal. The opening amount of the flow rate control valve that adjusts each actuator is calculated based on the calculated required operation flow rate, and the pump required discharge flow rate Qi is calculated based on the sum of the required operation flow rates.
Is calculated.

Then, based on the output horsepower diagram already input and set from the output selecting means 12, the first
The pump maximum dischargeable flow rate Qr according to the load state from the discharge pressure P detected by the detecting means 14a, 14b is calculated.

Next, the comparing means determines the required pump discharge flow rate Q.
i is compared with the maximum dischargeable flow rate Qr of the pump. According to the present embodiment, when the pump required discharge flow rate Qi is larger than the maximum dischargeable flow rate Qr, the pump maximum dischargeable flow rate Qr is output as the pump output value (pump output value Q0). When the pump request discharge flow rate Qi is less than or equal to the pump maximum discharge possible flow rate Qr, the pump request discharge flow rate Qi is output as the pump discharge flow rate Q0.

The output means adjusts the electromagnetic proportional pressure reducing valves 6a and 6b when the output value is converted into an electric quantity and outputs the electric quantity, and the pilot pressure corresponding to this adjusts the regulator 5. The regulator 5 moves the swash plate turning angle of the variable displacement hydraulic pump 3 to a fixed position, thereby causing the pump 3 to discharge a desired flow rate.

As described above, since the flow rate loss can be minimized by discharging only the flow rate necessary for operating the actuators 9 and 10, the output of the prime mover 2 can be maximized. .

In order to select the output horsepower of the prime mover 2, the apparatus of this embodiment is provided with the second detecting means 15 for detecting the actual rotation speed N of the prime mover 2. Using this, the pump pressure P is detected by the first detection means 14a and 14b in order to calculate the pump maximum dischargeable flow rate Qr.

There are cases where the prime mover 2 operates in a high area where air is insufficient, or mechanical errors cause the output to drop (even at the same rotational speed N). In such a case, when a load is applied, the rotation speed N of the prime mover 2 becomes equal to or lower than the reference value. At that point, the discharge amount is corrected to output a small flow rate even under the same load condition, and the pump maximum dischargeable flow rate Qr is calculated.

The apparatus of the present invention is provided with a plurality of third detecting means for detecting the operating speeds of the actuators 9 and 10 in place of the first detecting means 14a and 14b for the purpose of calculating the maximum pumpable discharge flow rate Qr. A detection means may be provided.
In this case, if the third detecting means is provided, the pump flow rate can be calculated by detecting the operating speed and the flow rate acting on the actuators 6 and 10. It is possible to detect the rotational speed N of the prime mover 2 by the second detection means 15 and to compensate the flow rate deviation according to the fluctuation of the load. Thus
The pump maximum dischargeable flow rate Qr of the hydraulic pump 3 can be calculated.

When calculating the pump request discharge flow Qi amount,
The required amount value of the operating means 11 can be changed according to the magnitude of the load. The structure is such that a full stroke of the driver's operating means 11 is adjusted and a calculation is performed so that the flow rate can be requested.

FIG. 2 is a diagram for explaining the regulator 5 in particular detail. In FIG. 2, numbers 21a and 21b
Indicates a spool. Numbers 22a, 2
2b shows a pilot piston. Numbers 23a and 23b are servo pistons (servo-
piston) is shown. For example, an electromagnetic proportional pressure reducing valve 6
When the pilot output pressure of "a" increases, the spool 21a is pushed out to the right through the piston 22a via a link. Therefore, the pressure of the pump acts on the large diameter portion of the servo piston 23a via the spool 21a. This pressure is the same as the pressure acting on the small diameter portion, but there is an area difference, and as a result, the servo piston 23a is moved to the right. Thus, the swash plate connection point of the pump connected to the servo piston 23a moves to the right. As a result, the inclination angle of the swash plate becomes small, and the pump discharge amount decreases. Conversely, as the pilot output pressure decreases, the pump discharge flow increases (negative contro
l).

FIG. 3 is an example of a schematic diagram showing the internal structure of the controller 1 for embodying the present invention. CPU2
5 executes the contents of the present invention in accordance with a control flowchart input as a program in the memory (for example, ROM portion) 31.

As shown in FIG. 3, the controller 1
Is an ON / OFF signal input unit 26 that receives an input from the output selection unit 12, a rotation counter unit 27 that receives an input from the rotation speed detection unit 15, and an A / D signal conversion input unit I28 that receives an input from the input detection unit. , An A / D signal conversion input section II28 which receives an input from the operation means 11, an actuator detector signal conversion section 30 which receives an input from an actuator, a memory 31, D / A signal conversion output sections 32 and 34, and an output signal The amplifiers 33 and 35 and the motor drive unit 36 are provided. These are CPU2 via the bus
Connected to 5.

FIG. 4 is a flowchart outlining an algorithm for carrying out the present invention.

The contents of the present invention will be described in detail below mainly using the flowchart of FIG. First, step 41
Then, an electric signal (voltage or current) corresponding to the operation amount φi input by the driver is input to the controller 1 through the operation means 11 (FIG. 1). More specifically, it is input to the A / D signal change input unit 29 (FIG. 3). In this way, the manipulated variable φi is read through the A / D signal change input unit 29.
Here, the relationship between the manipulated variable φi and the voltage (electrically generated signal Vi) output by the operating means 11 has a proportional output characteristic as shown in the characteristic diagram of FIG.

In step 42, the selection mode M input by the output selection means 12 (FIG. 1) and the rotation speed N of the prime mover 2 detected by the second detection means are read. Further, the discharge pressure (load pressure) P of the variable displacement hydraulic pump 3
Is read via the first detecting means 14a and 14b.

The second detecting means 15 is connected to the rotating portion of the prime mover 2 via a magnetic up sensor so as to form a gear structure, and the number of the second detecting means 15 corresponds to the rotating speed counter portion 27.
(FIG. 3), it has a structure for converting into a prime mover rotation speed N. As the first detection means 14a and 14b, a kind of known semiconductor pressure sensor is used, which has a proportional characteristic of the form of the output voltage according to the pressure change.

This pressure signal is sent to the A / D signal converter 28.
After being input via (FIG. 3), in step 43, the pump required discharge flow rate Qi corresponding to the operation amount φi of the operation means read in step 41 is calculated. For this calculation, the specific value represented by Qi = f (φi) has already been input. For example, it is input to the formula (or Data) like the value of Qmax in FIG. In this way, the value of the pump request discharge flow rate Qi is determined according to the operation amount φi by the operation means 11. When there are a plurality of operating means 11, the characteristic diagrams may differ from each other. In that case, a value obtained by adding all the corresponding values and the like to the operation amount φi of the operation means 11 becomes the pump request discharge amount Qi.

Next, at step 44, the actual maximum pump dischargeable flow rate Qr is calculated.

At this stage, the characteristic diagram of the prime mover 2 is selected according to the output mode for limiting the maximum output of the prime mover 2, the actual prime mover rotation speed N is known under this characteristic diagram, and the hydraulic pump pressure P is used. The horsepower used by the pump (motor output horsepower) W is required. The prime mover output horsepower W is expressed by the following equation.

W = P · Qr = P · D · N (Qr = D · N) N = motor rotation speed P = load pressure D = pump discharge flow rate per rotation Based on this equation, the motor 2 is overloaded. The actual maximum pump dischargeable flow rate Qr that can be discharged by the flow rate pump 3 within the maximum output range is calculated.

In step 45, the flow rate deviation ΔQ between the pump required discharge flow rate Qi of the operating means 11 calculated in step 43 and the actual pump maximum dischargeable flow rate Qr calculated in step 44 is obtained.

At step 46, it is judged if the flow rate deviation ΔQ is smaller than zero (0). This flow deviation Δ
When Q is smaller than zero (0), that is, when the pump request discharge flow rate Qi is smaller than the actual pump maximum dischargeable flow rate Qr, the pump request discharge flow rate Qi is set to the pump discharge flow rate Q0 in step 47. However, if the flow rate deviation ΔQ is larger than zero (0) or the same, that is, if the pump request discharge flow rate Qi is larger than the actual pump maximum dischargeable flow rate Qr, or the same, the output is restricted as belonging to the overload range. Therefore, in step 48, the actual maximum pump dischargeable flow rate Qr is set to the pump discharge flow rate Q0.

At step 49, the output voltage V0 corresponding to the pump discharge amount Q0 is calculated, and the controller 1 outputs the output voltage V0. More specifically, the output voltage V0 is output via the D / A signal converter 32 of the controller 1, and the output voltage V0 is input to the output signal amplifier 33. The input output voltage V0 is output to the output signal amplifier 3
It is amplified in 3 and converted into current value I0. Current value I0
The conversion to is executed based on the input / output characteristics as shown in the characteristic diagram of FIG. 6, for example. After this, the current value I0
Is supplied to the pump electromagnetic proportional pressure reducing valves 6a and 6b to drive the pump electromagnetic proportional pressure reducing valves 6a and 6b.

As shown in FIG. 2, the electromagnetic proportional pressure reducing valves for pumps 6a and 6b are provided with a third pressure generating oil for control signals.
The swash plate tilt point angle θ of the hydraulic pump 3 is adjusted with the pilot pressure from the pump (gear pump) 4 as a root. The relationship between the output current value I0 and the output pilot pressure Pi has an input / output characteristic as shown in FIG. 7, for example. When the swash plate tilting point angle θ moves according to the output pilot pressure Pi, the target discharge amount from the hydraulic pump 3 (pump discharge flow rate Q
0) is discharged. In this embodiment, the control having the relationship shown in FIG. 8, that is, the negative flow rate control in which the discharge flow rate (Q0) decreases as the pilot pressure (Pi) increases is adopted. In FIG. 8, the horizontal axis represents the pilot pressure (Pi) and the vertical axis represents the discharge flow rate (Q0). Thus, in response to changes in pilot pressure,
The swash plate tilt angle of the pump is controlled, and the discharge flow rate changes.

In this way, the driver's desired flow rate (pump request discharge flow rate Qi) is accurately discharged, and the maximum output is produced within a range where the prime mover 2 is not overloaded. Thus, according to this embodiment, the efficiency can be increased.

Next, the procedure for calculating the pump required discharge flow rate Qi in step 43 will be described in more detail with reference to FIG.

FIG. 9 is a combination of both a characteristic diagram showing the relationship between the manipulated variable φi of the operating means 11 and the pump flow rate Q, and a pump characteristic diagram showing the relationship between the load pressure P and the pump flow rate Q. The graph is shown.

In this embodiment, the driver's operating means 11 is used.
The pump discharge pressure (load pressure) P of the hydraulic pump 3 obtained by the first detecting means 14a and 14b is used to calculate the pump request discharge flow rate amount Qi from the input operation amount φi.

The relationship between the pump required discharge flow rate Qi and the manipulated variable φi (relationship of Qi = f (φi)) is simply expressed by the following equation, for example.

Qi = K × φi where K is the required flow coefficient. In the present embodiment, the value of the required flow coefficient K is the characteristic curve (W1 of the hydraulic pump 3
To W3) and the like and the pump discharge pressure P, the pressure is increased or decreased.

In the prior art, under the pump discharge pressure P, as long as the pressure does not change, the required operation amount φi of the operating means 11 is 100% or the required flow rate coefficient irrespective of the operation amount φi. K is fixed to a constant value. For example, Qi = K × φ shown in the left part of the graph in FIG.
The straight line of i shows a specific slope (for example, K = Kmax
It is fixed). Further, in the conventional technology, the load pressure of the pump is fed back by hydraulic pressure,
When the load pressure exceeds a certain pressure, the inclination angle of the swash plate of the pump is prevented from increasing and the engine is not overloaded (total horsepower control). Therefore, according to the conventional technique, even if the manipulated variable is, for example, a predetermined value (φ0) or more, the full horsepower control characteristic (Full Power Control Cha
The maximum dischargeable flow rate (Q
max) cannot increase above Q1. As described above, in the conventional method in which the pump output is controlled solely depending on the hydraulic pressure, the operation range is limited to the range of 0 (zero) to φ0, and the range becomes narrower as the load pressure becomes higher. .

However, in this embodiment, the detecting means 1
According to the discharge pressure of the pump detected by 4a and 14b, the controller 1 sets the required flow rate coefficient K to K1, K
An appropriate value will be selected from 2, K3, Kmax, and the like. That is, the required flow rate coefficient K is selected according to the change of the load pressure P in the pump output characteristic diagram of FIG. In FIG. 9, φmax means an operation amount of 100%. Further, in Qmin, the manipulated variable φi is the manipulated variable 1
It means the required pump flow rate Qi at 0%. The required flow rate coefficient K is selected from the range between Kmin and Kmax determined by the output characteristic curve W. When the output characteristic curve W is the curve indicated by W1, the range is between K1min and Kmax, and when the output characteristic curve W is the curve indicated by W2, the range is K2.
It is between min and Kmax.

When the output characteristic curve W2 is selected,
When the pump load pressure P is P1, K3 is calculated and selected as the required flow rate coefficient K from FIG. As a result, when the operation amount φi of the operating means 11 is φ1, Qi is K3.
As indicated by × φi, the pump request flow rate Qi becomes Q3. When the manipulated variable φi is 100% (φma
x), the required pump flow rate Qi becomes Q2. In this embodiment, when the manipulated variable φi is 90 to 100%, the required pump flow rate Qi is suppressed to a constant value. When the manipulated variable φi is 10 to 0%, the required pump flow rate Qi is constant (zero). In this embodiment, K3 is expressed as follows.

K3 = (Q2-Qmin) / (φ90% −φ10%) Incidentally, depending on the selection by the output selection means 12, the load pressure P
The maximum value of the pump request discharge flow rate Qi with respect to the change of is increased or decreased. In other words, when the output characteristic curve W1 is selected by the output selection means 12, the required flow rate coefficient K becomes K1 and the maximum value of the pump required discharge flow rate becomes Q1 under the load pressure P1. Also, the same pump load pressure P
Even under 1, when the output characteristic curve W2 is selected, the required flow rate coefficient K becomes K3. The maximum value of the pump request discharge flow rate Qi corresponding to this is Q2. Then, under the above conditions, the pump request discharge flow rate Qi decreases or increases according to the given output characteristic curve W in accordance with the change in the pump load pressure P. That is, the pump load pressure P changes from P1 to P
In the case of decreasing to 2, the required flow rate coefficient K changes from K2 to K1 even with the same output characteristic curve W1. As a result, the required pump amount changes even with the same manipulated variable φi. That is, when φi = φ1, the pump request discharge flow rate Qi changes from Q2 to Q4.

Even when the operations of the operating means 11 are combined and performed, the pump required discharge flow rate Qi can be calculated in the same manner as the above-described calculation of the pump required flow rate during the single operation. That is, when the two actuators 9 and 10 are operated by one hydraulic pump 3, for example, the output characteristic curve W selected by the output selection means 12 is W1, and the pump load pressure P is below P1. It is assumed that the operation amount φi of the first operating means is φ1 and the operation amount φi of the other second operating means is φ2. In such a case, the required flow rate coefficient K becomes K2. From K2, the first pump request amount becomes Q2, and the second pump request amount becomes Q3. Assuming that the total value of these is Qt and the pump maximum dischargeable flow rate determined from K1 is Q1max, these two values are compared to determine the pump request amount (where "maximum dischargeable flow rate Q1max" is the above-mentioned value). "Is the same as the" maximum pumpable discharge flow rate Qr ". More specifically, the total pump required flow rate Qt is the maximum dischargeable flow rate Q1ma.
less than or equal to x (Qt ≦ Q1ma
x), the total pump demand flow Qt is selected as the pump demand. That is, Qi = Qt. On the other hand, when the total pump required flow rate Qt is larger than the maximum dischargeable flow rate Q1max (when Qt <Q1max), the maximum dischargeable flow rate Q1max is selected as the pump request amount. That is,
Qi = Q1max.

In FIG. 9, in order to limit the maximum discharge flow rate, a separate third selecting means is added to the hydraulic pump 3 (or the maximum discharge flow rate is selected according to the output selecting means 12). The driver can select the maximum dischargeable flow rate Qmax according to the type of work by the third selecting means. In the output characteristic curve diagram of FIG. 9, the maximum discharge flow rate Qmax is determined by this selection, and the value of the required flow rate coefficient K is the first detection means 14.
According to the pump discharge pressure P detected from a and 14b,
The pump request discharge flow rate Qi is calculated.

In the example applied to the present invention, a straight line and a curved line are used as the required flow rate coefficient K and the output diagram WI, respectively. However, in the present invention,
Without being limited to this form, the form and the like can be freely changed into a mathematical expression or can be applied as a data according to the characteristics required by the hydraulic machine device and the driver.

As described above, the operation amount φi of the operation means 11 is
The optimum pump required discharge flow rate is calculated with respect to the pump load pressure P and the position change of the output characteristic curve line W selected by the output selection means 12, and the calculated value is output as the pump discharge flow rate Q0. As a result, it becomes possible to improve the operability in response to the driver's request, and in particular, it becomes possible to easily and accurately perform high-resolution fine work under high load pressure.

[0059]

According to the present invention, the following effects can be obtained.

First, the operation of the driver is improved.
In any load area, the driver operates 100
By adjusting the discharge flow rate of the hydraulic pump in the entire operating range of%, fine operation can be performed very easily even in a high load region, so that operability is improved.

Secondly, by adjusting the output in advance according to the kind of work required and the load level, it is possible to prevent unnecessary energy loss and maintain the durability of the mechanical device. Moreover, in addition to this, in order to control the discharge flow rate of the existing hydraulic pump, a hydraulic negative control (Negative control) system or full horsepower control (Full powerco
According to the prior art in applying the control circuit, etc., since the input control signal photo of the pump regulator is included in several pieces, not only the structure is very complicated but also the control accuracy is inferior. According to the system to which the present invention is applied, the structure is very simple and the processing is easy by controlling the regulator by one control input signal photo.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a pump output control device according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram showing a detailed view of a regulator of the present invention.

FIG. 3 is a schematic diagram showing an internal structure of a controller of the present invention.

FIG. 4 is a diagram showing a procedure of a control program by the controller of the present invention.

FIG. 5 is a graph showing an output voltage characteristic according to an operation amount of an operation step of the present invention.

FIG. 6 is a graph showing characteristics of input voltage and output current of the DC amplifier of the present invention.

FIG. 7 is a graph showing the input / output characteristics of the electromagnetic proportional pressure reducing valve of the present invention.

FIG. 8 is a graph showing negative characteristics of the pump regulator of the present invention.

FIG. 9 is a diagram showing a stage of a pump discharge required flow rate of the operating means and a pump output characteristic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 controller 2 prime mover 3 variable displacement hydraulic pump 4 third pump 5 regulator 6a, 6b electromagnetic proportional pressure reducing valve for pump control 7a, 7b electromagnetic proportional pressure reducing valve block 8 flow control valve block 9 hydraulic motor 10 hydraulic cylinder 11 operating means 12 output Means of selection

Continuation of the front page (56) Reference JP-A 1-312202 (JP, A) JP-A 62-75107 (JP, A) JP-A 64-6501 (JP, A) JP-A 62-220702 (JP , A) JP-A-58-134201 (JP, A) Actually opened 63-162982 (JP, U) Actually opened 62-115504 (JP, U) Special table 1-501241 (JP, A)

Claims (4)

(57) [Claims] 1. A prime mover that obtains a rotational force from a fuel injection device of a fuel injection device, at least one variable displacement hydraulic pump driven by the rotational force of the prime mover, and an operation amount of a driver as a specific signal. An operating means for switching and outputting, a plurality of actuators operated by the discharge flow rate of the hydraulic pump, and a flow direction and an amount of the hydraulic pressure transmitted from the hydraulic pump to the actuator according to an operation signal of the operating means. In a hydraulic machine device including a plurality of flow rate control valves to be adjusted, an output selecting means for selecting a magnitude of output horsepower of the prime mover, and a swash plate tilt angle of the variable displacement hydraulic pump are adjusted. And the electromagnetic proportional decompression valve that adjusts the regulator by generating pilot oil pressure in proportion to the amount of input electricity. And an electromagnetic hydraulic control device constituted by a first detecting means for detecting the discharge force of the variable displacement hydraulic pump and an electromagnetic control for totally controlling the above-mentioned components and the like, which is accepted by the operating means. First calculating means for calculating the pump required flow rate by combining operation signals, and second calculating means for calculating the maximum dischargeable flow rate of the hydraulic pump based on the selected value of the output selecting means and the pressure value read from the first detecting means. a comparing means for comparing the pump required flow rate and maximum delivery flow rates, and second selecting means for pumping required flow rate is to pump output flow rate value of the maximum discharge flow rate when the maximum discharge flow rate larger than the pump output flow and means for controlling the delivery rate of the hydraulic pump the value output by the solenoid proportional pressure reducing valve, with which, the first calculating means, to the first detection means Ri detected Pont
The maximum value of the pump delivery rate which is determined by the output diagram selected by the up load pressure and said output selecting means, relationship between the operation amount and the pump required delivery rate, (the pump required discharge flow rate) = (required flow rate coefficient) required flow coefficient in × (operating amount) is determined, the pump discharge flow rate control device, characterized that you arithmetic pump required flow against the operating amount of the operating means from the required flow rate coefficient. 2. The pump discharge flow rate control device according to claim 1, further comprising second detecting means for detecting an actual rotation speed of the prime mover,
The second calculating means calculates the compensating flow rate from the horsepower selection value of the output selection and the pump pressure value read by the pressure sensor by obtaining the deviation between the target rotation speed and the actual rotation speed,
A pump discharge flow rate control device for calculating a maximum dischargeable flow rate of a hydraulic pump based on the compensation flow rate. 3. The pump discharge flow rate control device according to claim 1, wherein the first detection means is not used, and instead, a plurality of third detection means for detecting the operating speed (or position) of the actuator or the like is used. the equipped, the second calculating means, and it detects the operating speed of the actuator from the third detection means calculates the operating rate of each actuator, further calculates a total delivery rate of the hydraulic pump based on the operating flow rate , The second calculating means calculates the deviation between the target speed and the actual speed of the prime mover, calculates the compensating flow rate with reference to the horsepower selection value of the output selection, and calculates the maximum dischargeable flow rate of the hydraulic pump based on the compensating flow rate. A pump discharge flow rate control device characterized by performing calculation. 4. In the pump discharge flow rate control device according to claim 1 maximum, in the third selection means for selecting the size of the maximum pump discharge flow rates, selected by the third selection means The required flow rate coefficient is calculated and selected according to the characteristic diagram of the operation amount of the operating means and the pump required flow rate according to the discharge flow rate, and the pump required flow rate is calculated from this required flow rate coefficient according to the operation amount of the operating means. A characteristic pump discharge flow control device.