KR19980067345A - Loader engine pump control system and method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine pump control apparatus and method for a loader, comprising: an engine for supplying driving horsepower to a traveling system for driving a driving wheel and a working system for driving a working device such as a bucket and a buoy; Flow rates of the discharge oil supplied to the bucket cylinder and the boom cylinder from the first and the second hydraulic pump, the bucket cylinder and the pour cylinder operated by the discharge oil of the first and the second hydraulic pump, the first and second hydraulic pump And a bucket control valve and a boolean control valve for controlling the direction, a bucket operating means and a boolean operation means for controlling the bucket control valve and the boolean control valve in proportion to an operation amount of the driver, and the operating pressure of the bucket or the boolean. An unloading valve for unloading the discharge oil of the second hydraulic pump into the hydraulic tank, and selectively opening / closing the unloading valve according to a predetermined electrical signal A key is an engine pump control apparatus for a loader including an electronic control valve, comprising: pressure detecting means for detecting a discharge pressure inside the discharge flow path of the second hydraulic pump; and a rotation speed of the engine provided at a predetermined position of the traveling device. And rotational speed detecting means for detecting rotational speed of the torque converter output shaft, and a controller for selectively outputting the electrical signal to the electronic control valve based on detection signals of the pressure detecting means and the rotational speed detecting means. It provides an engine pump control apparatus of the loader, characterized in that configured.

Description

Loader engine pump control system and method

The present invention relates to an engine pump control apparatus and method of a loader, and more particularly, to control the operating horsepower of the hydraulic pump in accordance with the working condition of the loader to increase the work efficiency and to prevent sudden changes in driving power during operation operation and hydraulic system An engine pump control apparatus and method of a loader to improve the stability of the.

The loader, which is one of the representative construction machinery, generally performs loading operations in which loads such as earth and sand are loaded into buckets and loaded into a nearby dump truck.

Fig. 1 is a hydraulic circuit diagram showing an engine pump control system of a loader according to the prior art, wherein a working system composed of a plurality of hydraulic pumps 2, 3 and 4 by a single engine 1 and a transmission not shown And a traveling system consisting of a driving wheel 16 is driven. In other words, part of the engine 1 power is used to drive hydraulic pumps 2, 3, and 4 to operate work devices such as pours and buckets, and a part of the remaining power is transmitted through a torque converter 14. It is necessary to operate the driving wheel 16.

Reference numerals 9 and 10 denote bucket cylinders and boost cylinders, which are actuators for operating the bucket and the booster, respectively, and reference numerals 7 and 8 denote the hydraulic pumps 2 and 3 and the actuators 9 and 10, respectively. A bucket control valve and a boolean control valve, which are installed and control the direction of the flow rate and the flow rate discharged from the hydraulic pumps 2 and 3, perform the start, stop and direction change of the actuators 9 and 10.

The hydraulic pump 4 is a pilot pump for transmitting the signal pressure to the hydraulic system, and according to the operator's operation command, the bucket cylinder 9 and the pour cylinder 10 described above are used to transmit the signal pressure of the pilot pump 4. A bucket operating lever 11 and a boolean operating lever 12 for feeding and controlling the bucket control valve 7 and the pour control valve 8 to be operated are provided.

Unloading part of the hydraulic oil discharged from the hydraulic pump 3 when a load is generated in the bucket cylinder 9 or the pour cylinder 10 between the discharge passage of the hydraulic pump 3 and the hydraulic tank 13 Although the loading valve 6 is installed, the unloading valve 6 is initially set in a state in which the discharge flow path of the hydraulic pump 3 and the hydraulic tank 13 are blocked by the valve spring 6A. When the operating pressure discharged from the above-mentioned hydraulic pump 2 between the loading valve 6 and the hydraulic tank 13 is more than a predetermined set value, the pressure is switched by the operating pressure of the bucket or the buoy to open the unloading valve 6. The setting valve 21 is installed.

The pressure setting valve 21 is initially set with the unloading valve 6 closed by the valve spring 21A when the discharge pressure from the hydraulic pump 2 is equal to or less than a predetermined set value.

Even when the discharge pressure from the hydraulic pump 2 described above is less than or equal to a predetermined value between the flow path L1 and the hydraulic tank 13 discharged to the hydraulic tank 13 when the aforementioned unloading valve 6 is opened. On the opposite side of the valve spring 20A, an electronic control valve 20 for selectively opening the unloading valve 6 in accordance with the application of an electrical signal by the controller 19 is provided.

Reference numeral 5, 5A is a relief valve for maintaining the pressure in the flow path of the hydraulic system to a predetermined operating pressure, 13 is a hydraulic oil storage tank, 15 is a propeller for power transmission between the front and rear traveling wheels 16 Shaft.

In the engine pump system of the loader configured as described above, when the loader loads the load into the bucket and loads the load into the dump truck, the necessary flow rate to the bucket cylinder 9 or the pour cylinder 10 is carried out when the self-employment is digging into the load. You will need to learn less traction and allow the loader to dig forward. In addition, when the load is excavated and moved to a dump truck, the required flow rate to the work device such as a buoy and a bucket is increased rather than a traction force.

In the case of excavating the load to be loaded into the truck by excavating the load by driving the bucket cylinder 11 or the pour cylinder 12 by the operating pressure discharged from the hydraulic pump (2 or 3) by driving the engine (1) Alternatively, since the working pressure of the bucket is increased, the working pressure of the bucket cylinder 11 or the pour cylinder 12 acts on the opposite side of the valve spring 21A of the tack setting valve 21, and switches it downward on the drawing.

As a result, a part of the hydraulic oil discharged from the hydraulic pump 3 is acted on the opposite side of the valve spring 6A of the unloading valve 6 by the orifice O, and the unloading valve 6 is opened. As part of the hydraulic oil discharged from the pump 3 is unloaded through the unloading valve 6, the corresponding operating torque of the engine 1 is utilized in the traveling system to ensure sufficient traction of the equipment. do.

The unloading valve 6 is selectively opened even when the operating pressure discharged from the hydraulic pump 2 is less than or equal to a predetermined value according to the operation state during operation by driving the bucket cylinder 11 or the pour cylinder 12 described above. . That is, the electric signal from the controller 19 is applied to the valve spring 20A opposite side of the solenoid control valve 20 by the driver's operation, and it switches to the upper side in the figure. Therefore, the use torque of the engine 1 is sent to the traveling system for utilization by the flow rate discharged from the hydraulic pump 3 by the opening of the unloading valve 6.

However, as described above, when the unloading valve 6 is selectively opened and closed in order to increase the digging speed and the digging force according to the working state of the loader to improve the driving towing force, the operation operability is poor due to the sudden running speed change of the loader. Of course, there is a problem that causes instability in the hydraulic system operation.

Therefore, an object of the present invention, by opening and closing the unloading valve repeatedly during unloading a part of the hydraulic oil discharged from the hydraulic pump in order to improve the driving towing according to the working conditions to prevent the sudden change of the driving force by adjusting the unloading time interval The present invention provides a loader engine pump control apparatus and method for improving operational maneuverability and ensuring stability in hydraulic system circuit operation.

1 is a hydraulic circuit diagram of an engine pump control apparatus for a loader according to the prior art.

2 is a hydraulic circuit diagram of an engine pump control apparatus for a loader according to the present invention.

Figure 3 shows the opening speed during unloading of the unloading valve according to the present invention

Explanation of symbols on the main parts of the drawings

1: engine

2: first hydraulic pump

3: second hydraulic pump

5, 5A: Relief Valve

6: unloading valve

7: bucket control valve

8: pour control valve

9: bucket cylinder

10: pour cylinder

11: bucket operation lever

12: Boolean operation lever

13: hydraulic tank

14: Torque Converter

15: Propeller Shaft

16: driving wheel

19: controller

20: electronic control valve

21: pressure setting valve

22: pressure detection sensor

23: engine speed detection sensor

24: Torque converter output shaft speed detection sensor

An object of the present invention described above is an engine for supplying driving horsepower to a traveling system for driving a driving wheel and a working system for driving a working device such as a bucket and a buoy, and first and second hydraulic pumps driven by the engine. Bucket control and the bucket cylinder operated by the discharge oil of the first and second hydraulic pump, the bucket control to control the flow rate and direction of the discharge oil supplied to the bucket cylinder and the pour cylinder from the first and second hydraulic pump A valve and a boolean control valve, a bucket operating means and a boolean operating means for controlling the bucket control valve and the boolean control valve in proportion to an operation amount of the driver, and the discharge oil of the second hydraulic pump according to the operating pressure of the bucket or the boolean. A row including an unloading valve for unloading the hydraulic tank and an electronic control valve for selectively opening and closing the unloading valve according to a predetermined electrical signal. An engine pump control apparatus comprising: a pressure detecting means for detecting a discharge pressure inside a discharge flow path of a second hydraulic pump; and a rotational speed of an engine and a torque converter output shaft provided at a predetermined position of the traveling device. And a controller for selectively outputting the electrical signal to the electronic control valve based on the rotation speed detecting means for detecting and the detection signal of the pressure detecting means and the rotation speed detecting means. By providing a pump control.

An object of the present invention described above is an engine for supplying driving horsepower to a traveling system for driving a driving wheel and a working system for driving a working device such as a bucket and a buoy, and first and second hydraulic pumps driven by the engine. Bucket control and the bucket cylinder operated by the discharge oil of the first and second hydraulic pump, the bucket control to control the flow rate and direction of the discharge oil supplied to the bucket cylinder and the pour cylinder from the first and second hydraulic pump A valve and a boolean control valve, a bucket operating means and a boolean operating means for controlling the bucket control valve and the boolean control valve in proportion to an operation amount of the driver, and the discharge oil of the second hydraulic pump according to the operating pressure of the bucket or the boolean. And a unloading valve for unloading the hydraulic tank, and an electronic control valve for selectively opening and closing the unloading valve according to a predetermined electrical signal. A further engine pump control method, comprising: a first step of detecting the rotational speed of an engine and torque converter output shaft of the traveling device and the pressure on the discharge flow path side of the second hydraulic pump; and the engine rotational speed and the torque converter output shaft. A second step of calculating a load degree generated in the traveling device according to a difference in the number of revolutions and calculating a load degree generated in the bucket and the negative cylinder according to discharge pressures of the first and second hydraulic pumps; And a third step of adjusting an unloading time interval of the unloading valve by applying a predetermined electrical signal to the electronic control valve according to the operation result of the second step. to provide.

According to a preferred aspect of the present invention, the electronic control valve may be configured to gradually open the unloading valve to prevent the sudden driving force of the loader from being changed by the discharge flow rate unloaded from the second hydraulic pump when the unloading valve is unloaded. It provides a method for controlling the engine pump of the loader, characterized in that to adjust the unloading time interval of the unloading valve by repeatedly applying an electrical signal to the.

Hereinafter, a preferred embodiment of the present invention will be described in detail with the accompanying drawings.

Figure 2 is a hydraulic circuit diagram of the engine pump control apparatus of the loader according to the present invention, Figure 3 is a view showing the gradual opening of the unloading valve by the present invention.

As shown in the figure, a traveling system including the engine 1, a driving wheel 16 connected and driven to the engine 1 and a bucket, a working system including a boolean, and a discharge of the second pump 3 An unloading valve 6 provided between the flow path and the hydraulic tank 13 to unload a part of the hydraulic oil discharged from the second hydraulic pump 3 when a pressure greater than a predetermined set value is generated in the first oil pump 2; A pressure setting valve 21 installed between the valve 6 and the hydraulic tank 13 to open and close the unloading valve 6 according to its pressure when a load occurs in the bucket cylinder 9 or the negative cylinder 10; An electronic control valve 20 installed between the oil passage L1 discharged from the hydraulic tank 13 and the hydraulic tank 13 when the loading valve 6 is opened to open and close the unloading valve 6 in accordance with an electrical signal. ) Is substantially the same as the configuration of the loader shown in FIG. Strategy, and was identical to the title quotes duplicate.

Therefore, according to a preferred embodiment of the present invention, in accordance with the application of the electrical signal to the above-described electronic control valve 20, the unloading of the discharge oil of the above-described second hydraulic pump 3 to the hydraulic tank 13 Means for controlling the unloading time interval of the loading valve (6).

The above-described means is provided with a pressure detection sensor 22 for detecting an internal pressure on the discharge flow path side of the second hydraulic pump 3, and an engine for detecting the rotational speed thereof at a predetermined position of the engine 1 of the traveling device described above. The rotation speed detection sensor 23 is installed, and the torque converter output shaft rotation speed detection sensor 24 for detecting the rotation speed thereof is installed in the turbine shaft 18 of the torque converter 14, and the pressure detection sensor 22 described above. ), The electrical signal is applied to the above-described electronic control valve 20 according to the detection signals of the engine speed detection sensor 23 and the torque converter output shaft speed detection sensor 24, thereby deactivating the aforementioned unloading valve 6. It is provided with a controller 19 to selectively open.

The controller 19 described above has the unloading valve 6 in order to prevent the sudden driving force of the loader from being changed by the discharge flow rate which is unloaded from the second hydraulic pump 3 when the unloading valve 6 is unloaded. The electrical signal for repeatedly opening and closing the above-described electronic control valve 20 is applied so that is gradually opened.

Referring to the operation of the embodiment according to the present invention configured as described above, the bucket cylinder 11 and the negative cylinder 12 by the operating pressure discharged from the first and second hydraulic pumps (2, 3) by driving the engine (1). The excavation of the load is carried out by driving the truck.

At this time, the hydraulic oil pressure discharged from the second hydraulic pump 3 detected by the pressure detection sensor 22 provided on the discharge flow path side of the second hydraulic pump 3 and the engine speed detection sensor provided at the predetermined position of the traveling device. The detection signal for the engine speed and the torque converter output shaft speed by the turbine shaft 18 rotation speed detection sensor 24 of the torque converter 14 and the torque converter 14 is input to the controller 19.

Due to this, the controller 19 compares the engine speed with the torque converter output shaft speed and calculates the degree of load generated in the traveling system according to the difference, wherein the load generated in the traveling system is loaded. It has a proportional relationship with the difference between the rotation speed and the torque converter output shaft speed.

In addition, the degree of load generated on the boom and the bucket is calculated by the operating pressure on the discharge flow path side of the second hydraulic pump 3, and the higher the operating pressure detected, the greater the degree of load.

Therefore, when the operating pressure discharged from the second hydraulic pump 3 is high and the difference between the engine speed of the traveling device and the torque converter output shaft speed is small, the controller 19 determines that there is little load on the traveling device. Thus, the electrical signal applied to the pre-control valve 20 from the controller 19 is blocked so that the unloading valve 6 maintains the initial state closed by the valve spring 6A.

As a result, all the working flow rates discharged from the first and second hydraulic pumps 2 and 3 are supplied to the bucket cylinder 9 and the pour cylinder 10, so that the excavation speed and the digging force can be improved.

On the other hand, when the operating pressure discharged from the second hydraulic pump 3 is low, but the difference between the engine speed of the traveling device and the torque converter output shaft speed is large, the controller 19 generates a load on the traveling device and thus the driving towing force is increased. I think it fell. As a result, the electronic control valve 20 is switched upward by the electrical signal applied from the controller 19 to the valve spring 20A opposite side of the electronic control valve 20, so that the unloading valve 6 To be open.

Accordingly, a part of the hydraulic oil discharged from the second hydraulic pump 3 is unloaded into the hydraulic tank 13 through the unloading valve 6, and the engine 1 using torque is unloaded to the traveling system. I send it and can secure enough driving towing force.

At this time, the unloading valve 6 has an electrical signal applied from the controller 19 to the electronic control valve 20 to replace the unloading valve 6 repeatedly so as to unload the interval of the unloading valve 6. Since it is possible to adjust, by supplying a part of the hydraulic oil supplied to the bucket cylinder (9) or the pour cylinder (10) to the traveling device system it is possible to prevent a sudden change in the towing force. This makes it possible to improve the driving operability of the loader.

As described above, the engine pump control apparatus and method of the loader according to the present invention has the advantage of improving the running force by varying the horsepower of the hydraulic pump in accordance with the working state of the loader, and the hydraulic oil discharged from the hydraulic pump It is to have the advantage of improving the operation operation and the stability of the circuit operation of the hydraulic system by preventing sudden change of driving force when unloading into the hydraulic tank.

Claims (3)

An engine for supplying driving horsepower to a traveling system for driving a driving wheel and a working system for driving a working device such as a bucket and a buoy, first and second hydraulic pumps driven by the engine, and the first and second hydraulic pressures. A bucket cylinder and a pour cylinder operated by the discharge oil of the pump, a bucket control valve and a pour control valve for controlling the flow rate and direction of the discharge oil supplied from the first and second hydraulic pumps to the bucket cylinder and the pour cylinder, the driver's Bucket operation means and boolean operation means for controlling the bucket control valve and the boolean control valve in proportion to the operation amount, and the unloading oil for unloading the discharge oil of the second hydraulic pump in accordance with the operating pressure of the bucket or the buoy to the hydraulic tank. An engine pump control apparatus of a loader including a loading valve and an electronic control valve for selectively opening and closing the unloading valve according to a predetermined electrical signal. In Pressure detecting means for detecting a discharge pressure inside the discharge flow path of the second hydraulic pump; Rotation speed detection means installed at a predetermined position of the traveling device and detecting rotation speed of the engine and rotation speed of the torque converter output shaft, respectively; And a controller for selectively outputting the electrical signal to the electronic control valve based on the detection signal of the pressure detecting means and the rotation speed detecting means. An engine for supplying driving horsepower to a traveling system for driving a driving wheel and a working system for driving a working device such as a bucket and a buoy, a first and a second hydraulic pump driven by the engine, and the first and second hydraulic pumps. A bucket cylinder and a pour cylinder operated by the discharge oil of the bucket, a bucket control valve and a booze control valve for controlling the flow rate and direction of the discharge oil supplied from the first and second hydraulic pumps to the bucket cylinder and the pour cylinder, the operator's operation amount A bucket operating means for controlling the bucket control valve and the boolean control valve in proportion to and an unloading valve for unloading the discharge oil of the second hydraulic pump into the hydraulic tank according to the operation of the bucket or the boolean. And, the engine pump control method of the loader including an electronic control valve for selectively opening and closing the unloading valve in accordance with a predetermined electrical signal In A first step of detecting the rotational speed of the engine and torque converter output shaft of the traveling device and the pressure on the discharge flow path side of the second hydraulic pump; The degree of load generated in the traveling device is calculated according to the difference between the engine speed and the torque converter output shaft, and the load degree generated in the bucket and the pour cylinder according to the discharge pressure of the first and second hydraulic pumps. A second step of calculating And a third step of adjusting an unloading time interval of the unloading valve by applying a predetermined electric signal to the electronic control valve according to the operation result of the second step. . The electronic control valve of claim 2, wherein the unloading valve is gradually opened to prevent sudden change of driving force of the loader due to discharge flow unloaded from the second hydraulic pump when the unloading valve is unloaded. The method of controlling the engine pump of the loader, characterized in that by repeatedly applying an electrical signal to adjust the unloading time interval of the unloading valve.