JPH02190536A - Controller for operation mode of oil pressure-driven vehicle - Google Patents

Abstract

PURPOSE:To raise the efficiency of operation by a method in which the actual traveling condition of vehicle is detected, a traveling drive mode is select ed, and when it is in no-traveling condition, operation drive mode is selected. CONSTITUTION:In a controller 4, vehicular speed signals V, operation position signals from a backward-forward switch lever 14, ON-OFF signals from a revolving number control selection switch 16, and pedal operating amount signals thetap are respectively read. Whether or not a vehicle runs is judged from the signals V, and when it is judged to be in traveling condition, a traveling drive mode is selected. Also, when it is not traveling, whether or not the switch 16 is on is judged. When the switch 16 is on, an operation drive mode is selected, whereas when it is off, whether or not the lever 14 is neutral is judged. When the lever 14 is not neutral, whether or not a travel pedal 12 is neutral is judged. Furthermore, when the pedal 12a is on, a travel drive mode is selected and when it is off an operation drive mode is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an operation mode control device for a hydraulically driven vehicle such as a wheeled hydraulic excavator.

B. Prior Art This type of operation mode control device, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-220702 by the present applicant, is capable of controlling a travel operation mode and a work operation mode in a wheeled hydraulic excavator, for example. can be selected. With this device, when the traveling operation mode is selected, the drive system is controlled by a combination of the maximum rotation speed of the prime mover, which is set to a high value, and the maximum discharge volume of the hydraulic pump, which is set to a small value, and the first work operation mode is selected. When selected, the drive system is controlled by a combination of the maximum rotational speed of the prime mover, which is set to a low value, and the maximum discharge volume of the hydraulic pump, which is set to a large value. The driving mode is selected by manually switching a mode selection switch provided on the driver's seat.

C0 Problems to be Solved by the Invention However, with such conventional devices, the mode selection switch must be operated every time the vehicle starts traveling from a task such as digging, which is a hassle. Further, if the machine continues to run in the 1-work operation mode, the desired driving torque cannot be obtained, and if the machine continues to work in the traveling operation mode, the desired work speed cannot be obtained.

A technical problem of the present invention is to automatically select an operation mode suitable for work or travel without having to manually switch each time work such as excavation or travel is started.

The present invention will be explained with reference to FIG. 1, which is a diagram corresponding to the claims. It is used as a device for controlling the driving mode of a traveling hydraulically driven vehicle having a drive system including a traveling actuator 9 driven by oil discharged from the hydraulic pump 5 and a working actuator 7 driven by the oil discharged from the hydraulic pump 5. It will be done.

This mode control device is a drive control device that selects either a driving mode suitable for driving or a work driving mode suitable for work other than driving, and controls the drive system to drive the vehicle in the selected driving mode. 101.

The above technical problem is solved by the following configuration.

In the invention of claim 1, as shown in FIG. 1(a), a traveling detection means 10 for detecting that the vehicle is actually traveling
2, and the drive control means 101 selects a driving operation mode to characterize the drive system when the detecting means 102 detects traveling.A hydraulic traveling drive vehicle to which the invention of claim 3 is applied has the above configuration. In addition, as shown in FIG. 1(b), there is a switching means 201 that switches the vehicle between forward, reverse, and neutral positions, and a travel pedal that controls the discharge amount from the hydraulic pump 5 to control the travel speed. A traveling operation member 204 is provided.

The above-mentioned technical problem is solved by the forward/reverse movement detection means 202 that detects the switching position of the switching means 201 and the traveling operation member 20.
The drive control means 101 is provided with a traveling operation amount detection means 203 for detecting the operation amount of 4, and the drive control means 101 is configured to detect that the switching means 201 is switched to the forward or reverse position by the forward/reverse movement detection means 202, and the driving operation amount detection means 203, the driving operation mode is selected even when it is detected that the driving operation member 204 is operated by a predetermined amount or more, and the drive system is characterized. The following conditions should be met.

E0 Effect - Claim 1 - When the running detection means 102 detects that the vehicle is actually running, the drive control means 101 selects the running mode and controls the prime mover and the variable displacement hydraulic pump 5. When the running of the vehicle is not detected, the work operation mode is selected and the prime mover and variable displacement hydraulic pump 5 are controlled.

Claim 3 - The forward/reverse detection switching means 202 detects that the switching means 201 is switched to the forward or reverse position, and the travel operation amount detection means 203 detects that the travel operation member 204 is operated by a predetermined amount or more. Then, the driving mode is selected. When this condition is not satisfied, the work operation mode is selected.

-Claim 4- When it is detected that the vehicle is actually in a traveling state, the traveling operation mode is set, and when it is detected that the switching means 201 is switched to the forward/reverse position and the traveling operation member 204 is operated. The vehicle enters driving mode.

In addition, in the above-mentioned sections and section E which explain the present invention in detail, some of the reference numerals of the embodiments are used in order to make the present invention easier to understand, but the present invention is not limited to the embodiments. .

F. Embodiment An embodiment of the present invention will be described based on FIGS. 2 to 4.

In FIG. 2, an engine (prime mover) 1 is a governor 1a
The pulse motor 2 is driven at a rotational speed corresponding to the rotational position of the pulse motor 2 that controls the motor. A potentiometer 3 for detecting the rotational speed is connected to the pulse motor 2, and a signal corresponding to the rotational position of the pulse motor 2, in other words, a signal corresponding to the rotational speed of the engine 1 is input to the controller 4. Here, the pulse motor 2 is driven by a drive signal from the controller 4.

The variable displacement hydraulic pump 5 is driven by the rotation of the engine 1, and discharges pressure oil corresponding to the rotation speed of the engine 1. 5a is a regulator that adjusts the discharge volume of this variable displacement hydraulic pump 5.

The oil discharged from the variable displacement hydraulic pump 5 is guided to the working actuator tough via the working control valve 6, and is also guided to the traveling actuator 9 via the traveling control valve 8.

Reference numeral 6a denotes a working lever, and by controlling the control valve 6 by switching the lever 6a, the flow rate and direction of oil discharged from the hydraulic pump 5 are controlled, and the working actuator 7 is driven and controlled. Further, 11 is a forward/reverse switching valve, 12 is a pilot valve, 13 is a hydraulic pump, and the forward/reverse switching valve 11 is a hydraulic pump.
When the travel pedal 12a is switched to the F position or the R position and the travel pedal 12a is depressed, the oil discharged from the hydraulic pump 13 flows into the pilot valve 1.
2, the pressure is set to a pressure corresponding to the amount of operation of the pedal 12a, and then guided to the pilot port 8a or 8b of the travel control valve 8 depending on the position of the forward/reverse switching valve 11.

As a result, the control valve 8 switches in the direction and stroke amount according to the pilot oil pressure, and the flow rate of pressure oil discharged from the variable displacement hydraulic pump 5 corresponding to the rotation speed of the engine 1 is transferred via the control valve 8. An amount corresponding to the stroke amount is guided to the traveling actuator 9. As a result, the traveling actuator 9 is driven, and the vehicle travels at a speed corresponding to the amount of operation of the pedal 12a.

In FIG. 2, 14 is a forward/reverse switching lever provided in the driver's cab, and when the lever is switched to the forward position 1iZ (F position) or the reverse position (R position), a switching signal from the battery BT is sent to the relay 15. The voltage is applied to the solenoid portion of the forward/reverse switching valve 11 via the normally closed switch SWI, and the forward/reverse switching valve 11 is switched to the F position or the R position, respectively. Furthermore, when the forward/reverse switching lever 14 is operated to the neutral position, the switching signal is cut off and the forward/reverse switching valve 11 is placed in the neutral position (N position).
Switch to

The relay 15 is activated when a rotation speed control selection switch 16 (described later) provided in the driver's cab is turned on, and its normally closed switch SW1 is turned off. When the switch SWI is off, the switching signal is cut off regardless of whether the forward/reverse switching lever 14 is operated to the F or H position, and the forward/reverse switching valve 11 is held at the N position.

A signal indicating whether the rotation speed control selection switch 16 is on or off is input to the controller 4, and the forward/reverse selector lever 14 is in either position (F, N).

An operation position signal indicating whether or not R) is being operated is also input to the controller 4.

Reference numeral 17 denotes a fuel lever for controlling the rotation speed provided at the driver's seat, and a signal corresponding to the amount of operation of this lever 17 is guided to the controller 4. Furthermore, in FIG. 2, 18 is a potentiometer that outputs a pedal operation amount signal θp corresponding to the operation amount of the travel pedal 12a, and this signal θp is input to the controller 4.

A vehicle speed sensor 19 outputs a signal V corresponding to the vehicle speed, and the vehicle speed signal V is input to the controller 4.

The controller 4 controls the rotation speed of the engine 1 by controlling the pulse motor 3 based on the operation amount of the fuel lever 17 and a signal from the potentiometer 3 corresponding to the actual engine rotation speed. On the other hand, if the rotation speed control selection switch 16 is on, the relay 15 is activated and the normally closed switch SWI is opened, so that the forward/reverse selector valve 11 is held at the neutral position, and the forward/reverse selector valve 11 is held in the neutral position, and the forward/reverse selector valve 11 is held at the neutral position, and the forward/reverse selector valve 11 is controlled in accordance with the amount of operation of the travel pedal 12a. A signal θp is sent from the potentiometer 18 to the controller 4, and the engine speed is controlled accordingly. 1 if the rotation speed control selection switch 16 is off.
When the forward/reverse switching lever 14 is switched to forward or reverse and the travel pedal 12a is operated, the vehicle travels.

The controller 4 also receives a vehicle speed signal V from a vehicle speed sensor 19, a pedal operation amount signal OP of a travel pedal 12a output from a potentiometer 18, and a forward/reverse switching lever 1.
An operation position signal indicating the operation position of No. 4 and a selection switch 16
Based on the on/off signal of , the travel operation mode or the work operation mode is selected according to the mode selection procedure shown in FIG.

In FIG. 3, the controller 4 first performs step S1.
At this point, the vehicle speed signal V, the operation position signal from the forward/reverse switching lever 14, the on/off signal from the 1 selection switch 16, and the pedal operation amount signal θp are respectively read. Next, the process proceeds to step S2, where it is determined whether or not ■≠0 for the vehicle speed signal V. It is determined that the vehicle is running, and the process advances to step S6 to select a running mode. When the vehicle speed signal is v=o, step S2 is denied and step S
Proceed to step 3. In step S3, it is determined whether the selection switch 16 outputs an on signal. If it is on, the answer is affirmative and the process proceeds to step S7 to select the 1 work operation mode. If the selection switch 16 is off, step S3 is denied and the process proceeds to step S4. In step S4, it is determined whether the forward/reverse switching lever 14 is in the neutral position. If the vehicle is neutral, the process proceeds to step S7, and if the vehicle is moving forward or backward, the process proceeds to step S5. In step S5, the travel pedal 12
It is determined whether or not a has been operated by a predetermined amount and is turned on.

If the answer is negative, the process proceeds to step S7, and if the answer is affirmative, the process proceeds to step S6.

According to such a procedure, the driving mode is selected under the following conditions.

■When the vehicle speed is detected.

(2) When the vehicle speed is not detected, the following three conditions are satisfied: the rotation speed control selection switch 16 is off, the forward/reverse switching lever 14 is in the forward or reverse position, and the travel pedal 12a is operated a predetermined amount or more.

Further, the work operation mode is selected under the following conditions.

■When the vehicle speed is not detected and the rotation speed control selection switch 16 is on.

■ When the vehicle speed is not detected, the rotation speed control selection switch 16 is off, and the forward/reverse switching lever 14 is in the neutral position. Travel pedal 12
When a is not operated by a predetermined amount or more.

Note that the operation mode selection procedure described above can be modified as follows.

(2) Steps 83 to S5 may be omitted, and the work operation mode may be selected when the vehicle speed signal V is v=O, and the travel operation mode may be selected when (2)≠0.

■The vehicle speed sensor 19 is omitted, and steps 83 to 3 in FIG.
A desired operation mode may be selected in step S5.

(2) The vehicle speed sensor 19 and the rotational speed control selection switch 16 may be omitted, and the driving mode may be selected only by steps S4 and S5 in FIG.

The procedure shown in FIG. 3 has a better rise characteristic of the engine rotational speed at the start of running than the procedure (2).

Further, in the above embodiment, the 1 rotation speed control selection switch 16
While the normally closed switch SW1 is turned on, the normally closed switch SW1 remains off. Therefore, even if the forward/reverse switching lever 14 is at the F or R position, the forward/reverse switching valve 11 is switched to the N position, and the vehicle will not run even if the travel pedal 12a is operated.

The engine speed can be controlled according to the amount of operation of the travel pedal 12a without operating the forward/reverse switching lever 14 to neutral each time.

Next, the travel mode and the work mode will be explained using a wheeled hydraulic excavator as an example.

In wheel hydraulic excavators, one engine is generally used for both excavation and travel, but the engine horsepower required for excavation work may be smaller than the engine horsepower required for travel. However, setting the engine horsepower to a high level with emphasis on driving performance is wasteful in terms of fuel consumption, noise, and cost from the perspective of excavation work; If the engine is set to a lower horsepower compared to the former with emphasis on the former, sufficient running performance will not be obtained when the excavator is mounted, and with wheeled hydraulic excavators, it is difficult to match excavation and running as far as engine performance is concerned.

Therefore, as mentioned above, the travel operation mode and the work operation mode are set respectively, but for example, it is possible to set an operation mode that combines the maximum engine rotation speed and the maximum discharge volume of the variable displacement hydraulic pump, as shown below. can.

That is, in the traveling mode, the maximum engine speed is set higher than in the work mode, and the maximum discharge volume of the variable displacement hydraulic pump 5 is set smaller than in the work mode.

To explain in detail with the N-Q diagram in FIG. 4, when the traveling operation mode is selected, the maximum discharge volume of the variable displacement hydraulic pump 5 is set to a small value qp, and the maximum engine speed is set to a large value N.
It is set to P and operated.

In addition, when the work operation mode is selected, the variable displacement hydraulic pump 5
The maximum discharge volume of the engine is set to a large value qε, and the maximum engine speed is set to a small value NE. Preferably, as shown in FIG. 4, the discharge flow rate Qo of the variable displacement hydraulic pump 5 is set in the range of engine rotational speed NE-NP when the traveling operation mode is selected.

Discharge flow rate Q of the variable displacement hydraulic pump 5 at the engine speed NE when the work operation mode is selected.

It is roughly equivalent to

In this way, the maximum engine speed and the variable displacement hydraulic pump 5
Instead of changing the maximum discharge volume of the variable displacement hydraulic pump, when selecting travel operation mode, only the engine speed is higher than when selecting work operation mode, or when selecting travel operation mode, the variable displacement hydraulic pump is set higher than when selecting work operation mode. Only the input horsepower may be increased. In this latter control method, the hydraulic pump p-q(
(p is the discharge pressure of the pump, q is the discharge volume of the hydraulic pump) is established as shown in Figure 6, and the characteristics of low input horsepower are used when working without increasing or decreasing the engine speed, and the characteristics of high input horsepower are used when driving. Select horsepower characteristic T and drive. This selection can be made, for example, by pre-memorizing a map of T in the controller 4 (FIG. 2) and controlling the pump regulator 5a by selecting the water or water depending on the traveling and work. Can be done. This method is advantageous in terms of noise because there is no fluctuation in engine speed even when driving and work are frequently changed.

In the configuration of the above embodiment, the controller 4° pulse motor 3 or the pump regulator 5a serves as the drive control means, the vehicle speed sensor 19 serves as the traveling detection means, the forward/reverse switching lever 14 serves as the switching means and the forward/reverse detecting means, and the traveling pedal 1
2a constitutes a driving operation member, and the potentiometer 18 constitutes a driving operation amount detection means.

In the above description, the pilot valve 1 is operated by the travel pedal 12a.
2 is operated to control the pressure of oil discharged from the hydraulic pump 13, and the direction of this pressure oil is controlled by the forward/reverse switching valve 11 to switch and control the traveling control valve 8. As shown in FIG. 5, switching of the travel control valve 51 and the work control valve 53 may be controlled by a drive signal from the controller 50. Note that in FIG. 5, the same parts as in FIG. 2 are given the same reference numerals.

That is, in FIG. 5, a signal corresponding to the operating amount of the travel pedal 12a and a signal corresponding to the switching position of the forward/reverse switching lever 14 are input to the controller 50, and the controller 50 operates the proportional electromagnetic type based on these signals. The travel control valve 51 is switched and controlled. As a result, the oil discharged from the hydraulic pump 5 is guided to the travel actuator 9 in the same way as described above, and the vehicle travels in a predetermined direction at a predetermined speed. Further, a work lever 52 that outputs a signal according to the amount of operation is also connected to the controller 50, and the controller 50 outputs a signal according to the operation amount.
switches and controls the proportional electromagnetic control valve 53 for work.

In this example as well, based on the same determination as described above, the traveling mode is selected during traveling and the working mode is selected when working, and the maximum engine speed and the maximum discharge volume of the variable displacement hydraulic pump are controlled.

G0 Effects of the Invention According to the present invention, the running mode is selected by detecting that the vehicle is actually running, and the working mode is selected when the vehicle is not running. There is no need to manually switch the operation mode each time before starting work or work, making it easy to operate. Furthermore, since the vehicle does not perform work while in the travel mode or travel while in the work mode, it is possible to achieve desired travel performance and work performance.

Furthermore, the present invention has the following advantages compared to the conventional method in which the driving mode or the working mode is selected simply depending on whether the forward/reverse switching lever is in the neutral position.

In this conventional system, the work operation mode is selected when the forward/reverse switching lever is left in the neutral position, but when the maximum rotational speed of the prime mover is set lower in this work operation mode than in the travel operation mode, the hydraulic pump discharge amount There is a risk that cavitation may occur due to a lack of Also,
As shown in Figure 7, a makeup circuit 6 is added to the travel hydraulic circuit.
0 is provided and the oil discharged from the operating system hydraulic pump 13 is guided to the hydraulic motor 9 via the check valve 61, there is a risk that the amount of oil from the makeup circuit 60 will be insufficient and cavitation will occur. There is also. However, in the present invention, since the actual running state is detected, the running mode is selected even when exiting the vehicle with the forward/reverse switching lever in the neutral position, and this problem does not occur.

Furthermore, with this method, when work is performed with the forward/reverse switching lever in the forward or reverse position, the driving mode is selected, but the engine speed is too high, causing problems with fuel consumption, noise, etc. The forward/reverse switching lever must be switched to the neutral position each time, resulting in poor operability; however, with the present invention, the work operation mode is selected even if the forward/reverse switching lever is left in the forward or reverse position. There are no problems.

Furthermore, a method may be considered in which the work operation mode is set when the forward/reverse switching lever is in the neutral position or the work operation lever is operated, but this method has the following problem. If you perform work with the forward/backward switching lever in either forward or backward motion, the work mode will be selected when the work lever is operated, and the travel mode will be selected when the work lever is set to neutral. However, the present invention does not cause such a problem.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram. 2 to 4 show an embodiment of the present invention, FIG. 2 is an overall configuration diagram of the operation mode control device according to the present invention, FIG. 3 is a flow chart showing the processing procedure of the controller, and FIG. 4 is a flow chart showing the processing procedure of the controller. N to explain an example of traveling operation mode and work operation mode
-Q diagram. FIG. 5 is an overall configuration diagram of an operation mode control device showing a modification of the present invention. Figure 6 explains mode switching based on pump input horsepower.
-q diagram. FIG. 7 is a hydraulic circuit diagram illustrating the makeup circuit. 1: Engine 2: Pulse motor 3.18: Potentiometer 4: Controller 5: Variable displacement hydraulic pump 8: Control valve 9: Traveling actuator 11: Forward/forward switching valve
12: Pilot valve 12a: Travel pedal 13: Hydraulic pump 14; Forward/forward switching lever 16: Engine speed control selection switch 17: Fuel lever 19: Vehicle speed sensor 101: Drive control means 1
02: Running detection means 201: Forward/forward switching means 202: Forward/forward detecting means 203: Operation amount detection means 204: Operating member for running

Claims (1)

[Scope of Claims] 1) A hydraulic pump that discharges pressure oil at a flow rate corresponding to the rotational speed of a prime mover, a traveling actuator that rotates with the oil discharged from the hydraulic pump and drives a traveling wheel, and a driving actuator that drives a traveling wheel from the hydraulic pump. A device that controls the driving mode of a traveling hydraulically driven vehicle having a drive system consisting of a working actuator and the like driven by discharged oil, and has a traveling driving mode suitable for driving and a working driving mode suitable for work other than driving. An apparatus comprising a drive control means for selecting one of the driving modes and controlling the drive system to drive the vehicle in the selected driving mode, the apparatus comprising a running detection means for detecting that the vehicle is actually running. A drive mode control device for a hydraulically driven vehicle, wherein the drive control means selects the drive mode and controls the drive system when the detection means detects running. 2) The driving mode control device for a hydraulically driven vehicle according to claim 1, wherein the traveling detecting means detects information representing the traveling speed of the vehicle. 3) A hydraulic pump that discharges pressure oil at a flow rate corresponding to the rotational speed of the prime mover, a travel actuator that rotates with the oil discharged from the hydraulic pump and drives the running wheels, and a travel actuator that is driven by the oil discharged from the hydraulic pump. It has a drive system consisting of work actuators, etc., and also controls the forward movement of the vehicle.
A device for controlling the driving mode of a traveling hydraulically driven vehicle, comprising a switching means for switching between reverse and neutral positions, and a traveling pedal for controlling the traveling speed by controlling the discharge amount from the hydraulic pump, Select either the driving mode or the work mode suitable for tasks other than driving.
A device comprising drive control means for controlling the drive system to drive the vehicle in a selected driving mode, comprising: forward/reverse detection means for detecting the switching position of the switching means; and detecting the amount of operation of the travel pedal. travel pedal detection means, and the drive control means determines that the switching means is switched to a forward or reverse position by the forward/reverse motion detection means, and that the travel pedal is operated by a predetermined amount or more by the travel pedal detection means. A drive mode control device for a hydraulically driven vehicle, characterized in that when it is detected that the drive mode is detected, the drive system is controlled by selecting the drive mode. 4) A hydraulic pump that discharges pressure oil at a flow rate corresponding to the rotational speed of the prime mover, a travel actuator that rotates with the oil discharged from the hydraulic pump and drives the running wheels, and a drive actuator that is driven by the oil discharged from the hydraulic pump. It has a drive system consisting of work actuators, etc., and also controls the forward movement of the vehicle.
A device for controlling the driving mode of a traveling hydraulically driven vehicle, comprising a switching means for switching between reverse and neutral positions, and a traveling pedal for controlling the traveling speed by controlling the discharge amount from the hydraulic pump, Select either the driving mode or the work mode suitable for tasks other than driving.
A device comprising drive control means for controlling the drive system to drive the vehicle in a selected driving mode, comprising: a running detection means for detecting that the vehicle is actually running; and a switching position of the switching means. forward/reverse detection means for detecting the movement of the travel pedal, and travel pedal detection means for detecting the amount of operation of the travel pedal, and the drive control means selects the travel operation mode when the travel detection means detects travel. At the same time, the forward/reverse detecting means detects that the switching means is switched to a forward or reverse position, and the traveling pedal detecting means detects that the traveling pedal is operated by a predetermined amount or more. A drive mode control device for a hydraulically driven vehicle, characterized in that the drive system is controlled by selecting the drive mode when the drive mode is selected. 5) The driving mode control for a traveling hydraulically driven vehicle according to claim 1, wherein when the traveling driving mode is selected, the drive control means sets the maximum rotation speed of the prime mover higher than in the working driving mode. Device. 6) The driving mode control for the traveling hydraulically driven vehicle according to claim 1, wherein the drive control means sets the input horsepower of the hydraulic pump to be larger when the traveling driving mode is selected than in the working driving mode. Device. 7) When the travel operation mode is selected, the drive control means controls the drive system using a combination of a high maximum rotational speed of the prime mover and a small maximum discharge volume of the hydraulic pump, and when the work operation mode is selected, 5. The driving mode control device for a hydraulically driven vehicle according to claim 1, wherein the drive system is controlled by a combination of a low maximum rotational speed of the prime mover and a large maximum discharge volume of the hydraulic pump.