JPH03168339A - Running speed controller of construction machine - Google Patents

Abstract

PURPOSE:To improve workability by inputting, into a controller, the running speed group set based on the combination of one-speed and two-speed of a running motor with an engine rotational mode, displaying the running speed through a running speed selection switch, and performing the switching automatically. CONSTITUTION:Several kinds of running speeds set based on the combination of an engine rotational mode with one-speed, two-speed of a running motor 46 are stored in a memory 40 of a controller 39. After a running speed selection switch 41 is set to a required running speed position according to the operational condition at the time of running, the selected running speed is displayed and is recognized by the controller 39, and the combination of the engine rotational mode with one-speed, two-speed of the running motor 46 stored in the memory 40 is read. A command signal is output to a mode change switch 43 for engine rotation, as well as to one-speed, two-speed change switch 44 for running motor, from the controller 39, and an actuator 45 for governor as well as the running motor 46 are operated so as to exhibit the required running speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates primarily to a traveling speed control device for construction machinery such as hydraulic excavators.

BACKGROUND OF THE INVENTION FIG. 3 is a circuit diagram showing a conventional travel speed control device. In the figure, 1 and 2 are variable displacement drive motors on the left and right, 3 and 4 are cylinders for adjusting tilt angles of the drive motors 1 and 2, respectively, 5 and 6 are speed switching valves, and 7.
8 are travel valves, 9 and 10 are hydraulic pumps,
11 is a pilot I pump, 12 is an oil tank, 13 is a solenoid valve for switching between 1st and 2nd speeds, 14 is a solenoid for solenoid valve ■3, 15 is a switch, 16 is a power supply, 17 is an engine, 1
8 is a governor for the engine 17, 19 is a stepping motor that is an actuator for the governor, 2o is a controller,
21 is an engine rotation mode changeover switch, and 22 is an engine rotation sensor.

Next, the configuration and functions of the conventional travel control device will be described with reference to FIG. This traveling speed control device includes a switching means for switching the engine rotation mode and a switching means for switching the traveling motors 1 and 2 to first speed or second speed. First, when changing the engine rotation mode, move the mode selector switch 21 to one of the following four positions: high speed rotation position, S position (medium speed rotation position), or FC position (low speed four rotation position). Switch. The switching operation signal is input to the controller 20. So controller 1 and roller 2
From 0, one command word is output to the stepping motor 19 based on the input signal.

This activates the stepping motor 19 to adjust the governor 18. As the rotation of the engine 17 changes, the rotation of the hydraulic pumps 9 and 10 also changes. Therefore, the hydraulic motors 1 and 2 are supplied with pressure oil from the oil pumps 9 and 10 corresponding to the engine rotation mode.

Next, the switching means for switching the traveling motor 1.2 to the first speed or the second speed will be described. First, when driving in 1st gear,
Keep the switch 15 in the off state. The tilting angle adjustment cylinder 3 of the travel motor 1 (the travel motor 2 operates in the same way as the travel motor 1, so only the travel motor 1 will be explained) is connected to an oil passage 23, a position A of the speed switching valve 5, and an oil passage. 24,
It communicates with the oil tank 12 via 25. Since the travel motor 1 is tilted to the large capacity side, when the travel valve 7 is operated, the travel motor 1 exerts a strong rotational force to perform first speed travel. Next, when performing a two-way run, the switch 15 is turned on. Since the solenoid 14 is energized, the solenoid valve 13 is switched from the tank communication oil passage position C to the pilot pressure application oil passage position 2. The pressure from the pilot pump 11 is applied to the oil path 26, the two positions of the solenoid valve 13, and the ura path 27.
28, it acts on the pilot pressure receiving portion 29 of the speed switching valve 5. The speed switching valve 5 is switched from the A position to the Open position. When the traveling valve 7 is operated, the pressure oil from the hydraulic bomb 9 is transferred to the oil passages 3o, 31, the traveling valve 7, the oil passage 32 or 3.
3, the oil is sent to the traveling motor 1. At that time, part of the pressure oil in the oil passage 32 or 33 is transferred to the oil passage 34 or 35.
, the shaft valve 36, the oil passage 37, the opening position of the speed switching valve 5, and the oil passage 23, and act on the cylinder 3. cylinder 5
Since the inner piston 38 moves against the spring force of the built-in spring, the travel motor 1 is tilted toward the small capacity side.

Therefore, the traveling motor 1 rotates at a high speed and runs in the second speed.Problems to be Solved by the Invention In the conventional traveling speed control device, the mode changeover switch for engine rotation is switched to one of three positions: H, S, and FC. At the same time, the desired traveling speed was selected by switching the traveling motor to first or second speed. There are three types of running speeds that can be set:
Also, since there are two types of travel motors, 1st speed and 2nd speed, there are as many as 6 types depending on the combinations. As a result, the operation of selecting the driving speed by the driver is cumbersome, which impedes the workability of the construction machine.

This invention solves the problems described in 2 above, and provides driving speed control that automatically switches engine rotation mode and driving mode 1st and 2nd speed when the driver selects the desired driving speed with a selection switch. The purpose is to provide equipment.

Means for solving the problems The means of this invention taken to solve the above problems are: a. Input into the controller a travel speed group set in advance based on the combination of the engine rotation mode and the first and second speeds of the travel motor; b. Also, the controller is provided with a travel speed selection switch; c. By operating the traveling speed selection switch, the selected traveling speed is displayed on the display, and the engine rotation mode and the traveling motor are automatically switched between first and second speed.

Action a. The memory of the controller stores a plurality of different travel speeds set based on the combination of the engine rotation mode and the first and second speeds of the travel motor.

mouth. When running the construction machine, the running speed selection switch is operated to switch to a required running speed position according to the work situation.

In this case, the selected travel speed value is immediately displayed on the display.

C. By operating the travel speed selection switch in item B, the controller recognizes the selected travel speed and sets the engine rotation mode and the travel motor 1 in the memory.
Read out the combination relationship with speed and 2nd speed. And con 1・
A command signal is output from the roller to the engine rotation mode changeover switch and the travel motor 1st/2nd speed changeover switch.

two. Based on the command signal in item 8 above, the engine rotation mode selector switch and the 1st/2nd speed selector switch for the travel motor are switched, so the governor actuator and the travel motor are controlled so that the required travel speed is achieved. Operate.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a block diagram showing an embodiment of a traveling speed control device according to the present invention. In the figure, 3 is a controller, 40 is a memory, 41 is a travel speed selection switch, 42 is a display, 43 is an engine rotation mode changeover switch, 44 is a travel motor 1st/2nd speed changeover switch, 4
5 is an actuator for the (engine) governor, and 46 is a travel mode. FIG. 2 is a chart showing the traveling speed groups stored in the memory 40.

Next, the configuration of the traveling speed control device according to the present invention will be explained as follows.
2 and 2 will be described. The engine rotation mode (H, S, FC modes) is set in advance in the controller 39,
A travel speed group (travel speed group consisting of travel speeds A, B, C, D, E, and F) set based on the combination relationship with the first and second speeds of the travel motor 46 was input.

In addition, a travel speed selection switch 41 is provided in each of the three controllers, and when the travel speed selection switch 41 is operated, the selected travel speed is displayed on the display section 42, and the engine rotation mode is switched and the travel motor 46 is set to 1st or 2nd speed. Speed switching is now done automatically. Note that when the traveling speed selection switch 41 is switched to the switching positions a, b, c, d, e, f, the set traveling speeds A, B, C, D, E,
I'm trying to make the most of F.

Next, the functions of the traveling speed control device according to the present invention will be described. The memory 40 of the controller 39 stores a plurality of different traveling speeds A, . F is memorized.

When the engine is operated to cause the construction machine to travel, the travel speed switch 41 is operated to switch to a required travel speed position depending on the work situation. In this case, the selected travel speed value (indicated by A, . . . , F) is immediately displayed. By operating the traveling speed selection switch 41, the controller 39 recognizes the selected traveling speed, and sets the engine rotation mode in the memory 40 and the 1st speed mode of the traveling motor 46.
Read out the combination relationship with 2nd speed. Then, the controller 39 outputs a command signal to the engine rotation mode changeover switch 43 and the travel motor 1 speed/2 speed changeover switch 44. Based on the command signal, the engine rotation mode changeover switch 43 and the travel motor 1st/2nd speed changeover switch 44 are switched, so that the (engine) governor actuator 43 and the travel motor 46 achieve the required travel speed. It operates as follows.

Effects of the Invention In the traveling speed control device according to the present invention, the controller is provided with a memory and a traveling speed selection switch connected to each other,
By operating the travel speed selection switch, the selected travel speed is displayed on the display, and the engine rotation mode and the travel motor are automatically switched between first and second speed.

Therefore, when the driver desires a desired traveling speed while working on the construction machine, the required traveling speed can be automatically obtained by simply switching the traveling speed selection switch to the desired position.

Therefore, in a construction machine equipped with the travel speed control device according to the present invention, it is possible to eliminate the troublesomeness of the travel speed control operation in the prior art, improve the travel speed control function of the construction machine, and increase its workability. can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a traveling speed control device according to the present invention, FIG. 2 is a chart showing a group of traveling speeds stored in a memory, and FIG. 3 shows a conventional traveling speed control device. It is a circuit diagram. 1 2. 4 6----------1 traveling motor 1 5. 4 4−−−−−−−−−−−−−
- 1st/2nd speed selector switch 17 for one travel motor Engine 18 Governor 1 9 4 5 -------------- Governor actuator 20 39 Controller 21. 43--11 Engine rotation mode selector switch 40 Memory 4 1--
-------1 Travel speed selection switch 4 2--------
−−−−−−−−−−−−−−−−−−−−−−1 display area or more

Claims (1)

[Claims] (1) In a travel speed control device for construction machinery, which is equipped with a switching means for switching the engine rotation mode and a switching means for switching the travel motor to 1st speed or 2nd speed, the controller is preset with the engine rotation mode and the 1st speed of the travel motor.・A travel speed group set based on the combination with 2nd gear is input, and a travel speed selection switch is provided on the controller, and when the travel speed selection switch is operated, the selected travel speed is displayed on the display, and the engine A travel speed control device for construction machinery, characterized in that rotation mode switching and travel motor switching between first and second speed are automatically performed.