JPS615903A - Control system of operation of car mount type concrete mixer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an operation control system for a vehicle-mounted concrete mixer that controls the operation of a hydraulic pump and an engine.

[Conventional technology]

The mixer drum in a vehicle-mounted concrete mixer is configured to rotate forward or reverse by a hydraulic pump driven by a driving engine of the vehicle.

In addition, each control of forward rotation, reverse rotation, and stop of this mixer drum is based on the operation of lever switches, button switches, etc.
This is accomplished by operating a servomotor as a servo actuator in response to a command from the controller, and adjusting the tilting angle of the hydraulic pump. In other words, by controlling the operating displacement of the servo motor, the mixer drum's stirring mode, charge mode, discharge mode, etc. are set, and the engine speed is also adjusted by adjusting the engine accelerator opening. ing.

[Problem that the invention seeks to solve]

By the way, when controlling the hydraulic pump and the accelerator opening using such a servo motor,
α) As shown in K, no matter which direction the hydraulic pump tilt angle is in the input mode or the discharge mode of the mixer drum,
The servo motor has the characteristic that it settles down to a constant value at a certain equal maximum displacement position, and as shown in Fig. I try to control it in the direction of increasing speed from the current state.

Therefore, if the input button or the exhaust button is continuously pressed, once the hydraulic pump reaches its maximum tilting angle, the engine speed may subsequently increase rapidly. In other words, even if the operator intends to operate the hydraulic pump to the maximum tilt angle by operating the input button or exhaust button, there is a risk that the engine speed will be increased all at once due to careless continuous operation. .

As a result, even experienced operators find it difficult to grasp the timing when increasing engine speed, and unskilled operators experience psychological anxiety, as well as the sudden high-speed rotation of the mixer drum. generation of noise,
There have been various problems such as fear of unexpected accidents such as entanglement accidents and adverse effects on mixer drive devices.

The present invention has been made by focusing on such conventional problems, and when operating the input button or the discharge button,
This is a vehicle-mounted concrete mixer in which the servo motor is temporarily stopped when the hydraulic pump reaches its maximum tilting angle, and then the engine speed increases only when the above buttons are operated again. The purpose is to provide an actuation control method.

[Means for solving problems]

To achieve this objective, the present invention determines whether or not the servo actuator has caused the hydraulic pump to reach the maximum tilting angle by operating the input button or the discharge button, and also determines whether the hydraulic pump has reached the maximum tilting angle. The hydraulic pump and the engine are activated through a first step of temporarily stopping the servo actuator when the input button or the exhaust button is operated again, and a second step of starting to increase the speed of the engine on the condition that the input button or the exhaust button is operated again. This allows for safe operation control.

[For production]

Therefore, if you keep pressing the input button or the discharge button,
After the servo actuator reaches the maximum tilting angle of the hydraulic pump, it temporarily stops, then continues to increase the accelerator opening and operates to raise the engine speed to the set rotation speed.

〔Example〕

FIG. 2 is a block connection diagram showing the configuration of the present invention. 1
2 is an operating device provided inside the vehicle, 2 is an operating device provided outside the vehicle, and 3 is a controller, which performs operations based on output signals from each operating device 1.2, position data memory 4, and a displacement detector to be described later. A signal to control the mixer drum or engine is calculated and output to the operating mote specified by either the device 1 or 2. Reference numeral 5 denotes a servo motor as a servo actuator that is driven and controlled by a servo motor drive circuit 6 that operates based on the output of the controller 3, and its forward rotation, reverse rotation, and displacement thereof are controlled.

It goes without saying that as an actuator to replace the servo motor 5, an air cylinder operated by air pressure from a vehicle compressor or a hydraulic cylinder operated by pressure hydraulic oil from a hydraulic pump may be used to achieve the same function. .

Further, the displacement of the servo motor 5 is transmitted via a link mechanism 7 to a discharge adjustment section (for example, a swash plate for tilting angle adjustment) of a hydraulic pump 8, and this hydraulic pump 8 is connected to an engine 9. It is designed to be driven by 'The accelerator of this engine 9 is operated by the servo motor 5 via a part of the link mechanism 7. 10 is a mixer drum driven by a hydraulic pump 8.

Reference numeral 11 denotes a displacement detector 41 for detecting the displacement of the servo motor 5 corresponding to the displacement position of the link mechanism 7 or the tilting angle of the hydraulic pump. The detection output of this is fed back into the controller 3.

A display device 12 displays the driving status of the mixer drum 10 using colored lamps or light emitting diodes.

Further, the controller 3 determines whether the mixer drum 10 is currently in a charging operation, a discharging operation, or an agitation operation based on the output of the displacement detector 11, and when in a stop mode such as an emergency, this determination data is used. Based on servo motor 5
Rotate it forward or reverse in the direction that stops it at the neutral position.

- The controller 3 operates the servo motor 5 in a neutral direction and sets the engine rotation to a low speed when the power switch of the servo motor drive circuit 6 including the servo motor 5 and the ignition circuit of the engine 9 is turned on or off. It acts to return it to the area.

Further, the controller 3 detects the maximum value of the control tilt angle of the hydraulic pump 8 based on the detection output of the displacement detector 11, and also determines whether the input button or the discharge button is continuously pressed, or whether the push button is released. This detects whether the button is pressed again within a preset time. If the controller 3 determines that the tilt angle of the hydraulic pump 8 is the maximum, the controller 3 temporarily stops the displacement operation of the servo motor 5 even if the input button or the discharge button is pressed continuously, and On the condition that the discharge button is pressed again after the push operation is released, the controller 3 increases the accelerator opening of the engine 9 while maintaining the above-mentioned tilt angle of the hydraulic pump 8. When enters the speed-up operation region, it becomes . In order to prevent this speed increase from becoming excessive, the controller 3 is configured to stop the engine speed increase in the set high speed operating range.

The specific configurations of the link mechanism 7, engine 9, and hydraulic pump 8 are the same as those proposed in the past. It may be the same as the

Next, the operating procedure of this operation control device will be explained with reference to the flowchart shown in FIG.

First, to briefly describe the operation of the block circuit, the power switch is closed to enable the operation of the servo motor 6 and the engine 9, and then the switch operation of either the operating device 1 or 2 is performed, for example. Specifies the stirring operation mode.

By this designation, a signal corresponding to this operation mode is selected from the memory 4 and input to the controller 3. On the other hand, the current position signal of the servo motor 5 detected by the displacement detector 11 is also input to the controller 3. and,
These two signals are compared and calculated, and the controller 3 controls the rotation of the servo motor 5 in a direction to reduce the difference between the two signals, and finally drives and controls the mixer drum to a specified operation mode.

Next, in such an operation control system, the operating devices 1 and 2
For example, when the input switch is turned on (step α), the controller 3 moves the servo motor 5 to the input mode side based on this operation instruction, and increases the tilting angle of the hydraulic pump 8 to the next level. I will do it. At the same time, the rotation of the mixer drum 10 also increases in speed in the forward direction (
Step b).

In this way, the servo motor 5 rotates in a direction that maximizes the tilt angle of the hydraulic pump 8, and the controller 3 determines whether the tilt angle of the hydraulic pump 8 has reached the maximum (step C). Then, the servo motor 5 is rotated until the maximum value is reached, and when it is determined that the maximum value is reached, the rotation of the servo motor 5 is temporarily stopped (step d).

At this time, the hydraulic pump 8 is maintained at the maximum tilt angle state.

In addition, in this state, the controller 3 determines whether or not the input button is kept being pressed (step e).
If it is determined that the closing button has been pressed again after the closing operation is released (step f), the servo motor 5 increases the opening degree of the axle via the ring mechanism 7. Therefore, the engine 9 starts operating at a higher speed than idling (step g). In this way, by increasing the speed, the engine 9
When the engine reaches a certain set high speed rotation range, the controller 3 determines this state (step h) and controls the servo motor 5 to stop any further speed increase of the engine 9 (step i). In this way, a series of input-side operations of the hydraulic pump 8 and the engine 9 are completed.

In addition, since FIG. 3 explains the operation from the stirring mode to the charging mode side, when the button switch is operated from the stirring mode to the charging mode side, the charging switch is not ON, so at this stage, The servo motor stops (step j). Also, continuous ON of the closing switch
If the closing switch is not turned on again after the state is released, the servo motor will stop at this stage (
Step k).

Furthermore, the activation of the ejection mode can also be controlled by similar means.

〔Effect of the invention〕

According to the present invention, when the tilting angle of the hydraulic pump due to the displacement of the servo actuator reaches the maximum due to the operation of the input button or the discharge button, when the displacement operation of the servo actuator is temporarily stopped and then operated again, Since the engine is made to start increasing speed, the engine is not operated at high speed all at once following the maximum tilt angle control of the hydraulic pump, as was the case in the past, and it is now possible to know the timing for increasing engine speed. The mixer drum can be easily operated, and psychological anxiety, especially for unskilled operators, can be eliminated.

In addition, it prevents unexpected sudden high-speed rotation of the mixer drum, which prevents noise generation, entrainment, and accidents. Accident, Ikugabo □1 (.

Therefore, it is possible to prevent an adverse effect on each drive device of the mixer.

[Brief explanation of drawings]

Figure 1 (a) (Ai is a characteristic diagram of changes in the tilt angle of the hydraulic pump and engine speed in a conventional concrete mixer, and Figure 2 is a diagram of the change in the operating control method for a vehicle-mounted cork concrete mixer of the present invention. system (1-ac block connection diagram,
Figure 3 is a flowchart showing the procedure of operation control. 1.2...operator, 3...controller, 5...
Servo actuator, 7... link mechanism, 8...
Hydraulic pump, 9...Engine, 1°...Mixer drum, 11...Displacement detector. Fig. 1 Discharge side --- 〇-One-Yu Input-

Claims (1)

[Claims] A hydraulic pump that drives a mixer drum mounted on a vehicle,
A servo actuator that controls the discharge of the hydraulic pump and the rotational speed of the engine, a displacement detector that detects the displacement of the servo actuator, an operator equipped with a charge button and a discharge button, and a charge button and a discharge button. A vehicle tower-mounted concrete mixer comprising: a controller for controlling the tilting angle of a hydraulic pump and the engine rotation speed based on the displacement instruction signal of the servo actuator and the displacement output signal of the displacement detector. In the control device, the servo actuator determines whether or not the hydraulic pump has reached the maximum tilting angle by operating the input button or the discharge button, and if the hydraulic pump has reached the maximum tilting angle. a first step of temporarily stopping the servo actuator; and a second step of starting to increase the speed of the engine on the condition that the input button or the eject button is once released and then operated again. Operation control system for vehicle-mounted concrete mixer.