JPH0443402Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a stop priority actuation device for a vehicle-mounted concrete mixer.

[Conventional technology]

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

In addition, to control the forward rotation, reverse rotation, and stop of the mixer drum, the servo actuator is actuated by a command from the controller based on the operation of a lever switch or button switch, and the tilting angle of the hydraulic pump is adjusted. It is done by doing. In other words, the stirring, charging, and discharging modes of the mixer drum are set by operating a servo motor, which is a servo actuator.

[Problem that the invention attempts to solve]

By the way, in such a vehicle-mounted concrete mixer, when two or more of the above-mentioned lever switches etc. are pressed, the control of the operation mode instructed by the switch that was pressed first is executed preferentially. For example, when attempting to stop the mixer drum due to work requirements or safety reasons, if the stop switch and the input switch or discharge switch are pressed almost simultaneously, the input switch or discharge switch may be pressed slightly more than the stop switch. If it happens too soon, the input or discharge operation will take priority and the mixer drum will immediately rotate at high speed in the forward or reverse direction. Therefore, sudden discharge of concrete onto the road and sudden noise caused by high speed engines have become major problems.

Therefore, the operator must operate the switch while checking the position of the switch and the rotational state of the mixer drum, which is a cumbersome task.

The present invention aims to solve such conventional problems by automatically setting the stop mode by the stop switch over other modes such as loading and discharging. To provide a stop priority actuation device for a vehicle tower-mounted mixer, in which the stop mode always takes priority as long as a stop switch is pressed, and other modes such as charging and discharging are not formed.

[Means for solving problems]

In order to achieve this objective, the present invention includes a mixer drum that is rotatably supported on a vehicle, a hydraulic pump that drives the mixer drum, and a servo actuator that controls the discharge of the hydraulic pump and the accelerator opening of the engine. a displacement detector for detecting the displacement of the servo actuator; an operating device for selecting the operation mode of the mixer drum; a displacement instruction signal for the servo actuator by the operating device; and a displacement output from the displacement detector. and a controller that operates the mixer drum in a specified operation mode based on the output signal,
The controller is characterized in that it has a stop priority circuit that creates a stop mode with priority over other operation modes by a stop operation of an operating device.

[Effect]

When a stop operation is performed, the controller controls the operation so that the servo actuator returns to the neutral position with priority over the input and discharge operations. Therefore, if the stop switch and the input switch or discharge switch are operated in parallel,
When the stop switch is released, the mode will automatically switch to input or discharge mode.

〔Example〕

FIG. 1 is a block connection diagram showing the configuration of the present invention. Reference numeral 1 denotes an operating device provided inside the vehicle, 2 an operating device provided outside the vehicle, and 3 a controller. , calculates and outputs a signal to control the mixer drum or engine to the operating mode specified by either the operating device 1 or 2. 5 is a servo motor as a servo actuator whose drive is controlled by a servo motor drive circuit 6 that operates based on the output of the controller 3;
Forward rotation, reverse rotation, and the amount of rotation thereof are controlled. Further, the rotation of the servo motor 5 is transmitted via a link mechanism 7 to a tilting angle adjusting swash plate of a hydraulic pump 8, and this hydraulic pump 8 is connected to an engine 9.
It hangs its head as if driven by something. The accelerator of this engine 9 is operated by a 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 that detects the displacement of the servo motor 5 corresponding to the displacement position of the link mechanism 7, that is, the tilting angle of the hydraulic pump, and the detection output of this is designed to be 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 rotating on the input side, the discharge side, or the stirring side based on the output of the displacement detector 11, and in a stop mode such as an emergency, this determination is made. Based on the data, the servo motor 5 is operated toward the neutral position.

Furthermore, when the power switch of the ignition circuit of the engine 9 is turned on or off, the controller 3 acts to stop the servo motor 5 at the neutral position and return the engine rotation to the set low speed range.

In addition, the controller 3 selects the signals of each operation mode of input, discharge, or stop specified by each of the operating devices 1 and 2, and prioritizes the signal of the stop mode from among the selected operation mode signals and controls the servo. Stop mode priority circuit 13 outputting to motor drive circuit 6
have.

Since the stop mode priority circuit 13 is provided in the controller 3, when the stop button switch is pressed, even if the button switch for each operation mode of loading or discharging is pressed, it is also possible to Even in the operating condition, when the servo motor 5 is operated in the neutral direction and the stop button switch is released, the operation mode corresponding to the input button switch or ejection button switch that is pressed at the same time or the original operation is activated. Return to the operating mode that corresponds to the situation.

Further, the priority circuit 13 stops the servo motor 5 when the input button switch and the ejection button switch are pressed at the same time, and when the pressing operation of one of the button switches is released, the other button switch is stopped. The servo motor 5 is set to the operating mode corresponding to the button switch being pressed.
will be activated.

In order to make the operator clearly aware of the display of each of the above operating modes, it is desirable to provide each button with a color-coded lighting display structure, and a well-known illuminated push button switch structure is adopted as such lighting display structure. be able to.

Next, the operation of the stop priority actuating device having such a structure will be explained according to the flowchart of FIG. 2.

First, in the above block circuit, the power switch is closed to enable the operation of the servo motor 5 and the engine 9, and then one of the operating devices 1 and 2 is operated to specify the operation mode, for example, stirring. do. Based on 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, displacement detector 1
The current position signal of the servo motor 5 detected in step 1 is also input to the controller 3. Then, 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.

In such a device, when the power switch is turned on (step a) and the circuit for driving the servo motor 5 is in operation, the servo motor 5 is set to operate the mixer drum 10 in the stirring mode, for example. When the hydraulic pump is controlled, when the controller 3 determines that the stop button switch has been pressed on the operating device 1 or 2 side (step b), the servo motor 5 is then displaced to the closing side. Based on the output of the displacement detector 11, the controller 3 determines whether or not there is one (step c). If it is determined that the servo motor 5 is on the closing side, the servo motor 5 is reversed (step d). Further, when it is determined that the servo motor 5 is not on the input side but is on the discharge side (step e), the servo motor 5 rotates normally (step f). In this way, when the servo motor 5 reaches the neutral position without being on either the input side or the discharge side, the drive of the servo motor 5 is stopped.

The preferential operation of the servo motor 5 to the stop side by operating the stop button switch is executed by the priority circuit 13 prior to the operation to the charging and discharging sides.

Note that in the block diagram of FIG. 1, there may be a disconnection accident in a part of the control circuit, for example, the displacement detection circuit of the servo motor 5 that connects the link mechanism 7 and the controller 3. Since the state of the servo motor 5 is unknown, the mixer drum 10 described above cannot be controlled. In such a case,
When the voltage sensor detects that the voltage output value of the displacement detector 11 has become, for example, 0 volts according to the flowchart in FIG. 3 (step h), and the controller determines that the voltage is 0 volts. (step i), stops the operation of the servo motor 5 (step j), displays an abnormality in the displacement detection circuit on the display device 12 (step k), and controls the tilting angle of the hydraulic pump 8 by the servo motor 5. automatically switches to manual mode (step 1).

After switching to the manual mode in this way, the operator directly specifies the desired operation mode. For example, when the input button switch is pressed (step m), the servo motor 5 is rotated in the forward direction (step n). If the ejection button switch is pressed without the input button switch being pressed (step o), the servo motor 5 is reversed (step p), and if neither the input button switch nor the ejection button switch is pressed, the servo motor 5 will be stopped (step q).

In other words, if an abnormality occurs in the circuit and the control operation becomes impossible, the servo motor can be controlled by manual button operation. In addition,
Abnormalities in the circuit include overload operation due to locking of the servo motor 5. In this case, the servo motor 5
The control can be switched to manual mode by measuring the current flowing through the resistor or by detecting and measuring the terminal voltage of the resistor through which this current flows.

[Effect of idea]

As explained above, according to the present invention, when the stop button switch is operated, even if the loading button switch and the discharging button switch are pressed, the process is stopped during either loading or discharging operation. However, even if multiple buttons are pressed at the same time, if one of them is the stop button, the control operation will be stopped in an emergency. It can be done quickly and reliably.

[Brief explanation of the drawing]

Fig. 1 is a block connection diagram of the stop priority actuating device of the present invention, Fig. 2 is a flow chart showing the priority stop order of the servo motor, and Fig. 3 is a flow chart showing the manual operation procedure when a control circuit abnormality occurs. . 1, 2...operator, 3...controller, 5...
...Servo actuator, 8...Hydraulic pump. 9
...Engine, 10...Mixer drum, 11...
Displacement detector, 13...stop priority circuit.

Claims (1)

[Scope of utility model registration request] A mixer drum rotatably supported on the vehicle;
A hydraulic pump that drives the mixer drum, a servo actuator that controls the discharge of the hydraulic pump and the accelerator opening of the engine, a displacement detector that detects the displacement of the servo actuator, and an operation mode of the mixer drum. and a controller for operating the mixer drum in an instructed operation mode based on a displacement instruction signal of the servo actuator by the operating device and a displacement output signal outputted by the displacement detector, A stop priority operating device for a vehicle tower-mounted concrete mixer, wherein the controller has a stop priority circuit that creates a stop mode based on a stop operation of an operating device, giving priority to other operation modes.