JPH0689536B2 - Grader equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grader device installed on a snow removal truck.

[0002]

2. Description of the Related Art Heretofore, in this type, the following has been done. In the road surface leveling work using a grader device of a conventional snow removal truck, an operator operates a plurality of operating levers and switches in a driver's cab in accordance with the hardness and depth of the pressed snow on the road surface. The operation is to remove the pressure snow from the road surface by moving the blade up and down while applying pressing pressure that matches the hardness and depth of the pressure snow to the road surface through the edge, and basically, When the hardness of the pressed snow is low, the cutting angle of the blade is small and the pressing pressure is low. As the hardness of the pressed snow is high, the cutting angle of the blade is large, and the pressing pressure is high, so that the pressed snow can be scraped well.

Therefore, depending on the skill level of the operator, the direction of travel is different from the left-right unbalanced state caused by the road structure such as the hardness of the snow, the change in the snow depth due to the longitudinal gradient of the road surface, undulations, weather conditions, etc. Not only paying attention to, but also confirming the finish condition with the rearview mirror, vibration transmitted through the vehicle and the inclination of the car body, and further using the five senses of the body literally such as the sound, sparks, and strange odor when the edge rubs the paved road surface The accuracy is increasing.

As the need for early road surface adjustment increases in the studless era, grader devices for snow removal trucks have been particularly emphasized because of their high workability that construction machines do not have. From the social background of the need for such high-speed road surface adjustment and lack of skilled labor, a grader device is required to have a reduced number of operating levers and switches and a device for automatically controlling blades, and it has begun to be put into practical use. There is. (Japanese Patent Laying-Open No. 2-47413) A safety mechanism against sudden overload during work is also widespread. (Actual development number 59-73458, etc.)

[0005]

Due to the structure of the grader device, the left and right pressing pressures are adjusted by a pair of left and right lifting hydraulic cylinders with respect to one blade. There is a characteristic that decreases, and the adjustment is 10
It takes a lot of skill for the operator to operate the lever in a short time and frequently while working and traveling on snow at ~ 50 km / h. In addition, even a small operation error at high speed may lead to a serious accident, so the operator The work was very tired.

However, the automatic control (Japanese Patent Laid-Open No. 2-47413) for reducing the burden on the operator controls the pressing pressure so that the pressure on the end side of the fluid pressure cylinder for moving the blades up and down the blades is maintained at the set pressure. Since the blade reversing fluid pressure cylinder is controlled independently so as to keep the blade angle at the set angle, and the operator sets the target value, the following problems occur.

Due to the structural feature of the grader device in which one pressure is pressed by the pair of left and right lifting hydraulic pressure cylinders, the pressure of the other is lowered, so that a correction command signal is output simultaneously with the left and right control amounts. However, since the fluid pressure is one system, only the one with a lighter load operates and the control of the pressing pressure is difficult to stabilize. The pressure generated in the pair of left and right fluid pressure cylinders is the pressure generated by its own weight when one end or the whole floats above the road surface due to piping resistance, surge pressure generated during control operation, delay in response to road surface gradients, etc. This is a total sum, and even if control is performed only by the pressure on the end side of the cylinder, accurate work cannot be performed. In particular, when the speed of the vehicle becomes high, it is dangerous in terms of maneuverability unless the pressing pressure suitable for the speed is properly set and accurately controlled.

Further, even if the cutting angle corresponding to the pressure snow is set by the blade angle, when the edge rubs, the sharp edge cross section of the tip is lost, so that the sticking to the pressure snow becomes worse and the friction resistance due to the ground contact area enlarged by friction. Increases and the cutting force decreases. Since it is extremely difficult for the operator to distinguish the friction of the edge while working, it is confirmed that the accuracy as planned is not obtained with five senses such as the above-mentioned confirmation of the rearview mirror, and the setting of the pressing pressure is frequently changed, On the contrary, it becomes a vicious cycle of accelerating the friction of the edge, and not only accuracy and efficiency cannot be obtained, but also the burden is not reduced so much.

Further, when the vehicle stops due to a traffic light during work, or when the vehicle speed is reduced due to overload and eventually the vehicle is forced to stop due to a slip state, a large amount of snow is being removed by the blades. It will remain deposited on the front part of the, and even if you try to start as it is, you can not push it because it slips and you will raise the blade to reduce the load and start, or you will back up and give it inertia and restart the work, In the former case, a step of compressed snow may be created, and the following vehicle may take the steering wheel, and in the latter case, the following vehicle may be inefficient and may collide with another vehicle, which is dangerous. In particular, if the load is too heavy, the road leveling work will remove the snow in one direction, which may cause the vehicle to flow greatly laterally at the same time as the slip due to the moment, which is dangerous for oncoming vehicles. is there. The above-mentioned safety mechanism (Actual No. 59-73458) is also a system in which it can be returned from the driver's seat by a lever or the like at the time of operation, but there is a problem that it is difficult to intuitively operate or return.

[0010]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems and is more effective than the input signals from the pressure sensor, the position sensor and the speed sensor of the detecting section in the grader device arranged on the snow removing truck. Targets of required pressing pressure and cutting angle that are pre-programmed for the work mode and vehicle speed that the operator selects in the operating section before or during work according to the snow pressure situation by calculating the pressing pressure, cutting angle, and vehicle speed Compared with the value, a safe and effective correction command signal at the pressing pressure, and for the cutting angle, the blade angle is corrected to maintain the target value of the cutting angle while sharpening the cutting edge according to the wear amount of the edge. A correction command signal is output to the fluid pressure actuator via the adjustment unit, and the input signal from the sensor is calculated to calculate the blade position, angle, pressing pressure, and safety mechanism operation return. How a control unit for the various states and outputs it as a graphic display signal, a grader apparatus having an automatic control system comprising a display unit for displaying it effectively.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a grader device for a snow removal truck which is a technical premise of the present invention. In FIG. 1, the grader device adjusts the pressing pressure of the blade 2 arranged on the lower surface of the central portion of the chassis 1 by a pair of left and right lifting hydraulic pressure cylinders 3, 3.
This is a device for adjusting the cutting angle of the blade 2 by means of the reversing fluid pressure cylinder 4.

FIG. 2 shows the structure of the detection unit, the operation unit and the control unit of the automatic control system. In FIG. 2, the head side of the pair of left and right lifting hydraulic cylinders 3, 3 of the blade 2
The pressure sensors 5, 5 ... Which detect the fluid pressures on the rod side and output as signals, detect the left and right up and down positions of the blade 2 built in the pair of left and right up and down fluid pressure cylinders 3, 3. Stroke sensors 6 and 6 for raising and lowering, a stroke sensor 7 for reversing that detects the reversing position of the blade 2 built in the fluid pressure cylinder 4 for reversing, and a propeller shaft rotation speed provided at the output portion of the transmission of the vehicle to detect the rotation speed. A rotation sensor 8 for speed detection and a proximity switch 9 for detecting the operation of the safety mechanism are mounted as a detection unit. When the operator selects a work mode according to the situation of snow pressure by the setting device 10 mounted near the driver's seat, the pressing pressure corresponding to the vehicle speed programmed for each mode and the cutting angle corresponding to the amount of edge wear are set. The target value is set automatically.

The control unit is a CPU which calculates from the input signals from the respective sensors, compares it with a target value, and outputs a correction command signal.
14, a memory 15 for storing a program, a memory 16 for temporarily storing stored data during work, a converter 17 for converting an input signal from a detection unit so that the CPU 14 can process it, input devices 18 and 18 for Bit signal, correction It is composed of output devices 19 and 19 for outputting a command signal as a contact, an analog converter 20 for converting an output signal, a relay 21, a graphic controller 22, and a stabilizing power supply 23.

FIG. 3 shows a fluid pressure circuit which constitutes the adjusting portion of the automatic control system. In FIG. 3, the fluid pressure circuit draws power from the flywheel PTO of the vehicle and supplies the fluid pressure.
A continuous fluid pressure pump 24, electromagnetic relief valves 25, 25A for adjusting the main pressure during operation of each of the left and right fluid pressure cylinders in two systems, and electromagnetic valves 26, 26 for adjusting the operation direction of each fluid pressure cylinder.・ ・ ・ ・ ・ ・ ・ ・ ・ Pilot check valves 27, 27 ・ ・ ・ that prevent the blade from dropping naturally due to fluid pressure leakage when the valve is in the neutral position.
, And the electromagnetic proportional relief valves 28, 28A for adjusting the pressure at the time of pressing the pair of left and right lifting hydraulic pressure cylinders, and the pressure sensors 5, 5, ...

4 and 5 show an automatic control flow. The control content will be described with reference to FIGS. 4, 5 and 2. When the operator selects a work mode by the setting device 10 before work according to the situation of pressure snow, a target value of a cutting angle corresponding to a pressing pressure corresponding to a vehicle speed and an edge wear amount, which will be described later, is set for each mode by a program. It is set automatically.

When the operator pushes the work button 11 on the operation portion, the electromagnetic relief valve 25 and the electromagnetic valve 26 are controlled so that the cutting angle calculated from the signal position of the stroke sensor 7 proportional to the cutting angle becomes a target value. Output the correction command signal. When the target cutting angle is reached, the left and right lifting height of the blade 2 is calculated from the signal values of the stroke sensors 6 and 6 built in the pair of left and right lifting hydraulic pressure cylinders 3 and, and a new edge is obtained at the current blade angle. The electromagnetic relief valves 25, 25 with the height at which they are grounded as a reference target value
A, electromagnetic valves 26, 26, electromagnetic proportional relief valve 2
A correction command signal is output to 8, 28A.

Next, the effective pressing pressure is calculated from the signal values of the head side and rod side pressure sensors 5, 5, ... Of the pair of left and right lifting hydraulic cylinders 3, 3. The electromagnetic relief valves 25, 25A and the electromagnetic valves 26, 26 for adjusting the cylinders respectively so as to obtain a target value according to the vehicle speed calculated from the signal value of the rotation sensor 8 as a pressure difference between the side and the rod side. A correction command signal is output to the electromagnetic proportional relief valves 28 and 28A. Two
The left and right ascending / descending are divided into two independent systems by the continuous fluid pressure pump 24, so that the blade 2 responds to the correction command signal.
Quickly descends in a well-balanced manner, and the left and right pressing pressures also stabilize at their target values.

During the work traveling, the above-mentioned control is continuously performed against the fluctuation of the input signal of the pressure / rotation speed, and even when the setting mode is changed during traveling, the pressing corresponding to the vehicle speed programmed for each mode. Change target value to pressure and forward button 1
Similar control is performed until 2 is pressed. The cutting angle during work traveling is the electromagnetic relief valve that adjusts the reversing fluid pressure cylinder by detecting the edge wear amount by a method described later with a cutting angle corresponding to the edge wear amount automatically set for each mode as a target value. 25, 25A, the electromagnetic valve 26, 26 outputs a correction command signal. When the operator presses the return button 13 of the operation portion during the operation of the safety mechanism, a return command signal is sent to the electromagnetic relief valve 25 and the electromagnetic valve 26 for adjusting the reversing fluid pressure cylinder 4 so that the return target position is reached. Output.

FIG. 6 is a diagram for explaining the effective pressing pressure. In Fig. 6, the pressure of the fluid pressure cylinder for moving up and down the blade is set to the pressure on the head side by the action of the pilot check valve and the pressure on the head side at a low pressure close to 0 kg / cm ² on the rod side. It is a state in which the supporting force of the fluid pressure cylinder multiplied by and the reaction force from the road surface including the vertical component of the cutting resistance are balanced. When the reaction force against the blade from the road surface decreases and the pressure on the head side decreases and a correction command signal that operates in the pressing direction is output to the fluid pressure cylinder, the pilot check valve opens and the rod side reaches the fluid tank. A pressure that causes a pressure loss in the pipe is generated. Therefore, an effective pressing pressure can be obtained by outputting the correction command signal such that the difference between the signals of the pressure sensors on the head side and the rod side becomes the set value.

FIG. 7 is a diagram for explaining vehicle speed control of pressing pressure. In FIG. 7, the pressing pressure is automatically set to a target value for each work mode selected by the operator, and increases from the minimum pressing pressure at a vehicle speed of 0 km / h (stopped state) in proportion to the vehicle speed at low speeds. It is constant at high speed, and decreases at high speed in proportion to the vehicle speed.

FIG. 8 shows the state of edge wear of the blade.
In FIG. 8, the edge wear amount is the difference in blade elevation height between the new edge state and the actual grounding position.

FIG. 9 shows changes in the lifting stroke during work. As shown in FIG. 9, the waveform of the ascending / descending stroke is a combination of a short wavelength waveform due to vertical movement of the vehicle due to the unevenness of the road surface and a long wavelength waveform due to the gentle undulation of the road surface and the vertical gradient Go away from the reference target position of. The amount of edge wear during work is calculated from the stroke signal value by removing the waveform with a short wavelength with a hardware filter and calculating the difference between the sampled signal value from the remaining waveform at regular intervals and the reference target value. Is required.

10 and 11 are views for explaining a method of controlling the cutting angle according to the amount of edge wear. As shown in FIGS. 10 and 11, by increasing the cutting angle from the reference angle in accordance with the amount of edge wear, a sharp cutting edge cross section of the tip is always formed, and when it becomes a constant angle, the control returns to the reference angle and the control is repeated. The edge wear amount storage data at the end of work is backed up until the next work, and is reset at the time of replacement with a new edge. A color liquid crystal monitor 29 is adopted for the display unit, and the position, angle and pressing pressure are calculated according to the shape of the front and side surfaces of the blade which is operated by calculating the input signal from each sensor from the control unit and outputting it as a graphic display signal. It effectively displays various states such as the return of the safety mechanism to operation.

FIG. 12 shows an example of the display screen of the monitor. In the embodiment, the rotation sensor for detecting the vehicle speed is mounted on the transmission unit, but it may be mounted on the tire, the axle, or the like, and the fifth wheel speed sensor or the non-contact speed sensor may be separately mounted on the working device or the vehicle. You may wear it. As the pressure sensor on the head side of the lifting / lowering fluid pressure cylinder of the embodiment, an electromagnetic proportional relief valve with a built-in sensor may be used, and a built-in sensor may be used. In the embodiment, the position of the blade is detected by the stroke sensor built in the reversing fluid pressure cylinder, but an angle sensor may be attached to the link portion of the device for detection. The color liquid crystal monitor used in the display unit in the embodiment is a liquid crystal monitor such as plasma or EL or C
RT or the like may be adopted, and it is also possible to confirm the finish status of the work photographed by a CCTV camera or the like.

The device of the present invention operates as follows. During road leveling work, the effective pressing pressure calculated by calculating the signal values of the pressure sensor on the head and rod sides of the lifting hydraulic cylinder, and the signal value of the position sensor that detects the reversal position of the blade are calculated. Amount of wear of the edge obtained by calculating the vehicle speed obtained by calculating the work mode in which each value of the cutting angle is set according to the operator's pressure snow condition and the signal value of the speed sensor, and the change in the vertical position of the blade By comparing with a target value that is automatically and appropriately determined by, a comprehensively appropriate corrected control amount signal is output to each fluid pressure actuator that operates quickly.

Therefore, due to the speed control of the pressing pressure, no step can be formed at the time of stop, it is difficult to slip even at low speed due to the load, and the work can be performed safely at high speed. The cutting force does not decrease and the work can be performed safely and with high accuracy and efficiency because the piercing of the blade is good and the frictional resistance due to the contact area is small. In addition, the operator's operation is to select the work mode, then check the graphic screen as needed in a state close to direct monitoring, and operate the button switches according to the instructions on the screen at the start / end of work and when the safety mechanism is activated. It will be.

[0027]

As described above, according to the present invention, the target value suitable for the situation of the compressed snow is appropriately set in consideration of the vehicle speed and the wear of the edge by the work mode selected depending on the situation of the compressed snow, and the automatic control is promptly performed. The situation can be effectively monitored in a state close to direct monitoring, and highly accurate road leveling work can be carried out efficiently and safely, which allows the operator to concentrate on the traveling operation of the vehicle, and the burden on it greatly. It will be reduced.

[Brief description of drawings]

FIG. 1 is a side view of a grader device for a snow removal truck.

FIG. 2 is a configuration diagram of an automatic control system.

FIG. 3 is a fluid pressure circuit diagram of the automatic control system.

FIG. 4 is a flowchart showing one part of an automatic control flow.

FIG. 5 is a flowchart showing the other part of the automatic control flow.

FIG. 6 is an explanatory diagram of effective pressing pressure.

FIG. 7 is an explanatory diagram of a vehicle speed control method for pressing pressure.

FIG. 8 is an explanatory diagram of an edge wear state of a blade.

FIG. 9 is an explanatory diagram showing changes in the lifting stroke during work.

FIG. 10 is an explanatory diagram of a method of controlling the cutting angle according to the amount of edge wear.

FIG. 11 is an explanatory diagram of a method of controlling the cutting angle according to the amount of edge wear.

FIG. 12 is an example of a display screen on a monitor.

FIG. 13 is an enlarged view of a part of FIG.

[Explanation of symbols]

 1 Chassis 2 Blade 3 Fluid hydraulic cylinder for lifting 4 Fluid cylinder for reversing 5 Pressure sensor 6 Stroke sensor 7 Stroke sensor 8 Rotation sensor 29 Color LCD monitor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeo Sawaguchi 8-3-3, Kikusui, Shiroishi-ku, Sapporo-shi, Hokkaido (72) Inventor Kazuo Watanabe 7-5-11, North, Nango-dori, Shiroishi-ku, Sapporo, Hokkaido ( 72) Inventor Masayuki Murotani, Nishimiyanosawa, Teine-ku, Sapporo, Hokkaido

Claims (1)

[Claims] 1. A grader device in which a pressing pressure of a blade arranged on a lower surface of a central portion of a chassis of a snow removal truck is adjusted by a pair of right and left fluid hydraulic cylinders for elevation, and a cutting angle of the blade is adjusted by a fluid hydraulic cylinder for reversal, The effective pressing pressure, cutting angle, vehicle speed, and edge friction amount are calculated from the signals detected by the pressure sensor, position sensor, and speed sensor for the work mode selected by the operator according to the situation of pressure snow, and according to the vehicle speed. Controls the fluid pressure actuator so that it can work at an appropriate pressing pressure and an appropriate cutting angle according to the amount of friction on the edge, and graphically displays various states such as blade position, angle, pressing pressure, and safety mechanism operation return. A grader device having an automatic control system for