JPH03143310A - Hydraulic pressure controller - Google Patents

Abstract

PURPOSE:To improve the accuracy of control by extending the electric charge time of the first pulse in the next pulse in case the time required for output of the next pulse after completion of the preceding electric-pulse charge exceeds the set time and canceling the delay of the motion. CONSTITUTION:The subject hydraulic pressure controller is equipped with a setting unit, a detector and a control valve so that a pulse signal may be sent out to a solenoid of the control valve corresponding to the difference between a detected value by the detector and the set value by the setting unit. In this hydraulic pressure controller, even when the time required for output of the next pulse after completion of the preceding electric-pulse charge exceeds the set value alpha, the electric charge time of the first pulse in the next pulse is extended to solve the former inconvenience of the delay in motion in the first pulse and to improve the accuracy of control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an automatic control device having an electromagnetic hydraulic control valve, and can be used in a power vehicle such as a tractor.

[Prior art and its issues] Conventionally, when a pulse signal is sent to a solenoid of a control valve in a machine equipped with an electromagnetic hydraulic control valve, the operation is affected by oil temperature, oil viscosity, solenoid temperature, etc. At the beginning of the process or after a certain period of time has elapsed from the non-energized state, the flow of oil does not follow a predetermined pattern, resulting in a slight delay in control. FIG. 5 shows this state.

Means for Solving Cax] The present invention aims to solve the above-mentioned problems, and has taken the following technical measures.

That is, it is equipped with a setting device, a detector, and a control valve, and is configured to send a pulse signal to the solenoid of the control valve according to the difference between the setting value set by the setting device and the detected value detected by the detector. In the configured hydraulic control device, if the time from the end of the previous pulse energization time to the next pulse output exceeds the set time α, the energization time of the first pulse of the next pulse is lengthened. The configuration of the hydraulic control device is characterized by:

[Embodiments] Hereinafter, embodiments of the present invention will be explained based on the drawings. This will be explained using an agricultural tractor as an example. First, to explain the configuration, the Go is an L-rafter, with front wheels 2.2 and rear wheels 3.3 at the front and rear of the fuselage, respectively, and a mission case 4.
A yuzuhami cylinder case 5 is fixedly attached to a part of the rear part. A dynamic hydraulic cylinder 6 is provided within the hydraulic cylinder case 5, and lift arms 7.7 are rotatably supported on both left and right sides of the hydraulic cylinder case 5.

1- A rotary tilling device 14 as a carving machine is connected to the rear end of the three-point link mechanism 12 consisting of the twin link 10 and the lower link 11.11, and the lift arm 7.7 and the lower link 11-111 In between is 1 riff and 1 hero.
5.15 is interposed and connected.

Among these lift rods 15.15, the lift rod 15 on one side (in this embodiment, the right side) is composed of a hydraulic cylinder 15a that can be expanded and contracted, and a lateral side of this hydraulic cylinder 15a is equipped with a device that detects the amount of expansion and contraction. A stroke detector 16 is provided. Reference numeral 20 denotes a hydraulic control lever, and a plowland height setting device 2 for detecting the height of the land working machine is attached to the cooperating portion of this control lever 23-O. On the other hand, the same for lift arm 7 on one side! The I+U section also has its F11 dynamic angle power, which means ground height detector 2 that detects the height of ground work equipment.
3 is attached, the rift 1-arm 7.7 moves to the height set by the operating lever 20, and stops 1.3. The position control mechanism is configured to do so.

I8 is an inclination detector mounted and fixed on the side of the extraction cylinder IJ cylinder case 5 of the 1-rafter 1, and detects the inclination of the tractor 1 in the left and right lateral directions.

Next, the configuration of the rotary tilling device 4 will be explained. The lower end of the rear cover 36 slides into contact with the ground and is configured to elastically press the rear cover 36 to evenly level the tilled soil surface. A plowing depth detector 37 for detecting the co-movement angle of the rear cover 36 is provided at the rear end of the upper part.

Is this the second figure? 1tlFj', a block diagram of the control device 4, is a ground height setting device 21 that sets the height of the work equipment, and a field height detector 23 that detects the actual placement of the lift arm 7.7. It is connected via an A/D converter 25 to a control section 27 consisting of a CPU. Reference numeral 28 is a lift switch that is directly connected to the control unit 27 without going through the A/D converter 25, and when this switch 28 is turned on, the working machine]-4 is at a maximum of 1-, and the lift is 1- to a maximum of 1-4. -, rises, and when turned off, descends to the position determined by the Ura FE operating lever 20.The tilling depth of the rotary tilling device 14 is detected by the dial-adjustable tilling depth setter 40 provided near the cockpit. tillage depth detector 3
7 is connected to a control section 27 via an A/D converter 25. Further, 41 is a slope setting device for adjusting the slope amount of the rotary tilling device]-4, and this slope setting device 41,
The stroke detector 16 and the tilt detector 18 are each connected to a control unit 27 via an A/I) converter 25. Reference numeral 29 denotes a control valve for controlling the supply of the working well to the draw cylinder 6, and is configured to be switchable by a lowering solenoid 30 and a lowering solenoid 31.

42 is a control valve of the hydraulic cylinder 15a for tilt control, which includes an extension solenoid 43 and a shortening solenoid 44.
It can be switched as appropriate. In addition, in the figure, the reference numeral 46 is a diversion valve, 47 is a hydraulic pump, and 48 is a relief valve.

Next, to explain the function, first, the set values by the ground height setting device 21, plowing depth setting device 40, and inclination setting device 41, the ground height detector 23, plowing depth sensor 37, inclination detector 18, and stroke Each detector detected by the detector 16 is read into the CPU, and the control amount necessary to maintain the rotary tiller 14 in a predetermined posture, for example, in a horizontal state, is calculated. At this time, the control amount is calculated from the difference between the set value and the detected (direct) plowing depth control, that is, the depth control, and for the slope control, the solenoid 4 of the control valve 42
Control valve 3 or 44 is energized to maintain the left and right posture of the work equipment at the set posture, and for depth control, control valve 2
The solenoid 30 or 31 of No. 9 is excited to control the lifting and lowering of the working machine, and control 1 to roll is performed so that the set depth is reached.

These control valves 29 and 42 are driven by pulses, and the flowchart in Figure 3 shows a specific control method for increasing the energization time of the first pulse when a pulse output is requested. The explanation will be based on Char 1-.

In this chart, the no-power timer is a timer for counting how many seconds the pulse output remains off. That is, when the previous pulse energization time turns off, this timer starts counting (step S2).
When the pulse cycle ends and there is a pulse output request, the pulse energization time and cycle are set (step S
3, S4.85). Then, the de-energization timer is set to the set value α(
α is about 1 second in this case), the pulse energization time is β
Just make it longer. FIG. 4 shows that the first pulse lengthened by β increases the amount of oil flowing into and out of the control valve.

In this way, 47. When output is started from the intensely energized state, the energizing time of the first pulse is made longer than the other pulses, so the amount of operation per pulse can be made uniform.

7- In addition, in this embodiment, the structure and operation were explained using the inclination control and depth control of the rafter as examples in 1. However, it is applicable not only to tractors but also to divine automatic control devices equipped with an electromagnetic pressure control valve. Of course, it is a good idea to apply it.

[Effects of the Invention] Since the present invention is configured as described above, it has the following technical effects.

That is, it includes a setting device, a detector, and a control valve, and sends a pulse signal to the solenoid of the control valve based on the difference between the set value set by the setting device and the value detected by the detector. In the extraction pressure control device configured as above, when the time from the end of the previous pulse energization time to the next pulse output exceeds a set time α, the energization time of the first pulse of the next pulse is lengthened. Therefore, the conventional problem of delay in operation caused by the first pulse can be solved, and control accuracy can be improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an overall 8-plane view, Fig. 2 is a block diagram, and Fig. 3 is a flowchart.
FIG. 4 is a graph showing the relationship between the pulse waveform and oil flow rate corrected using the device of the present invention, and FIG. 5 is a graph showing the relationship between the pulse waveform and oil flow rate corrected using the conventional device. 7, 7 2 4 Explanation of symbols 1-Rafter mission case lift arm 3-point link mechanism Ground work machine (rotary tillage device)

Claims (1)

[Claims] The device includes a setting device, a detector, and a control valve, and is configured to send a pulse signal to a solenoid of the control valve according to the difference between a set value set by the setting device and a detected value detected by the detector. In the hydraulic control device, when the time from the end of the previous pulse energization time to the next pulse output exceeds a set time α, the energization time of the first pulse of the next pulse is lengthened. Hydraulic control device.