JPS62244303A - Apparatus for elevating woriking machine - 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 [Industrial Application Field] The present invention relates to a working machine elevating device for a power agricultural machine that is used with a working machine such as a tiller attached thereto.

[Prior Art] A movable cuff 3a is widely used, which is provided with a working machine mounting means such as a link device, and which raises and lowers a working machine such as a power tiller by moving the mounting r stage up and down using hydraulic pressure. In this type of power machine, one working machine is raised and lowered by opening an electromagnetic control valve of a hydraulic system.

[9, Problems that Ming is trying to solve] However, since there are individual variations in the characteristics of 'FL magnetic control valves, there will be variations in the oil flow gutter even if the electricity is turned on for the same time, and fine adjustment will be required. When you want to do something, the work equipment moves a lot, or when the work is done. There was a problem in that the operating feel differed depending on the device. Such problems were particularly noticeable when lowering the work machine.

Stage L for Solving Problem E] In order to solve the problem described in Section E, the present invention has the following configuration.

In other words, is the power e-machine involved in the unreleased IJI powered by hydraulic power equipped with an electromagnetic control valve that is opened by pulsed energization? This is a work equipment lifting device that controls the lowering of the work equipment by placing a The present invention is characterized by the provision of a control means that gradually increases the energization time of the pulse to energize the control valve from a short time, and performs steady energization after the set time elapses.

[Function 1: When a lift start command is input, an initial pulse with a short energization time is sent, and then the pulse energization time gradually becomes longer until the set time elapses, so that one hydraulic fluid The flow tt can be gradually increased, and variations in performance of each control valve can be absorbed.

[Example] An embodiment shown in one drawing will be described below.

FIG. 1 shows an embodiment of a power agricultural machine according to the present invention, in which a link device 3 is provided at the rear of a body 2 of this power agricultural machine (tractor) 1. As shown in FIG.

The link device i! 13 is work Ia5 (tiller in this example)
is installed.

The link device 3 includes a top link 10 of one tree and a pair of lower links II and II on the left and right sides, and the top link 10 is connected to the mast 13 of the tiller A5, and the lower link II.

Reference numerals 11 are attached to the left and right sides of the transmission case 14 of the tiller 5, respectively. The lower link II, It is suspended on the hydraulic lift arm 17 of the tractor I by a lift rod 16.18 connected to its intermediate part.

The tractor l has a fttla control valve 20 for raising and lowering.
．． 21 and the control device! 9 is provided, and the lift arm 17 is rotated downward by the hydraulic pressure of this hydraulic system. This operation is performed using the position lever 24 provided on the side of the cockpit 23. Also, the lift arm 17, 11! An angle sensor 25 for detecting the rotation angle of the lift arm is provided in the section, and the angle of the lift arm set by the position lever 24 and the actual angle of the lift arm detected by the angle sensor 25 are It is designed to be compared.

Figure 2 shows control'! This is a block diagram showing the Ic position 19, in which a signal indicating the set position of the position lever 24 and a detection signal of the lift arm angle sensor 25 are supplied to the CPU 28 via the A/D converter 27, from which the lift valve is An opening/closing signal is supplied to the valve 20 and the lowering valve 21.

The electromagnetic control valves 20 and 21 are proportional solenoid valves that adjust the flow in proportion to the energization and darkness, and are operated by pulse signals. FIGS. 3(a) and 3(b) are diagrams showing the waveforms of the rising and falling pulse signals, respectively, and while the rising pulse signal is transmitted as a constant steady pulse PM from beginning to end, , the pulse signal for falling is
When a descending command is input by the position lever 24, an initial pulse Po is first transmitted, and then the energization time of the pulse gradually becomes longer until a certain period of time T has elapsed, and after the certain period of time T has elapsed, it reaches a steady state. Pulse PM is transmitted.

FIG. 4 is a flowchart outlining the operation of the control device '11ts. In the figure, the difference between the set position of the position lever 24 and the actual position detected by the lift arm angle sensor 25 is determined, and it is checked whether the operating direction is on the lowering side. If the operating direction is on the downward side, it is checked whether or not the downward movement has started, and if the downward movement has started, the on-time is set to the minimum value. As a result, the lowering valve (sub-magnetic valve) is opened for the on-time portion.

If the operation direction is downward and the downward movement has already started,
It is checked whether -7 hours T have elapsed since the start of F-falling, and if that time has not elapsed yet, the on-time is increased by a little Δt). When -7 hours T have passed since the start of descent, a predetermined control on time is set, and the hydraulic oil flow 1. ) also increases.

If the operating direction is not the downward direction, the timer is cleared and a check is made to see if a command from the prefecture has been issued.

1; If the 'yL command is issued, the control on time is set and the 1-sito 111 valve is turned on. Also, J
When the -57 command is not issued, O is set as the on-time and the valve output stops! I'm going to do it.

” - As mentioned above, when lowering one working machine, the on time gradually increases from the minimum time.

The relationship between 1&ψ of the hydraulic oil and time is shown in FIG. In this way, since the on-time of the valves at the start of descent does not reach the predetermined time all at once, even if there are differences in the characteristic values of individual valves, the differences are not noticeable, which eliminates the problem of differences in operational feel. It is possible. Furthermore, it becomes easy to adjust the position of the working machine.

[Effects of the Invention] As is clear from the explanation in J.2 below, the work equipment lifting device according to the present invention allows for easy fine adjustment when raising and lowering the work equipment, and there is no difference in the operational feeling, so that stable operation can be achieved. Now you can do it.

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a block diagram showing the configuration of the work machine lifting/lowering control, and Fig. 3 (a
) and (b) are explanatory diagrams of pulse signals for raising and lowering, respectively, Figure 4 is a flowchart showing the operation of the control device, and Figure 5 is energizing! This is a graph showing the relationship between the crossroads and the hydraulic oil flow H,+.

Claims (1)

[Claims] (1) A work equipment lifting device that controls the lifting and lowering of the working equipment by a hydraulic device equipped with an electromagnetic control valve that is opened by pulsed energization. A control means is provided for controlling the energization time of the pulse that energizes the lifting electromagnetic control valve from a short time gradually to a longer time until the set time has elapsed, and to perform steady energization after the elapse of the set time. A lifting device for work equipment featuring: