JPH02261908A - Actuator operation structure of working vehicle - Google Patents

Abstract

PURPOSE:To keep safety of stopping a motor by providing a first control means which operates an actuator after an manual operation means is set at a neutral stopping position gradually to the side of stopping, and a second control means which sets a plurality of different stopping operational characteristics, and a changeover means. CONSTITUTION:A plurality of relations between electric current values and time with respect to a solenoid proportional pressure reducing valve 3 are set after the time a1 when an operational lever 14 is set in a neutral stopping position N. A switch as a changeover means 15 is provided in order to select characteristics A1 to A3. When the characteristic A1 is selected by the switch 15 and the lever 14 is set in the neutral stopping position N, a hydraulic motor 13 is decelerated comparatively slowly and a swivel base is stopped with smoothness. On the other hand, when the characteristic A3 is selected and the lever 14 is set in a neutral position N, the motor 13 is decelerated comparatively speedily and the swivel base is stopped rapidly. Working efficiency is then improved while keeping the stopping safety of the motor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an actuator used in a work vehicle such as a construction machine or an agricultural vehicle, and particularly relates to an operating structure thereof.

[Conventional technology]

A backhoe, which is one type of work vehicle, is equipped with a hydraulic motor, which is one of the actuators, for driving a rotating base, and its operation structure is as follows.

In other words, there is a directional control valve that switches the supply and discharge direction of the hydraulic oil supplied to the hydraulic motor to determine the direction of rotation of the swivel base, and a flow rate that adjusts and controls the flow and @ to change the rotation speed of the swivel base. By connecting the control valve in series, the flow rate is controlled so that the greater the amount of operation from the neutral stop position of the control lever (equivalent to a human operating tool) for the directional control valve, the faster the turning speed of the turning base becomes. It is configured to operate the valve.

If you accidentally return the control lever to the neutral stop position while turning, the swivel base will also come to a sudden stop. Later, there is a structure in which the hydraulic motor gradually decelerates so that the swivel table stops without a shock.

[Problem to be solved by the invention]

The above-mentioned configuration is effective in case the control lever is suddenly returned to the neutral stop position by mistake, but if the swivel base does not stop as quickly as before when performing work that requires quick turning and stopping operations, it is effective. , there is a problem in terms of work efficiency.

Here, the present invention is designed to maintain safety when the actuator is stopped while improving work efficiency.

[Means to solve the problem]

The feature of the present invention is that the actuator operation structure for a working vehicle as described above is configured as follows. In other words, a first control means for gradually operating the actuator to the stop side with a delay from the time when the artificial operating tool for operating the actuator is operated to the neutral stop position, and a plurality of types of stop operation characteristics of the first control means are provided. The second set to something different
The present invention is provided with a control means and a switching means capable of selectively switching one of these stop operation characteristics, and its functions and effects are as follows.

[Function] When configured as described above, for example, as shown in Fig. 2,
By setting multiple types of characteristics (corresponding to (A,), (82), and (AI)) from the time when the human operating tool is operated to the neutral stop position (a,) until the actuator stops, the actuator The actuator can be made to stop relatively slowly from the time point (a,), or the actuator can be made to stop more quickly than the time point (a,).

Furthermore, as shown in FIG. 4, it is possible to quickly decelerate the actuator in the first half of the actuator's stop, and then slowly decelerate just before the actuator stops to bring it to a smooth stop.

〔Effect of the invention〕

As described above, it has become possible to select the stopping operation characteristics of the actuator according to the working condition, and it has become possible to have a wide range of functions from work that emphasizes safety to work that emphasizes efficiency.

〔Example〕

Embodiments of the present invention will be described below using a backhoe, which is one type of work vehicle, based on the drawings.

Figure 1 shows the hydraulic circuit of a backhoe, and shows the pump (
An electromagnetic proportional pressure reducing valve (
3), the first control valve (4) and the second control valve (5) are connected in series. This first control valve (4) controls the supply and discharge of hydraulic oil to a hydraulic cylinder (7) that swings the backhoe device (6) shown in Fig. 3 from side to side. 5) is for supplying and discharging hydraulic oil to a hydraulic cylinder (9) that drives the dozer (8) shown in FIG. 3 up and down.

A pair of oil passages (10) from the electromagnetic proportional pressure reducing valve (3)
) is connected to a directional control valve (11). This directional control valve (11) switches the direction of hydraulic oil supply to a hydraulic motor serving as an actuator (13) for driving the swivel base (12) as shown in FIG. As shown in FIG. 1, it is biased to a neutral stop position (lla) by a pair of springs (IIC).

Next, to explain in detail the connection between the operating lever as the human operating tool (14), the directional control valve (11), and the electromagnetic proportional pressure reducing valve (3), as shown in Fig. 1, the directional control valve (11) is provided with a pilot valve (16) for supplying and discharging pilot hydraulic oil for switching operation, and the swing-operated operating lever (14) and the pilot valve (16) are connected to a link mechanism (17). are mechanically interlocked and connected via.

In this case, the maximum stroke position of the operating lever (14) when turning to the right is 1t (R), and the maximum stroke position when turning to the left (L)
the spool (not shown) in the pilot valve (16)
Compatible with both stroke ends.

A potentiometer (1 day) for detecting the position of the spool (corresponding to the tilting angle of the operating lever (14)) is provided for the pilot valve (16), and a signal from this potentiometer (18) is transmitted to the control device. 2 (19). As a result, the control device (19) is configured such that the larger the tilting angle ((R) side or (L) side) of the operation 1/bar (14) is, the larger the flow rate to the directional control valve (11) is.
An operation signal is issued to the electromagnetic proportional pressure reducing valve (3). In other words, the structure is such that the larger the tilt angle of the operating lever (14) is, the faster the turning speed of the swivel table (12) becomes.

In case 2, if the operating lever (14) is moved even slightly to the (R) side or (L) side from the neutral stop position (N), that is, if the spool of the pilot valve (16) is operated even slightly, the pilot Pilot hydraulic oil is supplied from the valve (16) to the directional control valve (11), and the pilot hydraulic oil is supplied to the directional control valve (11).
) is switched.

Next, when the operating lever (14) is operated to the neutral stop position (N) during turning operation, the electromagnetic proportional pressure reducing valve (3)
The configuration for controlling the flow rate and stopping the swivel table (12) will be described in detail. Before that, when performing such an operation using the electromagnetic proportional pressure reducing valve (3),
3), the directional control valve (11) moves to the neutral stop position (l
If the hydraulic oil supply and discharge is cut off by operation la),
Since the flow rate cannot be controlled using the electromagnetic proportional pressure reducing valve (3),
A structure that allows the directional control valve (11) to return to the neutral stop position (lla) with a delay even if the operating lever (14) is suddenly returned to the neutral stop position (N) will be described in detail.

As shown in FIG. 1, at the neutral stop position (16a) of the pilot valve (16), a throttle portion (16b) is provided that provides resistance to the pilot hydraulic fluid from the directional control valve (11). As a result, when the operating lever (14) is operated to the neutral stop position (N) from a state in which the directional control valve (11) is switched to one side, the pilot valve (16) is also moved to the neutral stop position W in conjunction with this. (16a) is operated. In that case, the directional control valve (11) also has a spring (IIC).
Due to the biasing force, the pilot hydraulic fluid is pushed out toward the pilot valve (16) in an attempt to return to the neutral stop position (lla). In this case, resistance acts on the pilot hydraulic fluid at the throttle portion (16b), causing the directional control valve (11) to return to the neutral stop position (lla) with a delay.

Next, the operation of the electromagnetic proportional pressure reducing valve (3) will be described in detail.

In other words, after the time (a,) when the operating lever (14) is operated to the neutral stop position (N), the electromagnetic proportional pressure reducing valve (
3), a plurality of types of relationships between the current value (corresponding to the opening degree of the electromagnetic proportional pressure reducing valve (3)) and time are set as shown in FIG. And this property (AI), (A2)
A changeover switch is provided as a changeover means (15) for selecting , (A3).

Therefore, when characteristic (A1) is selected with the changeover switch (15), when the operating lever (14) is operated to the neutral stop position (N), the hydraulic motor (13) decelerates relatively slowly and the swivel base ( 12) stops smoothly. Conversely, when characteristic (A,) is selected, the hydraulic motor (13
) decelerates relatively quickly and the rotating platform (12) quickly stops.

[Another example]

The relationship between the current value and time of the electromagnetic proportional pressure reducing valve (3) after the time (al) when the operating lever (14) is operated to the neutral stop position (N) may be shown in FIG. The time it takes for the current value to reach the proportional pressure reducing valve (3) to become zero may be constant, but may vary during the time. As a result, the vehicle decelerates relatively quickly in the first half of turning and stopping, and decelerates slowly in the second half to come to a smooth stop.

In the present invention, a separate electromagnetic proportional pressure reducing valve is provided for the directional control valve (11), but a valve mechanism having both functions may be used.

Furthermore, the present invention is applicable not only to hydraulic motors (hydraulic cylinders, electric motors, etc.).

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The concave surface shows an embodiment of the actuator operation structure for a work vehicle according to the present invention, and FIG. 1 is a hydraulic circuit diagram of a backhoe, and FIG.
The figure shows the change in the current value to the electromagnetic proportional pressure reducing valve when the operating lever is operated to the neutral stop position, Figure 3 is an overall side view of the backhoe, and Figure 4 is the electric current value in another embodiment.
It is a figure which shows the change of the electric current value to an f proportional pressure reducing valve. (13)... Actuator, (14)...
...Human operating tool, (15)...Switching means, (
N)...Neutral stop position.

Claims (1)

[Claims] Actuator (13) Artificial operating tool (14)
A first step in which the actuator (13) is gradually operated to the stop side with a delay from the time when the actuator (13) is operated to the neutral stop position (N).
A control means, a second control means for setting the stop operation characteristic of the first control means to a plurality of different types, and a switching means (15) capable of selectively switching to one of these stop operation characteristics.
An actuator operation structure for a work vehicle equipped with.