JPH0225041B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a hydraulic control device for arbitrarily controlling hydraulic equipment such as a single cylinder or a plurality of cylinders. Conventionally, there are manual directional control valve systems and electromagnetic valve systems as means for controlling and operating hydraulic equipment such as a single cylinder or a plurality of cylinders, and both of these systems have advantages and disadvantages. This invention utilizes the advantages of both types and eliminates their disadvantages by combining one manual directional control valve and a single or multiple solenoid valves. The embodiment shown in FIG. 1 will be explained as follows. FIG. 1 shows a first embodiment of the present invention, in which 1 is a 4-port 3-position manual directional control valve;
2a, 2b, 2c are cylinders, 3a, 3b, 3c
4-port 2-position spring return type solenoid valve provided corresponding to each cylinder; 4a, 4b, 4c are solenoids of each solenoid valve; 5a, 5b, 5c are switches of each solenoid; The solenoid is connected in parallel to the power source 6 via a switch. In FIG. 1 above, each solenoid valve 3a, 3b, 3c
is connected in parallel to the pump P and tank T via the manual directional control valve 1, and by operating the manual switching lever 7 of the manual directional control valve 1, the switches of each solenoid can be combined as shown in the following table. let it operate,
Each solenoid valve can be activated.

[Table] In the above, when the manual switching lever 7 is operated, the solenoid switch is connected first. They are designed to operate in parallel. Next, FIG. 2 shows a second embodiment of the present invention, in which 1 is the same manual directional control valve as in FIG. 1, 2d and 2e are cylinders, and 3d and 3e correspond to each cylinder. 4-port 2-position spring return type solenoid valve, 4d and 4e are the solenoids of each solenoid valve, 5d and 5e are the switches of each solenoid, and these solenoids are connected in parallel to the power supply 6 via a switch. It is connected to. In FIG. 2 above, each solenoid valve 3d, 3e is connected in series to a pump P and a tank T via a manual directional control valve 1, and by operating a manual switching lever of the manual directional control valve 1, , the switches of each solenoid can be operated in combination as shown in the table below.

[Table] In the above, when the manual switching lever 7 is operated, the solenoid switch is connected first. They are designed to operate in series. In FIG. 2, in the series operation state, when the manual directional control valve 1 is in the state, the cylinder 2d is shortened,
The return oil is used to shorten the cylinder 2e, and in another state, the cylinder 2e is extended, and the return oil is used to extend the cylinder 2d. The shift pattern by the manual switching lever 7 in the case of FIG. 2 can be configured as shown in FIG. 3. FIG. 4 shows a third embodiment of the present invention, 1a
is a 6 port 3 position manual directional control valve, 2f, 2
g is the cylinder, 3f is a 4-port 2-position spring return type solenoid valve, 4f is its solenoid, 5f
indicates the switch, 3g indicates the 4-port 3-position solenoid valve, 4g ₁ , 4g ₂ indicates the solenoid, 5g ₁ , 5g ₂ indicates the switch, and each solenoid 4f, 4g ₁ ,
4g ₂ is connected to the power supply 6 via switches 5f, 5g ₁ , 5g ₂ .
are connected in parallel. The electromagnetic valves 3f and 3g shown in FIG. 4 are connected in series to a pump P and a tank T via a manual directional control valve 1a. The hydraulic circuit shown in Fig. 4 above can be used for raising and lowering the lift arm 10 of the front leader as shown in Fig. 5, and for scooping and dumping work equipment 11 such as a bucket at the tip of the lift arm, and can be used in the manual direction. By configuring the shift pattern of the manual switching lever 7 of the control valve 1a as shown in FIG. 6, operations as shown in the following table can be performed.

[Table] A specific example of the relationship between the above-mentioned manual switching lever 7 and each switch will be described below. 7 to 9, 1 is a manual directional control valve, 12 is a spool, and this spool 12
A manual switching lever 7 is connected via a joint pin 13. The manual switching lever 7 is movable within the shift groove 15 of the fulcrum metal fitting 14, and switches 16 are arranged and fixed at predetermined positions in the shift groove 15 to suit each control mode. The corresponding solenoid 17 is connected to a power source 18, and the manual switching lever 7 is connected to a power source 20 via a power source 19. In this case, the manual switching lever 7 is coated with a conductor or is itself made of a conductor, but is electrically insulated from the lever grip and the spool 12. With the above configuration, when the lever 7 is tilted to the right or left in FIG. 8 at any shift position within the shift groove 15 of the manual switching lever 7, the lever 7
is tilted about the joint pin 13, and first comes into contact with the switch 16 and the corresponding solenoid 17
The energizing circuit is turned on, thereby switching the solenoid valve first, and in this state, when the lever 7 is further pushed down in the same direction, the lever 7 will move the groove edge of the shift groove 15 of the fulcrum metal fitting 14 as a fulcrum. as manual directional control valve 1
The spool 12 is moved in the direction opposite to the direction in which the lever 7 is lowered. As a result, even though a solenoid valve is used, it is possible to perform inching operation (inching) using the manual directional control valve 1 while the solenoid valve is left in operation, and damage to the switch can be minimized. . FIG. 10 is an explanatory plan view showing the relationship between the manual switching lever 7 and each switch in which the above-mentioned construction principle is applied to the front loader operating circuit of FIGS. 4 and 6.
Since each switch may be arranged according to the operation table described above, a detailed explanation thereof will be omitted. As explained above, the present invention provides a circuit in which a plurality of hydraulic devices such as cylinders are provided with corresponding directional control solenoid valves, and connected to a pump and a tank via one manual directional control valve, and , a shift groove is provided in the fulcrum metal fitting of the manual switching lever of the manual directional control valve in a direction orthogonal to the spool operating direction of the lever,
By arranging the switch of the directional control solenoid valve on the shift groove, selecting a position of the lever in the shift groove, and operating the lever in the spool operating direction at that position, the directional control solenoid valve disposed at the shift position can be activated. Since the manual directional control valve is operated in conjunction with the switch being closed, fine movement and inching operations, which are the drawbacks of solenoid valves, are now possible by controlling the manual directional control valve side. obtain. Of course, speed control and flow rate control are also possible, and when used on a front loader, inching operation and speed control can be performed with a single operation lever to raise and lower the lift arm and operate the scoop/dump of the advanced work equipment, improving operability. It can be improved. In addition, the same operation is possible not only when there is only one hydraulic device installed as a control target, but also when multiple hydraulic devices are installed, and moreover, it can be operated individually as well as in conjunction with each other. In some cases, the switch can be shared, making it simple and inexpensive in terms of structure and cost.
It is also very convenient to operate. Furthermore, the effects of this invention can be summarized as follows. (b) Fine adjustment is possible, which is a disadvantage of solenoid valves. (b) Hydraulic lock and fluid resistance (flow force), which are disadvantages of solenoid valves, can be reduced. (c) By operating the manual switching valve, the speed control can be operated by the operator's own body (hands). (d) Even if a large number of solenoid valves are used, only one manual switching valve
Only one piece is needed, and high performance can be obtained at low cost. (e) Solenoid valves can be placed close to hydraulic actuators such as cylinders, making piping smarter and reducing the number of piping. (f) Advantages of manual switching valves: (Stable in terms of performance.
The operation is complete. It can be used in combination with the advantages of solenoid valves (such as easy remote control). (g) Solenoid valves and actuators can be easily added. (It can also be decreased.) (H) The relationship between lever position and operation can be changed only by the switch position.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing the first embodiment of the present invention, Fig. 2 is a hydraulic circuit diagram also showing the second embodiment, and Fig. 3 is an explanatory diagram of the shift pattern of the manual switching lever in that case. , Fig. 4 is a hydraulic circuit diagram showing a third embodiment of the present invention, Fig. 5 is a schematic explanatory diagram of the main parts of a front loader that is a specific application in that case, and Fig. 6 is a manual switching diagram in that case. 7 is a plan view showing the relationship between the manual switching lever and the switch; FIG. 8 is a side view thereof; FIG. 9 is a front view thereof;
FIG. 0 is a plan view showing the relationship between a manual switching lever and a switch of a front loader according to a third embodiment of the present invention. 1, 1a...Manual directional control valve, 2a to 2g...
Cylinder, 3a to 3g... Solenoid valve, 7... Operation lever.

Claims (1)

[Claims] 1 A circuit in which a plurality of hydraulic devices such as cylinders are provided with corresponding directional control solenoid valves and connected to a pump and a tank via one manual directional control valve, and the manual directional control valve is manually switched. A shift groove is provided in the fulcrum metal fitting of the lever in a direction perpendicular to the spool operating direction of the lever, the switch of the direction control solenoid valve is arranged on the shift groove, the position of the lever is selected within the shift groove, and the lever is positioned in the shift groove. A hydraulic control device characterized in that, by operating the spool in the spool operating direction, a manual directional control valve is operated in conjunction with closing a switch of a directional control solenoid valve disposed at the shift position.