JPH0762809B2 - Agricultural front loader load drive control composite circuit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a load drive control composite circuit for an agricultural front loader.

[Prior Art] Conventional agricultural front loaders, as shown in FIG. 9 to FIG. 11, include solenoids for directional control solenoid valves for lift cylinders, solenoids for directional control solenoid valves for winch motors as advanced working equipment, and the like. The drive circuit (2) of the load (1) and the input circuit (4) of the control circuit (3) are separate circuits, and the switch (S1) is separately provided for the drive circuit (2) and the input circuit (4).
(S2) is provided and a switch (S2) is provided in the drive circuit (2).
A variable resistor (VR) interlocking with is provided, and a resistor (not shown) is also provided in the control circuit (3) to set the power supply voltage to each operating voltage.

FIG. 9 shows another circuit controlled by the output of the control circuit (3), and FIG. 10 shows the relay of the drive circuit (2) of the load (1) by the output of the control circuit (3). 5) is operated, and FIG. 11 is a circuit in which the transistor switch (6) of the drive circuit (2) of the load (1) is operated by the output of the control circuit (3).

[Problems to be Solved by the Invention] In the conventional agricultural front loader, since the drive circuit (2) of the load (1) and the input circuit (4) of the control circuit (3) are separated, the resistor and the switch are separated. Needed separately. In addition, in Fig. 10 and Fig. 11, the switch (S1) must be turned on before the switch (S2), which makes adjustment of the switch extremely difficult, which reduces the operability of the agricultural front loader. This has been an obstacle to safety and prevention of malfunction.

The present invention has an object to solve the above problems of the conventional agricultural front loader.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a solenoid for switching operation of a directional control solenoid valve and a bucket for controlling the supply of hydraulic pressure to a lift cylinder that raises and lowers a lift arm of an agricultural front loader. A load consisting of a solenoid for switching operation of a directional control solenoid valve that controls the supply of hydraulic pressure to a dump cylinder or hydraulic motor that operates the tip working equipment of
A switch for operating the load, a variable resistor that is connected in series with the above switch to control the operating speed of the load, and has a variable resistance value linked with the operation of the switch, and a If the operating conditions such as safety are judged to be unsuitable and the conditions are not appropriate, the operating condition judgment circuit that normally turns off the load circuit via a relay or transistor switch, and the input voltage to this operating condition judgment circuit are constant And a control circuit having an input stabilizing circuit that holds the switch, the switch, the variable resistor, and a normally-on relay or transistor switch of the control circuit connected in series to the power source for the load. To form a load drive circuit, and for this load drive circuit, the operating condition determination circuit and the input stabilization circuit of the control circuit are shared in parallel with the power supply by sharing the switch. It is connected in the state.

[Operation] The input stabilization circuit prevents the operating condition determination circuit from malfunctioning even if the input voltage to the control circuit fluctuates in response to a change in the resistance value of the variable resistor due to the operation of the switch.

The operating condition determination circuit ensures the safety of the operation of the lift arm of the agricultural front loader and the tip working equipment.

Further, the switch and the variable resistor can freely change the operating speed of the lift arm of the agricultural front loader and the tip working equipment.

[Embodiment] FIG. 1 is a schematic diagram of a circuit of the present invention, in which (1) is a load, (2) is its drive circuit, (3) is a control circuit, and (4).
Is its input circuit, (S) is a switch, and (VR) is a variable resistor that works with the switch. By turning on the switch (S), the current required from the power supply to the drive circuit (2) of the load (1) can be changed. It is supplied through a resistor (VR), and at the same time, the input circuit (4) of the control circuit (3) is closed, and another device (not shown) is output through its output circuit (7). )) Is activated.

FIG. 2 shows that the relay contact (5a) of the drive circuit (2) of the load (1) is activated by the relay (5) provided in the output circuit (7) of the control circuit (3) as compared with FIG. The rest of the configuration is the same as that of FIG. 1 except for the difference.

FIG. 3 uses a transistor switch (6) instead of the relay (5) of FIG. 2, and the other structure is the same as that of FIG.

FIG. 4 is a switch suitable for application to a front end working device of an agricultural front loader, for example, a circuit for rotating a winch driving hydraulic motor forward and backward or a circuit for controlling a solenoid of a three-position directional control solenoid valve for a lift cylinder. 1 of (S)
An example is shown. In this switch (S), a movable contact piece (9) that is interlocked with an operation lever (8) is connected to a ground wire (10), Fixed terminals (11) and (12) are provided at symmetrical positions.
In 1) and (12), the circuit of Fig. 2 is connected symmetrically,
In FIG. 4, only one is shown. Resistors (13) and (14) are connected to the fixed terminals (11) and (12), and the movable contact piece (9) is in the neutral position of the operating lever (8) (state of FIG. 4). Is non-contact [OFF], and when the operating lever (8) is operated to the left or right, the movable contact piece (9) slides in contact with the resistor (13) or (14) to switch the switch (S). The resistance value is decreased as the operation angle of the operation lever (8) is increased with turning on, so that the operating speed and the operating force can be increased.

The solenoid shown in FIG. 4 is the solenoid (1a) of the directional control solenoid valve (18) of the lift cylinder (17) that moves up and down the lift arm (16) of the agricultural front loader (15) shown in FIG.
(1b) and operation circuit that operates solenoids (1c) (1d) of directional control solenoid valve (21) of dump cylinder (20) that performs squeezing and dumping [discharging] of tip working equipment (19) such as bucket Which applies to
(22) shows a hydraulic pump, and (23) shows a hydraulic tank.

FIG. 6 shows a concrete example of the control circuit (3). It shows the fluctuation of the input voltage from the input circuit (4) by the diode (D1) (D
2) A clamp circuit consisting of 2) keeps it constant, and a kind of delay circuit consisting of resistors (R1) (R2) and capacitor (C), the resistance value of the variable resistor (VR) when the switch (S) is turned on. An input stabilization circuit (2) that prevents the control circuit (3) from malfunctioning due to this effect when changing from high resistance to 0.
It is transmitted to the inverter (25) through 4), and the output [low level output] of this inverter (25) and the output [low level output] of the operating condition determination circuit (26) are AND circuit (27).
And an inverter (29) connected to the output circuit (7), the operating condition determination circuit (26) is a load (1).
The appropriate sensor (28) detects the safety and suitability of the operating conditions during the operation of the, and outputs the output. When the switch (S) is turned on, the suitability of the above operating conditions is determined. Then, the relay contact (5a) of the drive circuit (2) of the load (1) is controlled to be turned on.

The circuit of FIG. 6 is applied to the agricultural front loader (15) of FIG. 5 in combination with the switch (S) of FIG. In this case, the load (1) is a direct current load such as a direct current solenoid or a direct current motor, and the variable resistance (VR) that works with the switch (S) corresponds to the starting resistance of the direct current load. is there.

7 and 8 show an embodiment of the whole of the present invention,
The figure shows two switches (S) with one operating lever (8).
While (S) is adapted to be operated, four switches (S), (S), (S) and (S) are operated by operating one operating lever (30) in the cross direction. This shows the case where the above is performed, and the other structure is the same as that of the above-mentioned embodiment.

In FIG. 8, a hydraulic motor (20a) is attached in place of the dump cylinder (20) shown in FIG.
In this case, the winch drum (19a) is rotated to enable crane work.

[Advantages of the Invention] According to the present invention, there are the following advantages.

The input stabilization circuit can prevent the operating condition determination circuit from malfunctioning even if the input voltage to the control circuit fluctuates in response to the change in the resistance value of the variable resistor due to the adjustment of the switch.

The operating condition determination circuit can ensure the safety of the operation of the lift arm of the agricultural front loader and the tip working equipment.

The variable resistance that changes the resistance value in conjunction with the operation of the switch can freely change the operating speed of the lift arm of the agricultural front loader and the tip working equipment.

Since the control circuit having the input stabilization circuit and the operating condition determination circuit was connected to the load circuit of the agricultural front loader,
It is possible to prevent malfunction of the agricultural front loader and improve the safety of operation.

The load drive circuit and the control circuit input circuit can be smoothly operated by a single switch without malfunction or confusion, and the operability of the agricultural front loader can be improved.

[Brief description of drawings]

1 to 3 are schematic diagrams of a circuit of the present invention, FIG. 4 is a specific example of a switch, FIG. 5 is a schematic configuration diagram of an agricultural front loader, and FIG. 6 is a specific example of a control circuit. FIG. 7 and FIG. 8 show another example of the tip working equipment in the whole embodiment of the present invention. 9 to 11 show conventional circuit examples. (1) ... load, (2) ... driving circuit, (3) ... control circuit, (4) ... input circuit, (S) ... switch, (V
R) …… Variable resistance (15) …… Agricultural front loader, (16) …… Lift arm, (17) …… Lift cylinder, (19) …… Tip working equipment, (20) …… Dump cylinder, (20a ) …… Hydraulic motor, (18) (21) …… Direction control solenoid valve, (1a) (1b)
(1c) (1d) …… Solenoid (24) …… Input stabilization circuit, (26) …… Operating condition judgment circuit.

Claims (1)

[Claims] Claim: What is claimed is: 1. A dump cylinder or a hydraulic motor for operating a tip-end working device such as a solenoid for switching a directional control solenoid valve for controlling the supply of hydraulic pressure to a lift cylinder for raising and lowering a lift arm of an agricultural front loader and a bucket. A load consisting of a solenoid for switching operation of a directional control solenoid valve that controls the supply of hydraulic pressure, a switch for operating the load, and a switch for controlling the operating speed of the load, connected in series with the above switch, and operating the above switch. When the load resistance is variable and the resistance value is variable in conjunction with the adjustment, and if the operating conditions such as safety when the load is operating are judged to be unsuitable, the load circuit is normally turned on via a relay or transistor switch. A control circuit having an operating condition judging circuit for turning off the power and an input stabilizing circuit for keeping the input voltage to the operating condition judging circuit constant. A load drive circuit is configured by connecting the switch, the variable resistor, and the normally-on relay or transistor switch of the control circuit in series to the power source for the load, and A load drive control composite circuit for an agricultural front loader, characterized in that the operating condition determination circuit and the input stabilization circuit of the control circuit are connected to the load drive circuit in parallel with the power source sharing the switch.