JP3481009B2 - Cargo handling equipment for cargo handling vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo handling operation device for a cargo handling vehicle such as a wheel loader, which operates the cargo handling device by using fluid pressure in accordance with the purpose. [0002] In a wheel loader or the like, a cargo handling device such as a bucket or a boom is moved by a cylinder. The operation is performed by an operation lever, and there are a direct acting type in which a spool of a main valve is moved by a wire or the like and a pilot operated (POC) type operated by a hydraulic pilot. In a wheel loader or the like, various types of cargo handling work are performed by changing the cargo handling device to, for example, a logger type or a snow removing blade. In order to provide such a cargo handling device,
A large number of main valves with two-section spools are usually added, and the operation levers are either direct-acting or PO.
Regardless of the C type, the number of additional units has been increased. FIGS. 4 and 5 show a cargo handling operation device for operating the cargo handling device. This uses a hydraulic circuit including an actuator unit 1 for performing a cargo handling operation, a main valve 2 for switching the operation of the actuator unit 1, and a pilot valve 3 for switching the main valve 2 by operating an operation lever. The actuator section 1 has one side slide cylinder 4, two pitch cylinders 5a, 5
b, two angling cylinders 6a, 6b, two tilt cylinders 7a, 7b, two lift cylinders 8
a, 8b, and the rod expands and contracts depending on the hydraulic pressure flowing into each port and the direction thereof. The main valve 2 has five sections of control valves 2a to 2e provided for each cylinder, and the control valves 2a to 2d are three-position switching valves.
The control valve 2e is a four-position switching valve. And P
The port is connected to the main pump 9, the T1 port is connected to the RET port of the reducing valve 10, and the T2 port is connected to the oil tank 11, respectively. Also, A
One port is on the tail side of the side slide cylinder 4, B1
The port is connected to the rod side, the A2 port is connected to the tail side of each pitch cylinder 5a, 5b, and the B2 port is connected to the rod side. The A3 port is connected to the tail side of the angling cylinder 6a and the rod side of the angling cylinder 6b, and the B3 port is connected to the rod side of the angling cylinder 6a and the tail side of the angling cylinder 6b.
The four ports are connected to the tail side of the tilt cylinder 7a and the rod side of the tilt cylinder 7b, and the B4 port is connected to the rod side of the tilt cylinder 7a and the tail side of the tilt cylinder 7b. The port A5 is connected to the rod side of each of the lift cylinders 8a and 8b via the pilot check valve 12 and the flow regulator 13, and the port B5 is directly connected to the tail side. The pilot valve 3 comprises four sections and one section of pilot valves 3a and 3b for switching the direction of control fluid supplied to both ends of the spools of the control valves 2a to 2e. Further, the pilot valve 3 has a structure that switches according to the operation of the operation lever. The P port of the pilot valve 3a is connected to the assist pump 17 via the stop valve 14, the check valve 15, and the relief valve 16, and the T port is connected to the oil tank 11. A6 port is a pilot port Pa1 of the spool of the control valve 2a, and B6 port is a pilot port Pb.
1 connected. Further, port A7 is connected to pilot port Pa3 of the spool of control valve 2c, port B7 is connected to pilot port Pb3, and port A8 is connected to pilot port Pa2 and port B8 of the spool of control valve 2b. ing. Also, A
Nine ports are connected to the pilot port Pa5 of the spool of the control valve 2e, and port B9 is connected to the pilot port Pb5. The P port of the pilot valve 3b is connected to an assist pump 17 via a stop valve 14, a check valve 15, and a relief valve 16,
The port is connected to the oil tank 11. A10 port is pilot port P of spool of control valve 2d
The ports a4 and B10 are connected to the pilot port Pb4. In the drawing, reference numeral 34 denotes a solenoid valve , and reference numeral 18 denotes a check valve. With respect to this hydraulic circuit, there are two joystick type operation levers having two degrees of freedom and one operation lever having one direction of freedom. In the above configuration, the pilot valve 3 is switched according to the operation of the operation lever, and the control valves 2a to 2a are switched.
The hydraulic pressure is supplied to the spool 2e. Then, the spools of the control valves 2a to 2e move to control the valves 2a to 2e.
When e is switched, hydraulic pressure is supplied to one of the cylinders, and the rod of the cylinder expands and contracts according to the hydraulic pressure to perform the intended cargo handling operation. In the above-mentioned cargo handling device, depending on the type of the cargo handling device, the number of cylinders of the actuator 1 is increased, and accordingly, the number of control valves in the main valve 2 is increased. Further, a pilot valve for switching the control valve must be additionally provided. As a result, the number of operation levers for switching the pilot valve increases. When the number of operation levers increases, the operator of the cargo handling device must grasp the positions and movements of many operation levers. further,
Since the operation lever is additionally provided, a large space is required. SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a cargo handling operation device for a cargo handling vehicle in which the number of operation levers is reduced and the operation of the cargo handling device can be easily performed. Means for solving the problems according to the present invention are, as shown in FIG. 1, a plurality of control valves 2b in a main valve 2 including a plurality of control valves 2a to 2e for operating a cargo handling device. Operating lever 26 for switching between, 2c and 2d
And the remaining control valves 2a and 2d are connected to the electromagnetic valves 22 and 2
Operation switches 24 and 25 are provided for switching via the control lever 3, and the operation switches 24 and 25 are provided on the operation lever 26. In the above means for solving the problems, as shown in FIG. 1, when the operation switches 24, 25 are turned on, the electromagnetic valves 22, 2 are turned on.
Power is supplied to the solenoid 3 and the electromagnetic valves 22 and 23 are switched by the electromagnetic action. The hydraulic pressure supplied from the assist pump 17 moves the spools of the control valves 2a and 2d to switch the control valves 2a and 2d. Then, by switching the positions of the control valves 2a and 2d, the hydraulic pressure from the main pump 9 is supplied to the actuator unit 1, and the cargo handling device operates according to the hydraulic pressure. When the operation switches 24 and 25 are off, the electromagnetic valve 2
The control valves 2a and 2d are not switched, and the control valves 2 and 23 are not switched. Then, the main pump 9 and the actuator unit 1 are shut off by the control valves 2a and 2d.
As a result, the hydraulic pressure from the main pump 9 is not supplied to the actuator unit 1, and the cargo handling device maintains the state. Further, in response to the operation of the operation lever 26, hydraulic pressure is supplied to the spools of the control valves 2b, 2c, 2e, and the spools of the control valves 2b, 2c, 2e move, and the control valves 2b, 2c, 2e are moved. By the switching, the hydraulic pressure is supplied to the actuator unit 1, and the intended cargo handling operation is performed according to the hydraulic pressure. As shown in FIG. 1, a cargo handling operation device according to this embodiment includes a main valve 2 including five control valves 2a to 2e for operating an actuator unit 1 for a cargo handling device, and a main valve 2 in the main valve 2. A pair of pilot valves 19, 20, and 21 for switching the three control valves 2b, 2c, and 2e, and a joystick type having two degrees of freedom and an operating lever 26 having one direction of freedom are each provided. , Electromagnetic valves 22, 23 for switching the remaining control valves 2a, 2d, and operation switches 24, 25 for switching the electromagnetic valves 22, 23, and the operation switches 24, 25.
Is provided on one of the operation levers 26. This cargo handling operation device is different from the conventional cargo handling operation device shown in FIGS. 4 and 5 in that there is no danger or trouble even if the operation of the cargo handling device is somewhat rough, that is, a pilot valve for a cylinder that does not require fine operation. The electromagnetic valve 2
2, 23. Other configurations are the same as those of the conventional cargo handling operation device shown in FIGS. 4 and 5, and members having the same functions are denoted by the same reference numerals. The electromagnetic valves 22 and 23 are, as shown in FIG. 2, three-position switching valves having a solenoid and having an interior divided into three chambers. The electromagnetic coils are energized by supplying a 24 V DC power to the electromagnetic coils. When the solenoid is energized, the solenoid is operated and the three positions are switched. When the electromagnetic valve 22 is switched to the H position, the port A13 communicates with the port T, and the port B13 communicates with the port P. When the position is switched to the J position, the port A13 communicates with the port P, and the port B13 communicates with the port T. At the position I, which is the normal position, the ports A13 and B13 and the ports T and P are shut off. When the solenoid valve 23 is switched to the position K, the port A14 is connected to the port T,
Four ports are communicated with the P port. When the position is switched to the M position, the A14 port communicates with the P port, and the B14 port communicates with the T port. Then, the normal position L
In the position, A14 port, B14 port and T port, P
Both ports are shut off. The operating lever 26 is supported on the floor of the driver's seat (not shown) so as to be swingable about an axis. As shown in FIG. 3, a lever knob 27 which is formed in a streamlined shape for easy gripping is provided at the end thereof. The lever knob 27 has operation switches 24 and 25 mounted therein. Each operation switch 2
Reference numerals 4 and 25 denote contact bodies 2 mounted on the switch board 28.
9a, 29b, 30a, 30b and operation buttons 31a, 31b, 3 arranged on the surface of the lever knob 27 so as to be freely retractable.
2a, 32b, each contact body 29a, 29b,
30a, 30b are connected to the electromagnetic valves 22, 23 via wiring.
Connected to the electromagnetic coil. The operation buttons 31a, 31b, 32
a and 32b are formed in a substantially triangular shape, each vertex thereof is arranged in a cross shape toward the center of the lever knob 27, and the front side with respect to the center of the lever knob 27 is for tilting the plow or the like of the cargo handling device to the right. The lever knob 27 includes an operation button 31a, a tilt button 31b on the rear side that moves up left, a slide button 32a on the right side for moving a plow or the like, and a slide button 32b on the left side.
When you hold it, you press it with your thumb. The arrangement of these operation switches 24 and 25 is not limited. The operation switches 24 and 25 are
When each operation button 31a, 31b, 32a, 32b is pressed, the contact body 29a, 29b, 30a, 3 is pushed by the projection 33 of each operation button 31a, 31b, 32a, 32b.
0b is turned on, and a momentary push switch is turned on.
The solenoid 3 is energized, and the electromagnetic valves 22 and 23 are switched. It should be noted that a control circuit is provided to operate the operation switch 2.
Signals 4 and 25 may be input to the control circuit to control the energization of the electromagnetic valves 22 and 23 from the control circuit. In this case, since the signals of the operation switches 24 and 25 are once input to the control circuit, various controls can be performed. For example, if the operation for turning on the operation switches 24 and 25 is determined to be a dangerous operation by a sensor or the like for preventing danger, even if the operation switch is turned on, the cargo handling device does not operate.
It is conceivable to issue a warning to notify the danger. In the above configuration, when the operation button 31a is turned on, power is supplied to the solenoid for switching the electromagnetic valve 22 to the H position, the electromagnetic valve 22 is switched to the H position by electromagnetic action, and the hydraulic pressure supplied from the assist pump 17 is applied. Flows from the pilot port Pa4 of the main valve 2 via the P port and the B13 port of the electromagnetic valve 22. Then, move the spool of the control valve 2d,
The control valve 2d is switched. When the position of the control valve 2d is switched, hydraulic pressure from the main pump 9 is supplied to the tilt cylinders 7a and 7b, and the rods of the tilt cylinders 7a and 7b operate according to the hydraulic pressure.
The plow etc. of the cargo handling device tilts to the right. When the operation button 31b is turned on, power is supplied to a solenoid for switching the electromagnetic valve 22 to the J position, the electromagnetic valve 22 is switched to the J position by the electromagnetic action, and the hydraulic pressure supplied from the assist pump 17 is applied to the solenoid. It flows from the pilot port Pb4 of the main valve 2 through the P port and the A13 port of the valve 22. Then, the spool of the control valve 2d is moved to switch the control valve 2d. Further, by switching the position of the control valve 2d, the hydraulic pressure from the main pump 9 is supplied to the tilt cylinders 7a, 7b, and the rods of the tilt cylinders 7a, 7b operate in accordance with the hydraulic pressure, and the plow of the cargo handling device is moved. Etc. lean upward. When the operation button 32a is turned on,
Power is supplied to a solenoid that switches the electromagnetic valve 23 to the K position, the electromagnetic valve 23 is switched to the K position by an electromagnetic action, and the hydraulic pressure supplied from the assist pump 17 passes through the P port and the B14 port of the electromagnetic valve 23. It flows in from the pilot port Pa1 of the main valve 2. Then, the spool of the control valve 2a is moved to switch the control valve 2a. Further, by switching the position of the control valve 2a, the hydraulic pressure from the main pump 9 is supplied to the side slide cylinder 4, and the rod of the side slide cylinder 4 operates according to the hydraulic pressure, and the plow of the cargo handling device is moved. Slide left. When the operation button 32b is turned on, power is supplied to a solenoid for switching the electromagnetic valve 23 to the M position, the electromagnetic valve 23 is switched to the M position by electromagnetic action, and the hydraulic pressure supplied from the assist pump 17 is applied to the solenoid. It flows from the pilot port Pb1 of the main valve 2 through the P port and the A14 port of the valve 23. Then, the spool of the control valve 2a is moved to switch the control valve 2a. Further, by switching the position of the control valve 2a, the hydraulic pressure from the main pump 9 is supplied to the side slide cylinder 4, and the rod of the side slide cylinder 4 operates according to the hydraulic pressure, and the plow of the cargo handling device is moved. Slide right. When the operation switch 24 is in the OFF state, the electromagnetic valve 22 is at the I position, and the P port, T port and the A13 port, B13 port of the electromagnetic valve 22 are shut off. I don't know. Then, the main valve 9 and the tilt cylinders 7a and 7b are shut off by the control valve 2d. As a result, the hydraulic pressure from the main pump 9 is reduced by the tilt cylinders 7a and 7b.
And the rods of the tilt cylinders 7a and 7b do not operate, and the cargo handling device maintains its state. When the operation switch 25 is off, the solenoid valve 23 is in the L position, and the electromagnetic valves 23 are shut off between the P and T ports and the A14 and B14 ports. Does not switch.
Then, the main valve 9 and the side slide cylinder 4 are shut off by the control valve 2a. This allows
The hydraulic pressure from the main pump 9 is applied to the side slide cylinder 4
And the rod of the side slide cylinder 4 does not operate, and the cargo handling device maintains its state. The other control valves 2b, 2c and 2e are operated by operating the operation levers so that the pilot valves 19, 2
0 and 21 are switched, and hydraulic pressure is supplied to the spools of the control valves 2b, 2c and 2e. Then, the control valve 2b,
The spools 2c and 2e move to control valves 2b and 2e.
By switching between c and 2e, hydraulic pressure is supplied to any one of the cylinders, and the rod of the cylinder expands and contracts according to the hydraulic pressure to perform the intended cargo handling operation. In the method of switching the electromagnetic valve by the operation switch and further switching the control valve, since the switching of the electromagnetic valve is fast, the switching of the control valve is also fast and it is difficult to adjust the flow of hydraulic pressure into the cylinder. Difficult to operate finely. On the other hand, according to the method of switching the control valve by the operation lever, the manner of switching the control valve can be adjusted by operating the operation lever, so that the flow of hydraulic pressure into the cylinder can be adjusted, and fine operation is possible. As described above, since the number of operation levers is small and the operation switches are mounted on the operation levers, the operability is extremely improved. Moreover, the operation unit can be made compact without requiring a space for mounting the operation lever. In addition, expensive pilot valves can be reduced, and costs can be reduced. Further, in this embodiment, the control valve for the hydraulic cylinder for cargo handling that does not require fine operation is switched by an operation switch via an electromagnetic valve, and the control valve that requires fine operation is replaced by a pilot valve. Since the switching operation is performed by the operation lever via the valve, the cargo handling operation can be performed without lowering the accuracy of the cargo handling device. It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, the operation method of the cargo handling apparatus of the present embodiment is the POC type. However, even in the case of the direct-acting type, the operation lever is operated by operating some control valves of the main valve via the electromagnetic valves by the operation switches. Can be reduced. As is apparent from the above description, according to the present invention, an operation switch for switching some control valves in the main valve via an electromagnetic valve is provided, and the operation of the operation switch causes the operation of the electromagnetic valve. By switching the control valve, the number of operation levers can be reduced, and the operation switch is attached to the operation lever, so that the operability is greatly improved. In addition, even when an additional cargo handling device is added, it can be easily handled by providing a changeover switch, and a space for mounting an operation lever is not required, so that the operation section can be made compact. Further, the control valve for a cargo handling device which does not require fine operation is switched by an operation switch via an electromagnetic valve, and the control valve which requires fine operation is switched by an operation lever. Operability can be further improved without lowering the operation accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a cargo handling operation device of the present invention; FIG. 2 is a diagram showing a connection relationship between an electromagnetic valve and an operation switch; FIG. 3 is a plan view showing an operation lever; (B) is a sectional view taken along line AA, (c) is a sectional view taken along line BB. [FIG. 4] A hydraulic circuit diagram of a conventional cargo handling operation device. [FIG. 5] A hydraulic circuit diagram of a conventional cargo handling operation device. DESCRIPTION OF SYMBOLS 1 Actuator part 2 Main valve 3 Pilot valve 2a-2e Control valve 22,23 Electromagnetic valve 24,25 Operation switch 26 Operation lever

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-3836 (JP, A) JP-A-61-162500 (JP, A) JP-A-4-365798 (JP, A) JP-A-4- 358700 (JP, A) JP-A-7-61787 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B66F 9/24 B66F 9/20 E02F 9/00 G05G 1/06

Claims (1)

(57) [Claims] [Claim 1] A lift cylinder, an angle cylinder, a pitch cylinder, a side slide cylinder, and a tilt cylinder for operating a cargo handling device, five control valves for operating each cylinder, and a fine operation. Operation lever for switching each control valve for the required lift cylinder, angle cylinder and pitch cylinder, and fine operation are required
An operation switch for switching each control valve for a side slide cylinder and a tilt cylinder via a solenoid valve, wherein the operation switch is a cargo handling operation device provided on the operation lever, and a signal is input from the operation switch. A control circuit is provided, the control circuit comprising:
In the operation when the operation switch is turned on, when it is determined that the operation is dangerous by the sensor to prevent danger,
A cargo handling device for a cargo handling vehicle, wherein the cargo handling device is not operated even when the operation switch is turned on.