JPH05196009A - Hydraulic controller for cargo handling in industrial vehicle - Google Patents

Abstract

PURPOSE:To improve the operatability of a hydraulic apparatus for cargo handling by actuating this apparatus at a constant speed based on a command data stored in a memory means, regardless of the operation speed set value, when the operational quantity of an operation means is equal to or more than the standard operational quantity. CONSTITUTION:An operational direction and an operational angle theta of the lift lever 1 of a fork lift truck are detected by a lever control quantity detecting sensor 2 and output to a controller 3, and in CPU 5 in this controller 3, a driving current value is set from the operational angle theta and output voltage based on the set value of a variable volume 12 serving as an operation speed setting means. That is, when the operational angle theta is less than the prescribed operational angle, the first command data set as the gradient of the driving current value is varied according to the output voltage of the variable volume 12 read out from a memory 5a, and on the other hand, when the operational angle theta is equal to or more than the prescribed operational angle, the second command data set as the driving current value becomes maximum is read out from the memory 5a, and then, a lift cylinder 10 is driven and controlled through a control valve 8 based on each command data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control system for cargo handling in industrial vehicles such as forklifts.

[0002]

2. Description of the Related Art Conventionally, for example, when a fork of a forklift is moved up and down, ascending and descending is performed based on the operating direction of a lift lever 51 as shown in FIGS. The lever operation angle (operation amount) θ is used. That is, the electromagnetic proportional control valve 52 is switched based on the operation direction of the lift lever 51 to change the supply direction of the hydraulic oil supplied to the lift cylinder 53 to raise and lower the fork 54. Further, the supply or the outflow of the hydraulic oil of the electromagnetic proportional control valve 52 is adjusted based on the operation angle (operation amount) θ of the lift lever 51 to control the ascending / descending speed of the fork 54. The lift lever 51
The operating force of is linearly increased based on the operating angle θ of the lift lever 51.

The lift speed control of the fork 54 will be described in detail. The lever operation angle θ of the lift lever 51 is detected by a lever operation detection sensor 55 including a potentiometer, and this detection signal is output to the controller 56.

The controller 56 includes an A / D converter 57, a CPU 58, a ROM and RAM (not shown), and a D / D.
It is composed of an A converter 59 and a constant current amplifier 60. The detection signal from the lever operation detection sensor 55 is converted into a digital value by the A / D converter 57 and output to the CPU 58, and the CPU 58 calculates the operation angle θ of the lift lever 51 at that time. When the CPU 58 calculates the lever operation angle θ, it calculates a drive current value I for energizing the electromagnetic proportional control valve 52 with respect to the lever operation angle θ shown by the solid line in FIG. The drive current value I with respect to the lever operation angle θ shown in FIG. 15 has been previously tested or logically obtained, and is stored in a ROM (not shown) as data.

The CPU 58 outputs a drive control signal for the drive current value I to the D / A converter 59 in order to drive and control the electromagnetic proportional control valve 52 with the drive current value I, and the D / A converter 59 drives the drive control signal. The control signal is converted into analog, and the drive current value I is supplied from the constant current amplifier 60 to the electromagnetic proportional control valve 52. Electromagnetic proportional control valve 5
2 is a lift cylinder 53 for supplying hydraulic oil with a supply or outflow amount determined by the drive current value I (that is, the lever operation angle θ).
Supply to. Therefore, the drive current value I is obtained from the lever operation angle θ, and the drive current value I determines the amount of supply or outflow at that time and the ascending / descending speed. That is, the ascending / descending speed of the fork 54 is determined by the operation angle θ of the lift lever 51.

Further, as shown in FIG. 13, the CPU 58 is connected with a speed changeover switch 61 for controlling the ascending / descending speed of the lift cylinder 53 to operate at a very low speed. Then, for example, when the speed changeover switch 61 is turned off, the lifting speed of the lift cylinder 53 can be operated at a very low speed.

That is, when the lift lever 51 is operated while the speed changeover switch 61 is off, the CPU 58 calculates the operation angle θ of the lift lever 51 at that time. The CP
When U58 calculates the lever operation angle θ, the drive current value I to be flown to the electromagnetic proportional control valve 52 for the lever operation angle θ shown by the chain double-dashed line in FIG.

The CPU 58 sends a drive control signal for the drive current value I to the D / A converter 59 in order to drive and control the electromagnetic proportional control valve 52 with the drive current value I shown by the two-dot chain line in FIG. Output. The D / A converter 59 converts this drive control signal into an analog signal, and the constant current amplifier 60 supplies the drive current value I to the electromagnetic proportional control valve 52. The electromagnetic proportional control valve 52 has the drive current value I
The hydraulic oil is supplied to the lift cylinder 53 at a supply amount or an outflow amount determined by (that is, the lever operation angle θ). As a result, the lift cylinder 53 can be operated at a very low speed.

Therefore, since the drive current value I changes even if the operation angle θ of the lift lever 51 is the same, depending on the setting of the speed changeover switch 61, the lift cylinder 53.
Can be operated at a slow speed.

Further, when the speed change switch 61 is in the ON state and the lift lever 51 has a predetermined operating angle ± θ1 or more, the maximum drive current value I based on the characteristic shown by the solid line in FIG. 15 is obtained. The supply or outflow amount of hydraulic oil from the electromagnetic proportional control valve 52 is maximized. Therefore, the lifting speed of the lift cylinder 53 is maximized. On the other hand, when the speed changeover switch 61 is in the OFF state, the lift lever 5
1 becomes equal to or more than the predetermined operation angle ± θ1, the electromagnetic proportional control valve 52 is operated at the drive current value I shown by the chain double-dashed line in FIG.
The maximum supply or outflow of hydraulic oil from Therefore,
The amount of supply or outflow from the electromagnetic proportional control valve 52 shown by the dotted line in FIG. 15 is maximum. Therefore, the lifting speed of the lift cylinder 53 based on the characteristic shown by the dotted line in FIG. 15 is maximized.

[0011]

However, even if the lift lever 51 is operated by a predetermined operation angle ± θ1 or more in the state where the speed changeover switch 61 is in the OFF state, the operation shown in FIG.
The maximum drive current value I shown by the solid line is not obtained. Therefore, when it is desired to maximize the drive current value I as shown by the solid line in FIG. 15, the operation amount of the lift lever 51 must be set to a predetermined operation angle ± θ1 or more by turning on the speed changeover switch 61. There is a problem that is bad.

The present invention has been made to solve the above problems, and its purpose is to operate the cargo handling hydraulic equipment at a predetermined constant speed when the lift lever is operated beyond a reference amount. An object of the present invention is to provide a hydraulic control device for cargo handling in an industrial vehicle.

[0013]

In order to solve the above problems, the present invention solves the above-mentioned problems by operating amount detecting means for detecting an operating amount of an operating means for setting an operating speed of a hydraulic equipment for cargo handling, and the hydraulic equipment for cargo handling. A control valve for adjusting the operating speed by adjusting the flow rate of hydraulic oil, an operating speed setting means for arbitrarily changing the operating speed with respect to the operating amount of the operating means, and an operating amount within a reference operating amount of the operating means. For each set value of the operation speed setting means, the first command data for the operation amount and the operation amount equal to or larger than the reference operation amount of the operation means make the cargo handling hydraulic device constant regardless of the set value of the operation speed setting means. Storage means for storing second command data for operating at a speed, and when the operation amount of the operation means is within a reference operation amount, it is stored in the storage means for each set value of the operation speed setting means. When the hydraulic device for cargo handling is operated via the control valve based on the first command data for the operation amount of, and the operation amount of the operating means is equal to or greater than the reference operation amount, regardless of the set value of the operating speed setting means. The gist of the present invention is to include a cargo handling hydraulic control means for operating the cargo handling hydraulic device via the control valve based on the second command data of the storage means.

[0014]

When the operation amount of the operating means is within the reference operation amount based on the detection signal of the operation amount detecting means, the cargo handling hydraulic control means is stored in the storage means for each set value of the operating speed setting means. The hydraulic equipment for cargo handling is operated via the control valve based on the first command data for the quantity.
Further, when the operation amount of the operation device is equal to or larger than the reference operation amount based on the detection signal of the operation amount detection device, the cargo handling hydraulic control device is stored in the storage device regardless of the set value of the operation speed setting device. The cargo handling hydraulic equipment is operated at a constant speed via the control valve based on the command data.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. As shown in FIG. 1, the forklift is equipped with a lift lever 1 as an operating means for a lift operation in its driver's seat. Then, the operation direction and operation angle (operation amount) θ of the lift lever 1 are detected by a lever operation amount detection sensor (for example, a potentiometer) 2 as an operation amount detection means and output to a controller 3 as a cargo handling hydraulic control means. To be done. In the controller 3, the A / D converter 4 converts a detection signal from the lever operation amount detection sensor 2 into a digital signal and outputs the digital signal to the CPU 5.

The A / D converter 4 of the controller 3 has a variable volume 12 as an operating speed setting means.
Is connected, and an output voltage as a set value based on the setting of the variable volume 12 is output to the A / D converter 4. As shown in FIG. 3, the variable volume 12 is adapted to output an output voltage that linearly increases. Then, the variable volume 12 is set to HIGH
If set to, the output voltage is set to the maximum, and if set to LOW, the output voltage is set to the minimum.
It is possible to arbitrarily set the value from to HIGH. The output voltage of the variable volume 12 is converted into a digital signal by the A / D converter 4 and output to the CPU 5.

The CPU 5 detects the output voltage from the variable volume 12 and also detects the operation amount of the lift lever 1 based on the detection signal from the lever operation amount detection sensor 2. Then, the CPU 5 sets the drive current value I based on the operation angle θ of the lift lever 1 and the output voltage from the variable volume 12, and calculates the duty ratio based on the drive current value I. That is, as shown in FIG. 5, when the lift lever 1 has a predetermined operation angle (reference amount) ± θ1 or less, the CPU 5 causes the variable volume 12 to operate.
The first command data in which the inclination of the drive current value I changes based on the output voltage of the above is read from the memory 5a as the storage means, and based on the operation angle θ of the lift lever 1 with respect to the read first command data. The drive current value I is read out and the duty ratio is calculated.

Further, when the CPU 5 judges that the lift lever 1 has become equal to or more than the predetermined operation angle ± θ1 based on the detection signal of the lever operation amount detection sensor 2, the CPU 5 does not depend on the output voltage of the variable volume 12. Drive current value I
Is read out from the memory 5a and the duty ratio is calculated.

In this embodiment, if the output voltage of the variable volume 12 is set to the LOW side as shown in FIG.
The inclination (rate of increase) of the drive current value I with respect to the operation angle θ of the lift lever 1 is set small. That is, the drive current value I changes slightly with respect to the change rate of the operation angle θ of the lift lever 1. In addition, the output voltage of the variable volume 12 is set to HIGH.
If set to the side, the inclination of the drive current value I with respect to the operation angle θ of the lift lever 1 is set to be large. That is, the drive current value I greatly changes with respect to the change rate of the operation angle θ of the lift lever 1.

Then, the CPU 5 outputs the duty ratio based on the drive current value I of the level corresponding to the operation angle θ to the constant current amplifier 7 via the D / A converter 6, and the constant current amplifier 7 outputs the drive current value. A duty-controlled drive current based on I is supplied to the electromagnetic proportional solenoids 9a and 9b of the control valve 8. The electromagnetic proportional solenoids 9a and 9b are configured to control the opening and closing of control valves 29a and 29b, which will be described later, by the average drive current of the duty-controlled drive currents.

Therefore, the control valves 29a and 29b of the control valve 8 operate by the average drive current of the duty ratio based on the drive current value I of the level corresponding to the operation amount of the lift lever 1, and serve as a cargo handling hydraulic equipment. The flow rate of hydraulic oil supplied to or discharged from the lift cylinder 10 is adjusted. The expansion / contraction operation of the lift cylinder 10 is controlled, and the ascending or descending speed of the fork 11 is controlled.

Therefore, as shown in FIG. 6, when the output angle of the variable potentiometer 12 is set to the LOW side when the operating angle θ of the lift lever 1 is equal to or less than the predetermined operating angle ± θ1,
The ascending / descending speed of the fork 11 based on the operation angle θ of the lift lever 1 becomes low, and the output voltage of the variable volume 12 becomes H.
When set to the IGH side, the operating angle θ of the lift lever 1
The ascending / descending speed of the fork 11 based on Eq.

Further, when the operation angle θ of the lift lever 1 becomes a predetermined operation angle ± θ1 or more, the drive current value I becomes maximum regardless of the output voltage of the variable volume 12, and the performance of the control valve 8 itself becomes maximum. Fork 11
The ascending / descending speed of is the maximum (maximum) speed.

As shown in FIG. 7, the lever operation amount detection sensor 2 is connected to substantially the center of the lift lever 1, and the lever operation amount detection sensor 2 is mounted in a housing 13 having a rectangular box shape. . And the housing 13
Retaining pieces 14 are formed on both lower side surfaces of the so as to project from each other. A sliding member 15 is provided on the holding piece 14.
Are slidably provided, and storage chambers 16 are formed in the sliding members 15. The storage chamber 16
Is provided with a first spring 17, and the urging force of the first spring 17 urges the sliding member 15 away from the holding piece 14, and the holding piece 14 moves the lower end portion of the lift lever 1 into position. The lift lever 1 is sandwiched and held in a neutral state.

Insertion holes 18 are formed in the front end surface of the holding piece 14, respectively. In the insertion hole 18, the first
A second spring 19 having a smaller diameter than the spring 17 is inserted and held. Further, when the lift lever 1 is held in the neutral state by the holding piece 14, the tip of the second spring 19 is in a state of being separated from the inner end of the holding piece 14.

Therefore, as shown in FIG. 4, the operating force with respect to the operating angle θ of the lift lever 1 is proportionally increased by the urging force of the first spring 17 as the operating angle θ increases. Moreover, the lift lever 1 is operated at a predetermined operation angle ± θ.
When operated one or more times, the urging force of the second spring 19 is also added, so that the operation force is slightly increased. Therefore, the driver can perceptually know the area of the lift lever 1 up to the predetermined operation angle ± θ1 and the area of the predetermined operation angle ± θ1 or more.

Next, the hydraulic circuit of the control valve 8 will be described in detail. As shown in FIG. 2, the control valve 8 is supplied with hydraulic oil supplied from a hydraulic pump 20 by a supply conduit 21 and a diversion valve 22 via a main conduit 23 on the control valve 8 side. Further, a P for power steering is connected to the shunt valve 22 via a check valve 24.
An S pipe line 25 is provided.

A spool 26 is provided in the control valve 8 and oil chambers 27 for pilot operation are formed at both ends thereof. This oil chamber 2
7, the spool 26 is slidable.
A spring 28 is provided in the hydraulic pressure 27, and the spring 28 keeps the spool 26 always in the neutral position.

In the oil chamber 27, a control valve 29a controlled to be opened and closed by the electromagnetic proportional solenoids 9a and 9b,
29b is connected. Therefore, the constant current amplifier 7
A drive current having a duty ratio based on the drive current value I output from is supplied to the electromagnetic proportional solenoids 9a and 9b, and the control valves 29a and 29b are controlled to open / close with an average drive current based on the duty ratio. The control valves 29a, 2
By controlling the opening and closing of 9b, the flow rate of the hydraulic oil supplied to the control valves 29a and 29b is adjusted and supplied to the oil chamber 27.

A pilot drain pipe 30 is connected to each of the oil chambers 27 and is led out to a tank or a return pipe line. The pilot drain pipes 30 flow out from the oil chambers 27. A throttle valve (orifice) 31 that regulates the outflow amount of hydraulic oil is provided.

That is, the control valve 8 controls the opening and closing of the control valves 29a and 29b based on the energization of the ascending or descending electromagnetic proportional solenoids 9a and 9b to introduce the working oil into the oil chamber 27, while Of the working oil is discharged at a flow rate limited by the throttle valve 31 of the pilot drain pipe 30 to control the magnitude of the working oil pressure acting on the spool 26.
The spool 26 is displaced to a position in which the forces of are balanced.

Therefore, by controlling the opening of the control valves 29a, 29b based on the average drive current of the duty-controlled drive currents supplied to the electromagnetic proportional solenoids 9a, 9b, the position of the spool 26 corresponding to that is controlled. The lift cylinder 10 is supplied or discharged with an amount of hydraulic oil corresponding to the position of the spool 26. That is, the lift cylinder 10 moves up or down at a speed corresponding to the position of the spool 26.

Next, the operation of the cargo handling hydraulic control device configured as described above will be described with reference to the flow chart shown in FIG. In step 1, when the ignition switch is operated, the controller 3 is initialized. Then, in step 2, the CPU 5 causes A /
Variable volume 12 input via the D converter 4
The output voltage from is detected. Then, in step 3, the CPU 5 selects and reads the map of the drive current value I corresponding to the output voltage of the variable volume 12 from the map stored in the ROM or the like shown in FIG.

Next, in step 4, the CPU 5 sets A /
The operation angle θ from the lever operation amount detection sensor 2 input via the D converter 4 is detected. In step 5, the operation angle θ of the lift lever 1 is a predetermined operation angle ± θ1.
It is determined whether or not the above. And the lift lever 1
If the operation angle θ is less than the predetermined operation angle ± θ1, step 6
At 5, the CPU 5 sets the drive current value I corresponding to the operation angle θ of the lift lever 1 based on the selected map, and calculates the duty ratio based on the drive current value I.

Next, in step 7, the CPU 5 sets D
The duty ratio based on the drive current value I is output to the constant current amplifier 7 via the / A converter 6. The constant current amplifier 7 supplies the drive current whose duty is controlled by the duty ratio based on the drive current value I to the electromagnetic proportional solenoid 9
Energize a and 9b. Then, the control valves 29a and 29a are driven by the average drive current of the duty-controlled drive currents.
b is controlled to open and close. Therefore, the flow rate of the hydraulic oil supplied or flown out from the control valve 8 is adjusted, and the lifting speed of the lift cylinder 10 is adjusted. That is, the lifting speed of the lift cylinder 10 is set based on the output voltage of the variable volume 12 and the operation angle θ of the lift lever 1.

On the other hand, if the operating angle of the lift lever 1 is greater than or equal to the predetermined operating angle ± θ1 in step 5, step 8
At 5, the CPU 5 sets the drive current value I to the maximum regardless of the map selected based on the output voltage, that is, regardless of the setting of the variable volume 12, and calculates the duty ratio based on the maximum drive current value I. CPU5
Outputs this duty ratio to the constant current amplifier 7 via the D / A converter 6, and the constant current amplifier 7 supplies the duty-controlled drive current to the electromagnetic proportional solenoids 9a, 9b. Then, similarly to the above, in step 7, the control valves 29a and 29b are controlled to open and close, and the lift cylinder 10 is moved up and down. At this time, the hydraulic oil supplied or flown out from the control valve 8 has the maximum capacity of the control valve 8, so that the lifting speed of the lift cylinder 10 becomes the maximum (maximum) speed.

As a result, the variable volume 12 makes it possible to freely change and select the ascending / descending speed of the lift cylinder 10 according to the intended use, and improve the fine operability of the lift cylinder 10.

Even if the lift speed of the lift cylinder 10 is arbitrarily set by the variable volume 12, if the lift lever 1 is rotated by a predetermined operation angle ± θ1 or more, the controller 3 is set regardless of the setting of the variable volume 12. Maximizes the amount of hydraulic oil supplied or discharged from the control valve 8, so that the lifting speed of the lift cylinder 10 can be maximized. As a result, it is possible to improve the cargo handling operability without requiring the operation of the changeover switch as in the conventional case.

Therefore, for example, in the case where a cargo handling that easily collapses is stored on the shelf, the variable volume 12 is set to the LOW side and the lift lever 1 is operated at a predetermined operating angle ± θ1 or less while finely adjusting the lift cylinder 10. It can be carried out. After the cargo is stored on the shelf, the lift cylinder 1 can be lowered at the maximum speed by operating the lift lever 1 by a predetermined operation angle ± θ1 or more. Even in this case, it is not necessary to operate the changeover switch as in the conventional case, and the cargo handling work can be performed easily and easily.

Further, when the lift lever 1 has a predetermined operating angle of ± θ1 or more, the urging force of the second spring 19 is applied, so that the driver can sense whether the operating angle is ± θ1 or more. The adjustment operation of the lift lever 1 becomes easy. Further, when the lift lever 1 is operated over a predetermined operation angle ± θ1 or more, since the operation force becomes large, it is possible to prevent the lift lever 1 from being carelessly set to the predetermined operation angle ± θ1 or more.

Further, as another example of detecting the predetermined operation angle ± θ1 of the lift lever 1, it is also possible to configure as follows. As shown in FIGS. 9A and 9B, the lift lever 1
A circular cam 35 is provided on the above, and the cam 35 and the lever operation amount detection sensor 2 are connected by a connecting shaft 36.
A coil spring 37 is wound around the connecting shaft 36,
The ends 37a and 37b of the coil spring 37 are engaged with the engagement pieces 38 and 39 provided on the lever operation amount detection sensor 2 and the cam 35, respectively. Further, a cam surface 35a is recessed on the lower outer peripheral surface of the cam 35, and a ball 41 supported by the housing 13 via a spring 40 is brought into contact with the cam surface 35a.

Therefore, when the normal lift lever 1 is not operated, the lift lever 1 is connected to the end portion 37a of the coil spring 37,
37b holds the neutral state shown in FIG. 9 (a).
Then, when the lift lever 1 is set to a predetermined operation angle ± θ1 or more, the ball 41 tries to compress the spring 40 because the ball 41 tries to ride on the outer peripheral surface of the cam 35 over the cam surface 35a. At this time, as shown in FIG.
Since the repulsive force is generated, the driver is sensuously aware of the repulsive force of the spring 40, and the driver is informed that the lift lever 1 has a predetermined operation angle of ± θ1 or more.

Further, as shown in FIGS. 11A and 11B, a limit switch 42 may be provided instead of the spring 40. In this case, the limit switch 42 is turned on when the lift lever 1 becomes equal to or larger than the predetermined operation angle ± θ1. Since the controller 3 can judge that the lift lever 1 has become equal to or more than the predetermined operation angle ± θ1 based on this ON signal, the device can be made more reliable and safe.

Further, in the present embodiment, the speed control of the lift cylinder 10 is embodied, but in addition to this, the speed control of the tilt cylinder and the reach cylinder can be embodied.

Although this embodiment is embodied as a forklift, it can be applied to other industrial vehicles.

[0046]

As described above in detail, according to the present invention, when the lift lever is operated by the reference amount or more, the cargo handling hydraulic equipment can be operated at a preset constant speed. ..

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a forklift cargo handling hydraulic control device embodying the present invention.

FIG. 2 is a hydraulic control circuit diagram of a control valve.

FIG. 3 is a characteristic diagram of an output voltage output from the variable volume.

FIG. 4 is a characteristic diagram showing that the operating force changes with the operating angle of the lift lever.

FIG. 5 is a characteristic diagram showing that the characteristic of the drive current value changes according to the setting of the output voltage of the variable volume.

FIG. 6 is a characteristic diagram showing that the lifting speed of the lift cylinder changes depending on the setting of the output voltage of the variable volume.

FIG. 7 is a cross-sectional view showing an internal structure of a lift lever.

FIG. 8 is a flowchart illustrating the operation of the cargo handling hydraulic control device.

FIG. 9A is a front view showing another example of the lift lever, and FIG. 9B is a side view showing another example of the lift lever.

FIG. 10 is a characteristic diagram showing a change in operating force with respect to an operating angle of a lift lever of another example.

FIG. 11A is a front view showing another example in which a limit switch is provided on a lift lever, and FIG. 11B is a side view showing another example in which a limit switch is provided on a lift lever.

FIG. 12 is a characteristic diagram showing that the limit switch is turned on when the lift lever of another example provided with the limit switch has a predetermined operation angle or more.

FIG. 13 is a block circuit diagram of a conventional cargo handling hydraulic control device in a forklift.

FIG. 14 is a characteristic diagram showing a change in operating force with respect to an operating angle of a conventional lift lever.

FIG. 15 is a characteristic diagram showing a change in drive current value with respect to an operating angle of a conventional lift lever.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lift lever as operation means, 2 ... Lever operation amount detection sensor as operation amount detection means, 3 ... Controller as cargo handling hydraulic control means, 5a ... Memory as storage means, 8 ... Control valve, 10 ... Cargo handling Lift cylinder as hydraulic equipment for use, 12 ... Variable volume as operating speed setting means, θ1 ... Predetermined operation angle as reference amount

Claims (1)

[Claims] 1. An operation amount detecting means for detecting an operation amount of an operating means for setting an operating speed of a cargo handling hydraulic device, and a control valve for adjusting an operating speed by adjusting a flow rate of hydraulic oil of the cargo handling hydraulic device. An operation speed setting means for arbitrarily changing the operation speed with respect to an operation amount of the operation means, and an operation amount within a reference operation amount of the operation means for each set value of the operation speed setting means with respect to the operation amount. Storage means for storing 1 command data and second command data for operating the cargo handling hydraulic equipment at a constant speed regardless of the set value of the operating speed setting means when the operation amount is equal to or greater than the reference operation amount of the operating means. When the operation amount of the operation unit is within a reference operation amount, the operation amount setting unit stores the operation amount setting unit based on the first command data for the operation amount stored in the storage unit for each set value. When the hydraulic equipment for cargo handling is operated via the control valve, and the operation amount of the operating means is equal to or larger than the reference operation amount, the above-mentioned operation is performed based on the second command data of the storage means regardless of the set value of the operating speed setting means. A cargo handling hydraulic control device for an industrial vehicle, comprising: a cargo handling hydraulic control means for operating a cargo handling hydraulic device via a control valve.