JP2002321892A - Hook suspending length holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain sway of a suspending cargo by preventing a fluctuation in an extending/ contracting speed of a boom when switching an extending/contracting cylinder of the boom in a hook suspending length holder for holding the hook suspending length constant in extending/contracting operation of the boom. SOLUTION: This hook suspending length holder has an extension/contraction command means 19 for outputting an extension/contraction command signal for indicating an extending/ contracting direction and a speed of the boom, an extending/contracting cylinder detecting means 20 for detecting which of extending/contracting cylinders 6 and 7 is in an operation state, and a control signal output part 21 for arithmetically calculating an extension/ contraction control valve control signal 21a and a winch control valve control signal 21b . The control signal output part is constituted so as to shift and output the control signal by a detecting signal from the extending/contracting cylinder detecting means for obtaining the same boom extending/contracting speed even if either of the extending/contracting cylinders 6 and 7 is in an operation state when a speed command value of the extension/contraction command signal from the extension/contraction command means is the same when arithmetically outputting the extension/contraction control valve control signal from the extension/ contraction command signal from the extension/contraction command means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook hanging length holding device for keeping a hanging length of a hook hung at a tip end of a boom of a crane constant when the boom is extended and retracted. .

[0002]

2. Description of the Related Art (Explanation of a crane to which a hook hanging length holding device according to the present invention is attached)
As shown in FIGS. 2 and 3, the left and right outriggers 2, 2
A post 4 is mounted on the base 3 supported by the arm 4 so as to be pivotable, and a base end of a boom 5 is pivotally attached to the upper end of the post 4 so as to be able to move up and down. The boom 5 is extended and retracted by a plurality of telescopic cylinders described later, and is raised and lowered by an undulating cylinder 8.

Further, the post 4 which is a base end of the boom 5 is provided.
A winch 10 which is operated to be hoisted and lowered by a winch hydraulic motor 9 is disposed. A hook 12 is hung from a tip end of the boom 5 by a wire rope 11 which is operated to be wound up by the winch 10. I have.

The boom 5 is a multi-stage telescopic boom in which boom sections 5b, 5c, 5d at the distal end are sequentially inserted into the boom sections 5a, 5b, 5c at the proximal end so as to be extendable and retractable. Has a plurality of telescopic cylinders 6,
7, the extension and contraction operation is performed.

[0005] Among the plurality of telescopic cylinders 6, 7, the telescopic cylinder 6 is interposed between the boom section 5a at the most proximal end of the boom 5 and the next boom section 5b. Boom section 5
b.

[0006] The telescopic cylinder 7 is interposed between the boom section 5b and the next-stage boom section 5c.
c is operated to expand and contract. Boom section 5
b, 5c and 5d, a telescopic tuning device (known in the art composed of a sheave and a wire rope) for extending and retracting the boom section 5d with respect to the boom section 5c in conjunction with the telescopic operation of the boom section 5c with respect to the boom section 5b. , Not shown). The telescopic cylinder 7 causes the boom section 5d to expand and contract in addition to the telescopic operation of the boom section 5c.

The plurality of telescopic cylinders 6 and 7 are sequentially controlled to expand and contract by operating oil supplied and discharged by a single telescopic control valve 13 (a four-way three-position switching valve). The telescopic drive circuits of the telescopic cylinders 6 and 7 will be described in more detail as follows.

One of a pair of control ports of the expansion / contraction control valve 13 is connected to the extension operation side pressure oil chamber 6a of the extension cylinder 6 and the extension operation side pressure oil chamber 7a of the extension cylinder 7 via extension operation side pressure oil passages 13a1 and 13a2, respectively. Connected
The other of the pair of control ports of the expansion / contraction control valve 13 is connected to a reduction operation side pressure oil chamber 6b of the expansion / contraction cylinder 6 and a reduction operation side pressure oil chamber 7b of the expansion / contraction cylinder 7 via a reduction operation side pressure oil passage 13b.

The extension operation side pressure oil chamber 6 of the extension cylinder 6 is provided in the extension operation side pressure oil passage 13a1 from the extension control valve 13 side.
A mechanical check valve that always allows the flow of hydraulic oil to the a side and allows the reverse flow only when the telescopic cylinder 7 is fully contracted (mechanically related to the telescopic cylinder 7 so that it is opened when the telescopic cylinder 7 is fully contracted). (Mechanical check valve) 14 is provided. Further, the extension operation side pressure oil chamber 7 of the telescopic cylinder 7 is provided in the extension operation side pressure oil passage 13a2.
A mechanical check valve that always allows the flow of hydraulic oil from the a side to the telescopic control valve 13 side, and allows the reverse flow only when the telescopic cylinder 6 is fully extended (the telescopic cylinder is opened when the telescopic cylinder 6 is fully extended). A mechanical check valve 15 mechanically associated with 6 is interposed.

When the telescopic control valve 13 is switched to the extension side while the telescopic cylinders 6 and 7 are contracted, the extension operation side pressure of the telescopic cylinder 6 passes from the telescopic control valve 13 through the extension operation side pressure oil passage 13a1. Hydraulic oil is supplied to the oil chamber 6a, and hydraulic oil in the contraction-operation-side pressure oil chamber 6b of the telescopic cylinder 6 is discharged to the telescopic control valve 13 through the contraction-operation-side pressure oil passage 13b, whereby the telescopic cylinder 6 is extended. I do.
Until the telescopic cylinder 6 is fully extended, the mechanical check valve 15 interposed in the extension operation side pressure oil passage 13a2 is used.
Since the supply of hydraulic oil from the expansion and contraction control valve 13 to the expansion operation side pressure oil chamber 7a of the expansion and contraction cylinder 7 is prevented, the expansion and contraction cylinder 7 does not perform the expansion operation.

When the telescopic cylinder 6 is fully extended, the mechanical check valve 15 is opened and the telescopic cylinder 7 is extended. At this time, the operating oil of the contraction operation side pressure oil 7b of the expansion / contraction cylinder 7 is discharged to the expansion / contraction control valve 13 through the contraction operation side pressure oil passage 13b.

When the telescopic control valve 13 is switched to the contraction side in a state where the telescopic cylinders 6 and 7 are extended, the telescopic cylinder 6 of the telescopic cylinder 6 passes from the telescopic control valve 13 through the telescopic oil passage 13b. Hydraulic oil is supplied to the pressure operation chamber 6 b and the reduction operation side pressure oil chamber 7 b of the telescopic cylinder 7. The hydraulic oil in the extension-operation-side pressure oil chamber 7b of the telescopic cylinder 7 is discharged to the telescopic control valve 13 through the extension-operation-side pressure oil passage 13a2, whereby the telescopic cylinder 7 operates to contract. Until the telescopic cylinder 7 is fully contracted, the mechanical check valve 14 interposed in the elongating operation side pressure oil passage 13a1 prevents the hydraulic oil from being discharged from the elongating operation side pressure oil chamber 6a of the telescopic cylinder 6 to the telescopic control valve 13. Therefore, the telescopic cylinder 6 does not perform the contracting operation.

When the telescopic cylinder 7 is contracted to the minimum, the mechanical check valve 14 is opened, and the telescopic cylinder 6 is contracted.

Thus, the plurality of telescopic cylinders 6, 7
Is a single telescopic control valve 13 (a four-way three-position switching valve)
The expansion and contraction control is sequentially performed by the hydraulic oil that is controlled to be supplied and discharged.

The winch 10 (the winch hydraulic motor 9) is wound and fed out by hydraulic oil supplied and discharged by a winch control valve 16.

The direction and amount of switching of the telescopic control valve 13 and the winch control valve 16 can be arbitrarily operated by a crane operator. In FIG. 3, the operation lever 1 directly connected to each of the control valves 13 and 16 is shown.
It can be operated by 7 and 18.

As described above, in the crane to which the hook suspension length holding device according to the present invention is attached, the distal end boom sections 5b to 5d are sequentially extended and retracted into the base end boom sections 5a to 5c. Boom 5 fitted,
A plurality of telescoping cylinders 6 and 7, which perform telescopic operations sequentially by hydraulic oil supplied and discharged by a single telescopic control valve 13 to perform telescopic operations of different boom sections, and hydraulic oil supplied and discharged by a winch control valve 16 A winch 10 arranged on the base end side of the telescopic boom that winds and unwinds a wire rope 11, and a hook 12 suspended from the tip of the boom 5 via the wire rope 11, At the time of the crane operation, the outriggers 2 and 2 are grounded, and the post 4 is pivoted, the boom 5 is raised and lowered, and the telescopic operation is performed, and the winch 10 is rolled out to perform the crane operation.

(Basic Configuration of Hook Hanging Length Holding Device ...
In this type of crane, hook suspension length (hook suspension distance with respect to boom tip) is associated with extension and retraction of boom 5 in this type of crane.
L changes. That is, when the boom 5 is extended and contracted, the hook suspension length L is reduced, and when the boom 7 is contracted, the hook suspension length L is reduced. Therefore, when the boom 5 is extended, the hook 10 collides with the tip of the boom 5 by mistake, or when the boom 5 is contracted, the hook 10 is grounded without being noticed, and the wire rope 11 This causes a problem of loosening and causing turbulence in the winch 10 (the winch drum of the winch 10).

In order to cope with this problem, the extension / retraction operation of the boom 5 and the take-up / feed-out operation of the winch 10 are performed in conjunction with each other, and the length of the boom 5 is changed while keeping the hook hanging length L constant. There are known hook suspension length holding devices that can be used.

This type of hook hanging length holding device basically has a configuration as shown in FIG. In FIG. 3, which of the telescopic commanding means 19 for outputting the telescopic command signal 19a for specifying the direction and speed of expansion and contraction of the boom 5 and the plurality of telescopic cylinders 6 and 7 is in operation. And outputs the detection signal 20a by detecting the expansion and contraction control valve 13 and the winch control by receiving the expansion / contraction command signal 19a from the expansion / contraction instruction means 19 and the detection signal 20a from the expansion / contraction cylinder detection means 20. The control signal output unit 21 outputs a telescopic control valve control signal 21a and a winch control valve control signal 21b to the valve 16.

The expansion / contraction instruction means 19 arbitrarily outputs an expansion / contraction instruction signal 19a (electric signal) indicating the expansion / contraction direction and speed of the boom 5 by an operation of an operator.

The telescopic cylinder detecting means 20 detects whether the telescopic operation range of the boom 5 is in the telescopic operation range of the hydraulic cylinder 6 or the telescopic operation range of the telescopic cylinder 7.

The control signal output section 21 is provided with a telescopic control valve control signal 21a having a relationship necessary to maintain the hanging length L of the hook 12 constant during the telescopic operation of the boom 5 by the telescopic command signal 19a. And winch control valve control signal 2
1b is calculated and output using the telescopic command signal 19a and the telescopic cylinder detecting means 20.

In the control signal output section 21, the telescopic control valve control signal 21a output from the control signal output section 21
And the winch control valve control signal 21b are detected by the telescopic cylinder detecting means 20 when the necessary relationship for maintaining the suspension length L of the hook 12 constant during the telescopic operation of the boom 5 is provided. The reason why the signal 20a is involved is that the relationship between the switching amount of the telescopic control valve 13 and the telescopic speed of the boom 5 varies for each of the plural telescopic cylinders 6,7. In other words, even if the speed command value of the telescopic control valve control signal 21a is the same, the telescopic cylinder changes the telescopic speed of the boom 5. This means that the relationship between the telescopic control valve control signal 21a and the winch control valve control signal 21b required to keep the hanging length L of the hook 12 constant during the telescopic operation of the boom 5 is determined by the telescopic cylinder. This means that the detection signal 20a must be changed in accordance with Nos. 6 and 7, and the detection signal 20a from the telescopic cylinder detection means 20 is input to the control signal output unit 21 for this change.

In such a hook suspension length holding device, only by operating the extension / contraction command means 19, the extension / retraction operation of the boom 5 and the winding / unwinding operation of the winch 10 are performed in conjunction with each other, and the hook suspension length L Boom 5 while maintaining the
Since the length of the boom 5 can be changed, when the boom 5 is extended, when the hook 10 accidentally collides with the tip of the boom 5 or when the boom 5 is contracted, the boom 5 is noticed. The problem that the hook 10 is grounded without being solved is solved.

Next, a conventional hook suspension length holding device will be described with reference to FIG. Both the hook hanging length holding device according to the present invention and the conventional hook hanging length holding device have the above-described basic configuration. In the signal output section 21, the telescopic control valve control signal 21a and the winch control valve control signal 21b
Is calculated and output as follows.

Calculation output of telescopic control valve control signal 21a
, The expansion / contraction control valve control signal 21a is obtained as a function using only the expansion / contraction command signal 19a from the expansion / contraction control means 19 as a variable.

More specifically, the expansion / contraction command signal 19a from the expansion / contraction instruction means 19 is taken into the operation output section 22 of the expansion / contraction control valve control signal 21a inherent in the control signal output section 21.
The fetched expansion / contraction command signal 19a includes information on the expansion / contraction direction and speed.

The arithmetic output unit 22 calculates the speed based on the information included in the expansion / contraction command signal 19a relating to the capture.
A switching amount of the expansion / contraction control valve 13 (a switching amount from the neutral position) is calculated, and an expansion / contraction control valve control signal 21a for changing the expansion / contraction control valve 13 to the obtained switching amount is obtained.

Further, the arithmetic output unit 22 instructs whether the expansion / contraction instruction signal 19a indicates extension or contraction of the boom 5 based on information on the expansion / contraction direction included in the expansion / contraction instruction signal 19a relating to the loading. Judge whether there is
In the case of instructing extension, the telescopic control valve control signal 21a obtained above is transmitted to the telescopic control valve 13 (telescopic control valve 1).
3 switching actuator) for switching to the boom 5 extension side. When instructing reduction, the expansion / contraction control valve control signal 21a obtained above is sent to the expansion / contraction control valve 13 (an actuator for switching the expansion / contraction control valve 13).
The expansion / contraction control valve 13 is output to be switched to the boom 5 reduction side.

The expansion / contraction control valve 13 switched in this way, whether it is switching in the extension direction of the boom 5 or switching in the reduction direction of the boom 5, determines the amount of switching by the speed included in the extension / contraction command signal 19a. Is determined only depending on the information (speed command value) related to. Therefore, even if the speed command value of the extension / contraction command signal 19a is the same value, the extension / contraction speed of the boom 5 varies for each of the extension / contraction cylinders 6 and 7.

The operation of the winch control valve control signal 21b
With respect to the calculated force, the winch control valve control signal 21b includes an expansion / contraction command signal 19a from the expansion / contraction control unit 19 and an expansion / contraction cylinder detection unit 20.
Are determined as functions using both of the detection signals 20a as variables.

As described above, the switching amount of the expansion / contraction control valve 13 is determined only depending on the information (speed command value) related to the speed included in the expansion / contraction command signal 19a. Even if the values are the same, the extension / contraction speed of the boom 5 varies for each of the extension cylinders 6 and 7.
Therefore, when the winch control valve control signal 21b is obtained as a function using only the telescopic command signal 19a as a variable, both the telescopic range of the boom 5 by the telescopic cylinder 6 and the telescopic range of the boom 5 by the telescopic cylinder 7 are used. , The hanging length L of the hook cannot be kept constant.

For this reason, the winch control valve control signal 21b
Is obtained as a function using both the extension / contraction command signal 19a and the detection signal 20a of the extension / contraction cylinder detecting means 20 as variables.

More specifically, an expansion / contraction command signal 19a from the expansion / contraction instruction means 19 and a detection signal 20a from the expansion / contraction cylinder detecting means 20 are converted into a winch control valve control signal 21b included in a control signal output section 21 by an arithmetic output section 23. Take in. The fetched expansion / contraction command signal 19a includes information on the expansion / contraction direction and speed, and the detection signal 20a indicates whether the boom 5 is in the expansion / contraction operation area by the expansion / contraction cylinder 6 or in the expansion / contraction operation area by the expansion / contraction cylinder 7. It is a signal that can be determined.

The operation output unit 23 calculates the speed based on the speed information included in the expansion / contraction command signal 19a relating to capture.
Switching amount of winch control valve 16 (switching amount from neutral position)
And a winch control valve control signal 21b for switching the winch control valve 16 in accordance with the obtained switching amount. Here, the calculation of the switching amount of the winch control valve 16 is performed when the boom 5 is extended in the telescopic operation range by the telescopic cylinder 6, when the boom 5 is extended in the telescopic operation range by the telescopic cylinder 7, 6 and the boom 5 is contracted in the telescopic operation range of the telescopic cylinder 7, and the winch control valve control signal 21
b is determined for each of these cases.

The amount of switching of the winch control valve 16 when the boom 5 is extended in the telescopic operation range of the telescopic cylinder 6 is determined by the telescopic control valve control signal 21a output from the arithmetic output unit 22 as described above. 6, when the extension operation is performed in the expansion and contraction operation area, regardless of the extension operation, the amount of switching in the lowering direction (wire rope feeding direction) of the winch control valve 16 required to maintain the hook suspension length L constant. is there.

The switching amount of the winch control valve 16 when the boom 5 is extended in the telescopic operation range of the telescopic cylinder 7 is determined by the telescopic control valve control signal 21a output from the arithmetic output unit 22 by the telescopic control valve control signal 21a. When the telescopic cylinder 7 is extended in the telescopic operation range, the winch control valve 16 is switched to the lowering direction (wire rope feeding direction) necessary to maintain the hook hanging length L constant regardless of the elongating operation. Quantity.

The switching amount of the winch control valve 16 when the boom 5 is contracted in the telescopic operation range of the telescopic cylinder 6 is determined by the telescopic control valve control signal 21a output from the arithmetic output unit 22 as described above. When the retracting operation is performed in the telescopic operation range of the telescopic cylinder 6, the winch control valve 16 is switched to the winding direction (wire rope winding direction) necessary for maintaining the hook hanging length L constant regardless of the reducing operation. Quantity.

The amount of switching of the winch control valve 16 when the boom 5 contracts in the telescopic operation range of the telescopic cylinder 7 is determined by the telescopic control valve control signal 21a output from the arithmetic output unit 22 as described above. When the retracting operation is performed in the telescopic operation range by the telescopic cylinder 7, switching to the winding direction (wire rope winding direction) of the winch control valve 16 necessary to maintain the hook hanging length L constant regardless of the reducing operation. Quantity.

Further, the arithmetic output unit 23 instructs whether the extension / contraction instruction signal 19a indicates extension of the boom 5 or contraction based on information on the extension / contraction direction included in the extension / contraction instruction signal 19a relating to the take-in. And a detection signal 20 from the telescopic cylinder detecting means 20.
From a, it is detected whether the telescopic operation range of the boom 5 is the telescopic cylinder 6 or the telescopic cylinder 7.

When the extension / retraction command signal 19a indicates extension of the boom 5 and it is detected that the extension / reduction operation range of the boom is due to the extension / contraction cylinder 6, the winch control valve control signal 21b corresponding to the above is transmitted. To the winch control valve 16 (an actuator for switching the winch control valve 16).

When the extension / contraction command signal 19a indicates extension of the boom 5 and it is detected that the extension / reduction operation range of the boom is due to the extension / contraction cylinder 7, the corresponding winch control valve control signal 21b is transmitted to the winch. Control valve 1
6 (the actuator for switching the winch control valve 16).

When the expansion / contraction command signal 19a instructs reduction of the boom 5 and it is detected that the expansion / contraction operation range of the boom is due to the expansion / contraction cylinder 6, the corresponding winch control valve control signal 21b is transmitted to the winch. Control valve 1
6 (the actuator for switching the winch control valve 16).

When the extension / contraction command signal 19a instructs reduction of the boom 5 and it is detected that the extension / reduction operation range of the boom is due to the extension / contraction cylinder 7, the winch control valve control signal 21b corresponding to the above is sent to the winch. Control valve 1
6 (the actuator for switching the winch control valve 16).

As described above, in the conventional hook suspension length holding device, the control signal output section 21 has
The telescopic control valve control signal 21a and the winch control valve control signal 21b are obtained by using the telescopic command signal 19a from the telescopic command means 19 and the detection signal 20a from the telescopic cylinder detecting means 20.
Is calculated and output, the telescopic control valve control signal 21a is
The winch control valve control signal 21b is obtained by a function using only the expansion / contraction command signal 19a as a variable.
And the detection signal 20a from the telescopic cylinder detection means 20 are obtained as functions using variables as variables.

In other words, even if the speed command value included in the telescopic command signal 19a from the telescopic command means 19 is the same, the boom telescopic operation area by the telescopic cylinder 6 and the boom telescopic operation area by the telescopic cylinder 7 are different. Then, after admitting that the boom 5 expands and contracts at different speeds, the winch control valve 1
By changing the switching amount of 6 for each of the telescopic cylinders 6 and 7,
Hook suspension length L over the entire telescopic operation range of boom 5
The expansion / contraction control valve 13 and the winch control valve 1
6 is switched and controlled.

[0048]

In the above-described conventional hook suspension length holding device, the extension / retraction operation of the boom 5 and the winding / unwinding operation of the winch 10 are performed in conjunction with each other by operating the extension / contraction instruction means 19. Although the length of the boom 5 can be changed while keeping the hook suspension length L constant, the hook length holding device has the same speed command value of the expansion / contraction command means 19 relating to the operation. However, since the expansion / contraction operation speed of the boom 5 suddenly fluctuates between the expansion / contraction operation region of the boom 5 by the expansion / contraction cylinder 6 and the expansion / contraction operation region of the boom 5 by the expansion / contraction cylinder 7, the change in the expansion / contraction speed causes the hook to move. There is a problem that the suspended load locked to the swinging position 12 is dangerous due to swinging.

The present invention relates to an expansion / contraction instruction means 19 relating to an operation.
It is an object of the present invention to provide a hook suspension length holding device in which the extension / contraction operation speed of the boom 5 does not fluctuate even if the extension / contraction cylinder for extending / retracting the boom 5 changes if the speed command values of the boom 5 are the same.

[0050]

Means for Solving the Problems To solve the above problems, a hook hanging length holding device according to the present invention is configured as follows. The boom 5 in which the boom sections 5b to 5d on the distal end side are sequentially inserted into the boom sections 5a to 5c on the proximal end side so as to be extendable and contractible. A plurality of telescopic cylinders 6 and 7, which perform telescopic operation, a winch provided on the base end side of the boom 5 and operated to take up and unwind the wire rope 11 with hydraulic oil from a winch control valve 16, and via the wire rope 11. A hook hanging length holding device used for a crane provided with a hook 12 suspended from the tip of the boom 5, wherein the telescopic command means outputs a telescopic command signal 19 a for specifying the direction and speed of the boom 5 expansion and contraction. 19. Telescopic cylinder detecting means 2 for detecting which of the plurality of telescopic cylinders 6 and 7 is in operation
0, and a telescopic command signal 19 from the telescopic command means 20
a and a detection signal 20a from the telescopic cylinder detecting means 20, and a telescopic control valve control signal 21a having a relationship necessary to maintain the hanging distance L of the hook 12 constant during the telescopic operation of the boom 5. And a control signal output unit 21 for calculating and calculating a winch control valve control signal 21b and outputting the calculated signal to the telescopic control valve 13 and the winch control valve 16, respectively.
Wherein the control signal output unit 21 comprises:
When calculating and outputting the expansion / contraction control valve control signal 21a from the expansion / contraction command signal 19a from the expansion / contraction instruction means 19, if the speed instruction value of the expansion / contraction instruction signal 19a from the expansion / contraction instruction means 19 is the same, which of the telescopic cylinders 6 and 7 is used. In the operating state, the same boom expansion / contraction speed is obtained by shifting the detection signal from the expansion / contraction cylinder detection means 20 and outputting the same.
(b) calculating and outputting a b from a telescopic command signal (19a) from the telescopic command means (19).

The hook suspension length holding device according to the present invention comprises:
In this type of hook suspension length holding device (the configuration shown in the above "..." section), the control signal output section is configured as described above (the configuration below the "..." section). Therefore, if the speed command value of the expansion / contraction command means 19 relating to the operation is the same, the expansion / contraction operation speed of the boom 5 does not change even if the expansion / contraction cylinder for expanding / contracting the boom 5 changes. Therefore, when operating the extension / contraction command means 19 to extend and retract the boom 5 while maintaining the hook suspension length L, the swing of the suspended load locked on the hook 12 is suppressed, and a safe crane operation is performed. You can do it.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The hook hanging length holding device according to the present invention has the basic configuration of the hook hanging length holding device shown in FIG. That is, expansion / contraction instruction means 19 for outputting an expansion / contraction instruction signal 19a for instructing the expansion / contraction direction and speed of the boom 5, an expansion / contraction cylinder detecting means 20 for detecting which of the plurality of expansion / contraction cylinders 6 and 7 is in operation, and Receiving the extension / contraction command signal 19a from the extension / contraction instruction means 20 and the detection signal 20a from the extension / contraction cylinder detection means 20, and suspends the hook 12 during the extension / retraction operation of the boom 5.
Control signal output unit 21 for calculating and calculating the telescopic control valve control signal 21a and the winch control valve control signal 21b having a relationship necessary to maintain the constant value, and outputting them to the telescopic control valve 13 and the winch control valve 16, respectively. It is configured to include the following.

The hook suspension length holding device according to the present invention comprises:
Since the configuration of the control signal output unit 21 in the basic configuration described above has a feature, the following description will focus on this feature, and other configurations will be described with reference to FIGS. Invite.

FIG. 1 is a circuit diagram showing an embodiment of a hook hanging length holding device according to the present invention. In FIG. 1, a control signal output unit 2 in a hook hanging length holding device is shown.
In calculating and outputting the expansion / contraction control valve control signal 21a from the expansion / contraction command signal 19a from the expansion / contraction instruction unit 19, the expansion / contraction cylinders 6 and 7 are provided if the speed instruction values of the expansion / contraction instruction signal 19a from the expansion / contraction instruction unit 19 are the same. Is configured to shift and output the detection signal from the telescopic cylinder detecting means 20 so that the same boom telescopic speed can be obtained regardless of which one is in operation, and to transmit the winch control valve control signal 21b to the telescopic command means. Expansion / contraction command signal 19 from
It is configured to calculate and output from a.

Calculation output of telescopic control valve control signal 21a
About power

The control signal output section 21 outputs the expansion / contraction control signal 21 a from the expansion / contraction
In calculating and outputting the data from 9a, if the speed command value of the expansion / contraction command signal 19a from the expansion / contraction command means 19 is the same, the same boom expansion / contraction speed can be obtained regardless of which of the telescopic cylinders 6 and 7 is in operation. Cylinder detection means 20
The output is shifted according to the detection signal from the CPU.

More specifically, the expansion / contraction command signal 19a from the expansion / contraction instruction means 19 and the detection signal 20a from the expansion / contraction cylinder detecting means 20 are calculated and output from an expansion / contraction control valve control signal 21a inherent in the control signal output section 21. Take it into the unit 22. The fetched expansion / contraction command signal 19a includes information on the expansion / contraction direction and speed, and the detection signal 20a is
Is a signal capable of determining whether the region is a telescopic operation region by the telescopic cylinder 6 or a telescopic operation region by the telescopic cylinder 7.

The operation output unit 22 outputs the telescopic control valve 13 from the information on the speed contained in the telescopic command signal 19a.
And the amount of change (the amount of change from the neutral position)
An expansion / contraction control valve control signal 21a for switching the expansion / contraction control valve 13 according to the obtained switching amount is obtained. The required switching amount of the expansion / contraction control valve 13 increases / decreases according to the magnitude of the speed command value included in the expansion / contraction command signal 19a.

Here, the switching amount of the telescopic control valve 13 is calculated when the boom 5 is extended in the telescopic operation range by the telescopic cylinder 6, when the boom 5 is extended in the telescopic operation range by the telescopic cylinder 7, When the boom 5 is contracted in the telescopic operation range by the telescopic cylinder 6, and when the boom 5 is contracted in the telescopic operation range by the telescopic cylinder 7, the telescopic control valve control signal 21a is obtained in each of these cases.

Among the switching amounts of the expansion / contraction control valve 13 corresponding to the above, which are calculated by the arithmetic output section 22, the switching amount of the expansion / contraction control valve 13 when the boom 5 extends and extends in the expansion and contraction operation range of the telescopic cylinder 6 If the level of the speed command value included in the telescopic command signal 19a is the same between the boom 5 and the switching amount of the telescopic control valve 13 when the telescopic cylinder 7 performs the telescopic operation in the telescopic operation range, the same boom is used. The relationship is such that the elongation rate can be achieved. Further, the switching amount of the telescopic control valve 13 when the boom 5 is contracted in the telescopic operation range by the telescopic cylinder 6 and the switching of the telescopic control valve 13 when the boom 5 is contracted in the telescopic differential region by the telescopic cylinder 7. The amount is set so as to achieve the same boom reduction speed if the level of the speed command value included in the expansion / contraction command signal 19a is the same.

Further, the arithmetic and control unit 22 instructs whether the extension / contraction instruction signal 19a indicates extension of the boom 5 or contraction based on information on the extension / contraction direction included in the extension / contraction instruction signal 19a relating to the take-in. In addition to determining whether there is a telescopic cylinder, based on a detection signal 20a from the telescopic cylinder detecting means 20 relating to the loading, it is determined whether the telescopic operating area of the boom 5 is the telescopic operating area by the telescopic cylinder 6 or the telescopic operating area by the telescopic cylinder 7. to decide.

When the extension / contraction command signal 19a indicates extension and the detection signal 20a indicates the extension / contraction operation range of the extension / contraction cylinder 6, the extension / contraction control valve 13 (switching actuator of the extension / contraction switching valve 13) In response to this, the telescopic control valve control signal 2 for switching the telescopic control valve 13 to the boom 5 extension side to the switching amount calculated above.
1a is output. Also, the extension / contraction command signal 19a indicates extension and the detection signal 20a is
In this case, the expansion / contraction operation range is determined by the expansion / contraction control valve 13 (the actuator for switching the expansion / contraction control valve 13) to switch the expansion / contraction control valve 13 toward the boom 5 extension side to the switching amount calculated above. Control valve control signal 2
1a is output.

Further, when the expansion / contraction command signal 19a indicates a contraction and the detection signal 20a indicates the expansion / contraction operation range of the expansion / contraction cylinder 6, the expansion / contraction control valve 13 (an actuator for switching the expansion / contraction control valve 13). In response to this, the expansion / contraction control valve 13 outputs the expansion / contraction control valve control ear signal 21a for switching the expansion / contraction control valve 13 to the boom 5 reduction side to the switching amount calculated above. When the expansion / contraction command signal 19a indicates a contraction and the detection signal 20a indicates the expansion / contraction operation range of the expansion / contraction cylinder 7, the expansion / contraction control valve 13 (the switching actuator of the expansion / contraction control valve 13) is actuated. It outputs a telescopic control valve control signal 21a for switching the telescopic control valve 13 to the boom 5 reduction side to the switching amount calculated above.

As described above, when the control signal output section 21 outputs the expansion / contraction control valve control signal 21 a from the expansion / contraction command signal 19 a from the expansion / contraction instruction section 19 in the calculation output section 22, If the speed command value of the telescopic command signal 19a is the same, the telescopic cylinders 6, 7
Is shifted and output by a detection signal from the telescopic cylinder detecting means 20 so that the same boom telescopic speed is obtained irrespective of the operating state.

As a result, the boom 5 which expands and contracts by the expansion and contraction control valve control signal 21 a output from the control signal output unit 21 has the same speed command value included in the expansion and contraction command signal 19 a from the expansion and contraction command means 19. If there is, the extension speed or the contraction speed of the boom 5 does not fluctuate even if the telescopic cylinders 6 and 7 for extending and retracting the boom 5 change. The achieved extension speed or contraction speed of the boom 5 fluctuates depending only on the magnitude of the speed command value included in the extension / contraction command signal 19a from the extension / contraction command means 19 regardless of the change in the extension / contraction cylinders 6 and 7. . In other words, it changes as a function using only the speed command value included in the extension / contraction command signal 19a as a variable.

Of the winch control valve control signal 21b
Regarding the calculation output, the winch control valve control signal 21b is calculated and calculated from the expansion / contraction command signal 19a from the expansion / contraction command means 19.

More specifically, the expansion / contraction command signal 19a from the expansion / contraction instruction means 19 is taken into the operation output section 23 of the winch control valve 21b provided in the control signal output section 21. The received expansion / contraction command signal 19a includes information on the direction and speed of expansion / contraction. The operation calculation unit 23 calculates the switching amount of the winch control valve 16 (the switching amount from the neutral position) from the information on the speed (speed command value) included in the expansion / contraction command signal 19a.

Here, the calculation of the switching amount of the winch control valve 16 is performed separately when the boom 5 is extended and when the boom 5 is contracted. When the boom 5 is extended by the telescopic control valve control signal 21a output from the arithmetic output unit 22, the amount of switching of the winch control valve 16 during the extension operation of the boom 5 is set regardless of the extension operation. The winch control valve 16 required to maintain the suspension length L constant
Is the amount of switching in the unwinding direction (wire rope payout direction). In addition, the switching amount of the winch control valve 16 at the time of the reduction operation of the boom 5 is determined by the telescopic control valve control signal 21a output from the arithmetic output unit 22 described above.
Is the amount of switching of the winch control valve 16 in the winding direction (wire rope winding direction) required to maintain the hook suspension distance L constant regardless of the reducing operation.

As described above, the extension speed or the contraction speed of the boom 5 operated by the telescopic control valve control signal 21a output from the arithmetic output unit 22 is controlled by the telescopic command signal 19a.
And fluctuates as a function having only the speed command value included in. When the extension speed or the contraction speed of the boom 5 is determined as a function using only the speed command value included in the extension / contraction command signal 19a as a variable, the winch 10 (for the winch) required to keep the hook suspension length L constant. Obviously, the lowering or hoisting operation speed of the hydraulic motor 9) can be obtained as a function using only the speed command value included in the expansion / contraction command signal 19a as a variable.

[0070]

As described above, according to the hook hanging length holding device according to the present invention, the extension speed or the reduction speed of the boom 5 is the same if the speed command value of the expansion / contraction command means 19 relating to the operation is the same. For example, even if the telescopic cylinder for performing the telescopic operation of the boom 5 changes, the telescopic operation speed of the boom 5 does not change. Therefore, when operating the extension / contraction command means 19 to extend and retract the boom 5 while maintaining the hook suspension length L, the swing of the suspended load locked on the hook 12 is suppressed, and a safe crane operation is performed. You can do it.

[0071]

[Brief description of the drawings]

FIG. 1 is an explanatory view of a hook hanging length holding device according to the present invention.

FIG. 2 is an explanatory view of a crane to which a hook hanging length holding device according to the present invention is attached.

FIG. 3 is an explanatory diagram of a basic configuration of the present invention and a conventional hook suspension length holding device.

FIG. 4 is an explanatory view of a conventional hook length holding device.

[Explanation of symbols]

 1; crane, 2, 2; outrigger, 3; base, 4; post, 5; boom, 5a to 5d; boom section, 6; telescopic cylinder, 6a; extension operation side pressure oil chamber, 6b; 7; telescopic cylinder; 7a; hydraulic oil chamber on extension operation side; 7b; hydraulic oil chamber on reduction operation side; 8; hydraulic cylinder for winch; 9; hydraulic motor for winch; 10; winch; 11; wire rope; 12; hook; Control valve, 13a1; extension operation side pressure oil passage, 13a2; extension operation side pressure oil passage, 13b; reduction operation side pressure oil passage, 14; mechanical check valve, 15; mechanical check valve, 16; winch control valve, L; hook suspension Length; 17; operation lever; 18; operation lever; 19; telescopic command means; 19a; telescopic command signal; 20; telescopic cylinder detecting means; 21; the control signal output unit, 21a; expansion control valve control signals, 21b; winch control valve control signals, 22; operation output unit of the expansion control valve control signal 21a, 23; operation output unit of the winch control valve control signal 21b, or

Claims (1)

[Claims] A boom (5) in which distal boom sections (5b-5d) are sequentially inserted into a base end boom section (5a-5c) so as to be extendable and contractible, and are sequentially extended and retracted by hydraulic oil from a single telescopic control valve (13). And a plurality of telescopic cylinders 6 and 7 that perform telescopic operations of different boom sections, a winch that is provided on the base end side of the boom 5 and that operates to take up and unwind the wire rope 11 with hydraulic oil from a winch control valve 16. Boom 5 via wire rope 11
A hook hanging length holding device used for a crane provided with a hook 12 hung from a distal end portion, the expansion / contraction command means 19 for outputting an expansion / contraction command signal for instructing the expansion / contraction direction and speed of the boom 5, Telescopic cylinder 6,
7, the telescopic cylinder detecting means 20 for detecting which one is in the operating state, and the telescopic command signal 19a from the telescopic commanding means 19 and the detection signal 20a from the telescopic cylinder detecting means 20 are received, and the boom telescopic operation is performed. The telescopic control valve control signal 21a and the winch control valve control signal 21b having a relationship necessary to maintain the hanging distance L of the hook 12 constant during operation are calculated and calculated, and the telescopic control valve 13 and the winch control valve 16 are calculated. And a control signal output section for outputting the control signal output section 21a to the telescopic control valve control signal 21a.
Is calculated and output from the telescopic command signal 19a from the telescopic command means 19, if the speed command value of the telescopic command signal 19a from the telescopic command means 19 is the same, the telescopic cylinder 6,
7 is output by shifting with the detection signal 21a from the telescopic cylinder detecting means 20 so that the same boom telescopic speed can be obtained regardless of which one of the operating states is in operation. A hook suspension distance maintaining device configured to calculate and output from a telescopic command signal 19a from a command means 19.