JP2001048478A - Winch controlling method and winch controlling device for travelling crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily exact overhang/retracting operation while keeping a hook at a tip end portion of a boom member in a locking state, and to enable boom operation. SOLUTION: In this controlling method, under the condition in which a hook 9 is locked to a tip end portion of a boom member X, when the boom member X is operated in a direction increasing the wire 13 tension and the wire 13 is pulled out from a winch 15 accordingly, specified tension is added on the wire 13, and when the boom member X is operated in a direction decreasing the wire 13 tension, the wire 13 is wound in by the winch 15 with low torque and at a low speed. Consequently, the wire 13 tension is properly kept at the all time, which enables keeping a locking state of the hook 9 to the tip end portion of the boom member X due to the wire 13 tension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a winch control method and a winch control device for a mobile crane.

[0002]

2. Description of the Related Art In a mobile crane, particularly in a mobile crane in which a jib is stored sideways on a side of a boom and the jib is extended to the tip of the boom as required, There is a demand for simplifying the overhang / storage work by automatically performing the overhang / storage work.

On the other hand, in a mobile crane, there has conventionally been a demand that a hook hung by a wire from the end of a boom be held at the end of the boom in a locked state to enhance safety during non-operation. Yes, such a request
The same applies to a mobile crane with a jib in which a jib is attached to the tip of the boom.In such a case, the hook suspended from the tip of the jib by a wire in the storage position of the jib is used. It will be held in a locked state at the tip.

Therefore, in a mobile crane provided with a jib and holding a hook disposed on the jib side in a locked state at the tip of the jib, the operation of extending and storing the jib is automatically performed. If so, it is inevitable that the jib can be extended and stored while the hook is held at the tip of the jib in a locked state.

As one means for responding to such a demand, for example, as disclosed in Japanese Patent Application Laid-Open No. H8-12269, when the jib is extended and stored, the wire is arranged on the jib side to wind and unwind the wire. The winch is always
Operate to the winding side at low torque and low speed,
When the tension of the wire is increased with storage, the wire is pulled out by an external force against the winding force of the winch, while when the tension is reduced, the wire is wound by the winch, whereby the wire is wound. It is known that the tension is always kept constant so that the hook can be continuously held in a locked state during the operation of extending and storing the jib.

[0006]

However, according to the wire tension control method as in the above-mentioned known example, there are the following problems.

That is, in the conventional tension control method, when the operator selects the jib extension / retraction work, the tension control starts from that point in time regardless of whether the wire tension is actually changed or not. And this is overhanging
Since the configuration is maintained during the storing operation, (a) for example, even if the winch enters an abnormal operation state such as high torque and high speed winding, it is difficult to immediately stop the tension control and ensure safety. (B) For example, if the overhang / retraction operation is selected and the device is left for a long time, the tension control is maintained during that time, so the boom may be inadvertently inadvertently caused by the continuously applied wire tension. (C) Normally, at the time of jib overhanging work, as a preparatory work, the boom is appropriately extended to secure a space for swinging out the jib. If the extension speed of the boom is too fast, both the supply oil from the hydraulic pump to the hydraulic motor for driving the winch and the discharge oil from the hydraulic motor flow into the relief valve that reduces the winding force of the winch, and Exhaustion Since the amount of oil is large, the amount of oil flowing through the relief valve becomes excessive, and the set pressure increases due to the override characteristic of the relief valve.As a result, it becomes difficult to maintain the wire tension constant. And so on.

On the other hand, with the jib stored on the boom side,
Also in the boom work performed using a hook suspended by a wire from the tip of the boom, if the wire can be arranged on the jib in the storage position and the hook can be held in a locked state at the tip of the jib, Although it is convenient in terms of simplification of the extension and storage work of the jib, such a technique, including the above-mentioned known examples, has not been proposed yet. Therefore, conventionally, the jib-side wire is removed from the jib-side wire during the boom operation, and the jib-side wire is arranged on the jib-side extension when the jib is extended after the boom operation, and the hook provided at the tip thereof is provided. To the tip of the jib. For this reason, even if the jib overhanging / retracting work can be performed automatically, the advantage of this is diminished, and as a result, the workability of the entire mobile crane remains dissatisfied. Met.

Accordingly, the present invention provides a safe and easy operation for extending and storing the boom member while holding the hook at the tip of the boom member in a locked state. The main purpose is to make it possible to perform the boom work as it is.

[0010]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

In the first aspect of the present invention, the boom member X is mounted on the swivel 2 mounted on the vehicle 1 and the boom member X is connected to the hydraulic drive winch 15 disposed on the swivel 2 side by the wire 13 fed out. In a mobile crane in which the hook 9 is suspended from the tip of X and the wire 13 is wound by the winch 15 to lock and hold the hook 9 at the tip of the boom member X. When the boom member X is operated in a direction in which the tension of the wire 13 increases in a state where the hook 9 is locked at the tip of the boom member X, the wire 13 pulled out from the winch 15
The operation of the winch 15 is controlled such that when the boom member X is operated in a direction in which the tension of the wire 13 decreases, the wire 13 is wound at a low torque and at a low speed. It is characterized by:

In the second aspect of the present invention, the boom member X is attached to the swivel 2 mounted on the vehicle 1, and the boom member X is connected to the hydraulic drive winch 15 disposed on the swivel 2 by a wire 13 which is fed out. In a mobile crane in which the hook 9 is suspended from the tip of X and the wire 13 is wound by the winch 15 to lock and hold the hook 9 at the tip of the boom member X. When the boom member X is operated in a direction in which the tension of the wire 13 changes while the hook 9 is locked at the tip of the boom member X, the wire 13 is moved at a low torque and at a low speed. It is characterized in that the operation of the winch 15 is controlled so as to be involved in the winch 15.

In the third aspect of the present invention, the boom member X is attached to the swivel 2 mounted on the vehicle 1 and the wire 13 is fed out from the hydraulically driven winch 15 with the brake 59 disposed on the swivel 2 side. A mobile crane in which a hook 9 is hung from the tip of the boom member X, and the wire 13 is wound by the winch 15 so that the hook 9 is locked and held at the tip of the boom member X. , A hook engagement detecting means U for detecting a state in which the hook 9 is engaged with the tip of the boom member X, and whether the operation direction of the boom member X is a direction in which the tension of the wire 13 is increased or a direction in which the tension is decreased. And a first brake releasing means for releasing the brake 59 independently of the operation of the winch 15 A second brake releasing means R for releasing the brake 59 in association with the operation of the winch 15, and applying a predetermined tension to the wire 13 when the wire 13 is pulled out of the winch 15 by an external force. Tension applying means T, and the winch 15
With low torque and low torque
When the locked state is detected by the low-speed winding means P and the hook locking detecting means U and the operation in the tension increasing direction is detected by the operating direction detecting means V, the first brake releasing means Q and the tension While outputting an operation command together with the applying means T, when the hook locking detecting means U detects a locked state and the operating direction detecting means V detects an operation in a tension decreasing direction, the second brake is output. It is characterized by comprising a releasing means R and a control means W for outputting an operation command to the low torque / low speed winding means P.

In the fourth invention of the present application, the boom member X is mounted on the swivel 2 mounted on the vehicle 1 and the wire 13 is fed out from the hydraulically driven winch 15 with the brake 59 disposed on the swivel 2 side. A mobile crane in which a hook 9 is hung from the tip of the boom member X, and the wire 13 is wound by the winch 15 so that the hook 9 is locked and held at the tip of the boom member X. And a hook engagement detecting means U for detecting a state in which the hook 9 is engaged with the tip of the boom member X, and a state in which the boom member X is operated in a direction in which the tension of the wire 13 changes. Operating direction detecting means V for detecting, brake releasing means S for releasing the brake 59 in relation to the operation of the winch 15; The low-torque / low-speed winding means P for winding the punch 15 at a low torque and at a low speed, the hooked state detecting means U detects the locked state, and the operation direction detecting means V controls the operation in the tension change direction. A control means W for outputting an operation command to both the brake releasing means S and the low torque / low speed winding means P when detected is provided.

In the fifth invention of the present application, the third or fourth aspect
In the winch control device for a mobile crane according to the present invention, the boom member X needs to be stored and arranged on the side of the boom 3 and the telescopic boom 3 attached to the swivel base 2 so as to be able to move up and down. According to the boom 3 above
And the wire 13 is suspended from the distal end of the jib 4 in both the retracted position and the extended position of the jib 4 while the wire 13 is attached to the distal end of the jib 4 in an extended state. The hook 9 attached to the sub-wire 13 is configured to be locked and held at the tip of the jib 4. According to a sixth invention of the present application, in the winch control device for a mobile crane according to the third, fourth, or fifth invention, the low torque / low speed winding means P is provided.
A first low-pressure relief valve 71 interposed in an oil passage from a hydraulic pump 62 disposed in front of the main operation valve 65 of the winch 15; a hydraulic motor 60 for driving the winch 15; Low pressure relief valve 8 interposed in oil passage 126 branched from the oil passage between
5 is provided.

According to a seventh aspect of the present invention, in the winch control apparatus for a mobile crane according to the sixth aspect, the second low-pressure relief valve 85 is configured so that its set pressure can be switched in two stages. It is characterized by.

[0017]

According to the present invention, the following effects can be obtained by adopting such a configuration.

According to the winch control method for the mobile crane according to the first invention of the present application, the boom member X is connected to the wire 13 while the hook 9 is locked at the tip of the boom member X. When the wire 13 is pulled out from the winch 15 in the direction in which the tension of the wire 13 is increased,
When the boom member X is operated in the direction in which the tension of the wire 13 decreases, the winch 15
Are caught at low torque and at low speed.

As a result, irrespective of the operation direction of the boom member X, the wire 13 is always maintained at an appropriate tension without excessive tension being applied or slackened (that is, realizing tension control). The locking state of the hook 9 with respect to the tip of the boom member X due to the tension of the wire 13 is maintained, and accidental dropping of the hook 9 during work is prevented beforehand and surely, and safety in the workplace is reduced. Will be secured.

Further, in this case, the tension control of the wire 13 is executed on the assumption that the operation of the boom member X has been performed by the operator, in other words, that the operator is currently performing the operation. Therefore, for example, when the operation of the winch 15 becomes abnormal, the operator can immediately stop the operation (ie, stop the tension control of the wire 13) to avoid danger, and operate the mobile crane. The above high security will be ensured. Further, when the operator stops operating the boom member X, the tension control is also stopped at the same time, so that the boom member X is inadvertently contracted or raised by receiving the tension of the wire 13 during non-operation as in the related art. Therefore, high reliability is ensured in keeping the posture of the boom member X.

In the winch control method according to the present invention, the operating direction of the boom member X is set to
It is assumed that it is possible to detect whether the direction of the tension increases or decreases, and that the operation is a single operation and that the operation is continued for a predetermined period (for example, even if the operation direction can be detected, When the operation direction changes in a short period of time, the tension control of the wire 13 is not effective), and therefore, the working state adapted to such requirements, for example, when the boom member X is connected to the boom 3 and the jib 4, In a mobile crane having a jib and having a configuration in which the hook 9 is locked and held by the wire 13 at the tip of the jib 4, the hook 9 is locked. It is particularly suitable as a winch control method in a working state in which the jib 4 is extended or stored as it is.

According to the winch control method for the mobile crane according to the second invention of the present application, the boom member X is connected to the wire 13 while the hook 9 is locked at the tip of the boom member X. When the wire 13 is operated in the direction in which the tension changes, the winch 15 causes the wire 13 to be wound at a low torque and at a low speed. Therefore,
For example, when the operation is performed in a direction in which the tension of the wire 13 is increased, the wire 13 is pulled out against the winding force of the winch 15, and in a direction in which the tension of the wire 13 is reduced. In the case of the operation, the wire 13 is wound around the winch 15 at a low torque and a low speed, so that the tension is properly maintained (that is, tension control is realized). Of the boom member X is maintained, and the careless dropping of the hook 9 during the work is prevented beforehand and surely, so that safety in the workplace is secured.

Further, in this case, the tension control of the wire 13 is executed on the assumption that the operation of the boom member X has been performed by the operator, in other words, that the operator is currently performing the operation. Therefore, for example, when the operation of the winch 15 becomes abnormal, the operator can immediately stop the operation (ie, stop the tension control of the wire 13) to avoid danger, and operate the mobile crane. The above high security will be ensured. Further, when the operator stops operating the boom member X, the tension control is also stopped at the same time, so that the boom member X is inadvertently contracted or raised by receiving the tension of the wire 13 during non-operation as in the related art. Therefore, high reliability is ensured in keeping the posture of the boom member X.

In the winch control method according to the present invention, the operating direction of the boom member X is set to
If the operation can be detected in the direction in which the tension changes, it is applicable even if the operation direction changes in a short time. For example, the boom member X is composed of the boom 3 and the jib 4. Boom with a jib, wherein the jib 4
Is stored on the side of the boom 3 and another wire different from the wire 13 is hung from the tip of the boom 3 while the hook 9 is locked at the tip of the jib 4. The wire 1 during so-called “during boom work”
This is particularly suitable as a winch control method for the three sides.

According to the winch control device for the mobile crane according to the third invention of the present application, the hook locking detecting means U detects the locking state, and the operation direction detecting means V controls the operation in the tension increasing direction. When the detection is detected, the control means W outputs an operation command signal to the brake releasing means Q and the tension generating means T to release the brake 59 and the winch 1
A predetermined tension is applied to the wire 13 pulled out from the wire 5 by an external force. On the other hand, when the hook lock detecting means U detects the locked state and the operation direction detecting means V detects the operation in the tension decreasing direction, the control means W sends the second brake release means R
And an operation command is output to the low-torque low-speed winding means P, and the wire 13
Get caught at low speed.

As a result, irrespective of the operating direction of the boom member X, the wire 13 is always maintained at an appropriate tension without excessive tension being applied or slackened (that is, realization of tension control). In this state, the hook 9 is held in a state of being locked to the distal end of the boom member X by the tension of the wire 13, and accidental dropping of the hook 9 during work is prevented beforehand and reliably, and safety in the workplace is ensured. Will be secured.

Further, in this case, the tension control of the wire 13 by the control means W is performed when the hook 9 is in the locked state and the operator operates the boom member X, in other words, Since the operation is performed on the assumption that the operator is actually performing an operation, for example, if the operation of the winch 15 becomes abnormal, the operator immediately stops the operation (that is, the wire 1).
3) to avoid danger.
High safety in operation of the mobile crane will be ensured. Further, when the operator stops operating the boom member X, the tension control is also stopped at the same time, so that the boom member X is inadvertently contracted or raised by receiving the tension of the wire 13 during non-operation as in the related art. Therefore, high reliability is ensured in keeping the posture of the boom member X.

As described above, the winch control device according to the present invention can detect whether the operation direction of the boom member X is the direction in which the tension of the wire 13 increases or decreases, and the operation is simple. It is assumed that one operation is performed and that the operation is continued for a predetermined period (for example,
Even if the operation direction can be detected, if the operation direction changes in a short period of time, the tension control of the wire 13 will not be effective), and therefore, a work state adapted to such requirements, for example, the boom member X is a boom with a jib constituted by a boom 3 and a jib 4, and the hook 9 is locked and held at the tip of the jib 4 by the wire 13. This is a winch control device suitable for a working state in which the jib 4 is extended or retracted while the hook 9 is kept locked.

According to the winch control device for a mobile crane according to the fourth invention of the present application, the hook locking detecting means U detects the locking state, and the operation direction detecting means V controls the operation in the tension change direction. When detected,
An operation command is output from the control means W to both the brake release means S and the low torque / low speed winding means P, and the wire 13 is wound around the winch 15 at low torque / low speed. Therefore, for example, when the operation is performed in a direction in which the tension of the wire 13 increases, the wire 13 is pulled out against the winding force of the winch 15, and the tension of the wire 13 decreases. When the operation is in the direction, the wire 13 is wound around the winch 15 at a low torque and a low speed, so that the tension is properly maintained (that is, the tension control is realized).
The hook 9 is maintained in a locked state with respect to the tip of the boom member X due to the tension of the hook 9, and accidental dropping of the hook 9 during work is prevented beforehand and surely, and safety in the workplace is secured. Will be.

Further, in this case, the tension control of the wire 13 is performed when the hook 9 is in the locked state and the operator operates the boom member X.
In other words, since the operation is performed on the assumption that the operator is currently performing an operation, for example, when the operation of the winch 15 becomes abnormal, the operator immediately stops the operation (ie, the wire 13). Danger can be avoided by stopping the tension control of the mobile crane, and high safety in operation of the mobile crane can be secured. Further, when the operator stops operating the boom member X, the tension control is also stopped at the same time, so that the boom member X is inadvertently contracted or raised by receiving the tension of the wire 13 during non-operation as in the related art. Therefore, high reliability is ensured in keeping the posture of the boom member X.

In the winch control device according to the present invention, the operating direction of the boom member X is set to
If the operation can be detected in the direction in which the tension changes, it is applicable even if the operation direction changes in a short time. For example, the boom member X is composed of the boom 3 and the jib 4. Boom with a jib, wherein the jib 4
Is stored on the side of the boom 3 and another wire different from the wire 13 is hung from the tip of the boom 3 while the hook 9 is locked at the tip of the jib 4. It is particularly suitable as a control device for the winch 15 during the so-called “during boom operation”.

According to the winch control device for a mobile crane according to the fifth invention of the present application, the following specific effects can be obtained in addition to the effects described above or above. That is, according to the present invention, the boom member X is attached to the swivel base 2 so as to be able to move up and down.
And a jib 4 housed and arranged on the side of the boom 3 and attached to the tip of the boom 3 in an extended state as necessary, while the wire 13 connects the jib 4 to the jib 4. The jib 4 in both the retracted position and the extended position.
The hook 9 hung from the distal end of the jib 4 and attached to the sub-wire 13 is locked and held at the distal end of the jib 4. Maintaining the locked state of the jib 4 at the distal end thereof is ensured not only at the time of extending and storing the jib 4 but also at the time of the boom operation with the jib 4 stored therein. Further, higher workability and operability are ensured as compared with the case where the tension control of the wire 13 is performed only at the time of extending and storing the jib 4.

Also, the hook 9 is always locked at the tip of the jib 4 when the jib 4 is overhanging and retracting and during the boom operation. The work of attaching and detaching the wire 13 during and after the work is unnecessary, and the workability of the entire mobile crane is improved.

According to the winch control device for a mobile crane according to the sixth aspect of the present invention, the following specific effects can be obtained in addition to the effects described above or above. That is, according to the present invention, as the low-torque / low-speed winding means P, a first oil passage provided from the hydraulic pump 62 disposed in front of the main operation valve 65 of the winch 15 is provided.
And a second low-pressure relief valve 85 interposed in an oil passage 126 branched from an oil passage between the hydraulic motor 60 for driving the winch 15 and the counterbalance valve 52. For example, even if one of the two relief valves 71 and 85 malfunctions, the winch 1 is operated by the other relief valve.
5 is secured, and the winch 15
In low-torque, low-speed winding.

Further, when the wire 13 is pulled out from the winch 15 by an external force and given a predetermined tension, the winch 15 is rotated by the tension of the wire 13 and the hydraulic motor 60 performs a pumping operation. No hydraulic pressure is supplied from the hydraulic pump, and only the discharged oil from the hydraulic motor 60 flows through the second low-pressure relief valve 85. Therefore, for example, as in the conventional case, the wire 13 is pulled out of the winch 15 against the winding force while the winch 15 is being wound and operated.
The amount of oil flowing through the second low-pressure relief valve 85 is smaller than when both the supply oil from the hydraulic pump and the discharge oil from the hydraulic motor 60 flow through the second low-pressure relief valve 85. Since the influence of the override characteristic of the second low-pressure relief valve 85 can be reduced, the set pressure of the second low-pressure relief valve 85 is appropriately maintained, and as a result, the tension control of the wire 13 is performed more accurately. become.

According to the winch control device for a mobile crane according to the seventh aspect of the present invention, the following specific effects can be obtained in addition to the effects described above. That is, according to the present invention, the set pressure of the second low-pressure relief valve 85 is configured to be switchable in two stages.
When the winch 15 is driven by the rotational force of the hydraulic motor 60, the set pressure of the second low-pressure relief valve 85 is set higher, and the hydraulic pressure is increased by the winch 15 which is rotated as the wire 13 is pulled out. When the motor 60 is driven to perform a pumping operation, the set pressure of the second low-pressure relief valve 85 is set to a lower value, so that the tension of the wire 13 is the same. When the motor 60 performs the motor action, the mechanical efficiency set pressure needs to be increased, and when the hydraulic motor 60 performs the pump action, the mechanical efficiency set pressure needs to be reduced. The mechanical efficiency between the two is compensated by providing a difference in the supplied oil pressure so as to act in the opposite manner, and the tension when the wire 13 is pulled out and the wire 1
3 becomes as close as possible to the tension when the wire 3 is involved, and the accuracy of the tension control of the wire 13 is improved accordingly.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on preferred embodiments.

FIGS. 1 and 2 show a movable crane Z (retracted attitude) to which the winch control method and the winch control device according to the present invention are applied.

In this mobile crane Z, a boom 3 described below is mounted on a swivel 2 that is rotatably mounted on a vehicle 1 via a boom pivot 10 so as to be able to move up and down. Is provided so as to protrude from the tip of the boom 3 or to be stored in a laterally hugging state on the side of the boom 3 (in this embodiment, the boom 3 and the jib 4 are referred to as “boom member” in the claims. X ").

The boom 3 is a three-stage telescopic boom having a base boom 3A, an intermediate boom 3B and a tip boom 3C, and a boom head 3 is provided at the tip of the tip boom 3C.
D is provided. The boom 3 is driven to expand and contract by a built-in telescopic hydraulic cylinder and a telescopic wire (not shown) interlocked with the built-in telescopic hydraulic cylinder. Driven. Further, a pair of left and right and upper and lower boom-side pin receiving holes 17, 1 into which connecting pins 19, 19 (see FIG. 1) are automatically inserted and removed are provided at the front end side of the boom head 3D.
7, ... are provided.

A pair of right and left base sheaves 23, 24 are provided on the swivel 2 side so as to be located at the base end of the boom 3, that is, behind the base end 3Aa of the base boom 3A.
Is provided. And each of these base end sheaves 2
3 and 24, the main wire 12 pulled out from the main winch 14 disposed on the swivel 2 side and the other proximal end sheave 24
The sub-wire 13 pulled out from the sub-winch 15 (corresponding to the "winch" in the claims)
(Corresponding to the “wire” in the claims). A pair of left and right guide sheaves 25 and 26 are arranged on the upper surface near the distal end 3Ab of the base end boom 3A so as to correspond to the pair of left and right base end sheaves 23 and 24, respectively. Further, at the position near the upper surface of the boom head 3D, the front sheave 2 is provided.
A main hook 8 is attached to the main wire 12 that is pulled out below the boom via the distal sheave 27.

The jib 4 has a base jib 4A and an intermediate jib 4A.
B and a three-stage telescopic jib with a tip jib 4C,
It is driven to expand and contract by a built-in telescopic hydraulic cylinder and a telescopic wire (not shown) interlocked with the hydraulic cylinder. The base end of the jib 4, that is, the base end 4 of the base jib 4 </ b> A.
Aa is tiltably connected to the tip of the jib base 5 described below via a jib pivot 20 and is tilt-driven by a tilt hydraulic cylinder 7 disposed between the jib base 5 and the jib base 5. . Further, a guide sheave 29 is provided on the upper surface side of the distal end portion 4Ab of the base jib 4A, and a distal sheave 30 is provided on the upper end portion of the jib head 4D. A hook locking arm 22 is swingably attached to the lower end of the jib head 4D via a pivot pin 32. The hook locking arm 22 is attached to the sub-wire 13 above. The locked sub hook 9 can be locked (FIG. 2 shows the locked state of the sub hook 9).

The jib base 5 serves as a member for attaching the jib 4 to the boom 3 side. As described above, the jib base 5 is attached to the distal end of the jib 4 via the jib pivot 20. Are connected so as to be tiltable, and one end of the tilt hydraulic cylinder 7 is connected to a lower end thereof.

The base end of the jib base 5 is provided with a pair of left and right and upper and lower jib side pin receiving members so that the boom side pin receiving holes 17, 17,... Holes 18, 18, ... are provided. Therefore, as shown in FIG. 2, the jib base 5 has one boom-side pin receiving holes 17 on the boom 3 side and one jib-side pin receiving holes 18 on the jib base 5 side. And the connecting pin 19 is inserted and arranged therein so that the connecting pin 19 can be rotated about the connecting pin 19, and as shown in FIG. And the connecting pin 1
The posture can be changed between the "extended posture" (see FIG. 7) swinging out toward the front of the boom with the center 9 as the center. In this “extended posture”, the connecting pin 1 is inserted into the other boom-side pin receiving holes 17 on the boom 3 side and the other jib-side pin receiving holes 18 on the jib base 5 side.
The jib base 5 is fixed to the boom 3 side by inserting the jig 9.

Since the jib base 5 and the jib 4 are always connected as described above, the jib base 5
The “retracted posture” and “extended posture” of the jib 4
The “storage posture” and the “extended posture” are the same.
The posture change between the "storage posture" and the "extended posture" is performed by the expansion and contraction movement of the swing hydraulic cylinder 16 disposed between the jib base 5 and the boom head 3D.

Further, at the upper position near one of the jib side pin receiving holes 18 of the jib base 5, a turning back is provided with its rotation axis oriented in a direction substantially perpendicular to the turning surface of the jib base 5. A horizontal sheave 28 is provided. An intermediate sheave 31 is provided on the upper surface side of the tip of the jib base 5.

In FIGS. 1 and 2, reference numeral 11 denotes a cabin arranged on the swivel 2 side, and 21 denotes a jib 4.
Is a jib fixture for fixing to the boom 3 side in the "retracted posture", and reference numeral 50 denotes a cable reel arranged on the base end boom 3A side.

The overall structure of the mobile crane Z has been described above.

In the mobile crane Z, the main wire 12 of the main wire 12 and the sub-wire 13 is pulled out from the main winch 14 and then is moved from the base sheave 23 to the guide sheave 25. → The boom 3 is taken out from the boom head 3D of the boom 3 downward through the distal end sheave 27, and the main hook 8 is attached thereto. At the time of the boom work, the work is performed using the main wire 12 and the main hook 8 and In a non-working posture of the mobile crane Z (for example, a traveling movement posture; the posture of FIG. 1), the main hook 8 is fixed to the vehicle 1 side.

On the other hand, as shown in FIG. 7, the sub wire 13 connects the jib 4 to the boom head 3 of the boom 3.
1 and 8, the sub winch is stored in the "retracted position" in which the jib 4 is stored on the side of the boom 3, as shown in FIGS. 15 is pulled out from the jib 4 to the jib head 4D side, and the path is slightly different between the "storage posture" and the "extended posture". That is, in the “storage posture”, as shown in FIG.
After being pulled out from the sub winch 15, the jib head 4D is taken out from the jib head 4D through the base sheave 24 → guide sheave 26 → turned horizontal sheave 28 → guide sheave 29 → tip sheave 30. On the other hand, in the “extended posture”, the sub-wire 13 is pulled out from the sub winch 15 as shown in FIG.
Base sheave 24 → guide sheave 26 → intermediate sheave 31
The guide sheave 29 is taken out from the jib head 4D through the distal sheave 30.

Further, the mobile crane Z of this embodiment
In FIG. 7, as shown in FIG. 7, the jib 4 is extended and attached to the tip of the boom 3, the sub-wire 13 is pulled out from the tip of the jib 4, and the sub-hook 9 attached to the jib 4 is used. "Jib work" to carry out hanging load work
As shown in FIG. 8, the main hook 8 attached to the main wire 12 pulled out from the tip of the boom 3 is used while the jib 4 is stored on the side of the boom 3. "Boom work" to carry out lifting work
And two work modes can be selected.

In this embodiment,
The sub-hook 9 attached to the sub-wire 13 is in all crane states except during the jib operation, that is, “when the mobile crane Z is not operating” and “when the boom is operating”.
In both the “at the time of setting the storage posture” and the “at the time of the jib extension / retention work” described below,
The sub-hook 9 attached to the tip of the head is locked to the jib head 4D via the hook locking arm 22 and is maintained.

Here, the "locked state" of the sub-hook 9
As shown in FIG. 1, as shown in FIG. 1, the sub-wire 13 is wound by the sub-winch 15 to make it overwound, and the tension of the sub-wire 13 causes the sub-hook 9 to be integrated with the hook-locking arm 22. The jib 4 is rotated and stored on the lower surface of the jib 4.
Therefore, in order to continuously maintain the “locked state” of the sub hook 9 in both “during the boom operation” and “during the jib extension / retraction operation”, the tension of the sub wire 13 is always set to the predetermined tension. It is necessary to hold.

However, for example, the mobile crane Z
Even if the sub-hook 9 is set to the "locked state" by adjusting the tension of the sub-wire 13 in the "retracted posture" during non-working, the tension of the sub-wire 13 is not changed as described below. The operation is changed in accordance with the operation at the time (i.e., the operation on the boom 3 side) and the operation at the "during the jib extension / retraction work" (i.e., the operation of the boom 3 and the jib 4). In order to maintain the “locked state” of the sub hook 9 by keeping the tension of the sub wire 13 constant regardless of each operation,
It is necessary to control the tension of the sub wire 13 by controlling the operation of the sub winch 15. From this viewpoint, the present invention controls the tension of the sub-wire 13 so as to maintain the “locked state” of the sub-hook 9 in both “during the boom operation” and “during the jib extension / retraction operation”. Is the greatest feature, and in order to realize this, various configurations as described later are adopted.

Here, the sub hook 9 is in the "locked state".
In the state set in the above, the sub-wire 1
The operation that leads to an increase or decrease in the tension of No. 3 will be described below.

First, the operation at the time of “boom operation” is performed. At the time of “boom operation”, as shown in FIG.
With the jib 4 stored in the side of the boom 3, the boom 3 is extended and retracted and raised and lowered, and the main wire 12 is wound in and out by the main winch 14 so that the main boom 3 is moved from the boom head 3 </ b> D of the boom 3. This is a case where the lifting work is performed using the main hook 8 suspended via the wire 12. In this case,
The jib 4 is separated from the boom 3 and is held on the base end boom 3A side.

Therefore, of the operations during the “boom operation”, the raising operation of the boom 3 and the main winch 14
The operation of removing the suspended load to the ground by the unwinding operation described above appears as a decrease in the tension of the sub-wire 13. On the other hand, the bending operation of the boom 3 and the bending deformation of the boom 3 when the suspended load is grounded by the winding operation of the main winch 14 appear as a change in the tension of the sub-wire 13.

On the other hand, "when the jib is extended and stored"
FIG. 9 to FIG. 1 show the relationship between the operation at the time of extension and storage and the change in the tension of the sub-wire 13.
This will be described with reference to the “extension work procedure” shown in FIG.

When the jib 4 is to be extended from the non-working posture shown in FIG. 1, first, the jib base 5 is moved to the boom head 3D side of the boom 3 by the connecting pin 19 in this posture. connect. In addition, before and after the connection of the jib base 5 to the boom head 3D side, the sub-wire 13 is connected to the swivel base 2 via the folded horizontal sheave 28.
As described above, the sub hook 9 is pulled out from the sub wire 13 on the side toward the jib head 4D, and the sub hook 9 provided at the end of the sub wire 13 is in the "locked state".

Thereafter, as shown in FIG. 9, the boom 3 is appropriately raised, and the raising of the boom 3 appears as a decrease in the tension of the sub-wire 13. In addition, jib 4
At the time of the storing operation, the boom 3 is made to lie down, contrary to the above. In this case, the buckling of the boom 3 appears as an increase in the tension of the sub-wire 13.

Next, as shown in FIG.
Is extended by a predetermined amount to secure a space for swinging down the jib 4 below the boom 3. In this case, the extension of the boom 3 appears as an increase in the tension of the sub-wire 13. At the time of storing the jib 4,
The boom 3 will be reduced, and in this case,
The reduction of the boom 3 appears as a decrease in the tension of the sub-wire 13.

Next, as shown in FIG. 11, the tilt hydraulic cylinder 7 is reduced, and the jib 4 is swung downward. In this case, since the sub-wire 13 is hung around the intermediate sheave 31 with the downward swing of the jib 4, the downward swing is performed by the sub-wire 13.
Appears as an increase in the tension of When the jib 4 is retracted, the jib 4 is pulled up, contrary to the above. In this case, the pulling up of the jib 4 appears as a decrease in the tension of the sub-wire 13.

Next, as shown by a solid line in FIG. 12, the jib base 5 is turned forward from the side of the boom 3 integrally with the jib 4 by the swing hydraulic cylinder 16. In this case, the reversal of the jib 4 and the like is accompanied by a decrease in the amount of the sub-wire 13 wound around the folded horizontal sheave 28, and thus appears as a decrease in the tension of the sub-wire 13. When the jib 4 is stored, the jib 4 and the like are reversed from the tip end side of the boom 3 to the side.
3 as an increase in tension.

Next, as shown by a chain line in FIG. 12, the tilt hydraulic cylinder 7 is extended to tilt the jib 4 upward with respect to the jib base 5, and the tilt is moved to the front side of the boom 3. Overhang. In this case, the upward tilt of the jib 4 appears as a decrease in the tension of the sub-wire 13. When the jib 4 is stored, the jib 4 is tilted downward, contrary to the above, and the downward tilt appears as an increase in the tension of the sub-wire 13.

The above is the procedure for overhanging the jib 4 (and
Storage procedure).

As described above, the tension of the sub-wire 13 changes in the increasing direction or the decreasing direction with each operation of the "boom operation" and the "jib extension / retraction operation". In order to always maintain the tension properly and always maintain the “locked state” of the sub hook 9, tension control corresponding to a tension change based on each operation, that is, operation control of the sub winch 15 is required. It is what becomes.

Hereinafter, the operation control of the sub winch 15 for maintaining the “locked state” of the sub hook 9 will be specifically described.

First, FIG. 3 shows a system configuration of a winch control device for controlling the operation of the sub winch 15. In FIG. 3, reference numeral 40 denotes a controller which plays a central role in control (claims). (Corresponding to “control means W” in FIG. 3), and detection information is input to the controller 40 from various detectors described below.

First, on the boom 3 side, a main hook overwind detector 4 for detecting an overwound state of the main hook 8 is provided.
1 and a jib storage detector for detecting that the jib 4 is stored on the side of the boom 3, in other words, that the jib 4 is fixed to the boom 3 by the jib fixture 21. 42 and the crane operation, that is, the boom 3
The crane operation detector 43 (corresponding to the "operation direction detecting means V" in the claims) for detecting the presence / absence of the up / down and expansion / contraction operations and the operation of the main winch 14 and the sub winch 15 Brake 59 described later
(See FIG. 4) Brake release detector 44 for detecting release
And a winch operating pressure detector 45 for detecting the operating pressure of the sub winch 15. Detection information from each of these detectors is input to the controller 40.

On the jib 4 side, a subhook overwind detector 46 (corresponding to “hook engagement detecting means U” in claims) for detecting an overwound state of the subhook 9 is provided. A jib state detector 47 for detecting the state of the jib 4, that is, whether the jib 4 is in the "retracted posture" or "extended posture", and the tilt position of the jib 4, etc. And a hook lock detector 48 for detecting whether or not the sub hook 9 is in a "locked state" with respect to the jib head 4D (claims). (Corresponding to “hook engagement detecting means U”).

The detection information of the sub-hook overwind detector 46 is transmitted via the cable reel 50, and the detection information of the jib state detector 47 and the hook engagement detector 48 are transmitted via the transmitter 49 and the cable reel 50. Are input to the controller 40. In this embodiment, as described above, the main hook overwind detector 41 and the sub hook overwind detector 46 are arranged as separate systems. With this configuration, the “boom operation” in which the sub-hook 9 is locked to the tip of the jib 4 in the retracted posture as described above, and the load operation is performed by the boom 3 in this state, is possible. It is what becomes. That is, for example, when the main hook overwind detector 41 and the jib state detector 47 are arranged in the same system as in the related art, for example, the subwire 13 is overwound and the subhook 9 "Stopped"
It is not possible to determine whether this overwound is the sub-wire 13 or the main wire 12,
This is because, in some cases, the operation of the boom 3 acting on the overwinding side of the main wire 12, for example, a situation in which the falling operation cannot be performed may occur, and in order to prevent such a situation from occurring. Is required to remove the jib state detector 47 in advance.

On the other hand, the controller 40 controls the low-torque / low-speed winding means P, the first brake releasing means Q, the second brake releasing means R, the brake releasing means S, Control signals are output to the means T, the operation stopping means 36, and the hook locking confirmation means 37, respectively. By operating these means based on the control signal from the controller 40, the tension control of the sub-wire 13 through the operation control of the sub-winch 15 is realized. The state is maintained.

Of the above means, the low torque / low speed winding means P, the first brake releasing means Q, the second brake releasing means R, the brake releasing means S, the tension applying means T, and the operation stopping means 36 Each of the means is constituted by a hydraulic control member in a hydraulic circuit as described later, and the hook engagement confirming means 37 is constituted by a buzzer, an indicator lamp and the like arranged in the cabin 11.

Next, the configuration of the hydraulic circuit centering on the operation of the sub winch 15 will be described with reference to FIG.

In the figure, reference numeral 61 denotes a hydraulic pump for supplying pilot hydraulic pressure. The hydraulic pressure from the hydraulic pump 61 (that is, the pilot hydraulic pressure) is supplied via a hydraulic passage 111 to a turning operation valve 74 and a telescopic operation valve 75. And the electromagnetic switching valve 72 for automatic winding,
Are supplied to the sub winch operation valve 76, the main winch operation valve 77, and the undulation operation valve 78, respectively.

The expansion / contraction operation valve 75 is configured to selectively perform expansion / contraction operation of both the boom 3 and the jib 4 by operating a switching mechanism (not shown). Pressure switches 91 and 92 are provided in the passage 131, and the oil passages 130 and 1 are respectively provided.
An oil passage 122 is connected to both of the valves 31 via a shuttle valve 83.

The up / down operation valve 78 is configured to selectively perform up / down operation of the boom 3 and tilt operation of the jib 4 by each operation of a switching mechanism (not shown) in addition to the electromagnetic switching valve 79. The tilting side (and lower tilt side) oil path 132 and the raising side (and upper tilt side) oil path 13
3 are provided with pressure switches 97 and 98, respectively, and an oil passage 134 branches off from the oil passage 138 on the falling side (and the lower tilt side). And this oil passage 13
The oil passage 4 and the oil passage 122 are selectively connected to the oil passage oil passage 121 via the shuttle valve 82 so that a pilot oil pressure can be supplied to the electromagnetic switching valve 73 for releasing the brake.

The electromagnetic switching valve 73 is connected to an oil passage 116.
Is connected to the shuttle valve 80 via the. On the other hand, each of the oil passages 12 on the discharge side of the sub-winch
An oil passage 135 branched from 3, 124 and extending via the shuttle valve 68 is also connected to the shuttle valve 80. Therefore, the pilot oil pressure from the oil passage 116 and the pilot oil pressure from the oil passage 135 selectively
0 to the pilot port of the switching valve 84,
The switching valve 84 is turned on. The switching valve 84
Is operated in response to the pilot hydraulic pressure, and supplies the hydraulic pressure from the hydraulic pump 63 for supplying the brake release hydraulic pressure to the release oil chamber of the brake 59 of the sub winch 15 through the oil passage 125 to release the brake 59 and release the brake. The rotation of the sub winch 15 is enabled. In this case, the detection that the brake 59 is released is performed by the pressure switch 88 provided in the oil passage 125, and therefore, the pressure switch 88 corresponds to the brake release detector 44 in FIG. become.

The pressure switches 95, 9 are also provided in the oil passages 136, 137 of the main winch operation valve 77, respectively.
6 are provided, and these pressure switches 95, 96 are provided.
And the respective pressure switches 97 and 98 provided on the up / down operation valve 78 side and the respective pressure switches 91 and 92 provided on the expansion / contraction operation valve 75 side are “ON-OF”.
F "has a function of detecting whether the operation of the sub-wire 13 is an operation on the side where the tension of the sub-wire 13 is increasing or decreasing or an operation on the side where the tension of the sub-wire 13 is decreasing. Each of these pressure switches is connected to the crane operation detector 43 in FIG. And the jib state detector 47, and further corresponds to the "operation direction detecting means V" in the claims.

On the other hand, in FIG. 4, reference numeral 62 denotes a hydraulic pump for supplying winch drive hydraulic pressure.
The hydraulic pressure from 2 is connected to the pump port of the main operation valve 65 by an oil passage 141 via a switching valve 66. The main operation valve 65 is constituted by a pilot hydraulic three-position switching valve, and is connected to a winding port and a delivery port of a hydraulic motor 60 for driving the sub winch 15 via oil passages 123 and 124. Have been. When the main operation valve 65 is set at the position “a”, the oil passage 1
Hydraulic oil is supplied to the delivery port of the hydraulic motor 60 via 23, and to the winding port of the hydraulic motor 60 via the oil passage 124 when set to the position “c”.

A counterbalance valve 52 including a relief valve 53 and a check valve 54 is interposed between the oil passage 123 and the oil passage 124. A relief valve 55 is arranged between the hydraulic motor 60 and the hydraulic motor 60. Further, the oil passage 12
4, the hydraulic motor 60 and the counterbalance valve 5
An oil passage 126 interposed with the electromagnetic switching valve 57 is branched from an intermediate position between the oil passage 126 and the oil passage 123, and an oil passage 127 is branched from the oil passage 123. Further, between the oil passage 126 and the oil passage 127, two relief valves 85A, 85A are provided.
B are arranged in parallel, and both relief valves 8
An electromagnetic switching valve 87 is interposed at an intermediate position between 5A and 85B. The two relief valves 85A and 85B constitute a "second low-pressure relief valve 85" in the claims, and between these two, the relief valve 85A is more effective than the relief valve 85B. The set pressure is set higher. Further, each of the relief valves 85A, 85A
The pressure switch 56 provided in the oil passage 126 detects that any one of 5B is operated and the operating oil pressure supplied to the hydraulic motor 60 is low. Therefore, this pressure switch 56 corresponds to the winch operating pressure detector 45 in FIG.

On the other hand, an oil passage 129 extending from a vent port of a relief valve 67 provided in the oil passage 141 from the hydraulic pump 62 and an oil passage 128 extending from a vent port of a main relief valve (not shown) on the undulation side. , Is connected to a first low-pressure relief valve 71 via an electromagnetic switching valve 70. When the electromagnetic switching valve 70 is set to the position “a”, the hydraulic pressure supplied from the hydraulic pump 62 to each hydraulic actuator for operations other than turning is low pressure (that is, the first low pressure relief valve 71 (Set pressure). Further, when the electromagnetic switching valve 70 is set to the position “b”, the supply of the hydraulic pressure from the hydraulic pump 62 to the hydraulic actuator for operations other than the turning operation is stopped (therefore, the electromagnetic switching valve 70 is By setting this to the position “b”, the “operation stopping means 36” in FIG. 3 is configured). Further, when the electromagnetic switching valve 70 is set to the position "c", the hydraulic pressure supplied from the hydraulic pump 62 to all the hydraulic actuators including the turning is set to a high pressure, and a required crane operation is enabled. You.

In this hydraulic circuit, the pressure reducing valve 69
And the second low-pressure relief valve 85 and the electromagnetic switching valve 57 constitute the low-torque / low-speed winding means P.
And the switching valve 84 constitute the first brake releasing means Q. The main operating valve 65 and the switching valve 84 constitute the second brake releasing means R and the brake releasing means S (note that the second brake releasing means Q). The means R and the brake release means S have the same configuration, but they are individually shown according to the description of the claims), and the hydraulic motor 60, the electromagnetic switching valve 57, and the second low pressure relief The valve 85 constitutes the tension applying means T.

The above is the description of the hydraulic circuit.

In this embodiment, as described above, the tension of the sub-wire 13 is adjusted by adjusting the tension of the sub-wire 13 at both the time of “jib extension / retraction work” and “at the time of boom work”. The purpose is to maintain the “locked state”.

As described later, the basic concept of the control in this case is to adopt different control methods between "at the time of jib extension and storage" and "at the time of boom operation". At the time of "storage operation", different control methods are employed depending on whether the tension of the sub-wire 13 increases or decreases. Specifically, it is as follows.

When the operation in the direction of increasing the tension is performed at the time of the “jib extension / retraction operation” and the operation of the main operation valve 65 is not performed, the external force is applied to the sub-wire 13 while applying an appropriate predetermined tension to the sub-wire 13. The sub-hook 9 is allowed to be pulled out, and the “hooked state” of the sub-hook 9 is maintained.

When the operation is performed in the "jib extension / retracting operation" direction and in the direction of decreasing the tension, the sub winch 15 is rolled in at a low torque and a low speed, so that the sub wire 1 is retracted.
The tension of the sub-hook 9 is properly maintained, thereby maintaining the sub-hook 9 in the "locked state".

In the “during boom operation”, the operation state in which the tension of the sub-wire 13 changes is determined only by the operation state (in other words, the direction in which the tension of the sub-wire 13 increases or decreases). However, as long as the state changes, the sub winch 15 is operated in the winding direction at a low torque and a low speed, thereby maintaining the sub hook 9 in the "locked state".

The operation control of the sub winch 15 at the time of each of these operations is based on the premise that a crane operation that changes the tension of the sub wire 13 is performed.

From the viewpoint of the above-described control concept, the operation relations of the electromagnetic switching valves 57, 70, 72, 73, and 87 are summarized for each work, and this is shown in FIG.

Next, the actual control of the tension of the sub-wire 13 by the operation control of the sub-winch 15 performed by the controller 40 will be specifically described based on the hydraulic circuit diagram shown in FIG. 4 and the flowchart shown in FIG. I do.

In the flowchart of FIG. 6, after starting the control, first, in step S1, the current states of the boom 3 and the jib 4 are detected and read. These state detections are performed by the main hook overwind detector 41, the jib storage detector 42, the sub hook overwind detector 46, and the jib state detector 47 shown in FIG.

Next, in step S2, it is determined whether "boom work" or "jib extension / storage work" is currently being performed. If it is determined that none of these operations has been performed, the control waits until the operation is performed.

On the other hand, if it is determined that any of the above operations is being performed, the sub-hook 9 is determined in step S3.
Check if is in the "locked state". The “locked state” is confirmed based on signals from the sub-hook overwind detector 46 and the hook locked detector 48 in FIG.

If it is determined that the sub-hook 9 is not in the "locked state", the sub-wire 13 is wound by the sub-winch 15 to set the sub-hook 9 in the "locked state" (step S11). ). Note that the winding operation of the sub winch 15 in this case is performed by a normal winding operation different from tension control. By operating the sub winch operation valve 76 to the winding side, the pilot hydraulic pressure is reduced via the oil passage 114. This is performed by setting this to the position “c” over the main operation valve 65.

When the sub-hook 9 is already in the "locked state", and when the sub-hook 9 is not in the "locked state", the sub-hook 9 is brought into the "locked state" by the winding operation of the sub-winch 15, and then, The process proceeds to step S4, and the tension control of the sub-wire 13 is started.

In step S4, it is determined whether the current operation is a boom operation. If it is determined that the operation is "boom operation", it is next determined in step S5 whether or not a crane operation that changes the tension of the sub-wire 13 is currently performed. If the operation has not been performed, the control waits until the operation is performed, and when the operation has been performed, or immediately when the operation has been performed, the process proceeds to step S6, and the sub-wires are respectively executed. The sub winch 15 is operated to the winding side so that the sub-winch 13 is wound at a low torque and at a low speed.

This low torque / low speed entrainment will be described below with reference to the hydraulic circuit diagram of FIG. When it is detected that the crane operation has been performed such that the tension of the sub-wire 13 changes in “boom operation” (detected by the crane operation detector 43 in FIG. 3), at that time, FIG. , The electromagnetic switching valve 70 is set to the position “c”, and the electromagnetic switching valve 57 is
N ", the electromagnetic switching valve 72 is set to" ON ", the electromagnetic switching valve 73 is set to" OFF ", and the electromagnetic switching valve 87 is set to" ON ".

Therefore, the pilot oil pressure from the hydraulic pump 61 is transmitted from the oil passage 111 to the electromagnetic switching valve 72 →
Pressure reducing valve 69 → oil passage 113 → shuttle valve 81 → oil passage 114
Is applied to the position "c" side of the main operation valve 65,
The main operation valve 65 is switched from the position “b” to the position “c”. On the other hand, since the electromagnetic switching valve 70 is set at the position “c” and the first low-pressure relief valve 71 is invalid, the relief valve 67 holds the normal set pressure and the hydraulic pump 62 The operating oil pressure supplied to the operation valve 65 is maintained at a high pressure (that is, an oil pressure that enables normal boom work). The high operating oil pressure is applied to the oil passage 124 →
The sub-winch 15 is supplied to the entraining-side port of the hydraulic motor 60 through the check valve 54, and the hydraulic motor 60 rotates the sub winch 15 to the entraining side.
To a predetermined winding force. Further, a pilot oil pressure is applied to the switching valve 84 from the main operation valve 65 side via the oil passage 135 → the oil passage 120, and the switching valve 84 is set to “ON”, whereby the operation from the hydraulic pump 63 is performed. The hydraulic pressure is supplied to the brake 59 via the oil passage 125, and the brake 5
By release of 9, the rotation of the sub winch 15 is permitted.

In this case, the operating hydraulic pressure supplied to the hydraulic motor 60 has a high original pressure, but is reduced by the relief valve 85A of the second low-pressure relief valve 85 to a low pressure. The winding force of the sub winch 15 is kept small. That is, winding with low torque is realized. On the other hand, since the pilot oil pressure from the hydraulic pump 61 is reduced in pressure by the pressure reducing valve 69, the operation amount of the main operation valve 65 is equal to the pilot oil pressure during normal operation of the sub winch 15 (that is, the hydraulic pump From 61, the oil passage 112 → the sub winch operating valve 76
The hydraulic pressure supplied from the main operating valve 65 to the hydraulic motor 60 is suppressed to be smaller than when the sub winch 1 is supplied.
The winding speed of No. 5 is set to be low. As a result, low torque / low speed entrainment of the sub winch 15 is realized.

Therefore, when the tension of the sub-wire 13 changes in the increasing direction due to the operation of the crane, the sub-wire 13 resists the external force (for example, the extension of the boom 3) against the winding force of the sub-winch 15. The sub-hook 9 is maintained in the "locked state" by being pulled out by the force) and maintaining the tension properly. Conversely, when the tension of the sub-wire 13 changes in a decreasing direction,
Since the sub-wire 13 is wound by the sub winch 15 at a low torque and a low speed, the tension is properly maintained.
Is maintained. In other words, even if a crane operation is performed such that the tension of the sub-wire 13 changes during “boom operation”, the tension of the sub-wire 13 is always properly maintained, and the sub-hook 9 is “locked”. "State" is secured.

Returning to the flow chart of FIG. 6, the above-described tension control of the sub-wire 13 is continued until the boom operation is completed (step S8). , The brake 59 is not released,
In the case where the operating oil pressure of 0 is not set to a low pressure, the former abnormality is detected by the pressure switch 88, and the latter abnormality is detected by the pressure switch 56.)
In the meantime, the electromagnetic switching valve 70 is switched to the position “b”, and all the operations except the pivoting movement of the boom 3 (that is, the operation not affecting the tension of the sub-wire 13) are stopped, and the safety in operation is Is secured (Steps S7 and S
10). In addition to the automatic stop, for example, when the operator detects from the output of the hook engagement confirmation means 37 that the "engagement state" of the sub hook 9 is impaired during the operation of the crane, the operation is currently performed. Stopping the operation can immediately stop the transition to an abnormal situation,
This also ensures operational safety.

On the other hand, if it is determined in step S4 that the operation is not the “boom operation”, the process proceeds to step S12, and it is determined whether the operation is the “jib extension / storage operation”. Here, if it is determined that the “extension / storage operation” is not performed, the control waits until the “extension / storage operation” is performed. Then, when the work is performed, the process proceeds to step S13.

In step S13, the current overhang
In the storing operation, it is determined whether or not the operation on the side where the tension of the subwire 13 increases (that is, the tension side) is performed. In addition, this judgment
The jib state detector 47 and the crane operation detector 43 of FIG.
Is detected by

Here, when the operation on the side where the tension is increased is performed, the sub-wire 13 is pulled out with a constant external force applied thereto, whereby an excessive tension is applied to the sub-wire 13. The sub-hook 9 is maintained in the "locked state" without being hooked. The operation of pulling out the sub-wire 13 under the constant tension will be described below with reference to the hydraulic circuit diagram of FIG.

In this working state, as described above, the electromagnetic switching valve 70 is set to the position “a”, the electromagnetic switching valve 57 is “ON”, the electromagnetic switching valve 72 is “OFF”,
The electromagnetic switching valve 73 is “ON”, and the electromagnetic switching valve 87 is “ON”
Are set respectively. Therefore, the sub-wire 13
The operation on the side where the tension of the valve increases, that is, the expansion / contraction operation valve 75
The extension operation of the boom 3 or the jib 4 by the above, the raising operation of the boom 3 or the downward tilt operation of the jib 4 by the raising / lowering operation valve 78, or the “extended posture” of the jib 4
When the reversing operation is performed to the “retracted posture” from the oil passage 122 or the oil passage 134, the pilot oil pressure supplied to the shuttle valve 82 side is changed from the oil passage 121 to the electromagnetic switching valve 7.
3 → oil path 116 → shuttle valve 80 → supplied to the switching valve 84 via the oil path 120, and the switching valve 84 is set to “ON”. Accordingly, the operating oil pressure from the hydraulic pump 63 is supplied to the brake 59 via the oil passage 125, the brake 59 is released, and the rotation of the sub winch 15 is allowed.

On the other hand, the electromagnetic switching valve 72 is turned off.
Since the sub hook 9 is maintained in the "locked state", the sub winch operating valve 76 is not operated, and the sub winch control valve unit 64 is fixed at the position "b". You. For this reason, the oil passage 12 connecting the hydraulic motor 60 and the main operation valve 65 is provided.
3 and the oil passage 124 form a circulation passage, and no hydraulic pressure is supplied to the hydraulic motor 60. Moreover, in this state, since the electromagnetic switching valve 57 is “ON” and the electromagnetic switching valve 87 is “ON”, the sub winch 15
Is forcibly rotated by the tension applied to the sub-wire 13, the hydraulic motor 60 accordingly functions as a hydraulic pump under the set pressure of the relief valve 85B, and the pump resistance causes the sub winch 15 to move. A predetermined rotation resistance is given. As a result, the sub-wire 13 pulled out from the sub-winch 15 maintains a predetermined tension corresponding to the rotational resistance. Therefore, by pulling out the sub-wire 13 while maintaining the predetermined tension in accordance with the operation in the direction in which the tension of the sub-wire 13 increases, the tension of the sub-wire 13 is always properly maintained without being excessive, As a result, the "locked state" of the sub hook 9 is maintained. That is,
In this working state, the tension control of the sub-wire 13 is automatically performed in conjunction with the operation of increasing the tension of the sub-wire 13 without operating the main operation valve 65, and the sub-hook is controlled. Since the “locked state” of No. 9 is maintained, the tension control becomes easier.

In this case, since there is no supply of operating hydraulic pressure to the hydraulic motor 60 side, the relief valve 85B
Is only the discharge oil from the hydraulic motor 60. For example, when the hydraulic pressure is supplied to the hydraulic motor 60 and both the hydraulic pressure to the hydraulic motor 60 and the discharge oil from the hydraulic motor 60 flow. Therefore, there is no occurrence of an "override state" in the relief valve 85B, the set pressure is always properly maintained, and the tension control of the sub-wire 13 is more accurately performed. .

Returning to the flowchart of FIG. 6, when it is determined in step S13 that the operation of decreasing the tension has been performed, then in step S14, the sub-wire 13 is operated with low torque and low torque. The sub winch 15 is operated to the winding side so as to be wound at a low speed.

The low-torque, low-speed entanglement of the sub-wire 13 during the “jib extension / retraction work” is shown in FIG.
The following is a description based on the hydraulic circuit diagram of FIG.

If it is detected that the operation of the sub-wire 13 in the direction of decreasing the tension is performed during the “jib extension / retraction work” (the crane operation detector 43 and the jib state detector 47 in FIG. 3). At that time, as shown in FIG. 5, the electromagnetic switching valve 70 is set to the position “a”, the electromagnetic switching valve 57 is “ON”, and the electromagnetic switching valve 72 is “ON”. , The electromagnetic switching valve 73 is “OF
F ", and the electromagnetic switching valve 87 is set to" OFF ".

Therefore, the pilot oil pressure from the hydraulic pump 61 is transmitted from the oil passage 111 to the electromagnetic switching valve 72 →
Pressure reducing valve 69 → oil passage 113 → shuttle valve 81 → oil passage 114
Is applied to the position "c" side of the main operation valve 65,
The main operation valve 65 is switched from the position “b” to the position “c”. On the other hand, since the electromagnetic switching valve 70 is set at the position “a”, the relief valve 67 is set to a lower pressure side than the normal set pressure, and the hydraulic pump 62
5 is maintained at a low pressure. Then, this low-pressure operating oil pressure is supplied to the winding-side port of the hydraulic motor 60 via the oil passage 124 → the check valve 54,
The hydraulic winch 60 rotates the sub winch 15 toward the winding side to apply a predetermined winding force to the sub wire 13. Also, from the main operation valve 65 side, an oil passage 135 is provided.
→ A pilot oil pressure is applied to the switching valve 84 via the oil passage 120, and the switching valve 84 is set to “ON”.
The operating oil pressure from the hydraulic pump 63 is supplied to the brake 59 via the oil passage 125, and the rotation of the sub winch 15 is allowed by releasing the brake 59.

In this case, the operating oil pressure supplied to the hydraulic motor 60 has already been lowered by the first low-pressure relief valve 71. Even if the operating oil pressure is not reduced to a low pressure due to some inconvenience, Since the pressure is reduced by the second low-pressure relief valve 85, the working oil pressure supplied to the hydraulic motor 60 is reliably reduced. Therefore, the winding force of the sub winch 15 is reliably suppressed to be small, and the winding of the sub wire 13 with low torque is realized.

On the other hand, since the pilot oil pressure from the hydraulic pump 61 is reduced in pressure by the pressure reducing valve 69, the operation amount of the main operation valve 65 is equal to the pilot oil pressure during normal operation of the sub winch 15 (ie, The hydraulic pressure applied from the hydraulic pump 61 via the oil passage 112 to the sub winch operating valve 76) is smaller than when the hydraulic pump 61 is loaded. Therefore, the amount of hydraulic pressure supplied from the main operating valve 65 to the hydraulic motor 60 is reduced. The winding speed of the sub winch 15 is set to be low. As a result, low torque / low speed entrainment of the sub winch 15 is realized. Therefore, when the tension of the sub-wire 13 changes in the decreasing direction due to the crane operation, the sub-wire 13 is wound by the sub winch 15 at a low torque and at a low speed, so that the tension is properly maintained.
As a result, the “locked state” of the sub hook 9 is maintained.

The second low-pressure relief valve 8
5 is a high pressure side relief valve 85A and a low pressure side relief valve 8
5B, these two relief valves 85A, 85B
Is connected to the sub-wire 13 by the electromagnetic switching valve 87.
The hydraulic motor 60 functions as a drive source to drive the sub winch 15, and the hydraulic motor 60 functions as a hydraulic pump. The above sub winch 15
Considering the direction in which the mechanical efficiency acts between the case where the sub-wire 13 is driven and the case where the sub-wire 13 is driven, a substantially constant tension can be applied to the sub-wire 13 during any of the above operations. As a result, it is possible to more reliably maintain the sub hook 9 in the “locked state”.

Returning to the flowchart of FIG. 6 again, the low-torque and low-speed winding of the sub-wire 13 in step S14 and the action of applying the predetermined tension to the sub-wire 13 in step S15 are described in "Jib projecting / storing operation". Is continued (step S16),
If an abnormality occurs in the sub winch 15 on the way (for example, if the brake 59 is not released or the operating oil pressure of the hydraulic motor 60 is not low), the former abnormality is caused by the pressure switch. 88, the latter abnormality is detected by the pressure switch 56, respectively).
And all operations other than the pivoting movement of the boom 3 (that is, the operation that does not affect the tension of the sub-wire 13) are stopped, and work safety is ensured (step S16).
And step S10).

As described above, in this embodiment, the "locked state" of the jib 4 is determined not only when the jib 4 is "extended and stored" but also when the jib 4 is stored. At the time of “boom work”,
A great effect is obtained in terms of workability or operability in each of these works.

[Brief description of the drawings]

FIG. 1 is a side view of a mobile crane to which a winch control method and a winch control device according to the present invention are applied.

FIG. 2 is a plan view of the mobile crane shown in FIG.

FIG. 3 is a system block diagram of a winch control device according to the present invention.

FIG. 4 is a main part hydraulic circuit diagram of the winch control device according to the present invention.

FIG. 5 is an explanatory diagram of an operation relationship of an electromagnetic switching valve in the hydraulic circuit.

FIG. 6 is a control flowchart in a winch control method according to the present invention.

FIG. 7 is a view showing a jib working state of the mobile crane shown in FIG. 1;

FIG. 8 is a boom operation state diagram of the mobile crane shown in FIG. 1;

FIG. 9 is an explanatory diagram of a jib overhanging / retracting operation in the mobile crane shown in FIG. 1;

10 is an explanatory diagram of a jib overhanging / retracting operation in the mobile crane shown in FIG. 1.

FIG. 11 is an explanatory view of a jib overhanging / retracting operation in the mobile crane shown in FIG. 1;

FIG. 12 is an explanatory view of a jib overhanging / retracting operation in the mobile crane shown in FIG. 1;

[Explanation of symbols]

1 is a vehicle, 2 is a turntable, 3 is a boom, 4 is a jib, 5 is a jib base, 6 is a hydraulic cylinder for raising and lowering, 7 is a hydraulic cylinder for tilting, 8 is a main hook, 9 is a sub hook, and 10 is a boom pivot. Support shaft, 11 is cabin, 12 is main wire,
13 is a sub-wire, 14 is a main winch, 15 is a sub winch, 16 is a hydraulic cylinder for swing, 17 is a boom-side pin receiving hole, 18 is a jib-side pin receiving hole, 19 is a connecting pin, 20 is a jib pivot shaft, 21 Is a jib fixing tool, 22 is a hook locking arm, 23 is a proximal sheave, 24 is a proximal sheave, 25 is a guide sheave, 26 is a guide sheave, 27
Is a front sheave, 28 is a folded horizontal sheave, 29 is a guide sheave, 30 is a front sheave, 31 is an intermediate sheave, 35
Is tension automatic control means, 36 is operation stop means, 37 is hook engagement confirmation means, 40 is a controller, 41 is a main hook overwind detector, 42 is a jib storage detector, 43 is a crane operation detector, and 44 is a brake. Release detector, 45 is a winch operating pressure detector, 46 is a subhook overwind detector, 47
Is a jib state detector, 48 is a hook engagement detector, 49 is a transmitter, 50 is a cable reel, 52 is a counterbalance valve, 53 is a relief valve, 54 is a check valve, 55
Is a relief valve, 56 is a pressure switch, 57 is an electromagnetic switching valve, 59 is a brake, 60 is a hydraulic motor, 61 to 63 are hydraulic pumps, 65 is a main operation valve, 66 is a switching valve, 67 is a relief valve, and 68 is a shuttle. Valve, 69 a pressure reducing valve, 70 an electromagnetic switching valve, 71 a first low pressure relief valve, 72 and 73
Is an electromagnetic switching valve, 74 is a swing operation valve, 75 is a telescopic operation valve,
76 is a sub winch operating valve, 77 is a main winch operating valve, 78 is an up / down operating valve, 79 is an electromagnetic switching valve, and 80 to 83
Is a shuttle valve, 84 is a switching valve, 85 is a second low-pressure relief valve, 87 is an electromagnetic switching valve, 88 to 98 are pressure switches,
P is a low torque / low speed winding means, Q, R and S are brake releasing means, T is a tension applying means, U is a hook engagement detecting means, V is an operation direction detecting means, W is a control means, and Z is a movable type. It is a crane.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F205 AA06 CA03 CA07 CA10 CB02 DA04 FA01 KA10

Claims (7)

[Claims] 1. A swivel (2) mounted on a vehicle (1)
A boom member (X) is attached to the arm, and a hook (9) is hung from a tip end of the boom member (X) by a wire (13) drawn out from a hydraulic drive winch (15) arranged on the swivel (2) side. A mobile crane which lowers and holds the hook (9) by locking the hook (9) to the tip of the boom member (X) by winding the wire (13) with the winch (15); When the boom member (X) is operated in a direction in which the tension of the wire (13) increases while the (9) is locked to the tip of the boom member (X), the winch (15) When the boom member (X) is operated in a direction in which the tension of the wire (13) decreases, the wire (13) is pulled out of the wire (13). A winch control method for a mobile crane, wherein the operation of the winch (15) is controlled so that the ear (13) is involved at a low torque and a low speed. 2. A turntable (2) mounted on a vehicle (1).
A boom member (X) is attached to the arm, and a hook (9) is hung from a tip end of the boom member (X) by a wire (13) drawn out from a hydraulic drive winch (15) arranged on the swivel (2) side. A mobile crane which lowers and holds the hook (9) by locking the hook (9) to the tip of the boom member (X) by winding the wire (13) with the winch (15); When the boom member (X) is operated in the direction in which the tension of the wire (13) changes while the (9) is locked to the tip of the boom member (X), the wire (13) ) At a low torque and at a low speed so that the winch (1) is wound around the winch (15).
A winch control method for a mobile crane, characterized by controlling the operation of 5). 3. A turntable (2) mounted on a vehicle (1).
A boom member (X) is attached to the arm, and a hook (13) is hooked from the tip of the boom member (X) by a wire (13) drawn out from a hydraulic drive winch (15) with a brake (59) disposed on the side of the swivel (2). (9) is suspended, and the wire (1) is suspended by the winch (15).
3) In a mobile crane in which the hook (9) is engaged with and held by the tip of the boom member (X) by rolling in the hook, the hook (9) is positioned at the tip of the boom member (X). A hook engagement detecting means (U) for detecting a state in which the boom member (X) is engaged with the wire (1);
3) an operation direction detecting means (V) for detecting whether the tension is increasing or decreasing, and releasing the brake (59) by the winch (1).
The first brake releasing means (Q) which is performed independently of the operation of 5), and the release operation of the brake (59) is performed by the winch (1).
A second brake releasing means (R) performed in connection with the operation of 5);
5) a tension applying means (T) for applying a predetermined tension to the wire (13) when pulled out from the wire (13); and a low torque / low speed winding means (P) for winding the winch (15) at a low torque and at a low speed. And the first brake release means (Q) when the hook lock detection means (U) detects a locked state and the operation direction detection means (V) detects an operation in the tension increasing direction. While an operation command is output together with the tension applying means (T), the locking state is detected by the hook locking detecting means (U), and the operation in the tension decreasing direction is detected by the operating direction detecting means (V). And a control means (W) for outputting an operation command to the second brake releasing means (R) and the low-torque / low-speed winding means (P). C Lynch control device. 4. A swivel (2) mounted on a vehicle (1)
A boom member (X) is attached to the arm, and a hook (13) is hooked from the tip of the boom member (X) by a wire (13) drawn out from a hydraulic drive winch (15) with a brake (59) disposed on the side of the swivel (2). (9) is suspended, and the wire (1) is suspended by the winch (15).
3) In a mobile crane in which the hook (9) is engaged with and held by the tip of the boom member (X) by rolling in the hook, the hook (9) is positioned at the tip of the boom member (X). Hook engagement detecting means (U) for detecting a state in which the wire is locked to the section, and operation direction detecting means for detecting that the boom member (X) is operated in a direction in which the tension of the wire (13) changes. (V) and the release operation of the brake (59) is performed by the winch (1).
5) a brake releasing means (S) for performing the operation in association with the operation, a low-torque / low-speed winding means (P) for winding the winch (15) at a low torque and a low speed, and a hook engagement detecting means. The brake release means (S) when the locked state is detected by (U) and the operation in the tension change direction is detected by the operation direction detection means (V).
And a control means (W) for outputting an operation command to both the low-torque / low-speed winding means (P). 5. The telescopic boom (3) according to claim 3 or 4, wherein the boom member (X) is mounted on the swivel base (2) so as to be able to move up and down, and a side of the boom (3). And a jib (4) attached to the tip of the boom (3) in an extended state as necessary, while the wire (13) is connected to the jib (4). In both the retracted position and the extended position, the hook (9) suspended from the tip of the jib (4) and attached to the sub-wire (13) is locked and held at the tip of the jib (4). A winch control device for a mobile crane, wherein the winch control device is configured as follows. 6. The hydraulic pump (62) according to claim 3, 4 or 5, wherein the low-torque / low-speed winding means (P) is disposed in front of a main operating valve (65) of the winch (15). A first low-pressure relief valve (71) interposed in an oil passage from a hydraulic motor (60) for driving the winch (15); and a counterbalance valve (5).
A winch control device for a mobile crane, comprising a second low-pressure relief valve (85) interposed in an oil passage (126) branched from the oil passage between the two. 7. The winch control device for a mobile crane according to claim 6, wherein the second low-pressure relief valve (85) is configured such that its set pressure can be switched in two stages.