JP2585680Y2 - Hook storage device for self-propelled cranes - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-propelled crane such as a truck crane, a rough terrain crane or a truck-mounted crane, and more particularly to the storage of hooks thereof.

[0002]

2. Description of the Related Art In a self-propelled crane of this type, a hook is attached to the end of a boom prior to traveling of the self-propelled crane in order to prevent a hook suspended by a wire cable from shaking during traveling. It is necessary to perform localization (hereinafter referred to as storage).

On the other hand, in a crane that raises and lowers a hook with a winch composed of a wire cable and a winding drum, if the wire cable is wound up too much during crane operation, the hook may collide with the tip of the boom. .

[0004] To prevent such a risk, a winding detection switch is provided which is activated when the hook approaches the end of the boom by a predetermined value or more. By operating this winding detection switch, an alarm is issued and the winch lifting force is increased. (See Japanese Utility Model Laid-Open No. 2-57898). According to this method, the hook is stored and damage due to a collision during crane operation is reduced.

[0005]

However, according to such a conventional technique, the hook can be stored, and at the same time, the damage caused by the collision during the crane operation is reduced, but the occurrence of the collision itself is reduced. It cannot be forcibly prevented.

The present invention has been made based on this background, and forcibly prevents the collision between the hook and the boom tip during crane operation, and easily stores the hook at the boom tip. The task is to do so.

[0007]

According to a first aspect of the present invention, there is provided a hook storage device for a self-propelled crane, wherein a wire cable unwound from a winding drum is suspended via a tip end of a boom. A hook storage device of a self-propelled crane having a hook suspended from a hanging portion of the wire cable, wherein a winding detection switch that operates when the hook approaches a tip end of the boom by a predetermined value or more;
A winding stop circuit for stopping the winding of the winding drum by the operation of the winding detection switch, and prohibiting the operation of the winding stop circuit when the hook is stored to allow the winding of the winding drum. A storage switch,
The hydraulic circuit of the hydraulic motor that drives the winding drum includes at least one of a relief valve that puts the hydraulic circuit into a low pressure state and a flow control valve that limits the flow rate of the hydraulic circuit, and the winding detection switch is activated. Then, at least one of the relief valve and the flow control valve is operated so as to operate, and the operation of the storage switch cancels the drive stop of the hydraulic motor, thereby causing the hydraulic motor to operate at low pressure or low speed. , And can be driven.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 2 outlines the entire mechanical structure of the self-propelled crane, and then drives the driving device to the first position. This will be described with reference to the circuit diagram shown in FIG.

In FIG. 2, reference numeral 1 denotes a crane, which has a base 2, a swivel 3, a boom 4, and a hook 5.

The base 2 is fixedly formed on a vehicle body frame 6 of an automobile. On the upper surface of a central portion of the base 2, there is provided a swivel 3 configured to be able to turn in the direction of arrow A in the figure. The receiver 7 is installed vertically and a receiver 7 is installed inside the receiver, and a storage button 8 of the hook 5 is installed therein.
It is connected to the receiver 7.

A control device 11, such as a valve, for controlling the operation of the crane 1 is installed on the upper surface of the base 2.

A boom 4 is pivotally supported at the upper end of the swivel base 3 via a pivot. The boom 4 is configured to be swingable in the direction of arrow B in the figure. A winding drum 14 for a wire cable 13 of a winch 12 for driving a hook 5 to be described later is installed inside the swivel 3.

The boom 4 is composed of an outer cylinder 4a pivotally supported at the upper end of the swivel base 3 and an inner cylinder 4b housed telescopically therein, and is configured to be extendable and contractible in the direction of arrow C in the figure. ing.

A guide pulley 15 for guiding the wire cable 13 extending from the winding drum 14 and a winding detection switch 16 for detecting excessive winding of the wire cable 13 are provided at the end of the inner cylinder 4b of the boom 4. Is installed.

The lower part of the tip of the inner cylinder 4b has
The tip 13a of the wire cable 13 is fixed, and a weight 17 is fixed at a position on the wire cable 13 separated from the tip 13a of the wire cable 13 by an appropriate dimension. Where
The hook 5 is suspended via a pulley 18 installed therein.

Therefore, by changing the winding amount of the wire cable 13 by the winding drum 14, the hook 5 can be driven up and down as shown by the arrow D in the figure.

A rope 19 is stretched between the weight 17 and the winding detection switch 16.

The rope 19 is connected to an operation arm (not shown) of the winding detection switch 16, and in a normal case as shown in the drawing, the winding detection switch 16 is in an off state and the weight 17 is lifted. In this case, the winding detection switch 16 is turned on when the operating arm is displaced. When the winding detection switch 16 is turned on, an alarm buzzer sounds by an electric circuit (not shown).

In FIG. 1, reference numeral 9 denotes a transmitter. In this embodiment, a storage button 8 for the hook 5 is also provided in the transmitter 9, and the storage buttons 8 are wirelessly provided. The same operation as that described above can be performed. However, in some cases, the remote control device may be configured as a wired remote control device, and the installation of the remote control device is omitted, and only the storage button 8 installed on the base 2 is used. Is also good.

By the way, the crane 1 has a first
It is driven by a driving device 21 described with reference to the drawing.

That is, the driving device 21 is of an electro-hydraulic type, and includes a hydraulic pump 22 as a power source, a turning hydraulic motor 23 for driving the turning table 3 to rotate, and an up / down driving for driving the boom 4 up and down. Hydraulic cylinder 24, a hydraulic cylinder 25 for extending and retracting the inner cylinder 4b of the boom 4 with respect to the outer cylinder 4a, and a hydraulic motor for raising and lowering the take-up drum 14 of the winch 12 for raising and lowering the hook 5 26.

Oil passage 2 extending from the discharge port of hydraulic pump 22
7 is provided with a 6-port 3-position switching valve 28 having the same configuration, through which the turning hydraulic motor 23, the undulating hydraulic cylinder 24, the telescopic hydraulic cylinder 25, and the The lifting hydraulic motors 26 are connected respectively.

At a position on the discharge port side of the hydraulic pump 22 with respect to these switching valves 28, a drain passage 31 branched from the oil passage 27 is formed, and a main relief valve 32 is mounted in the drain passage 31. Have been.

The main relief valve 32 is a balance piston type relief valve having a pilot passage 33, and a normally closed solenoid on-off valve 35 is interposed on the drain 34 side of the pilot passage 33.

For this reason, the main relief valve 32
When the discharge pressure of the hydraulic pump 22 exceeds a set value and when the solenoid on-off valve 35 connects the pilot passage 33 to the drain 34, the drain passage 31
To make the oil pressure in the oil passage 27 extremely low. In this embodiment, a winding stop operation to be described later is performed.

In the neutral position 36, the switching valves 28 communicate the pressure oil from the oil passages 27 to the drains 34 through the respective valves, and close the respective hydraulic circuits passing through the turning hydraulic motor 23 and the like. It is in a state.

At the first offset position 37 of each switching valve 28, pressure oil from the oil passage 27 is introduced into each hydraulic circuit to cause the turning hydraulic motor 23 and the like to perform required operations. At the same time, the oil passage for returning the return oil accompanying the operation of the turning hydraulic motor 23 and the like to the drain 34 is opened.

Further, at the second offset position 38 of each switching valve 28, pressure oil is introduced into each hydraulic circuit in a direction opposite to the case of the first offset position 37, and the turning hydraulic motor 23 and the like are provided. Are driven in the opposite direction.

Therefore, in this crane 1,
Each switching valve 28 is normally connected to the oil passage 27 at a neutral position 36, and when each part needs to be actuated, one of the switching valves 28 is selectively replaced with a first offset valve. The position is switched to the position 37 or the second offset position 38 to perform a required operation.

The oil passage 27 in this embodiment
And a hydraulic motor 26 for lifting and lowering branched from the oil passage 27.
The lifting hydraulic passage 41 forms a lifting hydraulic circuit via a switching valve 28a (hereinafter, a suffix a is added for discrimination from other switching valves).

The low-pressure relief valve 4 is provided in the lifting oil passage 41 of the lifting hydraulic motor 26 of this embodiment.
2 and a flow control valve 43 are installed. At the first offset position 37, the lifting hydraulic motor 26 drives the hook 5 to move upward, and the second offset position 38
, The lifting hydraulic drive motor 26 drives the hook 5 downward.

The low-pressure relief valve 42 comprises a balance piston type relief valve, a check valve 44 and a pilot passage 45 installed on a drain passage 47 branching off from the lifting oil passage 41. A normally closed solenoid on-off valve 46 is interposed on the drain 34 side.

Therefore, when the solenoid on-off valve 46 connects the pilot passage 45 to the drain 34, the low pressure relief valve 42 connects the drain passage 47 to the drain 34.
To reduce the hydraulic pressure in the lifting oil passage 41 to a low pressure state.

The low pressure relief valve may be installed in the oil passage 27 in parallel with the main relief valve 32.

The flow control valve 43 is a solenoid-operated switching valve, and in the normal position 48, the pressure oil supplied to the lifting oil passage 41 can flow as it is without any substantial resistance. When activated and switched to the offset position 49, the flow rate of the pressure oil is limited under a certain restriction.

As such a flow control valve, a switching valve 28a for branching an elevating oil passage 41 from the oil passage 27 to the elevating hydraulic motor 26 is constituted by an electromagnetic proportional control valve. The control may be performed by controlling the control valve to a half spool state.

The solenoid on-off valves 35 and 46 and the flow control valve 43 in such a hydraulic system are controlled by an electric circuit 51 as follows.

The electric circuit 51 has a power supply 52, a winding detection switch 16, and a storage switch 53 which is closed by operating the storage button 8.

The storage switch 53 is configured to close the contact only when the storage button 8 is pressed. This is because it is preferable in terms of work safety to make the worker clearly aware that the hook 5 is being stored.

The electric circuit 51 includes a first relay 54, contacts 55 and 56, and a second relay 5 for controlling the energization of the solenoid on-off valve 35 and the like.
7 and these contacts 58 and 59 are provided.

The contents of control by the electric circuit 51 are as follows.

First, a description will be given of a case where the hook 5 is moved up and down by a normal crane operation by the crane 1 of this embodiment. Since the storage button 8 is not pressed, the storage switch 53 is turned off and the first switch is turned off. Relay 54
Is not energized, so that the open contact 5 of the first relay 54
5 is off, and the closing contact 56 remains on.

Therefore, the circuit from the power source 52 to the solenoid switching valve 46 is open, and as a result, the low pressure relief valve 42 is inoperable.

The power source 52 supplies the solenoid switching valve 35
The open contacts 58 and 59 of the second relay 57 are provided in the circuit from the power supply 52 to the flow control valve 43, so that the second relay 57 is energized, that is, the winding detection switch 16 The power supply to these solenoid switching valves 35 and the like is controlled by turning on and off.

Therefore, during the crane operation, when the wire cable 13a is wound up too much and the winding detection switch 16 is turned on, the second relay 57 is energized to turn on the respective open contacts 58 and 59, and the main relief is turned on. The solenoid on-off valve 35 and the flow control valve 43 of the valve 32
Work simultaneously.

By the operation of the solenoid on-off valve 35,
The pilot passage 33 opens, and the drain passage 31
4, the hydraulic oil discharged from the hydraulic pump 22 is not substantially supplied to the lifting / lowering oil passage 41, the lifting / lowering hydraulic motor 26 is stopped, and the hook 5 is stopped from being lifted. Become. .

As a result, it is possible to reliably prevent the hook 5 from colliding with the tip of the boom 4 due to the carelessness of the operator during the crane operation.

Next, the operation for storing the hook 5 will be described.

In storing the hook 5, the operator presses the storage button 8 of the transmitter 9, for example.

As a result, the storage switch 53 is closed via the receiver 7 of the base 2 and a sound circuit (not shown) sounds an alarm saying "Please move the boom to the running position. Store the hook." Is issued.

When the boom 4 is not in the running posture, if the operator stops pressing the storage button 8, the storage switch 8 is turned off and the state returns to the normal crane operation. The switching valve 28 such as the motor 23 may be operated to bring the boom 4 into a predetermined running posture.

When the storage switch 53 is turned on by pressing the storage button 8, the first relay 54 is turned on.
, The open contact 55 is closed, and the closed contact 56 is opened.

As a result, the main relief valve 32 is brought into an inoperative state, so that the normal winding operation of the winch 12 and the like are prohibited, and the operation of stopping the winding is prohibited.

That is, in this embodiment, the power supply 5
When the storage switch 53 is turned on, the closing contact 56 is turned off and the operation of the winding stop circuit M is prohibited.

Therefore, during the storing operation of the hook 5, the hook 5 does not stop at the winding position as in the crane operation.

At the same time, the low pressure relief valve 42 is activated by the solenoid switching valve 46 of the low pressure relief valve 42 connecting the pilot passage 45 to the communicating state.

Therefore, in the storing operation of the hook 5, the pressure oil in the lifting oil passage 41 is supplied to the low pressure relief valve 42.
Is driven by the set low pressure.

When the storage switch 53 is turned on, the switching valve 28a of the lifting oil passage 41 to the lifting hydraulic motor 26 is switched to the first offset position 37 by a solenoid or the like. The storing operation of the hook 5 can be performed by only the pressing operation.

At this time, if operations such as extension of the boom 4 and winding of the winch 12 are locked when the storage switch 53 is turned on, the safety of the storage operation is further improved.

When the hook 5 reaches a position higher than the winding position, the winding detection switch 16 is turned on, and the flow control valve 43 is switched to the offset position having the throttle, as described above, but during the crane operation. The hook 5 does not stop at the winding position as in the above, and the hook 5 is slowly stored at the tip of the boom 4.

As described above, in the crane 1 of this embodiment, the storage button 8 is provided, and if the storage button 8 is not pressed, the wire cable 13 is overwound.
When the lifting of the hook 5 is stopped and the storage button 8 is pressed, the stopping of the winding of the hook 5 is prohibited and the hook 5 is slowly lifted.
Handling of the self-propelled crane becomes easy.

In the embodiment described above, the low pressure relief valve 42 is operated instead of the main relief valve 32 by pressing the storage button 8, and the flow control valve 43 is operated by operating the winding detection switch 16. However, in the present invention, this is reversed, and the flow control valve is operated by pressing the storage button 8, and the low pressure relief valve 42 is operated instead of the main relief valve 32 by operating the winding detection switch 16. It may be that.

Further, according to the present invention, only one of the low-pressure relief valve 42 and the flow control valve 43 similar to the above is installed in the elevating oil passage 41 or the oil passage 27 and the storage switch 8 is pressed. It may be operated by either the operation or the operation of the winding detection switch 16.

That is, in these modified examples, the winding stop operation is prohibited by pressing the storage button 8, and the low pressure relief valve and the flow control valve are controlled by pressing the storage button 8 or operating the winding detection switch 16. To prevent collision of the hook with the end of the boom during crane operation and facilitate the operation of storing the hook at the end of the boom.

The storage switch 53 used in the embodiment is configured to close the contact of the storage switch 53 only when the storage button 8 is pressed, but the present invention is not limited to this. For example, the present invention can be implemented even if it is turned on or off alternately each time the storage button 8 is pressed, or can be implemented using a simple switch.

When the storage switch is configured using a simple switch, a storage release switch is separately provided,
It is preferable to improve the operability of the switch.

[0067]

According to the hook storage device of the self-propelled crane of the present invention, at least one of the relief valve and the flow control valve is provided in the hydraulic circuit for driving the hydraulic motor, and the winding detection switch is connected to the wire. When overwinding of the cable is detected, the winding stop circuit operates to stop the winding, and at the same time, the relief valve or the flow rate control valve is operated, and when the storage switch is operated in this state, the hydraulic motor is driven. The stop is released, the hydraulic motor is driven at low pressure or low speed, and the hook is raised and stored. Therefore,
Since the worker does not operate the retract switch during crane operation, if the wire cable is overwound, the winding operation of the wire cable is forcibly stopped and the hook collides with the end of the boom. Never do.

At the time of storing the hook, the operator can operate the storage switch to raise awareness of the storing operation of the hook, and the operation of the winding stop circuit is prohibited. The hook is not stopped and the hook is stored smoothly.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a driving device.

FIG. 2 is a schematic explanatory view of a self-propelled crane.

[Explanation of symbols]

 M Winding stop circuit, 1 Self-propelled crane 4 Boom 5 Hook 12 Winch 13 Wire cable 14 Winding drum 16 Winding detection switch 26 (For lifting / lowering) hydraulic motor 41 Lifting / lowering oil passage 42 Low pressure relief valve 43 Flow control valve 53 Storage switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B66C 23/00-23/94 B66D 1/54

Claims (1)

(57) [Scope of request for utility model registration] 1. A hook storage device for a self-propelled crane, wherein a wire cable unwound from a winding drum is suspended via a tip end of a boom, and a hook is suspended from a suspension portion of the wire cable. A winding detection switch that operates when the hook approaches the tip of the boom by a predetermined value or more; a winding stop circuit that stops winding the winding drum by operating the winding detection switch; At the time of storage, the operation of the winding stop circuit is prohibited, and a storage switch that allows the winding drum to be wound and a hydraulic circuit of a hydraulic motor that drives the winding drum put the hydraulic circuit into a low pressure state. And at least one of a relief valve and a flow control valve for restricting a flow rate of the hydraulic circuit. At least one of the pressure valve and the flow control valve is operated, and the operation of the storage switch cancels the drive stop of the hydraulic motor so that the hydraulic motor can be driven at low pressure or low speed. A hook storage device for a self-propelled crane, characterized in that: