JPH11180677A - Safety device of crawler crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily confirm the present mode by setting a traveling-crane change-over switch adjacently to a traveling lever, and providing a lever lock for switching the changeover switch to crane work mode in the traveling lever lock position, and switching it to traveling mode side in the lock release position. SOLUTION: When an operator sets a lever lock 62 to a release position in working, a traveling-crane change-over switch 45 is ON by the lever lock 62. Consequently, a traveling-crane selector valve is switched to open position, and a crawler crane is laid in traveling mode. In this traveling mode, hydraulic fluid is returned to a crane-side return passage without being supplied to the hydraulic actuator of the crane, and the crane is laid in non-operating state. On the other hand, when the lever lock 62 is set to lock position, the change- over switch 45 is OFF by the lever lock 62. Consequently, the traveling-crane selector valve is switched to close position, and the crawler crane is set to crane work mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crawler crane in a traveling mode, in which an operator touches a crane operating lever, the crane does not operate, and in a crane working mode, the operator touches the traveling lever. However, the present invention relates to a crawler crane safety device that ensures the safety of crane work by preventing the crawler from operating.

[0002]

2. Description of the Related Art As shown in FIG.
Is equipped with a crane 4 and an outrigger 5 for securing the stability of the machine body 3 during crane operation on a machine body 3 that can travel by the left and right crawlers 2 that are lower traveling bodies. The crane 4 is provided with a column 7 which can be swiveled with respect to the body 3.
The boom 8 is pivotally supported so as to be able to move up and down, and a hook 9 is suspended from the tip of the boom 8 which expands and contracts.

When performing an operation, the operator first operates the traveling lever 6 to move the crawler crane 1 to the operation position, and extends the outrigger 5 back and forth and right and left as shown in FIG. I do. When the outrigger 5 is extended, the crane operation lever 10 is operated to rotate, raise, lower, expand and contract the boom 8 of the crane 4 to carry out crane operations such as lifting and hanging the load W.

The crawler crane 1 is hydraulically driven, and its hydraulic circuit has conventionally been configured as shown in FIG. Here, a traveling circuit 21 for operating the traveling hydraulic motors 20 of the left and right crawlers 2 is connected to a discharge circuit 12 of the hydraulic pump 11 and a tank 14 via a traveling switching valve 22.
And a tank circuit 15 for returning the working oil to the tank circuit 15. A return filter 13 is provided in the tank circuit 15.

The traveling switching valve 22 is a three-position switching valve. By operating the traveling lever 6 to switch the traveling switching valve 22 to the forward position, the traveling hydraulic motor 20 rotates forward and the crawler crane 1 is rotated. Moves forward, and the travel switching valve 22
Is switched to the retreat position, the traveling hydraulic motor 20 rotates in the reverse direction, and the crawler crane 1 retreats. In addition,
The speed of the traveling hydraulic motor 20 can be changed by a traveling hydraulic motor speed changeover switching valve 23.

A crane-side supply circuit 41 for supplying hydraulic oil to a plurality of hydraulic actuators (not shown) of the crane 4 is connected downstream of the traveling switching valve 22. Is connected to a crane-side return circuit 42 for returning hydraulic oil from the hydraulic actuator. When the traveling switching valve 22 is in the neutral position, the crane-side supply circuit 41 and the discharge circuit 12 of the hydraulic pump 11 communicate with each other, so that the hydraulic actuator of the crane 4 can be operated.

[0007] A bypass oil passage 43 is connected between the crane-side supply circuit 41 and the crane-side return circuit 42, and a traveling / crane switching valve 44 is provided in the bypass oil passage 43. The traveling / crane switching valve 44 is a normally-closed electromagnetic valve, and its solenoid is connected to a normally-open traveling / crane switching switch 45 for performing a switching operation between a traveling mode and a crane operation mode. The traveling / crane changeover switch 45 is provided on the meter panel 46 in front of the driver's seat, and is switched by direct operation by an operator.

In this circuit configuration, the traveling / crane selector switch 45 is turned on and the traveling / crane selector valve 44 is turned on.
In the driving mode in which the crane side supply circuit 41 and the crane side return circuit 42
Is communicated through. In this traveling mode, even if the traveling switching valve 22 is in the neutral position and the hydraulic oil is supplied from the discharge circuit 12 to the crane-side supply circuit 41, the supplied hydraulic oil passes through the bypass oil passage 43 to the tank. Circuit 15
As the crane 4 is not supplied to the hydraulic actuator of the crane 4, even if the crane operation lever 10 is operated, the crane 4 does not operate.

The traveling switching valve 22 is operated by operating the traveling lever 6.
Is switched to the forward or backward position, the crawler 2
Moves forward or backward. At this time, the hydraulic oil is not supplied to the crane-side supply circuit 41, so that the crane 4 does not operate.

That is, in the traveling mode, the crane 4 has a circuit configuration in consideration of safety so as not to operate. In the crane operation mode in which the traveling / crane switching switch 45 is turned off and the traveling / crane switching valve 44 is closed, the bypass oil passage 43 is shut off. In this crane operation mode, if the traveling switching valve 22 is in the neutral position, the hydraulic oil is supplied from the discharge circuit 12 to the crane-side supply circuit 41.
Is supplied to the hydraulic actuator of the crane 4 via the crane 4, so that the crane 4 is operated by operating the crane operation lever 10, and the crane operation can be performed.

[0011]

However, in this circuit configuration, the traveling switching valve 22 is not used in the crane operation mode.
Can be switched to a forward position or a reverse position. For this reason, if the operator accidentally operates the traveling lever 6 in the crane operation mode, the traveling hydraulic motor 20 rotates and the crawler 2 operates, so that an excessive force acts on the outrigger 5 and the outrigger 5 is actuated. There is a risk that the balance of the body 3 may be lost due to detachment from the slipper 51, or the crawler crane 1 may move unexpectedly.

Further, since the switching between the traveling mode and the crane operation mode is performed by switching the traveling / crane switching switch 45 provided on the meter panel 46, it is possible to recognize which mode is being performed during the operation. And there is a problem that an erroneous operation is likely to occur due to an erroneous mode recognition by an operator.

The present invention solves such a problem in a crawler crane, and it is easy for an operator to recognize whether the crawler crane is in a traveling mode or a crane working mode. The crane does not work even if you touch the operating lever,
It is another object of the present invention to provide a crawler crane safety device that can prevent a crawler from operating even when an operator touches a traveling lever in a crane operation mode.

[0014]

A safety device for a crawler crane according to the present invention comprises a traveling circuit for operating a hydraulic motor for traveling the crawler, a crane-side supply circuit for operating a hydraulic actuator of the crane, and a crane-side supply circuit. A return circuit, a travel switching valve for switching hydraulic oil supply to the travel circuit and the crane-side supply circuit by operating the travel lever, and a bypass oil passage connecting the crane-side supply circuit and the crane-side return circuit; A traveling / crane switching valve for switching between a traveling mode provided in the bypass oil passage and a crane working mode in which the bypass oil passage is communicated and a traveling / crane switching valve for switching the traveling / crane switching valve. In a hydraulically driven crawler crane provided with a crane changeover switch, a traveling Lever lock that switches the travel / crane switch to the crane operation mode at the lock position to lock the travel lever, and switches the travel / crane switch to the travel mode at the release position to unlock the travel lever. The above-mentioned subject is solved by providing.

When the lever lock is released, the travel / crane selector switch is switched to the travel mode side by the lever lock, so that the travel / crane selector valve is switched to the open position, the bypass oil passage is communicated, and the crawler crane is operated. It becomes a driving mode. Therefore, even if hydraulic oil is supplied to the crane-side supply circuit via the traveling switching valve, the supplied hydraulic oil returns to the crane-side return circuit through the bypass oil passage and is not supplied to the hydraulic actuator of the crane. Operating the crane operating lever does not operate the crane. When the traveling switching valve is switched to the forward or backward traveling position, the crawler moves forward or backward.
At this time, the crane does not operate.

When the lever lock is set to the lock position, the traveling / crane changeover switch is switched to the crane operation mode by the lever lock, so that the traveling / crane switching valve is switched to the closed position, and the crawler crane enters the crane operation mode. In the crane operation mode in which the bypass oil passage is interrupted, when hydraulic oil is supplied to the crane side supply circuit via the traveling switching valve, the crane is operated by operating the crane operation lever to perform the crane operation. Can be.

Further, even if the operator tries to operate the traveling lever by mistake in the crane operation mode, the traveling switching valve cannot be switched because the traveling lever is locked by the lever lock. Absent.

Since the operator can easily visually recognize whether the lever lock is at the release position or the lock position, the operator can easily recognize whether the crawler crane is in the traveling mode or the crane operation mode.

That is, the safety device for the crawler crane has a configuration in consideration of safety so that the crane does not operate in the traveling mode and the crawler does not operate in the crane operation mode.

If the safety device of the crawler crane is provided with a spring for holding the lever lock at the lock position and the release position, the lever lock can be more reliably held at the lock position and the release position.

[0021]

FIG. 1 is a perspective view showing a lever lock of a crawler crane safety device according to an embodiment of the present invention and a mounted state of a traveling / crane changeover switch, and FIG. 2 is a release position of the lever lock. Front view showing the state of FIG. 3, FIG.
FIG. 4 is a plan view showing a state of the lever lock release position, FIG. 4 is a front view showing a state of the lever lock lock position, and FIG. 5 is a plan view showing a state of the lever lock lock position.

The basic configuration of the crawler crane is the same as that shown in FIG. 6, and the crawler crane 1 has a crane 4 and a crane 4 on a machine body 3 which can travel by left and right crawlers 2 which are lower traveling bodies. An outrigger 5 for securing the stability of the body 3 is provided. Crane 4
The boom 8 is pivotally supported on a column 7 that can pivot with respect to the body 3 so that the boom 8 can be raised and lowered. A hook 9 is suspended from the tip of the telescopic boom 8.

In order to carry out the work, the operator first operates the traveling lever 6 to move the crawler crane 1 to the working position, and extends the outrigger 5 back and forth and left and right as shown in FIG. I do. When the outrigger 5 is extended, the crane operation lever 10 is operated to rotate, raise, lower, expand and contract the boom 8 of the crane 4 to carry out crane operations such as lifting and hanging the load W.

The hydraulic circuit in the crawler crane 1 is the same as that shown in FIG. 8, and a traveling circuit 21 for operating the traveling hydraulic motors 20 of the left and right crawlers 2 is provided with a hydraulic switching valve 22 via a traveling switching valve 22. Discharge circuit 1 of pump 11
2 and a tank circuit 15 for returning hydraulic oil to the tank 14. A return filter 13 is provided in the tank circuit 15.

The traveling switching valve 22 is a three-position switching valve. When the traveling lever 6 is operated to switch the traveling switching valve 22 to the forward position, the traveling hydraulic motor 20 rotates forward and the crawler crane 1 is rotated. Moves forward, and the travel switching valve 22
Is switched to the retreat position, the traveling hydraulic motor 20 rotates in the reverse direction, and the crawler crane 1 retreats. In addition,
The speed of the traveling hydraulic motor 20 can be changed by a traveling hydraulic motor speed changeover switching valve 23.

A crane-side supply circuit 41 for supplying hydraulic oil to the hydraulic actuator of the crane 4 is connected to the downstream side of the traveling switching valve 22.
A crane-side return circuit 42 for returning hydraulic oil from a hydraulic actuator of the crane 4 is connected. When the traveling switching valve 22 is at the neutral position, the crane-side supply circuit 41 and the discharge circuit 12 of the hydraulic pump 11 communicate with each other, so that the hydraulic actuator of the crane 4 can be operated.

A bypass oil passage 43 is connected between the crane-side supply circuit 41 and the crane-side return circuit 42, and a traveling / crane switching valve 44 is provided in the middle of the bypass oil passage 43. The traveling / crane switching valve 44 is a normally closed solenoid valve, and its solenoid is connected to a normally open traveling / crane switching switch 45.

In the crawler crane 1 having the above structure,
The traveling / crane changeover switch 45 is, as shown in FIG.
It is installed on a side surface of a lever stand 61 that supports the traveling lever 6.

At the upper end of the lever stand 61, a lever lock 62 is pivotally connected to the traveling lever 6 and the traveling / crane switch 45. The lever lock 62 is a U-shaped plate in a plan view as shown in FIG. 3, and locks the travel lever 6 as shown in FIGS. Operation. At this time, the traveling / crane changeover switch 45 is OFF.

As shown in FIG. 2 and FIG.
In the release position in which the traveling lever 2 is turned to the traveling / crane switch 45, the traveling lever 6 is unlocked and can be operated. At this time, the lever lock 62 pushes the travel / crane switch 45, and the travel / crane switch 45 is turned on.

A spring 63 for holding a position is mounted between the lever stand 61 and the lever lock 62, so that the lever lock 62 is securely held at the lock position and the release position.

During operation, the operator operates the lever lock 62.
When the is in the release position, the traveling
The crane changeover switch 45 is turned on, the traveling / crane changeover valve 44 is switched to the open position, and the bypass oil passage 43
Are communicated, and the crawler crane 1 is in the traveling mode.
Therefore, even if hydraulic oil is supplied to the crane-side supply circuit 41 via the traveling switching valve 22, the supplied hydraulic oil returns to the crane-side return circuit 42 through the bypass oil passage 43 to the hydraulic actuator of the crane 4. Is not supplied,
Even if the crane operation lever 10 is operated, the crane 4 does not operate. When the traveling switching valve 22 is switched to the forward or backward traveling position, the crawler 2 moves forward or backward. At this time, the crane 4 does not operate.

When the lever lock 62 is in the lock position,
The traveling / crane switching switch 43 is turned off by the lever lock 62, the traveling / crane switching valve 44 is switched to the closed position, and the crawler crane 1 enters the crane operation mode. In the crane operation mode in which the bypass oil passage 43 is blocked, when hydraulic oil is supplied to the crane-side supply circuit 41 via the traveling switching valve 22, the crane 4 is operated by operating the crane operation lever 10, Crane work can be performed.

Further, even if the operator tries to operate the traveling lever 6 by mistake in the crane operation mode, the traveling switching valve 22 cannot be switched because the traveling lever 6 is locked by the lever lock 62, so that the crawler 2 cannot be operated. There is no danger of operation.

Since the operator can easily visually recognize whether the lever lock 62 is at the release position or the lock position, the operator can easily recognize whether the crawler crane 1 is in the traveling mode or the crane operation mode.

That is, the safety device for the crawler crane has a configuration in consideration of safety so that the crane 4 does not operate in the traveling mode and the crawler 2 does not operate in the crane operation mode.

[0037]

As described above, according to the crawler crane safety device of the present invention, the operator can easily recognize whether the crawler crane is in the traveling mode or the crane working mode. The crane does not operate even if the operation lever is touched, and the crawler does not operate even if the operator touches the traveling lever in the crane operation mode, so that the operation can be performed safely.

In addition, safety devices for crawler cranes include:
If a position holding spring for holding the lever lock at the lock position and the release position is provided, the lever lock can be more reliably held at the lock position and the release position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an attached state of a lever lock and a traveling / crane changeover switch of a safety device for a crawler crane according to an embodiment of the present invention.

FIG. 2 is a front view showing a state of a lever lock release position.

FIG. 3 is a plan view showing a state of a lever lock release position.

FIG. 4 is a front view showing a state in which a lever lock is in a lock position.

FIG. 5 is a plan view showing a state of a lock position of a lever lock.

FIG. 6 is a side view of the crawler crane.

FIG. 7 is an explanatory diagram of a working state of the crawler crane.

FIG. 8 is a hydraulic circuit diagram of the crawler crane.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crawler crane 2 Crawler 3 Body 4 Crane 5 Outrigger 6 Travel lever 7 Column 8 Boom 9 Hook 10 Crane operation lever 11 Hydraulic pump 12 Discharge circuit 14 Tank 15 Tank circuit 20 Travel hydraulic motor 21 Travel circuit 22 Travel switching valve 23 Travel Valve for hydraulic motor shift 24 Traveling circuit switching valve 41 Crane side supply circuit 42 Crane side return circuit 43 Bypass oil passage 44 Traveling / crane switching valve 45 Traveling / crane switching switch 61 Lever stand 62 Lever lock 63 Spring

Claims (2)

[Claims] 1. A traveling circuit for operating a hydraulic motor for traveling of a crawler, a crane-side supply circuit and a crane-side return circuit for operating a hydraulic actuator of a crane, and a traveling circuit and a crane side by operating a traveling lever. A travel switching valve that switches the supply of hydraulic oil to the supply circuit, a bypass oil path that connects the crane-side supply circuit and the crane-side return circuit, and travel that is provided in the bypass oil path and communicates with the bypass oil path. In a hydraulically driven crawler crane provided with a traveling / crane switching valve for switching between a mode and a crane operation mode in which the bypass oil passage is shut off, and a traveling / crane switching switch for performing a switching operation of the traveling / crane switching valve, Move near the travel lever
A crane changeover switch is installed, and the traveling / crane changeover switch is switched to the crane working mode at the lock position for locking the traveling lever, and the traveling / crane changeover switch is switched to the traveling mode at the release position for unlocking the traveling lever. A safety device for crawler cranes, which is provided with a lock. 2. The crawler crane safety device according to claim 1, further comprising a position holding spring for holding the lever lock at the lock position and the release position.