JP2002284496A - Safety gear for cargo handling vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety gear for a cargo handling vehicle, capable of avoiding possible inclination when a boom is in a loaded condition. SOLUTION: The safety gear for the cargo handling vehicle comprises a limit switch 43 for detecting that an outrigger 8 is at a ground position and pressure switches 63, 64 for detecting that a pre-charge pressure in a boom cylinder 18 exceeds a given value. When the limit switch 43 detects that the outrigger 8 is apart from the ground position and the pressure switch 63 or 64 detects that the pre-charge pressure in the boom cylinder 18 exceeds the given pressure, the operation of the boom cylinder 18 is stopped. In this construction, no loading space is supported by the rise of the outrigger 8 and when the boom lifts a slag pan (the pressure switch is operated) the operation of the boom cylinder 18 is stopped, thereby avoiding the possible inclination of the loading space due to the weight of the slag pan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a cargo handling vehicle used, for example, to lift and transport a slag pan on a steel mill or a wagon.

[0002]

2. Description of the Related Art Conventionally, when lifting and transporting, for example, a slag pot (an example of an article to be transported), a cargo handling vehicle shown in FIG. 3 has been used. That is, the cargo handling vehicle 1 comprises a front track head 2 and a rear trailer 5, where the track head 2 is composed of wheels 3 and a driving unit 4, and the trailer 5 is a loading platform 7 having wheels 6 A pair of outriggers 8 are provided in the rear left-right direction (vehicle width direction). A front portion of the trailer 5 is connected to a rear portion of the track head 2 via a vertical shaft 9 or the like, and a steering cylinder device 10 is provided between the track head 2 and the trailer 5. The outrigger 8 is configured to be movable in the vertical direction, and the rear part of the carrier 7 is supported when the outrigger 8 is lowered and is in contact with the ground.

[0003] Cargo handling means 11 provided on the carrier 7
Has a pair of booms 12 in the left-right direction (vehicle width direction),
These booms 12 are pivotally moved up and down and back and forth by connecting the base ends of the booms 12 to a pair of support members 13 erected at the rear end of the loading platform 7 by a horizontal shaft 14. It can be configured freely. The free ends of both booms 12 are integrated by a connecting member 15 in the left-right direction.

A vertical surface extending from the base end to the middle of both booms 12, that is, the upper surface when rotated into the loading platform 7 and the lower surface when rotated backward with respect to the loading platform 7. Is rotated into the carrier 7 (FIG. 3).
A locking portion 12A extending upward is provided integrally with the solid line),
The locking portion 12A has a C-shaped locking surface 16 that is opened upward (outside).

[0005] A pair of left and right cylinder devices 17 (hereinafter referred to as boom cylinder devices) for rotating the boom 12 are provided.
8 (hereinafter referred to as a boom cylinder) is connected via a pin 21 to a pair of brackets 20 erected at the front end of the carrier 7. Piston rod 19 extending backward
Is connected to the boom 12 via a pin 22 and a bracket 23.

At a middle portion of the boom 12, a holding means 25 for a slag pot 30 is provided. The holding means 25 is of a lock type, and includes a lock pin 26 and a pin operating device
It is composed of When the lock pin 26 is operated in the left-right direction (vehicle width direction) by the pin operation device 27, the lock pin 26 is configured to be freely engageable and disengageable from a lock hole formed in the slag pot 30.

The operating part 4 of the track head 2 includes operating levers (hereinafter, referred to as boom levers) 33 of the boom cylinder device 17 and operating levers (hereinafter, referred to as boom levers) 8 of the outrigger 8.
An outrigger lever 34) and an operation lever 35 of the pin actuator 27 are provided.

The boom cylinder 18 and the outrigger 8
FIG. 4 shows a hydraulic circuit for driving the motor. In FIG. 4, 41
Is a cylinder for each outrigger 8. Each of these outrigger cylinders 41 has a limit switch 42 that is turned on when the outrigger 8 is raised to the storage position and a limit switch that is turned on when the outrigger 8 is lowered to the ground position (position detection). (Example of means) 43 is provided. Also, the boom cylinder 18 and the outrigger cylinder 4
1 is provided with a main valve M for supplying pressure oil to each of the control valves 1 and a pilot valve P for supplying control oil for driving the main valve M. And outrigger lever 3
Control oil is supplied from the outrigger section 44 of the pilot valve P to the outrigger section 45 of the main valve M in response to the operation 4 (up or down), and pressure oil is supplied to each outrigger cylinder 41 from the outrigger section 45 of the main valve M. As a result, each outrigger 8 is raised or lowered. In addition, control oil is supplied from the boom section 46 of the pilot valve P to the boom section 47 of the main valve M in response to the operation (extension or contraction) of the boom lever 33, and the boom section 47 of the main valve M supplies each boom cylinder 18.
Supply of pressurized oil to each boom cylinder 18
Is extended or contracted. The boom section (an example of a control valve) 47 of the main valve M of the boom cylinder 18 supplies pressure oil to the tail side of the boom cylinder 18 and drains pressure oil on the rod side of the boom cylinder 18; A three-port, three-position switching valve having a neutral position for filling pressure oil at 18 and a position for supplying pressure oil to the rod side of the boom cylinder 18 and draining pressure oil at the tail side of the boom cylinder 18. By switching the pressure oil supplied to the tail side and the rod side of the boom cylinder 18, the boom cylinder 18 is extended or contracted, and the boom 12 is rotatably driven in the front-rear direction. When the boom section 47 of the main valve M is in the neutral position, the pressure oil is filled and the operation of the boom cylinder 18 is stopped. Control oil is supplied to each section 44, 46 of the pilot valve P from an auxiliary oil pump (not shown), and pressure oil is supplied to each section 45, 47 of the main valve M from a main oil pump (not shown). It is supplied and each drain is returned to an oil tank (not shown).

A boom control line 48 connecting the boom section 46 of the pilot valve P and the boom section 47 of the main valve M (extension side) has a first pressure switch that operates when the hydraulic pressure of the line 48 becomes higher than a predetermined pressure. Further, a boom control line 50 that connects the boom section 46 of the pilot valve P and the boom section 47 of the main valve M (contraction side) is provided with a second boom control line 50 that operates when the hydraulic pressure of the line 50 becomes equal to or higher than a predetermined pressure. A pressure switch 51 is provided. These pressure switches 49 and 51 operate when control oil is sent from the boom section 46 of the pilot valve P to the boom section 47 of the main valve M.

Although not shown, the green lamp is turned on by the operation of the limit switches 42 of the left and right outriggers 8 (turned on at the storage position), and the red lamp is operated by the operation of the limit switch 43 (turned on at the ground position). Is turned on, and when the pressure switch 49 or 51 is operated, that is, when the control oil is sent to the main valve 47 by operating the boom lever 33, the buzzer sounds.

According to such a conventional structure, when the slag pot 30 containing slag (mine slag) is lifted and transported, for example, the outrigger 8 is first lowered by operating the outrigger lever 34 to be grounded. 3 are supported by the left and right outriggers 8, and then, as shown by the imaginary line A in FIG. 3, the locking surfaces 16 of both booms 12 engage with a pair of suspension pins 31 provided on the slag pot 30. Is done. At this time, both booms 12 are rotated rearward around the left-right axis 14 by the extension movement of the boom cylinder device 17.

In this state, when the boom cylinder 18 is contracted and moved by operating the boom lever 33, the slag pot 30 is lifted via the boom 12 which is turned upward, and the boom 12 is further turned forward. After that, the slag pot 30 is positioned on the bed 7 as shown by the solid line in FIG. Then, the outrigger 8 is raised and stored by operation of the outrigger lever 34, and is transported to a target place.

When the vehicle arrives at the target place, the outrigger 8 is lowered by operating the outrigger lever 34 and grounded, and the holding means 2 incorporated in the boom 12 is operated by operating the operating lever 35 of the pin operating device 27.
5, the pin actuating device 27 in the lock pin 2 is driven.
The slag pot 30 is held (locked) on the boom 12 side by operating the 6 in the left-right direction and engaging with the lock hole. With the slag pot 30 held by the holding means 25 in this manner, the boom cylinder 18 is moved to the boom lever 33.
As the boom 12 is rotated rearward by the reverse action of the operation described above, the slag pot 30 swings backward in the upside down direction as shown by the imaginary line B in FIG. Thus, the slag is discharged from the slag pot 30. Thereafter, the state is returned to the state shown by the solid line in FIG.
The outrigger 8 is raised by operating the outrigger lever 34, and the empty slag pot 30 is transported.

[0014]

In the above-described conventional configuration, when the slag pot 30 is to be lifted (when a load is applied to the boom 12) while the outrigger 8 is not grounded, the cargo handling vehicle 1 is weighted by the weight. There was a risk of leaning toward the slag pot 30.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a safety device for a cargo handling vehicle that can avoid the risk of tilting when the boom is in a load state.

[0016]

In order to achieve the above-mentioned object, the present invention according to claim 1 is provided with an outrigger which can be moved up and down on a carrier, and is provided on the carrier so as to be able to rotate back and forth. A safety device for a cargo-handling vehicle that lifts and conveys an object to be conveyed by rotating a boom by a contraction movement of a boom cylinder, wherein: a position detection unit that detects that the outrigger is at a ground contact position; A pressure detecting means that operates when the sealing pressure of the cylinder exceeds a certain value, wherein the position detecting means detects that the outrigger has moved away from the ground position, and the pressure detecting means reduces the sealing pressure of the boom cylinder to a certain value. When the exceeding is detected, the operation of the boom cylinder is stopped.

According to this configuration, when the boom is rotated upward by the contraction movement of the boom cylinder to lift the conveyed object, that is, when pressure oil is supplied to the boom cylinder, the boom cylinder is moved. The sealing pressure increases and the pressure detecting means operates. At this time, the operation of the boom cylinder is stopped unless the outrigger moves away from the ground contact position and the position detecting means does not operate. Alternatively, if the outrigger is raised (moves away from the ground contact position) while the pressure detecting means is operating, the operation of the boom cylinder is stopped. Therefore, when the outboard is not supported by the outrigger and the boom lifts the load, or when the boom lifts the load, or when the outrigger stops supporting the load, the weight of the load is The risk of the carrier tilting is avoided.

According to a second aspect of the present invention, in the first aspect, the control valve of the boom cylinder is provided with a position for supplying the hydraulic oil to the tail side of the boom cylinder, And a switching valve having a position for supplying pressure oil to the rod side of the boom cylinder, and the operation of the boom cylinder is stopped by returning the control valve to the neutral position. It is characterized by the following.

According to this configuration, when the control valve is returned to the neutral position, the pressure oil of the boom cylinder is sealed, and the operation of the boom cylinder is stopped. Claim 3
The invention according to claim 1 is the invention according to claim 1 or 2, wherein a manual operating means is provided, and the operation of the boom cylinder is permitted by operating the manual operating means. .

In operation, when an object to be transported is lifted and loaded on a carrier, there is a task of raising the outrigger and lowering the boom in a state where the object to be transported is lowered to the carrier half. According to this configuration, the transported object is lifted by the boom in a state where the outrigger is lowered and grounded, and the carrier is supported by the outrigger, and thereafter, when the outrigger is raised, the operation of the boom cylinder is stopped.
At this time, when the manual operation means is operated, the operation of the boom cylinder is permitted, the boom can be lowered, and the above operation can be performed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main part hydraulic circuit diagram of a cargo handling vehicle according to an embodiment of the present invention. Note that the mechanical structure of the cargo handling vehicle is the same as the above-described conventional configuration (FIG. 3), and description thereof will be omitted. The same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, a (extension side) boom control line 48 is newly added to the first 4 port 2 position.
The solenoid valve 61 is inserted, the second solenoid valve 62 at the 4 port 2 position is inserted into the (contraction side) boom control line 50, and a third pressure switch is connected to the outlet (cylinder tail side) of the boom section 47 of the main valve M. 63 is provided, and a fourth pressure switch (an example of pressure detecting means) 64 is provided at an outlet (cylinder rod side) of the boom section 47 of the main valve M.
The first solenoid valve 61 is configured to communicate with the boom control line 48 when its exciting coil is excited (extension side), and to shut off when it is not excited. The second solenoid valve 62 is configured so that its exciting coil Is configured to communicate with the boom control line 50 when excited (retracted side), and cut off when not excited.

The third pressure switch 63 and the fourth pressure switch 64 are provided when the pressurized oil is supplied to the boom cylinder 18 and the filling pressure exceeds a certain value (when a load is applied), that is, when the slag pot is a conveyed object. It is set so as to operate when the 30 is raised or lowered. The first pressure switch 49 is provided between the first solenoid valve 61 of the (extension side) boom control line 48 and the boom section 46 of the pilot valve P, and the second pressure switch 51 is connected to the (retraction side) boom. It is provided between the second solenoid valve 62 of the control line 50 and the boom section 46 of the pilot valve P.

The boom lever 33 is provided with a switch (an example of a manual operation means; hereinafter referred to as a manual operation means) which is turned on by manual operation.
A cancel switch 65 is provided. FIG. 2 shows an electric circuit diagram relating to the operation of the boom 12 and the outrigger 8.

As shown in FIG. 2, the first pressure switch 49
Alternatively, a buzzer (boom buzzer) 71 that is sounded by the operation of the second pressure switch 51 is provided, and is turned on when both the limit switches 42 of the left and right outriggers 8 are operating (turned on in the storage position). A green (G) lamp 72 is provided, and a red (R) lamp 73 and a buzzer (outrigger buzzer) 74 that light up when any of the left and right limit switches 43 are operating (turned on at the ground position). Is provided.

The relay D which is excited when both the limit switches 42 of the left and right outriggers 8 are operating (turned on at the storage position), and the left and right limit switches 4
A relay B which is excited when both 3 are operating (turned on at the ground position) is provided, the first pressure switch 49 or the second pressure switch 51 is operated, and the contact a of the relay D (when the relay is excited). A red rotating lamp 76 with a buzzer alarm which is sounded and lit when a contact 75 operating when it is on is provided. The red rotating light 76 with a buzzer alarm is installed in the operation unit 4.

The OR circuit of the third pressure switch 63 and the fourth pressure switch 64 of the boom cylinder 18 includes:
The contact b (contact which turns on when the relay is not excited) 77 of the relay B and the relay A (excitation coil) are connected in series, and the relay A operates the third pressure switch 63 or the fourth pressure switch 64. The relay B is configured to be excited when the relay B is not excited (when at least one of the pair of outriggers 8 is not grounded).

The relay C is connected to the a contact 78 of the relay A.
(Excitation coil) and the cancel switch 65 are connected in series, and the relay C is configured so that the relay A is excited and the cancel switch 65 is excited.

The first solenoid valve 61 and the second solenoid valve 61
The excitation coils 61a and 62a of the solenoid valve 62
The a contact 78 of the relay A and the a contact 79 of the relay C
Is connected to a parallel circuit consisting of a series circuit of the relay A and the b contact 80 of the relay A, and is configured to be excited when the relay A is excited and the relay C is excited, or when the relay A is not excited. Have been.

The operation of the boom 12 and the outrigger 8 by the hydraulic circuit and the electric circuit will be described. When the control power is turned on, first, the first solenoid valve 61 and the second solenoid valve 61 are turned on.
Power is supplied to the exciting coils 61a and 62a of the solenoid valve 62 via the contact b of the relay A, so that the first solenoid valve 61 and the second solenoid valve 62 operate,
(Extension side) Boom control line 48 and (Retraction side)
The boom control line 50 connects between the boom section 46 of the pilot valve P and the boom section 47 of the main valve M, so that the boom 12 can be operated. (1) Lighting of the red rotary light 76 with buzzer alarm when the boom lever 33 is operated The outrigger 8 is raised and retracted (both the left and right limit switches 42 are on, the relay D is excited, and the contact a is on. In this state, when the boom lever 33 is operated, the boom control line 48 or 50 through the boom section 46 of the pilot valve P is operated.
Control oil is supplied to the first pressure switch 49 or the second pressure switch 49.
The pressure switch 51 operates and the red rotating light 7 with buzzer alarm
6 operates, the buzzer sounds, and the red rotating light 76 turns on and rotates.

When the outrigger 8 is lowered, the left and right limit switches 42 are both turned off, the relay D is not excited, and the contact a is turned off. Therefore, power is not supplied to the red rotary light 76 with buzzer alarm, and the buzzer stops. Then, the red rotating light 76 is turned off. (2) Interlock of the operation of the boom 12 “When the outriggers 8 descend” When the outriggers 8 descend,
The limit switches 43 of the left and right outriggers 8 (on at the ground position) are both turned on, and the red (R) lamp 7 is turned on.
3 lights up, the outrigger buzzer 74 sounds, and the relay B is excited.
Is turned off, and the power supply to the relay A is cut off (the relay A is not excited). Therefore, regardless of the load on the boom 12, the b-contact of the relay A is turned on, and power is supplied to the exciting coils 61a, 62a of the first solenoid valve 61 and the second solenoid valve 62 via the b-contact of the relay A. As described above, the operation of the boom 12 can be performed.

When the outrigger 8 is raised (no load), the limit switches 42 of the left and right outriggers 8 (on at the storage positions) are both turned on, and the green (G) lamp 72 is lit. I do. Also, the limit switches 43 (on at the ground position) of the left and right outriggers 8 are both off when the outrigger 8 is away from the ground position (during or rising), so that the relay B is in a non-excited state. This relay B
Is turned on.

However, when there is no load, the boom cylinder 1
Since the pressure switches 63 and 64 of No. 8 do not operate,
The power supply to the relay A remains interrupted (the relay A is not excited). Accordingly, the contact b of the relay A remains in the ON state, and the relay A is connected to the exciting coils 61a and 62a of the first solenoid valve 61 and the second solenoid valve 62.
Of the boom 12 as described above.
Operation becomes possible.

"When the outrigger 8 is raised (during load)" When the outrigger 8 is being raised or raised, the relay B is in a non-excited state as described above.
The contact 77 is turned on.

In this state, when the slag pot 30 is grasped and lifted by the boom 12 (when the boom lever 33 is operated), when the slag pot 30 is lifted from the ground, the sealing pressure on the rod side of the boom cylinder 18 increases, or When the slag pot 30 is lifted from the carrier 7, the tail-side sealing pressure of the boom cylinder 18 increases, and the fourth pressure switch 64 on the rod side or the third pressure switch 63 on the tail side operates. Then, the relay A is excited to operate, the contact 80 of the relay A is turned off, and the power supply to the exciting coils 61a, 62a of the first solenoid valve 61 and the second solenoid valve 62 is cut off. The operation of the second solenoid valve 62 is turned off, and the (extension side) boom control line 48 and the (contraction side) boom control line 50 are both shut off,
The control oil pressure of the boom section 47 of the main valve M is lost, and the boom section 47 of the main valve M is set to the neutral position. Therefore, even if the boom lever 33 is operated, the boom 12 is not operated. Therefore,
When the outrigger 8 is not grounded, the boom 12
When the slag pot 30 is lifted, the fourth pressure switch 64 or the third pressure switch 63 operates to stop the operation of the boom.

In operation, when the slag pot 30 is loaded on the loading platform 7 with the slag pot 30, the outrigger 8 is raised and the boom 12 is lowered in a state where the slag pot 30 is partially lowered onto the loading platform 7. If the outrigger 8 is raised in a state where the slag pan 30 is supported by the boom 12 (during load), the boom 12 cannot be operated as described above. At this time, the cancel switch 65 is operated. When the cancel switch 65 is turned on, the relay C is excited via the a-contact 78 which is turned on because the relay A is excited, so that the a-contact 79 of the relay C is turned on, and the a-contact of the relay A is turned on. The power is supplied to the exciting coils 61a and 62a of the first solenoid valve 61 and the second solenoid valve 62 via the contact 78 of the relay C and the a contact 79 of the relay C,
Therefore, the first solenoid valve 61 and the second solenoid valve 62 are operated, and the boom section 46 of the pilot valve P and the boom section 47 of the main valve M are operated by the (extension side) boom control line 48 and the (contraction side) boom control line 50. The connection is established, the boom 12 can be operated, and the above-described special work can be performed. When the operation of the cancel switch 65 is stopped, the operation of the boom 12 cannot be performed again.

As described above, when the outrigger 8 is lowered and grounded, or when the outrigger 8 is away from the grounded position and is in a no-load state (a state in which the slag pan 30 is not supported), the boom 12 can be freely moved. When the slag pot 30 is lifted in a state where the slag pan 30 can be operated and the outrigger 8 is away from the ground position (in a state of being raised or raised and stored), the operation of the boom 12 is stopped, and the cargo handling vehicle is stopped. 1 is prevented from tilting due to the weight of the slag pot 30, and danger can be avoided.

When the outrigger 8 is stored and the slag pot 30 is being lifted, if the cancel switch 65 is operated, the boom 12 can be freely operated only when the slag pot 30 is being operated. The above-described special operation of raising the outrigger 8 and lowering the boom 12 with the lowering of the boom 12 can be performed in a state where the outrigger 8 is lowered on the carrier 7.

When the boom lever 33 is operated in a state where the outrigger 8 is not grounded, the red rotating light 76 with a buzzer alarm operates, the buzzer sounds, and the red rotating light 7
By turning on and rotating 6, it is possible to inform the worker in advance that the outrigger 8 is not lowered and the bed 7 may be tilted when the slag pot 30 is lifted by the boom 12.

In the present embodiment, the slag pot 30 having the hanging pins 31 is shown as the transported object having the locked portion, but the slag pot 30 having the hanging pins may be used.
It can handle various transported objects.

In the present embodiment, the release of the outrigger 8 from the contact position is detected by turning off the limit switch 43 (ON at the contact position). ) Is turned on, it is also possible to detect that the outrigger 8 has left the ground position.

[0042]

As described above, according to the present invention, when the load carrier is not supported by the outrigger and the load is lifted by the boom, it is possible to avoid the possibility that the load container tilts due to the weight of the load. it can.

[Brief description of the drawings]

FIG. 1 is a main part hydraulic circuit diagram of a cargo handling vehicle according to an embodiment of the present invention.

FIG. 2 is a main part electric circuit diagram of the cargo handling vehicle.

FIG. 3 is a side view of a conventional cargo handling vehicle.

FIG. 4 is a hydraulic circuit diagram of a main part of a conventional cargo handling vehicle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cargo handling vehicle 2 Truck head 5 Trailer 7 Carrier 8 Outrigger 10 Steering cylinder device 11 Cargo handling means 12 Boom 17 Boom cylinder device 18 Boom cylinder 30 Slug pot (conveyed material) 33 Boom lever 34 Outrigger lever 41 Outrigger cylinder 42, 43 Limit switch 45 Boom section of main valve (control valve) 61, 62 Solenoid valve 63, 64 Pressure switch 65 Cancel switch M Main valve P Pilot valve

Claims (3)

[Claims] An object is lifted by rotating a boom provided on a carrier such that the carrier is vertically movable by a retractable movement of a boom cylinder. A safety device for a cargo-handling vehicle to be transported, comprising: a position detection unit that detects that the outrigger is at a ground contact position; and a pressure detection unit that detects that a sealing pressure of the boom cylinder has exceeded a predetermined value, When the position detecting means detects that the outrigger has left the ground position, and the pressure detecting means detects that the sealing pressure of the boom cylinder has exceeded a certain value,
A safety device for a cargo handling vehicle, wherein the operation of the boom cylinder is stopped. 2. A control valve for the boom cylinder, a position for supplying pressure oil to the tail side of the boom cylinder, a neutral position for filling the pressure oil for the boom cylinder, and a position for supplying pressure oil to the rod side of the boom cylinder. The safety device for a cargo handling vehicle according to claim 1, wherein the switching valve includes a switching valve, and the operation of the boom cylinder is stopped by returning the control valve to a neutral position. 3. A cargo handling vehicle safety device according to claim 1, wherein a manual operation means is provided, and operation of the boom cylinder is permitted by operation of the manual operation means.