JPS5921808B2 - Dump truck with crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crane-equipped dump truck equipped with a cargo box and a crane.

Generally, a crane-equipped dump truck has a cargo box mounted on the undercarriage so that it can be tilted backwards, and a crane is installed between the cargo box and the driver's seat, and the crane lifts the dust box etc. There is a system in which the cargo is loaded into a cargo box, and the cargo is discharged by tilting the cargo box.

Each boom of the crane is moved by the telescoping motion of a hydraulic cylinder, and the cylinders are further controlled by a directional control valve.

The neutral position of the directional control valve is a closed center type, and when it is in the neutral position, the oil in the cylinder does not move.
Therefore, each boom of the crane can be held fixed without the cylinder moving in both the contraction direction and the extension direction.

However, in the above-mentioned crane-equipped dump truck, each boom of the crane is positioned outside the tilting range of the cargo box when the cargo box is tilted to discharge the loaded material.
If the crane boom is stopped above the cargo box and the cargo box is tilted due to an incorrect operation, the boom and the cargo box will collide violently because the boom is held fixed by the directional control valve. There was a problem of damage to the boom or cargo box.

The present invention has been made in view of this problem, and even if the boom of the crane is positioned above the cargo box and the cargo box and boom come into contact with each other when the cargo box is tilted, the boom will not be able to carry the load. To provide a dump truck with a crane that moves by following the tilting of the box, thereby preventing damage to the crane or cargo box.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, reference numeral 1 is a dump truck with a crane, in which a cargo box 3 is tiltably supported on a chassis 2 by a pin 4 at the rear lower end. A crane 6 is placed between the seat 5 and the seat 5.

The cargo box 3 is divided into a front cargo box 3a and a rear cargo box 3b, and both the front and rear cargo boxes 3a and 3b are rotatably connected to each other by a connecting shaft 7 at the lower center end. 3a is provided with rollers 8 on the lower surface of the front end so as to be able to slide on the rails 9 of the chassis 2, and the rear cargo box 3b has a tailgate 10 held at its upper end at the rear, and there is a space between the rear cargo box 3b and the chassis 2. is connected to the dump cylinder 11.

The cargo box 3 is folded in half by the extension of the dump cylinder 11, and the upper end of the central portion is opened to form an input port 12, and a fan-shaped plate 1 is provided to close the gap on the side surface that is created when the container is opened.
3 is fixed on one side to the front packing box 3a, and the other side is stored in the rear packing box 3b, and protrudes when the slot 12 is opened.

Further, the front cargo box 3a and the rear cargo box 3b are connected to the side lashing device 1.
4, they can be connected together.

The crane 6 lifts the dust box 15 and carries it above the input port 12, and a swivel platform 16 is mounted on the chassis 2.
The swivel table 16 has two swivel cylinders 17, 17 connected to each other, and a column 18 erected on the top thereof.
A hoisting boom 19 is provided at the tip of the support column 18, and a hoisting boom 1
A bending boom 20 is rotatably attached to the tip of the bending boom 9, and a first telescoping boom 2 is disposed within the bending boom 20.
1, a second telescoping boom 22 is disposed within the first telescoping boom 21.
is telescopically inserted and retracted.

Further, a hoisting cylinder 23 is connected between the support column 18 and the hoisting boom 19, a bending cylinder 24 is connected between the hoisting boom 19 and the bending boom 20, and a bending cylinder 24 is connected between the bending boom 20 and the first and second telescopic booms. A telescopic cylinder 25 is connected between the booms 21 and 22, and the dust box 15 is suspended from the tip of the second telescopic boom 22 via a hook 26, and each cylinder 23.2
4,25 telescopic movements of each boom 19°20.21.
Move 22.

Also, a jack cylinder 27 is provided on both sides of the center portion of the vehicle chassis 2, and the jack cylinders 27 support the chassis 2 when the crane 6 is in operation.

The hydraulic circuit 28 connected to each cylinder 17, 23, 24° 25 and the jack cylinder 27 of the crane 6 includes:
As shown in FIG. 3, a refraction cylinder directional control valve 29 that controls the refraction cylinder 24, a telescopic cylinder directional control valve 30 that controls the telescopic cylinder 25, an undulation cylinder directional control valve 31 that controls the undulation cylinder 23, A swing cylinder directional switching valve 32 for controlling the swing cylinder 17 and a jack cylinder directional switching valve 33 for controlling the jack cylinder 27 are provided in parallel, and each directional switching valve 29, 30.
31.32.33 pump side ports 29a, 30a, 3
1a, 32a, 33a are connected in parallel to a supply path 37 having a strainer 35 and a hydraulic pump 36 connected to an oil tank 34, and tank side ports 29b, 30b, 31b,
32b.

33b is connected in parallel to a discharge passage 38 connected to the oil tank 34, and the supply passage 37 and the discharge passage 38 are connected via a relief valve 39.

The rear port 24a of the refraction cylinder 24 is connected to the counterbalance valve 40 to connect the refraction cylinder directional control valve 290B.
The front port 24b is fully connected to the pilot line 40a of the counterbalance valve 40, and the front port 29C is fully connected.

The neutral position of the bending cylinder directional switching valve 29 is of a closed center type, with a manual lever 41 on one side and a spring 42 on the other side, so that the oil in the bending cylinder 24 does not move when in the neutral position. , the refractive boom 20 is held fixed.

Rear port) 25a and front port) 2 of the telescopic cylinder 25
5b are respectively connected to the A boat 30c and the B port 30d of the telescopic cylinder directional switching valve 30, and the neutral position of the telescopic cylinder directional switching valve 30 is also a closed center type, and a manual lever 43 is provided on one side. In the neutral state, the oil in the telescopic cylinder 25 does not move, and the first and second telescopic booms 2L22 can be held fixed.

The rear port 23a of the hoisting cylinder 23 is connected to B of the hoisting cylinder directional control valve 31 via a counterbalance valve 44.
The front port 23b is connected to the pilot line 44a of the counterbalance valve 44, and is fully connected to the front port 31c.

The neutral position of the directional switching valve 31 for the hoisting cylinder is in the form of a pressure port block, and a manual lever 45 is provided on one side.
d are both connected to the tank side port 31b, and the luffing cylinder 23 allows oil to flow in from the rear port 23a.
Only extension movement is possible, and the lifting boom 19 can be moved upward.

The rear port t17a of the one swing cylinder 17 is connected to the front port 32c of the swing cylinder directional control valve 32, and is also connected to the discharge passage 38 via the relief valve 46, and is also connected to the pilot line 46a of the relief valve 46. The rear port 17a of the other swing cylinder 17 is connected to the B port 32d of the swing cylinder directional control valve 32, and is further connected to the discharge passage 38 via the check valve 47. The front ports 17b, 1'7b of both swing cylinders 17, 17 are They are connected to each other and to the rear port 17a of one swing cylinder 17 via a check valve 50.

The neutral position of the directional switching valve 32 for the swing cylinders is of a closed center type, and a manual lever 51 is provided on one side, and in the neutral position, the oil in both swing cylinders 17, 17 does not move, and the swing base 16 is Can be held fixed.

The rear port (27a) of the jack cylinder 27 is connected to the rear port (A) of the jack cylinder directional control valve 33 via the stop valve 52.
Connected to port 33c, front port) 27b is connected to B port 3
3d, the neutral position of the directional control valve 33 for the jack cylinder is a closed center type, and a manual lever 53 is provided on one side.
The oil 7 does not move, and the cylinder cylinder 27 can be held fixed.

Note that 54 is a hydraulic pump, and although not shown, the dump cylinder 11 of the cargo box 3 and the like are not connected.

Next, to explain the operation, when loading garbage into the cargo box 3, as shown in FIG. The packing box 3 is folded in half, the input port 12 is opened,
Subsequently, the directional control valves 29, 30, 31, 32, and 33 are operated to operate the support column 18 and each boom 19, 20, and 21, 22 to lift the dust box 15 and throw in the garbage.

Also, when discharging garbage, use the front loading box 3a and the rear loading box 3.
Extend the dump cylinder 11 with b secured,
The cargo box 3 is tilted rearward as one body to be discharged.

At that time, each boom 19.20, 21.22 of crane 6
is positioned outside the tilting range of cargo box 3, but
As shown in Figure 4, each boom 19
, 20° 21.22 are positioned above the cargo box 3, and when the cargo box 3 is tilted, the upper front end of the cargo box 3 and the undulating boom 19 come into contact.

When the cargo box 3 and the hoisting boom 19 come into contact, the directional control valve 31 controlling the hoisting cylinder 23 is in the neutral position, so the cargo box 3 will tilt and the hoisting boom 19 will move upward. Then, the piston of the undulation/cylinder 23 is pulled out, and therefore the oil in the undulation cylinder 23 flows to the front port 23.
It flows out from b.

On the other hand, the opposite side of the piston becomes a negative pressure, and the oil flowing out from the front port 23b flows in from the rear port 23a via the A port 31c and the B port 31d.

In addition, the underpressure oil for the piston rond is replenished from the tank side.

As a result, the luffing cylinder 23 follows the tilting movement of the cargo box 3.
is extended and the hoisting boom 19 moves upward.

As described above, according to the crane-equipped dump truck of the present invention, the two ports that can be connected to the hoisting cylinder when the directional control valve that controls the hoisting cylinder is in the neutral state are both connected to the tank side port, so that the boom of the crane may be damaged due to erroneous operation. The loading box is tilted while positioned above the loading box, and when the loading box contacts the boom, the boom moves upward following the tilting of the loading box, so the loading box or boom does not move. Work can be done safely without any damage.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention, and FIG. 1 is a side view of a dump truck with a crane when it is running, FIG. 2 is a side view of the same when it is loaded, and FIG. 3 is a diagram showing each cylinder of the crane. FIG. 4 is a side view of the crane-equipped dump truck showing the connection between the cargo box and the crane. 1... Dump truck with crane, 2... Chassis, 3... Loading box, 3a... Front loading box,
3b... Rear cargo box, 6... Crane,
16... Swivel base, 17... Swivel cylinder, 18... Strut, 19... Lifting boom, 20... Refraction boom, 21 ......First telescopic boom, 22...Second telescopic boom, 23
・・・・・・Elevation cylinder, 24 ・・・Refraction cylinder, 25 ・・・ Telescopic cylinder, 29.30.3
1.32, 33... Directional switching valve, 29a, 30
a, 31 a, 32a, 33a...Pump side port, 29b, 30b, 31 b, 32b. 33b...tank side port, 29c, 30c. 31c, 32c, 33cmA port, 29d. 30d, 31d, 32d, 33d...
・B port, 36.54...Hydraulic pump, 40
, 44... Counter balance valve.

Claims (1)

[Scope of Claims] 1. A cargo box is mounted on a vehicle chassis so as to be freely tiltable, and a crane having a lifting cylinder linked to a boom pivotally supported by a support is placed between the cargo box and the driver's seat. , the outlet sides A and B of a pressure port flock type directional control valve are connected to the undulating cylinder, and the two outlet sides A and B are connected to the undulating cylinder when the directional control valve is in the neutral state.
A dump truck with a crane characterized in that both ports are connected to a tank side port. 2. A crane according to claim 1, wherein the cargo box is divided into a front cargo box and a rear cargo box, and the front cargo box and the rear cargo box are pivotably connected to each other. dump truck.