JPS5830860Y2 - excavator - Google Patents

Description

[Detailed Description of the Invention] The present invention is of a type in which an arm on which a packet for excavation is mounted at one end is mounted on a boom, and the packet is horizontally pushed out by the boom and arm to excavate earth and sand. It concerns excavators.

Conventionally, this type of excavator has a boom 4 which is tilted up and down by a boom cylinder 3 at the front part of a revolving body 2 on a traveling body 1 shown in FIG. An arm 6 to be swung is pivotally mounted, and the arm 6
It has a structure in which a bucket 1-10, which is rotated by a packet cylinder 9 connected via a pair of rigid links 7.8, is pivotally attached to the tip of the bucket 1-10.

When carrying out a loading operation using this excavator, the packet 10 is drawn toward the traveling body 1 as shown in the figure, and from this position the packet 10 is pushed out horizontally to the front as shown in FIG.

Next, after operating the packet cylinder t to tilt the bucket l-10 back to the position of the imaginary line, the boom cylinder 3 was operated to raise the packet 10 and install it inside the packet 10, as shown in FIG. An earth unloading cylinder (not shown) is operated to open the front of the packet 10 and the earth is dumped onto the loading platform of a truck or the like.

When the soil ejection is completed, the packet 10 is closed and returned to the position shown in Fig. 1.

In addition, when tilting back the packet 10 in FIG. 2, when the rod of the packet cylinder 9 is extended, the link 7 rotates to the position of the imaginary line, and the link 7 rotates to the position of the imaginary line, and the link 7 rotates to the position of the imaginary line.
・When the bucket hits the brim 11, the rotation of the bucket) 10 is stopped and the tilt-back operation ends.

In the foregoing operation, when returning the bucket 10 from the position of FIG. 3 to the position of FIG. 1, the boom 4 shown in FIG. The quadrilateral formed by the arm 6, the link 7, and the packet cylinder 9 is in a state where its deformation is restrained by the stopper 11.

That is, even if pressure oil is applied to the rod retraction side oil chamber 5b of the arm cylinder 5, the rod will not move.

For this reason, in conventional excavators, the arm cylinder 5
At the same time as the above operation, the packet cylinder 9 can be operated to retract the packet 10 to return it to the position shown in FIG.
is connected to an oil tank 13 via an overload relief valve 12 to relieve the pressure oil in the oil chamber 9a.

However, in the former case, in addition to operating the boom 4 and arm 6, it is also necessary to operate the packet cylinder 9, which makes the operation complicated and also requires that the oil be discharged from the hydraulic pot.
・Since the part is sent to the bucket cylinder 9, there is a disadvantage that the operation is slow.
:j:δ・Although this can be solved, there is a drawback that high pressure is generated in the rod retraction side oil chamber 5b of the arm cylinder 5, which slows down the operation.

In order to increase the tilt-back force of the dirt bucket 10 by 1 minute, the capacity of the bucket cylinder 9 is increased, and the contraction force of the cylinder 5 increases by 1 minute. packet 10
2 will not be able to pull it to the position shown in Figure 1.

In particular, recent trends have shown that the tilt-back force of this type of excavator has been strengthened. Therefore, solving the above problem is important.

In view of the above-mentioned point, the present invention provides an excavator that can easily and quickly tilt back the bucket I and move the arm in the t2 state.

The present invention connects the bucket cylinder's bucket cylinder +, l, and back side oil chambers to the oil tank via over-low relief valves, and connects the overload relief valves to the arm cylinder's a=, 2. It is characterized in that it is configured to be operated by the sum of the pressure in the retraction side oil chamber and the pressure in the bucket chill l-back side oil chamber of the bucket cylinder.

An embodiment of the excavator of the present invention will be described below with reference to FIGS. 4 and 5.

In the figures, the same reference numerals as in FIGS. 1 to 30 indicate the same things.

/Kent cylinder cylinder 9 has a bucket chill l-back side oil chamber, in the case shown, a rod extrusion side oil chamber 9a, a bar opening, a relief valve 14, and an oil tank 15.
It is connected to.

The 1-bar load relief bar is Fli 4
Rod extrusion side oil chamber 9a (, 7) of self-packet cylinder 9
It is configured to operate based on the sum of the J pressure and the pressure in the arm retraction side oil chamber of the arm cylinder 5, in the case shown, the rod retraction side oil chamber 5b.

FIG. 5 shows the overload relief valve 14.
A structural example is shown in which the valve body 14a has a spool 14C in its sleeve 14b, a bow 114d that communicates with the rod extrusion side oil chamber of the bucket cylinder, and a valve body 114d that communicates with the rod retraction side oil chamber of the arm cylinder. Bows 1 to 14f communicating with the bow h14e and the oil tank 15 are provided.

The spool 14e normally sets the relief pressure;
The ball l-14d and the boat 14f are closed by being pressed by the ring 14g.

When a high pressure E acts on the bows 1 and 14d, that is, high pressure is generated in the rod extrusion side oil chamber of the bucket cylinder and acts on the pressure receiving part 14h of the spool 14C, the spool 14C is moved to the pressure receiving part 14i. It moves against the spring 14g due to the sum of the acting pressure and the high pressure, and connects the Po River 14f with the Po River 14d.

Since the excavator of the present invention is constructed as described above, in order to pull back the arm 6 from the posture shown in FIG. When the oil is sent, the arm 6 tries to be pulled back, but the boot 184, the arm 6 and the link 7. A part of the quadrilateral formed by the bucket 1 and the cylinder 9 is blocked by the bath I and the collar 11 and its deformation is restrained.
High pressure is generated in the oil chamber 9a on the rod extrusion side.

The oil chambers 5b and 9a respectively correspond to the spool receiving portions 141 of the over-low relief valves 7-14 shown in FIG.
1, Mi, the pressure oil in the rod extrusion side oil chamber 9a of the bucket I/cylinder 9 is overbake-drilled by the sum of the self pressure and the pressure in the rod retraction side oil chamber 5b of the arm cylinder 5. - The oil tank 15 is relieved by the valve 14.

That is, the pressure in the rod extrusion side oil chamber 9a of the bucket cylinder 9 is lower than the pressure in the rod retraction side oil chamber 5b of the arm cylinder 5.

Therefore, the opposing force of the bucket cylinder 9 is reduced, and the arm 6 can be easily pulled back.

During the 1-'jj earthing work, pressure is normally generated in the rod extrusion side oil chamber 5a of the arm cylinder 5, so no pressure is generated in the rod retraction oil chamber 5b.

Therefore, the overload relief valve] 4 will be relieved at the same pressure as a normal overload relief valve, and the work will not be hindered.

In the above embodiment, the pressure receiving portions 14h, 1 of the overload relief valve 14 and the pool 14C are
If the surface area of 4i is selected appropriately, data X can be obtained at any pressure.
.

It is possible to set the bucket cylinder type when pulling back.

As described above, in the excavator of the present invention, the pressure in the oil chamber on the packet tilt back side of the bucket I/cylinder can be set to an arbitrarily low pressure only when the arm is pulled back, so it is possible to tilt back the packet/arm easily and Can be pulled back quickly.

Furthermore, even if the tilt back force is set sufficiently large, the arm can be pulled back.

Further, since the operation of the packet cylinder is not required when the arm is pulled back, operation can be performed easily and quickly.

Furthermore, by appropriately setting the angle of the stopper, the angle of the packet can be set to a substantially horizontal angle suitable for excavation when the arm has finished being pulled back, so that excavation work can be carried out immediately.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of the operation of a conventional excavator, and Figure 4
The figure shows an embodiment of the excavator according to the present invention, and FIG. 5 is a sectional view showing the structure of the overload relief valve according to the present invention. 1... Running body, 2... Rotating body, 3...
...Boom cylinder, 4...Boom, 5.
...Arm cylinder, 5b...Rod retraction side oil chamber, 6...Arm, 7, 8...
Link, 9...Packet cylinder, 9a...
...Rod extrusion side oil chamber, 10...Packet,
11... Stopper, 14... Overload IJ IJ valve, 143... Valve body, 14C... Spool, 14 d,
14 e, 14 f-...boat, 14g...
...Spring, 14h, 14i...Pressure receiving part, 15...Oil tank.

Claims (1)

[Scope of utility model registration request] A boom that is raised and raised by a boom cylinder is pivotally attached to the front part of the rotating body on the traveling body, an arm that is swung by an arm cylinder is pivotally attached to the tip of the boom, and the arm is rotated by a packet cylinder at the tip of the arm. In the excavator, the packet tilt back side oil chamber of the packet cylinder is connected to an oil tank via an overload relief valve, and the overload An excavator characterized in that the relief valve is configured to be operated by the sum of the pressure in the arm retraction side oil chamber of the arm cylinder and the pressure in the packet tilt back side oil chamber of the packet cylinder.