JPH0720191Y2 - Discharge direction switching device for both side dump buckets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a discharge direction switching device for both side dump buckets mounted on a construction machine such as a wheel loader.

(Prior Art) Conventionally, both side dump buckets equipped in this type of construction machine are configured to selectively discharge the earth and sand contained in the buckets to the left side or the right side.

The device shown in Fig. 10 is generally used as a device for switching the discharge direction.

That is, the side dump cylinder a
The side dump cylinder a is expanded and contracted to provide pins b and c provided on the left and right of the bucket.
The bucket can be dumped to the left or right around the center.

In addition, hooks f and g that can be engaged with the pins b and c by the lock cylinders d and e are provided near the pins b and c, and one of these hooks f and g can be connected to the pins b and c. By engaging one and releasing the other, the side dump of the bucket is enabled as follows.

When side-dumping the bucket, first, the side-dump switching switch h is used to select the side-dump direction. As a result, the left or right switching valve i, j is energized so that one of the valves i, j (valve j in the figure) is in the communication position, and in this state the lock / release switch k
Is switched to the release side and the lock / release switching valve 1 is put in the release position, hydraulic pressure is supplied from the pump m to the right side lock cylinder e, and the right side hook g is released.

Next, in this state, by switching the side dump operation valve n from the neutral position to the raised position, hydraulic pressure is supplied from the pump o to the side dump cylinder a, the side dump cylinder a is extended, and is locked by the hook f. The bucket is side-dumped around the existing pin b, and the earth and sand stored in the bucket is discharged to the left, for example.

At this time, the switch p that has been turned on in the side dump cylinder a is turned off, the lock / release switch k is also turned off, and the lock / release valve 1 is returned to the neutral position.

On the other hand, when the side dump is completed and the bucket is returned, the lock / release switch k is turned to the lock side. However, since the switch p is off at this time, the lock / release switching valve 1 holds the neutral position.

Then, the side dump cylinder a reaches the stroke end and the switch p is turned on, and at the same time, the lock / release switching valve 1 is set to the lock position, oil is supplied to the bottom side of the lock cylinder e, and the hook g is locked by the lock cylinder e. By rotating and engaging the pin c, the side dump operation of the bucket is completed.

(Problems to be solved by the invention) However, in the conventional discharge direction switching device for the side dump bucket described above, when the side dump operation is performed, first the lock,
After operating the release switch k, the side dump operation valve n
Since the operation lever n ′ must be operated, the operation is complicated, and the lock and release switch k, the lock, and the release changeover valve 1 are also required, so that the structure is complicated and expensive. was there.

(Means and Actions for Solving Problems) The present invention was made in order to solve the above-mentioned problems, and in a state in which one of the pins provided on both sides of the bottom of the bucket is locked with a hook and the other is released. By dumping the above-mentioned buckets with the side cylinders so that the side dumps can be performed in any of the left and right directions, in the side ducts that connect the side dump cylinders and the side dump operation valves that control the side dump cylinders, , A left / right switching valve that is switched by a side dump switching switch that selects the side dump direction and that is returned to the neutral position by a switch that is turned off when the side dump cylinder is extended is provided. To supply hydraulic pressure to the left and right lock cylinders By doing so,
The side dump of the bucket has been made possible without the need for lock and unlock operations and the lock, unlock switch and lock, and unlock switch valves for performing these operations.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. 1 to 9.

1 to 3 show the details of the pins 2 provided on both sides of the bottom of the bucket 1 and the lock cylinder 14 for locking and unlocking the pins 2, between the brackets 1a protruding from the bucket 1. A pin 2 is horizontally mounted on the pin 2, and a collar 5 is rotatably supported on the pin 2 via a bush 4.

Each pin 2 is supported from above by a collar 5 in a recess 8a of a pin receiving bracket 8 projecting from a cradle 7a provided on the vehicle body 7 side, and is horizontally mounted between the pin receiving brackets 8 as well. A collar 11 is supported on the shaft rod 9 via a bush 10, and the base ends of hooks 12 are fixed to both ends of the collar 11.

A lock cylinder 14 is laid horizontally between the lever 13 fixed to the middle portion of the collar 11 and the vehicle body 7 side. The lock cylinder 14 rotates the hook 12 about the shaft rod 9, The pin 2 is locked and unlocked.

On the other hand, a side dump cylinder 16 is installed upright between the upper center of the bucket 1 and the vehicle body 7, and hydraulic pressure is supplied to the side dump cylinder 16 and the left and right lock cylinders 14 from the hydraulic circuit shown in FIG. I am

Explaining this next, the hydraulic pressure discharged from the hydraulic pump 18 is supplied to the side dump cylinder 16 via the side dump operation valve 19, whereby the side dump cylinder 16 expands and contracts.

A part of the hydraulic pressure is supplied from one of the left and right switching valves 20, 21 to the lock cylinder 14 on the left or right side, and the check valve 22, 23 communicate with each other.

Next, the operation will be described. For example, when the bucket 1 is to be dumped to the left, first, the side dump changeover switch 24 is manually changed over to the left side to change the right side changeover valve.
21 is energized, and in this state, the side dump operating valve 19 is raised from the neutral position 19 ₁ to the operating position 19 ₂ by the operating lever 19a.

As a result, the discharge pressure of the hydraulic pump 18 flows into the right side lock cylinder 14 and, as shown in FIG.
At the same time when the hook 12 engaging with the is released, part of the hydraulic pressure also flows into the side dump cylinder 16 and the side dump cylinder 16 extends, so that the bucket 1 centered on the pin 2 on the left side in FIG. ) Will be side dumped to the left as shown in.

Further, as the side dump cylinder 16 extends, the switch 25, which has been turned on by the operating piece 16a of the side dump cylinder 16 until now, is turned off as shown in FIG. 6 (b), so that the switching valve 21 on the right side is neutral. After returning to the position, the hook 12 is held in the release position.

On the other hand, when the bucket 1 is held in the state of being side dumped to the left side as shown in FIG. 7 (a), the side dump operation valve 19 is set to the neutral position as shown in FIG. 7 (b).
19 Return to ₁ .

As a result, the discharge pressure of the hydraulic pump 18 is completely reduced by the relief valve 26.
It is drained to the tank 27, the hydraulic pressure does not flow to the circuit, and the bucket 1 is held in the left side dump state.

In the case of returning from this state to the bucket 1 to the original position, it switches the side dump operation valve 19 to the lowered position 19 ₃ from the neutral position 19. (See FIG. 8B).

As a result, the side dump cylinder 16 is shortened and the bucket 1 is returned to its original position as shown in FIG. 9 (a). At the same time, the side dump cylinder 16 reaches the stroke end and the operating piece 16a causes the switch 25 to move to the 9th position. When it is turned on as shown in FIG. 6B, the right side switching valve 21 is energized via the side dump switching switch 24, and the valve 21 is in the communication position again, so that the hydraulic pressure from the hydraulic pump 18 is applied to the lock cylinder 14. The side dump operation is completed by flowing into the bottom side, rotating the hook 12, and locking the pin 2 by the hook 12.

Note that the switch 25 is closed only when the side dump cylinder 16 is at the most contracted position (only when the bucket is placed on the bucket base), and when the changeover switch 24 is operated, the left and right changeover valves 20 and 21 are changed over so that the lock cylinder 14 Oil is sent to one side to lock and unlock the bucket rotating shaft.

Also, since the switch 25 is open except when the side dump cylinder 16 is in the most contracted position (that is, the dump operation position), electricity does not flow even if the changeover switch 24 is accidentally touched, so the left and right changeover valves 20, 21 are shut off. Since it is in position and the lock cylinder does not operate, a very safe circuit configuration is obtained.

The above operation is for side dumping the bucket 1 to the left side. However, for side dumping to the right side, the side dump changeover switch 24 is simply put to the right side, and the subsequent operation is the same as the above, and the description thereof is omitted. .

(Effect of device) As described in detail above, this device allows side dumping in a desired direction by simply selecting the dumping direction with the side dump selector switch and switching the side dump operating valve with the operating lever when side dumping the bucket. Since the conventional lock and release operations are unnecessary, the operability is further improved, and the lock and release switches and the lock and release changeover valves are not required, so that the configuration can be simplified and the cost can be reduced.

Therefore, according to the present invention, a safety circuit can be provided at a low cost with a very simple structure so that the lock cylinder will not operate even if the changeover switch is erroneously operated during the side dump operation.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a perspective view around the lock cylinder, Fig. 2 is a sectional view taken along the line II-II in Fig. 1, and Fig. 3 is a line in the line III-III in Fig. 1. FIG. 4 is a circuit diagram of this device, and FIG. 5 is (a), (b) through 9
Figures (a) and (b) are explanatory diagrams of the operation, and FIG. 10 is a conventional explanatory diagram. 1 is a bucket, 2 is a pin, 12 is a hook, 14 is a lock cylinder, 16 is a side dump cylinder, 19 is a side dump operating valve, 20, 21 are changeover valves, 24 is a side dump changeover switch, and 25 is a switch.

Claims (1)

[Scope of utility model registration request] 1. Pins 2 provided on both sides of the bottom of a bucket 1.
By locking the one side with the hook 12 and releasing the other side, by dumping the bucket 1 with the side dump cylinder 16, the side dump buckets can be side dumped in any of the left and right directions. A switch 25 that is switched in the middle of the pipeline connecting the dump cylinder 16 and the side dump operating valve 19 that controls the dump cylinder 16 by a side dump changeover switch 24 that selects the zide dump direction and that is turned off when the side dump cylinder 16 extends. The left and right switching valves 20 and 21 that are returned to the neutral position by means of the two side dump buckets that supply hydraulic pressure to the left and right lock cylinders 14 that lock and unlock the hook 12 through the switching valves 20 and 21. Discharge direction switching device.