JPS6317975B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum soil removal device used for digging up soil mainly when installing or repairing underground pipes.

This type of vacuum earth removal device is equipped with a collection chamber for collecting earth and sand via a vacuum hose and a filter chamber, and the two chambers are communicated with each other so that the negative pressure suction force from the vacuum suction blower is transmitted to the filter chamber. The structure extends to the collection chamber through the foil, and when the collected soil from the vacuum hose enters the collection chamber, the dynamic pressure decreases and the air and soil are separated, and the soil is deposited in the collection chamber. It is necessary to adopt a configuration in which only fine dust is brought into the filter chamber together with air, and the fine dust is separated and removed by the filter.

In such a configuration, in order to avoid clogging of the filter as much as possible during operation, various considerations are made to avoid the flow of earth and sand from the collection chamber into the filter chamber. However, it is unavoidable that fine dust carried by the suction airflow adheres to the filter, and the amount thereof is considerable. If the filter chamber is opened to clean the filter when the filter becomes clogged, the suction tilling operation must be interrupted each time.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a vacuum soil evacuation device that can eliminate clogging of filters during operation.

For this purpose, the present invention focuses on the fact that when a filter becomes clogged, there is a difference in air pressure between the suction side and the suction side of the filter chamber, and this pressure difference is detected and the air pressure is adjusted to a predetermined value. Once the dust has reached that point, the filter is vibrated, and the fine dust adhering to the filter surface is brushed off by the vibration, so that the filter can be unclogged while the soil suction operation continues. It is characterized by:

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional side view of the entire vacuum earth removal device according to the present invention, and the reference numeral 1 in the figure is a towed truck body;
This is equipped with a diesel engine 2 and a large vacuum suction blower 3 driven by the engine, which are connected for power via a coupling ring 4. Furthermore, a vacuum enclosure 7 having an earth and sand collection chamber 5 and a filter chamber 6 therein is mounted at the rear of the truck body 1. The collection chamber 5 and the filter chamber 6 are divided into front and rear sections via a passage 8, and the passage 8 is formed by a partition wall 9 on the collection chamber 5 side and a partition wall 10 on the filter chamber 6 side. It communicates with the chamber 5 through its top communication port 8a, and with the filter chamber 6 through its bottom communication port 8b.

A connection port 11 for a vacuum hose is opened in the upper part of the rear wall of the collection chamber 5, one end of a vacuum hose 12 is connected to the connection port 11, and the other end of the vacuum hose 12 is extended to the excavation site and connected to its tip. A dirt suction nozzle 12a is provided. Further, inside the collection chamber 5, a coil spring 13 is provided, which is located between the opening of the hose connection port 11 and the top communication port a of the passage 8, and is tensioned diagonally by a coil spring 13 so as to face the hose connection port 11. A collision plate 14 is arranged. And the collision plate 1
4, a shock absorber 15 such as a rubber plate is attached to the side facing the opening of the hose connection port 11. In addition, a soil discharge port 16 is opened at the bottom of the collection chamber 5, and an opening/closing door 17 that is opened and closed by hydraulic pressure or pneumatic pressure is arranged here so as to be movable back and forth, and a seal such as a rubber plate is installed here. A material 18 is attached around the soil discharge port 16 in order to maintain airtightness around the opening/closing door 17. A piston rod 19 is connected to the side of the opening/closing door 17, and the piston rod 19 is connected to a piston (not shown) of a piston/cylinder mechanism 20 using hydraulic or pneumatic pressure.

On the other hand, the filter chamber 6 has a large number of bottomed cylindrical filter elements 21 disposed therein.
As shown in an enlarged view in FIG. 2, the filter element 21 includes a cap 21b having an engaging flange 21a at the top, and an upper opening of a bottomed cylindrical bag 21c made of cloth is fixed to the cap 21b. A coiled bone member 21d is inserted inside the bag 21c to maintain its shape. The filter element 21 is inserted from the suction side to the suction side through a large number of mounting holes 22a provided in a partition wall plate 22 that partitions the filter chamber 6 into a suction side and a suction side, and is supported by a flange 21a. be done. A support plate 24 is provided at the bottom of the filter chamber 6 and is pulled downward by a spring 23, and the bottom of the filter element 21 is fixed to this plate with bolts and nuts 26 via washers 25. has been done. Further, the support plate 24 is provided with a large number of through holes 24a so as not to obstruct air circulation within the filter chamber 6.

Furthermore, a relief valve 27 is provided at the top of the filter chamber 6 to prevent external air from flowing in and creating an ultra-vacuum when the negative pressure exceeds a certain level. Further, the suction side of the blower 3 is communicated with the suction side chamber formed above the partition wall plate 22 via a duct 28. Further, a gate 29 that can be opened and closed manually is provided at the bottom of the filter chamber 6, so that fine dust that has fallen within the filter chamber 6 can be removed as appropriate.

In the filter chamber 6, a top space 6a on the suction side and a lower space 6b on the suction side include:
Pressure detectors 30 and 31 are respectively provided to detect the respective internal air pressures. The detectors 30 and 31 are adapted to supply detected pressure value signals to a comparator 32, and the comparator 32 is supplied with a desired pressure difference value signal from a pressure difference reference setting device 33. There is. Then, in the comparator 32, the difference between the signals from the detectors 30 and 31 is determined,
When it exceeds the signal difference from the pressure difference reference setter 33, a drive signal is given to the exciter 34. The vibrator 34 is connected to the support plate 24
The vibration exciter 34 applies mechanical vibration to the support plate 24 to cause the filter element 21 to vibrate.
is starting to vibrate.

In such a configuration, when the engine 2 is started, a vacuum negative pressure is applied to the filter chamber 6 and the collection chamber 5 by the action of the blower 3, and the vacuum suction force is applied to the vacuum hose 12, so that the nozzle 1 at the tip of the hose 12
When the excavated earth and sand are placed in front of the area to be discharged, the excavated earth and sand are drawn into the collection chamber 5 through the hose 12 together with the surrounding air. And the collision plate 14
At this time, due to the drop in dynamic pressure within the collection chamber 5, dirt, water droplets, etc. with large specific gravity accumulate at the bottom of the collection chamber 5. On the other hand, the air containing fine dust detours around the collision plate 14 and flows from the top communication port 8a of the passage 8 to the passage 8.
The fine dust is separated by the filter element 21 in the filter chamber 6, and then passed through the duct 28 to the blower 3.
They are drawn towards it.

In this case, when the filter element 21 is clogged with fine dust in the filter chamber 6, a pressure difference is generated between the top space 6a and the bottom space 6b in the filter chamber 6, and a pressure value signal is sent via the detectors 30 and 31. is applied to the comparator 32, and as described above, when a comparison is made and a set pressure difference is reached, the exciter 34 is activated. As a result, the support plate 24 held by the spring 23 is vibrated, and the fine dust adhering to the surface of the bag 21c is shaken off to the lower part of the filter chamber 6. This fine dust is discharged to the outside by opening the gate 29, and when the gate 29 is closed, a negative pressure suction action occurs again, and the bag 21c regains its breathability and exhibits a predetermined filter effect.

As described in detail above, the present invention has a collection chamber for collecting earth and sand via a vacuum hose and a filter chamber, and the two chambers are communicated with each other so that the negative pressure suction force from the vacuum suction blower is applied to the filter chamber. The filter chamber is partitioned into a suction side and a suction side through a filter installed in the chamber, and is equipped with a support that elastically supports the filter. It is equipped with a detection means for detecting a pressure difference between a suction side and a suction side of a filter chamber divided through a filter, and when the pressure difference reaches a predetermined value, the detection means detects it and supports the filter. Since the body is configured to vibrate using a vibrator, if the filter becomes clogged during work, this will be automatically detected and the fine dust will be shaken off from the filter surface using mechanical vibrations, eliminating the clog. can be done. Therefore, even in a vacuum soil evacuation device that sucks in a considerable amount of dust, practical effects such as being able to work continuously for a long time and not having to interrupt work to clean the filter can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view of the entire device showing one embodiment of the present invention, FIG. 2 is a vertical sectional side view showing an enlarged filter element, and FIG. 3 is a block diagram of the main part of the electric circuit. 1... Truck body, 2... Engine, 3... Blower, 4... Coupling, 5... Collection chamber, 6...
Filter chamber, 7... Vacuum enclosure, 8... Passage, 8a
...Top connection, 8b...Bottom connection, 9,10
... Bulkhead, 11 ... Hose connection port, 12 ... Vacuum hose, 12a ... Suction nozzle, 13 ...
Coil spring, 14... Collision plate, 15... Impact buffer, 16... Soil discharge port, 17... Opening/closing door, 1
8... Seal material, 19... Piston rod, 20
... Piston cylinder mechanism, 21 ... Filter element, 21a ... Engagement flange, 21b ... Cap, 21c ... Back, 21d ... Bone member, 22
...Partition plate, 22a...Mounting hole, 23...Spring, 24...Support plate, 24a...Through hole, 25...
...Washer, 26...Bolt/Nut, 27...Relief valve, 28...Duct, 29...Gate, 3
0, 31...Detector, 32...Comparator, 34...
exciter.

Claims (1)

[Claims] 1 It has a collection chamber that collects earth and sand via a vacuum hose and a filter chamber, and both chambers are communicated with each other so that negative pressure suction force from a vacuum suction blower is applied to the collection chamber through the filter of the filter chamber. In the filter chamber, the filter chamber is divided into a suction side and a suction side through a filter installed in the chamber, and includes a support that elastically supports the filter, and a filter chamber divided through the filter. is equipped with a detection means for detecting a pressure difference between the suction side and the suctioned side, and when the pressure difference reaches a predetermined value,
A vacuum soil removal device for earth and sand, characterized in that the filter support is vibrated by a vibrator upon detection by the detection means.