JPS5933754B2 - shield tunneling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shield excavator that excavates a tunnel.

In conventional shield excavators, when correcting the direction of excavation, pressure oil is sent only to a selected one of the multiple shield jacks arranged around the inner circumference of the shield body. The configuration is such that an operation is performed in which the jack is extended by the shield jack, and pressure oil is not sent to the unselected shield jack.

The arrangement and operation of the shield jack of this conventional shield tunneling machine will be explained with reference to FIGS. 1 to 3.

As shown in FIGS. 1 and 2, between the lip 1a provided on the inner circumferential side of the shield body 1 and the segment 4, a plurality of shield jacks 2 are installed at positions equally divided along the circumference. is placed.

3 is a tail seal for preventing the infiltration of earth and sand; FIG. 1 shows a state in which the shield jack 2 is extended and in contact with the distal end surface of the segment 4.

FIG. 3 is a hydraulic circuit diagram of the shield jacks 2a to 2n.On-off type switching valves 5a to 5n are provided on the head side of each shield jack 2a to 2n, respectively. The rod sides of the switching valves 5a to 5n and the shield jacks 2a to 2n communicate with a directional switching valve 6, and by switching the directional switching valve 6, the operating direction of the shield jacks 2a to 2n ( (Extension, Contraction) is now selected.

By the way, when a shield excavator excavates a tunnel, it normally moves forward while constantly adjusting its direction, so it is necessary to control the shield jack quite frequently to correct the direction. Shield Jack 2
If this is done by extending a, 2b, and 2c, first open the switching valve 5.
Operate a, sb, and 5c to obtain shield jack 2a.
, 2b, 2c are connected to the oil passage 7, and the directional control valve 6 is operated to send high pressure oil from the high pressure pump 8.

In this case, the shield jack on the side that does not require digging is 2 m.
.

Since the corresponding switching valves 5m and 5n are closed to 2n, no pressure oil is sent to the jack, and the jack is not extended.

Further excavation continued, and in order to correct the direction, in addition to shield jacks 2a, 2b, and 2c, a new shield jack of 2 m,
If you want to add 2n, use the corresponding switching valve 5m, 5n.
Operate to connect the head sides of shield jacks 2m and 2n to oil path T.

In this case, the added shield jacks 2m and 2n extend with almost no load until they reach segment 4, so during that time, pressure oil is sent only to the shield jacks 2m and 2n. As a result, the pressure in the oil passage 7 decreases, and the shield jacks 2a, 2b, 2c, which had been extending until then, stop extending, and the excavation work is temporarily interrupted.

And shield jacket 2m. 2n presses the segment 4, the shield jacks 2a, 2b, 2
High-pressure oil will also be sent to c, and excavation work will begin again.

In this way, in conventional shield excavators, when operating a newly selected and added shield excavator,
Since excavation work is always interrupted once, efficiency is greatly reduced.

In addition, when newly selected and added shield jacks are operated, a drop in pressure in the hydraulic circuit including oil passage 7 is unavoidable as described above, so the previous pressure cannot be maintained and the shield There is a risk that the main body 1 will move backward.

In order to prevent this, first of all, the switching valves 5a respectively correspond to the shield jacks 2a, 2b, and 2c which have continued to extend until then.

5b and 5c to temporarily close the circuits of these jacks, and then operate switching valves 5m and 5n to supply pressure oil to shield jacks 2m and 2n, so that only shield jacks 2m and 2n can be switched to shield jacks. Tsuki 2a, 2b
, 2c, and once the same stroke is reached, the switching valves 5a, 5b, 5 are closed.
Open c and shield jackets 2a, 2b, 2c,
It is necessary to extend 2m and 2n at the same time and excavate.

Therefore, in this case, it is necessary to operate the switching valve every time the direction is corrected, which is troublesome, and the efficiency is greatly reduced.

The present invention has been made based on the above-mentioned problem, and is such that the stroke of the shield jack selected during excavation work and the stroke of all other shield jacks that are not selected during pressing work are always the same. It is an object of the present invention to provide a shield excavator having a configuration that allows continuous direction correction without interrupting the excavation work and without requiring the operation of a switching valve, which was required each time a direction correction is made. The purpose is to

The shield excavator of the present invention is provided with, in addition to a high-pressure hydraulic pump that is a hydraulic source that provides thrust for shield excavation work, a low-pressure hydraulic source that can obtain the pressure that allows the shield shirt 10 to be extended under a light load. The present invention is characterized in that it includes a switching valve that selects and supplies high pressure oil from the high pressure hydraulic pump and low pressure oil from the low pressure oil source to the shield jack.

The details of the present invention will be explained below with reference to the embodiment shown in FIG.

In FIG. 4, the same reference numerals as those in FIG. 3 indicate components having the same or equivalent functions, and therefore redundant explanation will be omitted.

Reference numeral 9 is a low-pressure hydraulic pump added according to the present invention, and the hydraulic pressure obtained by the pump is such that the shield jack can be extended under a light load.

Note that pressure setting relief valves attached to the low-pressure hydraulic pump 9 and the high-pressure hydraulic pump serving as a hydraulic power source for shield excavation work are not shown.

10 is each shield jack 2 from the low pressure hydraulic pump 9
This is a follow-up switching valve that selects whether or not to perform a follow-up operation, which will be described later, by controlling the supply of low-pressure oil to switching valves 11a to 11n provided corresponding to a to 2n.

The switching valves 11a to 11n receive low-pressure oil supplied from the low-pressure hydraulic pump 9 through the follow-up switching valve 10 and oil passage 12, and the directional switching valve 6 from the high-pressure hydraulic pump.
and high-pressure oil supplied through the oil pump 7 are selectively supplied to the corresponding shield jacks.

In the configuration shown in FIG. 4, the directional switching valve 6 is selectively switched, for example, the switching valves 11a and 11b.

When high pressure oil is sent to 11c, the switching valves 11a and 11b.

Shield jacks 2a, 2b corresponding to 11c.

High pressure oil is sent to 2c to cause it to expand, and a high thrust is applied between it and the segment 4 shown in FIG.

At the same time, a follow-up switching valve 10 connected to the low pressure pump 9
Stroke of shield jacks 2a, 2b, 2c when opened, low pressure oil is sent to shield jacks 2m, 2n, etc. other than shield jacks 2a, 2b, 2c via remaining switching valves 11m, 11n, etc. and extend almost simultaneously to the same stroke.

In this case, the shield jacks 2a, 2b, 2c should be
Thrust forces such as m and 2n should not exceed a certain pressure that can be extended with a light load.

In this state, further high pressure oil is sent to the shield jack 2a.
, 2b and 2c are extended, excavation begins.

Of course, in this case as well, low-pressure oil is sent at the same time, and the remaining shield jacks follow and extend by the same amount as the extension amount of the shield jacks 2a, 2b, and 2c.

During excavation, new direction corrections should be made (in addition to shield jacks 2a, 2b, and 2c, shield jacks 2m,
When adding 2n, the shield jacket is already 2m.
, 2n have extended strokes and are in contact with segment 4, so just by switching the switching valves 11m, 11n from the low pressure side to the high pressure side, high pressure oil immediately flows to the shield jacks 2m, 2n.
The shield jacks 2a, 2b,
A high thrust acts between segment 2c and segment 4 at the same time.

Therefore, there is no pressure drop in the hydraulic circuit, and there is no interruption of the propulsion work due to a temporary stop in the extension of the shield jack.

Further, the switching valves 11a to 11n only need to be operated at the time of selection, and the operation that was required in the conventional circuit every time the direction is corrected other than at the time of selection is completely unnecessary.

In this embodiment, the switching valves 6, 10, and 11 are manually operated, but each switching valve may be replaced with an electric, hydraulic, or pneumatic type, or may be combined with automatic control. It is also possible to match.

Furthermore, although the low-pressure oil source is shown as supplying low-pressure oil from the low-pressure hydraulic pump 9, it is not limited to the low-pressure hydraulic pump 9 (the low-pressure oil may be supplied from the high-pressure hydraulic pump 8 through a pressure regulator).

As mentioned above, when using a shield excavator, if you want to add a shield jack during excavation to correct the direction, etc., with the conventional model, the added shield jack is almost the same as the shield jack that was extended up until then. Since the other shield jacks do not extend until they reach the full length and hit the segment, excavation stopped during that time, but in the present invention, all the shield jacks hit the segment and extend, so the shield jack Even when adding thrust to increase thrust, the changeover can be done instantly and there is no downtime.

Furthermore, in conventional shield tunneling machines, it was necessary to operate the switching valve each time the direction was corrected, but in the present invention, only the switching valve selection operation is required.

Therefore, according to the present invention, the efficiency of excavation work can be greatly improved, and the switching operation for direction correction can be performed extremely easily.

In addition, as mentioned above, the shield jack selection can be changed without stopping time, so direction corrections can be made frequently.
Accurate direction correction is possible.

This also makes it possible to use it in combination with automatic direction correction control.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the arrangement of the shield jack of a general shield excavator, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a circuit showing the hydraulic circuit of a conventional shield jack. FIG. 4 is a circuit diagram of a hydraulic circuit of a shielded jack showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Shield body, 2a-2n... Shield jack, 4... Segment, 6... Directional switching valve, 8...
...High pressure hydraulic pump, 9...Low pressure hydraulic pump, 10.
...Following switching valve, 11a to 11n...Switching valve.

Claims (1)

[Claims] 1. In a shield excavator that performs excavation work by installing multiple shield jacks in the shield body, segments, and mechanisms, a high-pressure hydraulic pump is used as a hydraulic source to provide thrust for the shield jack for propulsion work, and a shield jack is installed in the shield jack. A low-pressure hydraulic power source that can extend the rod with a light load is provided corresponding to each shield jack, and high-pressure oil from the high-pressure hydraulic pump and low-pressure oil from the low-pressure hydraulic source are selected to supply the shield jack. A shield excavator characterized in that it is equipped with a switching valve that supplies water to the shield.