JPH03166500A - Water feeding device for mortar kneading - Google Patents

Abstract

PURPOSE:To enhance the stabilization of driving under the same condition by disposing a pressure control valve with a bypass passage in a water feeding pipeline for feeding water to a mortar injector from a water tank for storing the supplied water of a main pump by a pump, and interposing a trace amount flow rate fixed value control valve. CONSTITUTION:A main feeding pipe 20 from a main pump 2 is branched, a part of which is introduced to a water tank 11, and a water feeding pump 12 exclusive for a mortar injector 1 is interposed in a water feeding pipeline 10. In a bypass passage 17 to the water tank 11, a pressure control valve 13 is provided on the discharge side of the water feeding pump 12 to reduce the fluctuation of discharge pressure of the water feeding pump 12. At the time of water pressure fluctuations such as the start of the water feeding pump 12 and the stop of the mortar injector 1, water is circulated from the pressure control valve 13 into the water tank 11 through the bypass passage 17, and also an automatic air vent valve 4, a pressure gauge 16, a trace amount flow rate fixed value control valve 14 are interposed. Hence, stable water feeding can be conducted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a mortar mixing water supply device for supplying a stable amount of water to a continuous mixing mortar injection machine for fixing rock bolts mainly in tunnel excavation work, etc. It is.

[Conventional technology]

Conventionally, when excavating mountain tunnels, etc., the NATM construction method has been adopted, in which a large number of rock bolts are embedded in the excavated cross section and mortar is sprayed on top of them.

When mixing the mortar used to fix rock bolts, as shown in the water supply circuit diagram in Figure 4, water is supplied to the continuous mortar injection machine 1 by the main pump 2, which is the water supply source for both inside and outside the tunnel. A water supply pipe 10 having a three-way valve 3, an automatic air bleed valve 4, a solenoid valve 5, and a flow meter 7 is connected to the main pump 2, and the main pump 2 is connected to the mortar injection machine 1. Water is supplied directly, and in order to reduce the water supply pressure from the main pump 2, a two-stage pressure reduction system is adopted for the water supply pipe IO, and two pressure reducing valves 8A and 8B are used to achieve the specified level. I'm trying to get water pressure.

On the other hand, in order to obtain a predetermined flow rate of water to the mortar injection machine 1, the amount of water supplied is adjusted by a flow rate regulating valve 6.

Therefore, fluctuations tend to occur in the amount of water supplied by the main pump 2, which is the water supply source used for tunnel excavation.
For example, fluctuations of about ±10 occur in mortar flow values.

In addition, when the length of the main water supply pipe 20 from the main pump 2 increases with the depth of tunnel excavation, the set water supply amount changes, and the rotation of the power supply such as the generator that drives the main pump 2 when it starts up. The amount of water supplied also changes due to fluctuations.

As a result, there was a problem in that it was necessary to periodically calibrate the amount of water supplied, which was time-consuming.

Furthermore, unless a stable amount of water is supplied to the mortar injection machine 1 at all times, the water-cement ratio of the mortar will fluctuate, and as a result, the rock bolts will not be stably fixed.

[Problem to be solved by the invention]

The present invention was made in order to solve the above-mentioned conventional problems, and in particular, it is possible to always maintain a stable and constant amount of water supplied for mixing mortar to a mortar injection machine for embedding rock bolts in tunnel excavation work. The problem to be solved is to provide a water supply device for mixing mortar.

[Means to solve the problem]

As a means for solving the above problems, the water supply device for mortar mixing of the present invention is provided with a water tank that temporarily stores a part of the water supplied from the main pump of the water supply source, and the water tank is dedicated to the mortar injection machine. A system constructed by installing a pressure regulating valve with a bypass path to the water tank in the water supply pipe that supplies water via the water supply pump, and further interposing a minute flow rate fixed value control valve in the water supply pipe. Once the supply water is stored in the water tank, it flows into the water supply pipe using a dedicated water supply pump, but when the water pressure fluctuates, such as when the water supply pump is started or when the mortar injection machine is stopped, the supply water is pumped into the water tank using a pressure regulating valve. Water is circulated, and the amount of water supplied is set and secured using a constant flow rate control valve.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.
The figure is a water supply circuit diagram of a water supply device for mortar mixing according to an embodiment of the present invention, FIG. FIG. 3 is a diagram showing the mortar flow value and the number of continuous measurements when the apparatus shown in FIG. 1 is employed.

First, the apparatus according to the embodiment of the present invention shown in FIG. 1 is similar to the conventional example shown in FIG. The same parts in FIG. 4 and FIG. 1 are indicated by the same part numbers.

Therefore, in this embodiment, the main water supply pipe 20 is branched from the main pump 2, which is the water supply source for water required during excavation.
A water tank II is provided to temporarily store a part of the supplied water, and a water supply pump 12 dedicated to supplying water from the water tank 11 to the mortar injection machine 1 is connected to a water supply pipe that connects between the water tank 1l and the mortar injection machine 1. It is interposed in the road IO.

Further, this water supply pipe 10 is provided with a bypass path 17 to the water tank 11, and the bypass path 17 is provided with a pressure regulating valve 13.

This pressure regulating valve 13 is installed on the discharge side of the water supply pump 12 and bypassed to the bypass passage 17 as described above in order to reduce fluctuations in the discharge pressure of the water supply pump 12. For example, an attle valve It is also possible to adopt a commonly used one.

By interposing this pressure regulating valve 13, the water supply pump 12
When water pressure fluctuates, such as when the mortar injection machine 1 is started or when the mortar injection machine 1 is stopped, water is circulated from the pressure regulating valve 13 into the water tank 11 via the bypass passage 17.

Further, this water supply pipe 10 is provided with an automatic air bleed valve 4, a pressure gauge 16, a flow meter 7, and a solenoid valve 5, as well as a minute flow rate fixed value control valve 14, which allows a predetermined value to be set. The amount of water is set and secured.

As this minute flow constant value control valve 14, for example, a commercially available one called Flowmatic ξni valve can be used, and fine adjustment of the set flow rate is performed using this. Reference numeral 4 denotes a control valve that, once the flow rate is set, attempts to ensure the set flow rate by itself even if differential pressure fluctuations occur, so that a constant amount of water is always supplied to the mortar injection machine 1.

Moreover, one pressure reducing valve 8 is interposed in this water supply pipe 10, and the water pressure of the mortar injection machine 1 is adjusted by this.

In addition, what is shown by 15 in FIG. 1 is a mortar injection machine cleaning line provided with a three-way valve 3.

As described above, in the water supply device of the present invention, the main pump 2 and the mortar injection machine 1 are not directly connected in terms of circuit,
The mortar injection machine 1 has its own water tank 11 and a dedicated water supply pump 12, and the water supply pipe 10 is connected to the water tank via a pressure regulating valve 13 with a bypass passage and a small flow constant value control valve 14. As a result of an experiment using the actual device of the device in the above embodiment, it was found that the actual discharge water amount Qw and the value indicated by the flow meter 7 are different from the indicated value of the flow meter 7 as shown in FIG. It was confirmed that the discharged water amount Qw could be obtained as expected.

In addition, the relationship between the mortar flow value and the number of continuous measurements N when the discharge water amount QW = 5.41/Il + in is also shown in Figure 3, where the mortar flow value is always in a stable state with little fluctuation. It was confirmed that there is.

[Effects of the Invention] According to the water supply device for mortar mixing of the present invention described above, the operation of the mortar injection machine is not affected by fluctuations in the main pump of the water supply source, and the length of the main water supply piping does not affect the operation of the mortar injection machine. However, the effect is that stable operation is possible under the same conditions in any work place.

In addition, since the pressure regulating valve deals with fluctuations in water pressure when the mortar injection machine is started or stopped, fluctuations in the amount of water supplied are eliminated, resulting in more stable water supply.

Furthermore, the constant flow rate control valve allows a constant amount of water to be supplied to the mortar injection machine without being affected by slight pressure fluctuations during operation, resulting in a constant water-cement ratio in the mortar. This method has the advantage that rock bolts can be anchored with stable mortar flow values, resulting in better work performance.

[Brief explanation of the drawing]

Fig. 1 is a water supply circuit diagram of a water supply device for mortar kneading in an embodiment of the present invention, and Fig. 2 is a relationship diagram between the actual discharge amount of water and the indicated value of a flowmeter when the device of Fig. 1 is adopted. 3 is a diagram showing the mortar flow value and the number of consecutive measurements when the device shown in FIG. 1 is adopted, and FIG. 4 is a water supply circuit diagram of a conventional water supply device for mixing mortar. 1... Mortar injection machine, 2... Main pump, 10...
- Water supply pipe, 11... Water tank, 12... Water supply pump, 13... Pressure adjustment valve, 14... Micro flow rate constant value control valve.

Claims (1)

[Claims] A water tank is provided to temporarily store a portion of the water supplied from the main pump of the water supply source, and a bypass path to the water tank is installed in the water supply pipe that supplies water from the water tank to the mortar injection machine via a dedicated water pump. A water supply device for mortar kneading that is equipped with a pressure regulating valve and a micro flow constant value control valve in the water supply pipe.