Filler injection system for rock bolt hole, and filler injection method

Abstract

To provide a method of filling material injected into a rock bolt hole formed in the ground capable of reducing the difference between the actual discharge volume from an injection pump and the integrated flow measured by a flow meter.SOLUTION: An injection pipe 19 extending from an injection pump 10 is inserted into a rock bolt hole 5, and a filler 6 from the injection pump 10 is injected into the rock bolt hole 5. The discharge flow rate q of the filler 6 is measured by a flow meter 20. When the accumulative injection amount Q based on the flow rate measured by the flow meter 20 has reached the injection amount before filled Q1 in which the required filling amount Q0 of the rock bolt hole 5 is subtracted by the inertial discharge forecast amount Q2 of the filler 6 during the inertial discharge time after the injection pump 10 stops, an indication light 40 and / or a buzzer 45 are used to instruct the injection pump 10 to stop. After the injection pump 10 is stopped, the injection flow rate is continued to be measured until the inertial injection time has elapsed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rock bolt construction method in which a rock bolt is inserted into a rock bolt hole formed in a natural ground such as around a tunnel or a slope, and particularly relates to a system and an injection method for injecting a filling material into the rock bolt hole before or after the insertion.

Background Art

[0002] For example, in the construction of a mountain tunnel, in order to stabilize the excavated natural ground, a rock bolt construction method is performed in which a rock bolt is inserted from the tunnel excavation surface into the natural ground. The rock bolt construction method includes a step of forming a rock bolt hole in the natural ground and injecting a filling material such as mortar into the rock bolt hole (see Patent Document 1, etc.).

[0003] In the injection step, after inserting the tip of an injection pipe extending from an injection pump to the inner end of the rock bolt hole, a filling material such as mortar is pumped by the injection pump. As a result, the filling material is discharged from the tip of the injection pipe and injected into the rock bolt hole. While injecting, the injection pipe is gradually pulled toward the operator side. When the filling material overflows from the operator side opening that opens to the tunnel excavation surface in the rock bolt hole, it is determined that the rock bolt hole is filled with the filling material, and the injection pump is stopped. Then, a rock bolt is inserted into the rock bolt hole. After inserting a rock bolt into the rock bolt hole, there may be a case where a filling material is filled in the gap between the inner circumference of the rock bolt hole and the rock bolt.

[0004] Patent Document 1 describes that by providing a flow meter in an injection pump and obtaining the filling amount of the filling material, it is useful for judging the presence or absence of construction defects and the state of the surrounding natural ground.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When a flow meter is provided in an injection pump as in Patent Document 1, it is considered that a system for determining whether filling is completed from the measured value can be constructed. On the other hand, according to the inventor's findings, when a certain amount of filling material was discharged from the injection pump, the integrated measured flow rate by the flow meter was less than the certain amount. In view of such findings, an object of the present invention is to reduce the deviation between the actual discharge amount by an injection pump and the integrated measured flow rate by a flow meter in the step of injecting a filling material into a rock bolt hole formed in the natural ground.

Means for Solving the Problems

[0007] In order to solve the above problems, the inventor has conducted intensive research. As a factor causing a deviation between the actual discharge amount by the injection pump and the integrated measured flow rate by the flow meter, it can be cited that the filling material extruded from the injection pump into the injection pipe has inertia. Since this type of filling material has a relatively large mass, it also has a large inertia, and even when the power supply to the injection pump is stopped, it continues to flow through the injection pipe for a while and is discharged from the tip of the injection pipe. It is considered that the inertial discharge amount after the power supply is stopped causes the deviation from the integrated measured flow rate. In view of such circumstances, the system of the present invention is a filling material injection system for injecting a filling material into a rock bolt hole formed in the natural ground, an injection pump for discharging the filling material, an injection pipe extending from the injection pump and inserted into the rock bolt hole, a flow meter for measuring the discharge flow rate of the filling material, a determination unit for determining whether the injection amount of the filling material into the rock bolt hole based on the measured flow rate by the flow meter has reached a pre-injection amount obtained by subtracting the predicted inertial discharge amount of the filling material during the inertial discharge time after the stop of the injection pump from the required filling amount of the rock bolt hole, a stop instruction unit for instructing the stop of the injection pump according to the determination, comprising, after the injection pump stops, the flow meter continuing measurement until the inertial discharge time has elapsed.

[0008] Preferably, the filler injection system a flow meter that measures the flow rate of the discharged filler, a calculation unit that calculates the predicted inertial discharge amount based on the measured flow rate by the flow meter, and further comprises.

[0009] Preferably, the stop instruction unit includes a reporting unit for the stop. Examples of the reporting unit include an indicator light, a buzzer, a monitor, etc.

[0010] Preferably, the stop instruction unit includes an output unit for a command signal that automatically stops the injection pump.

[0011] The method of the present invention is a filler injection method for injecting a filler into a rock bolt hole formed in the ground by an injection pump, a step of inserting an injection pipe extending from the injection pump into the rock bolt hole to perform the injection, a step of measuring the discharge flow rate of the filler with a flow meter, when the injection amount of the filler into the rock bolt hole based on the measured flow rate by the flow meter reaches the pre-injection amount obtained by subtracting the predicted inertial discharge amount of the filler during the inertial discharge time after the injection pump stops from the required filling amount of the rock bolt hole, a step of instructing the stop of the injection pump, comprising, after the injection pump stops, continuing the step of measuring the discharge flow rate until the inertial discharge time has elapsed.

[0012] Preferably, the filler injection method a step of measuring the discharge flow velocity of the filler with a flow meter, a step of calculating the predicted inertial discharge amount based on the measured flow velocity by the flow meter, and further comprises. The predicted inertial discharge amount may be set according to the length of the injection pipe. The inertial discharge prediction amount may be set according to the height difference between the injection pump and the rock bolt hole.

Advantages of the Invention

[0013] According to the present invention, in the step of injecting a filler into a rock bolt hole formed in the natural ground, the deviation between the actual discharge amount by the injection pump and the integrated measurement flow rate by the flow meter can be reduced. Therefore, the required amount of filler can be injected into the rock bolt hole.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a mountain tunnel 1 under construction. In the mountain tunnel 1, a rock bolt 3 is driven from a tunnel excavation surface 1a sprayed with shotcrete (not shown) into the natural ground 2.

[0016] In the rock bolt work, a rock bolt hole 5 is drilled in the natural ground 2 by a drill jumbo 4. Mortar 6 (filler) is injected into the formed rock bolt hole 5 by a filler injection system 9, and then the rock bolt 3 is inserted.

[0017] As shown in FIG. 1, a transport vehicle 8 such as a 4t truck has entered the mountain tunnel 1 under construction. The transport vehicle 8 is parked near the drill jumbo 4. A filler injection system 9 is loaded on the loading platform of the transport vehicle 8. The filler injection system 9 includes an injection pump 10, an injection pipe 19, a flow meter 20, a flow velocity meter 21, a control panel 30, and alarm units 40 and 45.

[0018] As shown in Fig. 2, the injection pump 10 is constituted by a general concrete placing pump and includes a pump section 11, a mixer 12, and an on-off switch 13. A hopper 14 (solid raw material input section) is provided above the mixer 12. A water supply passage 15 (liquid raw material input section) is connected to the mixer 12.

[0019] A cylindrical pump section 11 extends from the mixer 12. A screw 11a is provided inside the pump section 11.

[0020] The operation of starting and stopping the injection pump 10 is performed by the on-off switch 13. By the operation of the injection pump 10, the cement 6a (solid raw material) charged into the hopper 14 and the water 6w (liquid raw material) from the water supply passage 15 are kneaded in the mixer 12 to produce mortar 6 (filler). The mortar 6 is pushed out from the pump section 11 to the injection pipe 19 by the rotation of the screw 11a.

[0021] As shown in Fig. 1, the injection pipe 19 extends from the discharge port 11p of the pump section 11 to the elevated work platform 4d of the drill jumbo 4 and is inserted into the rock bolt hole 5 to be injected therefrom.

[0022] As shown in Fig. 2, a flow meter 20 and a flow velocity meter 21 are interposed between the discharge port 11p and the injection pipe 19 or in the middle of the injection pipe 19. The flow meter 20 measures the discharge flow rate q (instantaneous flow rate) of the mortar 6 from the injection pump 10. Preferably, the flow meter 20 is an electromagnetic flow meter that detects the electromotive force (voltage) generated by the electromagnetic induction action of the flow of the fluid (conductor) and the magnetic field. More preferably, the flow meter 20 is a digital flow meter that outputs the detected voltage, that is, the measured value of the mortar flow rate, as a digital signal.

[0023] The flow velocity meter 21 measures the flow velocity v of the mortar 6 discharged from the injection pump 10. Preferably, the flow velocity meter 21 is a digital flow velocity meter that outputs the measured flow velocity value as a digital signal. Note that the flowmeter 20 may also serve as a flow velocity meter, and the flow velocity may be calculated by dividing the flow rate by the cross-sectional area of the flow path. The flow velocity meter 21 may also serve as a flowmeter, and the flow rate may be calculated by multiplying the flow velocity by the cross-sectional area of the flow path.

[0024] As shown in FIG. 2, the control panel 30 includes a processing unit 31 (determination unit, calculation unit), a signal conversion unit 32, and a setting unit 33. Preferably, the outer casing 34 of the control panel 30 has a waterproof and dustproof specification. The processing unit 31 includes a CPU 31a and a storage unit 31m, and performs a control operation of the filler injection system 9. In the storage unit 31m, a control program and arithmetic expressions for operating the filler injection system 9 are stored. Examples of the arithmetic expressions include arithmetic expressions for calculating the inertial discharge prediction amount Q2, which will be described later. The processing unit 31 may be configured by a personal computer (hereinafter referred to as "PC") or may be configured by a programmable logic controller (hereinafter referred to as "PLC").

[0025] The processing unit 31 and the signal conversion unit 32 are wired-connected by an Ethernet cable 35 or the like. Note that the processing unit 31 may include the signal conversion unit 32.

[0026] The signal conversion unit 32 is configured by, for example, an Ethernet switch. Through the signal conversion unit 32, the processing unit 31 and various input / output devices are connected so as to be able to transmit signals. Input devices connected to the signal conversion unit 32 and thus to the processing unit 31 include the on-off switch 13, the flowmeter 20, the flow velocity meter 21, the setting unit 33, and the like. Output devices connected to the signal conversion unit 32 and thus to the processing unit 31 include the indicator lamp 40 and the buzzer 45, and the like.

[0027] The setting unit 33 receives input of various setting values. Examples of the setting values include the required filling amount Q0 of the mortar 6 (filler) into each lock bolt hole 5. The required filling amount Q0 is the volume of the mortar 6 required to fill the lock bolt hole 5 to its full capacity, and is derived based on, for example, the volume of the lock bolt hole 5, that is, the product of the diameter of the drilling bit and the drilling depth. The required filling amount Q0 may be set in consideration of the cross-sectional area of the lock bolt 3.

[0028] Preferably, the setting unit 33 is a digital device that receives a set value numerically (digitally) and outputs it to the signal conversion unit 32 as a digital signal. The set value such as the required filling amount Q0 by the setting unit 33 is input to the processing unit 31 via the signal conversion unit 32. The processing unit 31 (determination unit) determines, based on the measured flow rate q by the flow meter 20 and the required filling amount Q0 etc. by the setting unit 33, whether the mortar injection amount into the rock bolt hole 5 has reached the amount corresponding to the injection pump stop timing (the pre-filling injection amount Q1 described later), etc.

[0029] As shown in FIG. 2, the indicator lamp 40 (alarm section by light) is preferably arranged at a place with a good view of the mortar injection site in the tunnel 1. For example, the indicator lamps 40 are respectively provided at the upper ends of the columns 44 erected on the transport vehicle 8.

[0030] The indicator lamp 40 includes, for example, three (a plurality of) light emitting sections 41, 42, 43 arranged vertically. These light emitting sections 41 to 43 have different light emitting colors from each other. For example, the upper light emitting section 41 emits red light, the middle light emitting section 42 emits yellow light, and the lower light emitting section 43 emits blue or green light respectively, but the present invention is not limited to this. Preferably, the indicator lamp 40 is a rotary indicator lamp in which the light emitting sections 41 to 43 are rotated.

[0031] The indicator lamp 40 is controlled to blink by the control panel 30. The degree of mortar injection into each rock bolt hole 5 is notified by the number of lit light emitting sections 41 to 43 in the indicator lamp 40. As the number of lit light emitting sections 41 to 43 increases, it indicates that the injection degree is large. The lighting of all the light emitting sections 41, 42, 43 represents an instruction to stop the injection pump 10.

[0032] Also, the buzzer 45 (alarm section by sound) is controlled by the control panel 30. The alarm sound from the buzzer 45 represents an instruction to stop the injection pump 10. The indicator lamp 40 and the buzzer 45 constitute a stop instruction unit that gives an instruction to stop the injection pump 10 according to the determination by the processing unit 31 (determination unit).

[0033] In the rock bolt work, the mortar (filler) is filled into the rock bolt hole 5 by operating the filler injection system 9 as follows. <Required filling amount setting process> In advance, the required filling amount Q0 of the mortar 6 (filler) in the rock bolt hole 5 to be injected is set by the setting unit 33. The set required filling amount Q0 is sent to the processing unit 31 and stored in the storage unit 31m. By inputting values such as the length and inner diameter of the rock bolt hole 5, which are the calculation factors of the required filling amount Q0, into the setting unit 33, the input data may be sent to the processing unit 31 via the signal conversion unit 32, and the required filling amount Q0 may be calculated in the processing unit 31. Preferably, the required filling amount setting process is executed each time the length or cross-sectional area of the rock bolt hole 5 to be injected is changed.

[0034] <Injection pipe insertion process> As shown in FIG. 1, the operator B in charge of the injection pipe operation rides on the elevated work platform 4d of the drill jumbo 4, for example, and inserts the injection pipe 19 from the hand-side opening 5a of the rock bolt hole 5 to be injected into the inside of the rock bolt hole 5. When the tip of the injection pipe 19 is inserted to the far end of the rock bolt hole 5, a signal is given.

[0035] <Injection pump operation start process> The operator A in charge of the injection pump operation performs an operation to start the operation by the on / off switch 13 of the injection pump 10 in response to the signal.

[0036] <Injection process> By operating the injection pump 10, the mortar 6 is pumped from the injection pump 10 into the injection pipe 19, discharged from the tip of the injection pipe 19, and injected into the rock bolt hole 5. The operator B gradually pulls the injection pipe 19 toward the hand side while injecting. As a result, the mortar 6 is filled from the far end inside the rock bolt hole 5 toward the hand side.

[0037] <Flow measurement process> In the injection process, the flow rate q (L / min) of the mortar 6 is measured by the flow meter 20. The measured mortar flow rate is input to the processing unit 31 via the signal conversion unit 32. The processing unit 31 calculates the current measured injection amount Q (L) of the mortar 6 in the rock bolt hole 5 during injection by integrating the input measured flow rate.

[0038] <Injection degree calculation step> Furthermore, the processing unit 31 reads out the set value of the required filling amount Q0 from the storage unit 31m, and calculates the ratio R between the measured injection amount Q and the required filling amount Q0 by the following formula. R = Q / Q0 (1) The ratio R indicates the mortar injection degree with respect to the required filling amount Q0 in the rock bolt hole 5 during injection.

[0039] The processing unit 31 adjusts the number of the light emitting parts 41 to 43 to be lit among the indicator lights 40 according to the calculated injection degree R. The operator B in charge of the injection pipe operation can accurately grasp in real time the injection degree of the mortar 6 in the rock bolt hole 5 during the injection operation by looking at the lighting status of the indicator light 40. According to the lighting status, the pulling condition of the injection pipe 19 to the operator's side is adjusted. Thereby, the operator B can pull the injection pipe 19 to the operator's side at an appropriate speed without relying on intuition.

[0040] <Inertial discharge prediction amount calculation step> In parallel with the flow rate measurement by the flow meter 20, the discharge flow velocity v (m / min) of the mortar 6 is measured by the flow velocity meter 21. The measured flow velocity v is input to the processing unit 31 via the signal conversion unit 32. The processing unit 31 (calculation unit) calculates the inertial discharge prediction amount Q2 based on the measured flow velocity v.

[0041] Specifically, the inertial discharge prediction amount Q2 is the amount (L) of the mortar 6 that is predicted to be discharged by inertia even after the injection pump 10 is stopped. Since the inertial force of the mortar 6 discharged from the injection pump 10 depends on the velocity v of the mortar 6, the inertial discharge prediction amount Q2 is represented by a functional formula (2) with the velocity v as a variable. Q2 = f(v) (2) Equation (2) may be a linear function of the velocity v or a quadratic function of the velocity v. The CPU 31a reads the function equation (2) from the storage unit 31m, applies the measured value of the flow velocity v to the function equation (2), and performs calculations to obtain the predicted inertia discharge amount Q2. The predicted inertia discharge amount Q2 is, for example, about several percent to several tens of percent of the required filling amount Q0.

[0042] <Example 1 of Variation in Calculation of Predicted Inertia Discharge Amount> The predicted inertia discharge amount Q2 may be set according to the length L19 of the injection pipe 19. The larger the injection pipe length L19, the greater the flow resistance and the smaller the predicted inertia discharge amount Q2. The injection pipe length L19 is input in advance by the setting unit 33. The value of the input injection pipe length L19 is stored in the storage unit 31m. During the predicted inertia discharge amount calculation process, the CPU 31a reads the value of the injection pipe length L19 from the storage unit 31m and calculates the predicted inertia discharge amount Q2. The predicted inertia discharge amount Q2 may be calculated from the velocity v and the injection pipe length L19. The function equation (2) may include the velocity v and the injection pipe length L19 as variables.

[0043] <Example 2 of Variation in Calculation of Predicted Inertia Discharge Amount> The predicted inertia discharge amount Q2 may be set according to the height difference ΔH between the injection pump 10 and the lock bolt hole 5. When the lock bolt hole 5 is at a higher position than the injection pump 10, the larger the height difference ΔH, the smaller the predicted inertia discharge amount Q2. The height difference ΔH is input in advance by the setting unit 33. Strictly speaking, the height difference ΔH from the discharge port 11p of the injection pump 10 to the hand side opening 5a of the lock bolt hole 5 is input. The value of the input height difference ΔH is stored in the storage unit 31m. During the predicted inertia discharge amount calculation process, the CPU 31a reads the value of the height difference ΔH from the storage unit 31m and calculates the predicted inertia discharge amount Q2.

[0044] The inertial ejection prediction amount Q2 may be calculated from the velocity v or the injection pipe length L19 and the height difference ΔH. The functional expression (2) may include the velocity v or the injection pipe length L19 and the height difference ΔH as variables. The inertial ejection prediction amount Q2 may be calculated from the velocity v, the injection pipe length L19, and the height difference ΔH. The functional expression (2) may include the velocity v, the injection pipe length L19, and the height difference ΔH as variables. The inertial ejection prediction amount calculation step may be performed from the start or the initial stage of the injection step, or may be executed from the stage where the injection has advanced to a certain extent (for example, about 1 / 2 to 2 / 3 of the required filling amount Q0).

[0045] <Injection pump stop timing determination step> Furthermore, the processing unit 41 (determination unit) obtains the pre-filling injection amount Q1 by subtracting the inertial ejection prediction amount Q2 from the required filling amount Q0. Q1 = Q0 - Q2 (3) Then, it is determined whether or not the measured injection amount Q has reached the pre-filling injection amount Q1.

[0046] <Reporting step (injection pump stop instruction step)> When it is determined that the measured injection amount Q has reached the pre-filling injection amount Q1 (Q ≥ Q1), the processing unit 31 outputs a full lighting command to the indicator light 40 via the signal conversion unit 32. As a result, all of the three light emitting units 41, 42, and 43 are lit. That is, a report is made to instruct the stop of the injection pump 10 by the light emission from the indicator light 40. In addition, an alarm sound for instructing the stop of the injection pump 10 is reported from the buzzer 45.

[0047] <Injection pump stop step> In response to this, the operator A performs an operation to stop the operation by the on-off switch 13 of the injection pump 10. As a result, the supply of driving power to the injection pump 10 is stopped, and the operation of the injection pump 10 is stopped.

[0048] <Modification example of the injection pump stop step> Instead of manual stop by Operator A, the processing unit 31 (output unit) may output an automatic stop command signal to the injection pump 10 via the signal conversion unit 32, and the injection pump 10 may be automatically stopped according to the command signal.

[0049] <Inertial discharge process> During the inertial discharge time after the stop of the injection pump 10, the mortar 6 continues to be discharged from the tip of the injection pipe 19 due to inertia. After the stop of the injection pump 10, Operator B holds the tip of the injection pipe 19 inserted into the rock bolt hole 5 during the inertial discharge time. As a result, the mortar 6 discharged by inertia is injected into the rock bolt hole 5. Therefore, it is possible to prevent the mortar 6 for inertial discharge from being wasted and discharged outside the rock bolt hole 5. The inertial discharge time is, for example, about several seconds to several tens of seconds, preferably about 2 seconds to 5 seconds.

[0050] The actual discharge amount Q3 of the mortar 6 due to inertia after the injection pump stops approximates the inertial discharge predicted amount Q2 obtained by Equation (2). Q3≒Q2 (4) The total actual discharge amount Qt after the inertial discharge time elapses is the value obtained by adding the inertial actual discharge amount Q3 to the pre-filling injection amount Q1. Qt = Q1 + Q3 (5) Therefore, from Equations (3) to (5), the total actual discharge amount Qt approximates the required filling amount Q0. Qt≒Q0 (6) In this way, the rock bolt hole 5 can be filled with the required amount of mortar 6.

[0051] <Flow measurement continuation process> Even after the stop of the injection pump 10 (supply of driving power is stopped), the power supply to the flow meter 20 is continued until at least the inertial discharge time elapses. Then, the measurement of the mortar flow rate by the flow meter 20 is continued until the inertial discharge time elapses. Thereby, the deviation between the final integrated injection amount Qe and the total actual discharge amount Qt after the inertial discharge time elapses by the measurement of the flow meter 20 can be reduced.

[0052] The processing unit 31 stores the final integrated injection amount Qe (≈ Qt) in the storage unit 31m as the total injection amount into the rock bolt hole 5, and resets the integrated injection amount. The data such as the stored injection amount is used for creating documents such as work daily reports.

[0053] The operator B pulls out the injection pipe 19 from the hand-side opening 5a of the rock bolt hole 5 filled with mortar. Subsequently, by operating the drill jumbo 4, the rock bolt 3 is driven into the rock bolt hole 5 filled with mortar. In this way, for each drilled rock bolt hole 5, after the mortar 6 is filled, the rock bolt 3 is driven in.

[0054] The present invention is not limited to the above-described embodiment and can be variously modified. For example, the present invention can be applied not only to tunnel construction but also to slope work and the like as long as it is a method for injecting a filling material into a rock bolt hole formed in a natural ground. That is, when driving a rock bolt into a slope, the present invention can also be applied to the step of injecting a filling material into the rock bolt hole of the slope. The reporting unit may be composed of only one of the indicator lamp 40 and the buzzer 45, and the other may be omitted. The reporting unit may include a monitor that displays the injection degree and thus reports the injection stop timing. The filling material injection system according to the present invention is not limited to the pre-injection method in which mortar is injected into the rock bolt hole 5 and then the rock bolt 3 is inserted, but is also applicable to the post-injection method in which the rock bolt 3 is inserted into the rock bolt hole 5 and then mortar injection is performed. The filling material is not limited to mortar and may be a foaming resin such as a urethane-based resin.

Industrial Applicability

[0055] The present invention is applicable to, for example, rock bolt work in mountain tunnels.

Explanation of Reference Numerals

[0056] 1 Mountain tunnel 2 Rock mass 3 Rock bolt 5 Rock bolt hole 5a Hand-side opening 6 Mortar (filling material) 9 Filling material injection system 10 Injection pump 13 On-off switch 19 Injection pipe 20 Flowmeter 21 Flow velocity meter 30 Control panel 31 Processing unit (judgment unit, calculation unit, output unit) 33 Setting unit 40 Indicator light (alarm unit) 41, 42, 43 Light emitting part 45 Buzzer (alarm unit)

Claims

1. A system for injecting a filler into a rock bolt hole formed in the ground, comprising: an injection pump for discharging the filler; an injection pipe extending from the injection pump and inserted into the rock bolt hole; a flow meter for measuring the discharge flow rate of the filler; a determination unit for determining whether the injection amount of the filler into the rock bolt hole based on the measured flow rate by the flow meter has reached a pre-injection amount obtained by subtracting a predicted inertial discharge amount of the filler during an inertial discharge time after the stop of the injection pump from a required filling amount of the rock bolt hole; a stop instruction unit for instructing the stop of the injection pump according to the determination; The filler injection system is characterized in that the flow meter continues measurement until the inertial discharge time elapses after the stop of the injection pump.

2. a flow velocity meter for measuring the flow velocity of the discharged filler; a calculation unit for calculating the predicted inertial discharge amount based on the measured flow velocity by the flow velocity meter; The filler injection system according to claim 1, further comprising the above.

3. The filler injection system according to claim 1 or 2, wherein the stop instruction unit includes a reporting unit for the stop.

4. The filler injection system according to claim 1 or 2, wherein the stop instruction unit includes an output unit for outputting a command signal for automatically stopping the injection pump.

5. A method for injecting a filler into a rock bolt hole formed in the ground by an injection pump, comprising: inserting an injection pipe extending from the injection pump into the rock bolt hole to perform the injection; measuring the discharge flow rate of the filler with a flow meter; when the injection amount of the filler into the rock bolt hole based on the measured flow rate by the flow meter has reached a pre-injection amount obtained by subtracting a predicted inertial discharge amount of the filler during an inertial discharge time after the stop of the injection pump from a required filling amount of the rock bolt hole, instructing the stop of the injection pump; The filler injection method is characterized in that the measurement process of the discharge flow rate is continued until the inertial discharge time elapses after the stop of the injection pump.

6. measuring the discharge flow velocity of the filler with a flow velocity meter; calculating the predicted inertial discharge amount based on the measured flow velocity by the flow velocity meter; The filler injection method according to claim 5, further comprising the above.

7. The filler injection method according to claim 5, wherein the predicted inertial discharge amount is set according to the length of the injection pipe.

8. The filling material injection method according to claim 5, wherein the inertial ejection prediction amount is set according to the height difference between the injection pump and the rock bolt hole.

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