JPH0324550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the level of fresh concrete in a hopper for a concrete pump.

Generally, when placing ready-mixed concrete (hereinafter referred to as ready-mixed concrete) using a truck mixer truck and a concrete pump truck, the ready-mixed concrete is poured from the truck mixer truck into the hopper of the concrete pump truck, and the fresh concrete poured into the hopper is The concrete is pumped through a feed pipe to the casting site using a concrete pump, and then discharged from the discharge port of the feed pipe.

Conventionally, when the concrete pump truck and the ready-mixed concrete placement site are far apart, the concrete pump is configured to be remotely controllable so that workers at the pouring site can control the operation of the concrete pump using a transceiver. is being done. Using a transceiver to perform pouring at the pouring site has the advantage of being able to freely control the discharge amount of ready-mixed concrete while being at the pouring site, but it also poses the following problems. .

In other words, when the level of fresh concrete received into the hopper from the mixer drum of the truck mixer vehicle becomes lower than the opening of the ready-mixed concrete transfer cylinder that communicates with the hopper while the ready-mixed concrete is being pumped, air will be sucked and pressure-fed along with the ready-mixed concrete. , this air is discharged from the discharge port of the feed pipe together with the ready-mixed concrete,
Alternatively, discharge into the hopper from the gap between the switching valve in the hopper and the concrete cylinder,
This discharged air causes the ready-mixed concrete to scatter around the concrete, making the pouring site and the area around the hopper of the concrete pump dirty and dangerous. Also,
On the other hand, if the level of ready-mixed concrete becomes abnormally high,
There is a risk that it will overflow from the hotspot. To prevent this phenomenon, it is necessary for workers to monitor the level of ready-mixed concrete, but this requires a monitor other than the workers at the pouring site to be attached to the side of the concrete pump truck. There is a problem in terms of reducing the number of workers. For this reason, devices have been developed that use sensors to detect the level of ready-mixed concrete in the hopper, and use this detection signal to automatically stop concrete pump operation or issue an alarm, but accurate detection is not possible. This method requires many sensors, complicates the device, and has drawbacks that make it difficult to implement in practice.

In the present invention, the mixer drum and the concrete pump are operated in a state where the amount of fresh concrete pumped from the hopper by the concrete pump exceeds the amount of fresh concrete put into the hopper by the mixer drum, and the amount of ready-mixed concrete in the hopper gradually decreases. When the capacity falls below the level of the ready-mixed concrete capacity detector installed in the hopper, the amount of ready-mixed concrete put into the hopper by the mixer drum is relative to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. At least one of the mixer drum and the concrete pump is controlled so that the level of the ready-mixed concrete is The mixer drum and concrete pump recognize that the level is one step lower than the above detector, and set the mixer drum and concrete pump so that the amount of fresh concrete put into the hopper by the mixer drum is relatively increased relative to the amount of fresh concrete pumped from the hopper by the concrete pump. The level of ready-mixed concrete in the hopper is controlled by controlling at least one of the mixer drum and the concrete pump, and the amount of ready-mixed concrete pumped from the hopper by the concrete pump is lower than the amount of ready-mixed concrete input into the hopper by the mixer drum. When the mixer drum is in operation and the amount of ready-mixed concrete in the hopper gradually increases, and the amount of ready-mixed concrete exceeds the level of the ready-mixed concrete capacity detector installed in the hopper, the amount of ready-mixed concrete thrown into the hopper by the mixer drum increases. At least one of the mixer drum and the concrete pump is controlled so that the amount of fresh concrete pumped from the hopper is reduced relative to the amount of fresh concrete pumped by the pump, and even after the reduction control is performed and the timer measures a predetermined time, the amount of fresh concrete is If the level of ready-mixed concrete does not fall below the level of the detector, it is recognized that the level of ready-mixed concrete is one step higher than the level of the above-mentioned detector, and the amount of ready-mixed concrete put into the hopper by the mixer drum is equal to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. The above-mentioned conventional problems are solved by controlling at least one of the mixer drum and the concrete pump to control the level of fresh concrete in the hopper so that the level of fresh concrete is further reduced relative to the concrete level. To provide a method for controlling the level of ready-mixed concrete in a hopper for a concrete pump, which is capable of detecting ready-mixed concrete and efficiently controlling its level with a suitable device, thereby making pouring work safe and easy, and helping to save labor. With the goal.

The present invention will be explained below based on the drawings.

1 to 6 are for explaining the method of the present invention, and 1 in the figures is a concrete pump truck. This concrete pump truck 1 includes a fresh concrete level detection device 3 that detects the fresh concrete level l in the hopper 2, and a truck mixer truck 5 based on the fresh concrete level l detected by the fresh concrete level detection device 3 and the number of strokes s of the concrete pump 4. The concrete pump 4 is provided with a control device 7 that changes the rotation speed of the mixer drum 6 to control the amount of fresh concrete received (injected) from the mixer drum 6 to the hopper 2, and stops the concrete pump 4.

The ready-mixed concrete level detection device 3 detects the ready-mixed concrete level l in the hopper 2 at five positions, and two electrode rods (detectors) 8 and 9 are placed inside the hopper 2 at a predetermined distance from each other in the vertical direction. The hopper 2 is electrically insulated from the hopper 2, supported by a support bracket, and vertically arranged. A power source for passing a detection current is connected between each electrode rod 8, 9 and the hopper ₂ , and an electric circuit (not shown) is constructed. When the electrode rod 9 comes into contact with fresh concrete, a fresh concrete level _l3 higher than this fresh concrete level _l4 is detected. Furthermore, the above electric circuit has three timers.
T ₁ , T ₂ , and T ₃ are incorporated, and after the level l of the fresh concrete in the hopper 2 gradually decreases and the concrete is separated from the lower electrode rod 8, the electrode still remains at the time t ₁ second has passed. If it remains away from the rod 8, the ready-mixed concrete level l is conveniently determined to be _l5 , which is lower than _l4 (described later), and after the above-mentioned upper electrode rod 9 detects the ready-mixed concrete level _l3 , t After ₂ seconds, electrode rod 9
is still in contact with the ready-mixed concrete, the ready-mixed concrete level l
This is also conveniently determined to be l ₂ higher than l ₃ (described later).
If the electrode rod 9 is still in contact with the ready-mixed concrete after _t2 seconds and _t3 seconds have passed since _l3 was detected, the ready-mixed concrete level l is _l1 higher than _l2 . The system is such that decisions are made based on convenience (see below).

The control device 7 outputs a control signal m for changing the rotational speed of the mixer drum 6 of the truck mixer vehicle 5 based on the ready-mixed concrete level l detected by the ready-mixed concrete level detection device 3 and the number of strokes s of the concrete pump 4, and It emits a stop signal p for the pump 4. That is, based on the five levels of ready-mixed concrete l ₁ , ..., L ₅ detected by the above-mentioned ready-mixed concrete level detection device 3,
As shown in FIG. 2, the fresh concrete level area in the hopper 2 is divided into six areas a, . . . , f in order from the highest level. Furthermore, the number of strokes s of the concrete pump 4 is configured such that two detection signals are input, one for a small number and one for a large number of strokes.
As shown in FIG. 3, the optimum rotational speed (discharge speed of ready-mixed concrete) of the mixer drum 6 for each ready-mixed concrete level range b, ..., e except for "mixer drum stop", "low-speed rotation", and " While the control mode is set to 4 stages of "medium speed rotation" and "high speed rotation", when the number of strokes is "high", for each ready-mixed concrete level range a, ..., d except for ready-mixed concrete level ranges e and f. Similarly, the rotation speed of the mixer drum 6 is
“Mixer drum stop”, “low speed rotation”, “medium speed rotation”,
It is set in order in four stages, including "high speed rotation". Further, a stop command for the concrete pump 4 is set for a ready-mixed concrete level region f in a state where the number of strokes of the concrete pump 4 is "low" and a ready-mixed concrete level region e in a state where the number of strokes is "high". FIG. 4 shows the electrical configuration of this control device 7.
The detection signal of the fresh concrete level l sent from the input interface 7a to the input interface 7a enters the CPU (central processing unit) 7d via the buffer 7b and decoder 7c.
Necessary calculations are performed by the CPU 7d, and the results of the calculations are sent to the output interface 7f via the decoder 7c and buffer 7e, so that a control signal m is output. This control signal m is configured to be sent to the control device 12 of the toku mixer vehicle 5 via the connection cable 10 and connector 11.

By the way, the above-mentioned "convenient judgment" is, after all, an assumption. For example, after the upper electrode rod 9 detects the fresh concrete level l ₃ , the electrode rod 9 is still in contact with the ready-mixed concrete when t ₂ seconds have elapsed. In this case, the amount of fresh concrete fed from the mixer drum 6 to the hopper 2 and the amount of fresh concrete pumped by the concrete pump 4 are almost the same, and the fresh concrete level l remains within the fresh concrete level range c, or the amount of fresh concrete fed is I don't actually know if the level is rising because it's more than the amount being pumped.

However, as soon as the ready-mixed concrete level l reaches _l4 to _l3 (ready-mixed concrete level range c), control is performed to lower the rotational speed r of the mixer drum 6 by one step to reduce the amount of ready-mixed concrete fed into the hopper 2. Even after controlling in this way, the fresh concrete level l does not decrease within the scheduled time and continues to be in contact with the electrode rod 9. This means that either the input amount or the pumped amount of fresh concrete, or both, It is assumed that a change has occurred that does not occur.
Even if it is hypothetical, it is more reasonable to perform control by comprehensively determining that the fresh concrete level l has reached _l2 in order to prevent the ready-mixed concrete from overflowing from the hopper 2.

This idea is the same for the other two expedient judgments. Note that even if the above judgment is incorrect because the actual amount of raw concrete input and the amount of pumped concrete are approximately equal, there will be no actual damage. In addition, the amount of fresh concrete charged and the amount of pumped concrete are not always constant even if the rotation speed r of the drum mixer 6 and the number of strokes s of the concrete pump 4 are constant. Regarding the change in rotational resistance due to a decrease in the remaining amount of ready-mixed concrete, on the concrete pump truck 1 side, it often changes due to vertical, horizontal, etc. movement of the feed pipe 20, bending, etc.

Here, the concrete pump 4 is started when the ready-mixed concrete level l reaches the ready-mixed concrete level range c, and is configured to reverse when a reverse switch _S4 is turned on. When this reverse rotation signal is input, the mixer drum 6 of the truck mixer vehicle 5 is configured to stop rotating. In addition, the control device 7
The control signal m from to the mixer drum 6 is sent directly to the truck mixer vehicle 5, and is also switched and sent to an external speaker 13 via a voice synthesis circuit, based on the voice command from the speaker 13. The operator of the truck mixer vehicle 5 can also manually operate the mixer drum 6.

On the other hand, the control device 12 of the truck mixer vehicle 5
receives the control signal m from the control device 7 of the concrete pump vehicle 1 to stop the mixer drum 6 of the truck mixer vehicle 5 and to control its rotation speed. That is, the hydraulic pump servo motor 14 is operated by the signal from the control device 12, the swash plate 15a of the well-known drive motor hydraulic pump 15 of the mixer drum 6 is operated, and the hydraulic pump 15 is stopped or started. The revolution speed r of the well-known engine 17 at which the engine servo motor 16 is operated to drive the hydraulic pump 15.
The speed is controlled in three stages: high speed, medium speed, and low speed.

In the figure, reference numeral 18 is a remote control box equipped with a microphone, and by carrying this remote control box 18 to the pouring site and operating it, the worker can check operating data such as pressure of the concrete pump 4 at the pouring site. At the same time, it is possible to remotely control the concrete pump 4, etc., and to give appropriate instructions to the driver of the truck mixer vehicle 5, etc. using a microphone.

Next, the method of the present invention will be explained.

In the method of the present invention, when pouring fresh concrete into a predetermined place using a concrete pump truck 1, the level l of fresh concrete in the hopper 2 is controlled in multiple stages using the electrode rods 8, 9 and timers _T1 , _T2 , _T3 . It is intended to be controlled. That is, after the boom 19 is launched and the feed pipe 20 is installed to the site, the main switch S ₁ of the control device 7, the leveler switch S ₂ of the ready-mixed concrete level detection device 3, and the pumping switch S ₃ of the concrete pump 4 are turned on in this order. I'll put it in. Then, the mixer drum 6 and the concrete pump 4 are automatically operated, and the pouring of ready-mixed concrete progresses, but at this time, the hopper 2
The ready-mixed concrete level l within the container is automatically controlled to the optimum level.

Figure 5 is a flow diagram of this ready-mixed concrete level control.
A case where the number of strokes s of the concrete pump 4 is small (for example, a case where the number of strokes s is less than 25) is shown. To explain this, first, a current is applied to the electrode rod 8 for detecting a low level, and it is detected whether the ready-mixed concrete level l is lower than _l4 or higher than _l4 (step _ST1 ). As a result, if it is detected that the fresh concrete level l is higher than _l4 , the process moves to step _ST2 , and if it is detected that l is lower than _l4 , the process moves to step _ST3 . step
In ST ₂ , a current is applied to the electrode rod 9 to detect whether the fresh concrete level l is lower than l ₃ or higher than l ₃ .

When it is detected in step _ST2 that the fresh concrete level l is higher than _l3 , it is determined whether or not timer _T2 is activated (step _ST4 ), and if it is not activated, it is activated. (step ST ₅ ), and sends a signal to make the mixer drum 6 rotate at a low speed (for example, 400 rpm at the engine 17 speed) (step ST 5).
_ST6 ). Also, if timer T ₂ is activated, it starts counting and waits for t ₂ seconds (for example, 1.5 seconds) to elapse (step ST ₇ ), and even if the count ends after t ₂ seconds, the electrode rod 9 If the detection current is flowing through the electrode rod 9, the hydraulic pump 15 is stopped and the mixer drum 6 is stopped (step ST ₈ ), and if the detection current in the electrode rod 9 is cut off before t ₂ seconds have elapsed, the process moves to the above step ST ₆ . .

Furthermore, if no current flows through the electrode rod ₉ and the ready-mixed concrete level l has not reached _l3 in step ST2, the timers _T2 and _T1 are reset in sequence (step ST2).
ST ₉ , ST ₁₀ ), rotate the mixer drum 6 at medium speed (for example, 700 rpm at the engine 17 rotation speed r).
send a signal to change the position (step ST ₁₁ ). Furthermore, in step ST ₃ , it is determined whether or not the timer T ₁ is activated, and if it is not activated, it is activated (step ST ₁₂ ), and the mixer drum 6 is rotated at high speed (for example, the rotation speed of the engine 17 is set to r). 1000rpm) (step ST ₁₃ ). On the other hand, if timer T ₁ is activated, it starts counting and waits for t ₁ seconds (for example, 1.5 seconds) to elapse (step
ST ₁₄ ), if the detection current still does not flow through the electrode rod 8 even after the count ends after t ₁ second has elapsed, the concrete pump 4 is stopped (step ST ₁₅ ), and the above detection is performed before t ₁ second elapses. If the current flows, the above steps will be carried out.
Move on to ST ₁₃ . In this way, the electrode rods 8 and 9 and the timers T ₁ and T ₂ are connected to the concrete pump 4.
When the number of strokes s is large (for example, when the number of strokes s is 25 or more), use electrode rods 8 and 9 and timers T ₂ and T ₃ to adjust the fresh concrete level l.
can be controlled automatically.

FIG. 6 shows a waveform chart (time chart) of fresh concrete level control. To explain this, first, when the main switch S ₁ is turned on, the electrode rods 8 and 9 of the ready-mixed concrete level detection device 3 A detection current flows through. Next, turn on the leveler switch above.
When S ₂ enters, there is no ready-mixed concrete in the hopper 2 at first, and the ready-mixed concrete level l is in the ready-mixed concrete level region f, so the detection signals of the electrode rods 8 and 9 are cut off. In this state, when the pumping switch _S3 is turned on, the hydraulic pump 15 of the truck mixer vehicle 5 is started, the engine 17 is rotated at high speed, and the mixer drum 6 starts discharging fresh concrete into the hopper 2. Then, the amount of ready-mixed concrete in the hopper 2 gradually increases, but when the ready-mixed concrete level l exceeds the ready-mixed concrete level area d and reaches the ready-mixed concrete level area c, the electrode rod 9 detects this, and the control device 7 sends the concrete A signal is issued to start the pump 4, and
A signal is output that reduces the rotational speed r of the engine 17 to a low speed. When the engine 17 is decelerated to reduce the discharge speed of the ready-mixed concrete, and the concrete pump 4 is started to pump out the ready-mixed concrete, the amount of ready-mixed concrete in the hopper 2 decreases, and the ready-mixed concrete level 1 becomes the ready-mixed concrete level range d. Then, the detection signal of the electrode rod 9 is cut off, the rotational speed r of the engine 17 is set to a medium speed by the control device 7, and the discharge amount of ready-mixed concrete is increased. Accordingly, the ready-mixed concrete level l changes from the ready-mixed concrete level range d to the ready-mixed concrete level range c again, and the electrode rod 9 detects this and changes the rotational speed r of the engine 17 to a low speed. At this time, after the electrode rod 9 detects fresh concrete,
When ready-mixed concrete is still detected even after t ₂ seconds, it is determined that the ready-mixed concrete level l is in the ready-mixed concrete level region b, the hydraulic pump 15 is stopped, and the discharge of ready-mixed concrete is stopped. Then, the ready-mixed concrete level l is in the ready-mixed concrete level range c
When the vehicle returns to , the hydraulic pump 15 is started again and the engine 17 is rotated at low speed. In this way, the ready-mixed concrete level l is detected by the ready-mixed concrete level detection device 3, and based on this detection signal, the control device 7 controls the amount of ready-mixed concrete discharged by changing the rotation speed r of the engine 17, etc. Note that if the number of strokes s of the concrete pump 4 increases here, as mentioned above,
Controlled to different control mode. Furthermore, once the concrete pump 4 has been stopped, the timing for starting it again is when the ready-mixed concrete level l reaches the ready-mixed concrete level range c.

Furthermore, if the concrete pump 4 becomes clogged due to foreign matter, etc., turn on the reverse switch _S4 as shown in FIG. Then, the oil pump 15 is stopped and discharge of ready-mixed concrete is interrupted.

Incidentally, in the above description, the case where fresh concrete is received into the hopper 2 from the mixer drum 6 of the truck mixer vehicle 5 has been described, but the same applies to the case where fresh concrete is received from other mixer drums. Moreover, in the above, two electrode rods 8, 9 and three timers T ₁ , T ₂ ,
Although T ₃ was used, it goes without saying that these numbers are not limited to this. Furthermore, the number of strokes s of the concrete pump 4 may be detected not in two ways but in three or more ways, and a control mode may be set for each number of strokes to control the ready-mixed concrete level.

As described above, in the present invention, the mixer drum and the concrete pump are operated in a state where the amount of fresh concrete pumped from the hopper by the concrete pump exceeds the amount of ready-mixed concrete input into the hopper by the mixer drum, and the ready-mixed concrete in the hopper is gradually removed. When the capacity of ready-mixed concrete falls below the level of the ready-mixed concrete capacity detector installed in the hopper, the amount of ready-mixed concrete thrown into the hopper by the mixer drum will be equal to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. At least one of the mixer drum and the concrete pump is controlled so that the concrete pump increases relative to the concrete pump, and when the fresh concrete does not reach the level of the detector even after the increase control is performed and the timer measures a predetermined time, recognizes that the level of ready-mixed concrete is one level lower than the above-mentioned detector, and so that the amount of ready-mixed concrete thrown into the hopper by the mixer drum increases relative to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. At least one of the mixer drum and the concrete pump is controlled to control the level of ready-mixed concrete in the hopper, and the amount of ready-mixed concrete pumped from the hopper by the concrete pump is lower than the amount of ready-mixed concrete input into the hopper by the mixer drum. When the above-mentioned mixer drum and concrete pump are operated and the amount of ready-mixed concrete in the hopper gradually increases, and the amount of ready-mixed concrete exceeds the level of the ready-mixed concrete capacity detector installed in the hopper, the mixer drum transfers the ready-mixed concrete into the hopper. At least one of the mixer drum and the concrete pump is controlled so that the amount of input is reduced relative to the amount of fresh concrete pumped from the hopper by the concrete pump, and the timer measures a predetermined time while the reduction control is performed. If the level of ready-mixed concrete does not fall below the level of the above-mentioned detector even after this, it is recognized that the level of ready-mixed concrete is one step higher than the level of the above-mentioned detector, and the amount of ready-mixed concrete put into the hopper by the mixer drum is changed to the level of ready-mixed concrete by the concrete pump. The structure is such that the level of ready-mixed concrete in the hopper is controlled by controlling at least one of the mixer drum and the concrete pump so that the amount of fresh concrete in the hopper is further reduced relative to the amount of pumped concrete from the hopper.
Accurate level control can be performed. Furthermore, considering that it is virtually impossible to install many detectors in the hopper of a concrete pump, this is an extremely practical and effective method. Furthermore, since the ready-mixed concrete level in the hopper can always be maintained at an optimum level, pouring work can be performed safely and easily, and labor can be saved.

[Brief explanation of drawings]

The figures are for explaining the method of the present invention. Figure 1 is an overall schematic diagram showing the state in which ready-mixed concrete is being poured by a concrete pump truck, Figure 2 is a schematic block diagram of the control system, and Figure 3 is a schematic diagram of the control system. 4 is a block diagram of a control device for a concrete pump truck, FIG. 5 is a flow diagram of ready-mixed concrete level control, and FIG. 6 is a waveform diagram showing an example of control. 1... Concrete pump truck, 2... Hotsupa,
3... Ready-mixed concrete level detection device, 4... Concrete pump, 5... Truck mixer vehicle, 6... Mixer drum, 7... Control device, 8, 9... Electrode rod (detector), T ₁ , T ₂ , T ₃ ...Timer.

Claims (1)

[Claims] 1 The mixer drum and concrete pump are operated in a state where the amount of ready-mixed concrete pumped from the hopper by the concrete pump exceeds the amount of ready-mixed concrete put into the hopper by the mixer drum, and the amount of ready-mixed concrete in the hopper gradually decreases, and the capacity of ready-mixed concrete is reduced. When the level falls below the level of the ready-mixed concrete capacity detector installed in the hopper, the amount of ready-mixed concrete thrown into the hopper by the mixer drum increases relative to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. control at least one of the mixer drum and the concrete pump, and if the fresh concrete does not reach the level of the detector even after the increase control is performed and the timer measures a predetermined time,
The mixer drum recognizes that the level of ready-mixed concrete is one step lower than the level detected by the above-mentioned detector, and increases the amount of ready-mixed concrete thrown into the hopper by the mixer drum relative to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. and a concrete pump to control the level of ready-mixed concrete in the hopper, and the mixer drum is controlled in a state where the amount of ready-mixed concrete pumped from the hopper by the concrete pump is lower than the amount of ready-mixed concrete input into the hopper by the mixer drum. The concrete pump was operated and the amount of ready-mixed concrete in the hoppa gradually increased.
When the capacity of ready-mixed concrete exceeds the level of the ready-mixed concrete capacity detector installed in the hopper, the amount of ready-mixed concrete thrown into the hopper by the mixer drum is relative to the amount of ready-mixed concrete pumped from the hopper by the concrete pump. At least one of the mixer drum and the concrete pump is controlled so that the concrete pump decreases, and if the fresh concrete does not fall below the level of the detector even after the timer measures the predetermined time after the reduction control is performed, the fresh concrete Recognizing that the level of the concrete is one level higher than that of the above-mentioned detector, the mixer drum and A method for controlling the level of ready-mixed concrete in a hopper for a concrete pump, comprising controlling at least one of the concrete pumps to control the level of ready-mixed concrete in the hopper.