JPH0326272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concrete pump truck used for pumping fresh concrete into a pipe to a required placement site at a concrete placement site during construction work.

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 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 pouring site are far apart, the concrete pump is configured to be able to be controlled remotely, and workers at the pouring site control the operation of the concrete pump using a transceiver. Things are 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 suctioned and pressure-fed along with the ready-mixed concrete. This air is discharged from the discharge port of the feed pipe along with the ready-mixed concrete, or flows into the hopper from the gap between the switching valve and the concrete cylinder in the hopper, and these discharged air causes the ready-mixed concrete to spread around the surrounding area. The problem is that it scatters, staining the pouring site and the area around the concrete pump hopper, and is dangerous. Conversely, if the level of the ready-mixed concrete becomes abnormally high, there is a risk that it will overflow from the hopper. 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.

The present invention detects the level of ready-mixed concrete in a hopper using a ready-mixed concrete level detection device, and changes the rotational speed of a mixer drum such as a truck mixer using a control device based on the level of ready-mixed concrete detected by the ready-mixed concrete level detection device. This method solves the above conventional problems by controlling the amount (injected), and the level of ready-mixed concrete in the pouring pad can be automatically maintained at the optimum range at all times, making pouring work safe and easy. The purpose of the present invention is to provide a concrete pump truck that can be used for various purposes and that can save labor.

Hereinafter, the present invention will be explained in detail based on the drawings.

1 to 4 show an embodiment of the present invention, and numeral 1 in the figures is a concrete pump vehicle.
This concrete pump truck 1 includes a fresh concrete 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. It is provided with a control device 7 that controls the amount of fresh concrete received from the mixer drum 6 to the hopper 2 by changing the rotation speed of the mixer drum 6, 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 has two electrode rods 8 and 9 spaced vertically apart from each other by a predetermined distance in the hopper 2. , is disposed vertically with respect to the hopper 2 while being supported by a support bracket in an electrically insulated state, and each electrode rod 8 is connected between the hopper 2 and each of the electrode rods 8 and 9 via fresh concrete in the hopper 2. , 9 and the hopper 2 are connected to form an electric circuit (not shown), and when one electrode rod 8 comes into contact with the ready-mixed concrete, the ready-mixed concrete level _l4 is reached, and the other electrode rod 9 reaches the ready-mixed concrete level. When in contact with this ready-mixed concrete level l ₄ higher ready-mixed concrete level
l ₃ are now detected individually. Furthermore, a timer is incorporated in the electric circuit, so that the level l of the ready-mixed concrete in the hopper 2 gradually decreases, and after it has separated downward from the lower electrode rod 8,
If the electrode bar 8 remains away from the electrode bar 8 after ₁ second has elapsed, it is conveniently determined that the fresh concrete level l is _l5 , which is lower than _l4 (described later), and the above electrode bar 9 is If the electrode rod 9 is still in contact with the ready-mixed concrete after t ₂ seconds have passed after detecting the level _l3 , it is also conveniently determined that the ready-mixed concrete level l is _l2 , which is higher than _l3 ( (Postscript) On the other hand, if the electrode rod 9 is still in contact with the ready-mixed concrete after t ₂ seconds and t ₃ seconds have passed since the electrode rod 9 detected the ready-mixed concrete level l ₃ , the ready-mixed concrete level l becomes l. In this case as well, it is conveniently determined that l ₁ is even higher than ₂ (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. In addition, the number of strokes s of the concrete pump 4 is configured such that two types of detection signals are inputted, one for a small number and the other 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 f is "mixer drum stop" and "low-speed rotation" in order. , "medium speed rotation", "high speed rotation" and four stages of control mode,
In the state where the number of strokes is "high", each ready-mixed concrete level area a, ..., except for ready-mixed concrete level areas e and f,
Similarly, the rotational speed of the mixer drum 6 is sequentially set in four stages: "mixer drum stop", "low speed rotation", "medium speed rotation", and "high speed rotation" for d. Ready-mixed concrete level range f in a state where the number of strokes is “small”;
A stop command for the concrete pump 4 is set for the ready-mixed concrete level region e in a state where the number of strokes is "high". And this control device 7
A control signal m from to the mixer drum 6 is configured to be sent to a control device 12 of the truck mixer vehicle 5 via a connecting cable 10 and a connector 11.

By the way, the above-mentioned "judgment of convenience" is just an assumption. For example, the upper electrode rod 9
If the electrode rod 9 is still connected to the ready-mixed concrete after t ₂ seconds have elapsed after detecting the ready-mixed concrete level l ₃ , the amount of input from the mixer drum 6 to the hopper 2 and the pressure-feeding of the ready-mixed concrete by the concrete pump 4 are determined. Is the amount almost the same and the ready-mixed concrete level l remains in the ready-mixed concrete level range c, or is the input amount greater than the pumped amount and the level is rising?
Actually I don't know.

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 logical to perform control by comprehensively determining that the level of ready-mixed concrete has reached _l2 in order to prevent overflow of ready-mixed concrete 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 area c, and reverses when a reverse switch _S4 is activated. When the reverse signal is input, truck mixer truck 5
The mixer drum 6 is configured to stop rotating. Further, the control signal m from the control device 7 to the mixer drum 6 is not only sent directly to the truck mixer vehicle 5, but also switched and sent to an external speaker 13 via a voice synthesis circuit. The operator of the truck mixer vehicle 5 can also manually operate the mixer drum 6 based on the voice command.

On the other hand, the control device 12 of the truck mixer vehicle 5
In response to the control signal m from the control device 7 of the concrete pump truck 1, the mixer drum 6 is stopped and its rotation speed is controlled. That is, the oil pump servo motor 14 is operated by the signal from the control device 12, and the swash plate 15 of the oil pump 15 for the drive motor of the mixer drum 6 is operated.
a is operated, the well-known oil pump 15 is stopped or started, and the engine servo motor 16 is operated, so that the rotational speed γ of the engine 17 that drives the oil pump 15 is set in three stages: high speed, medium speed, and low speed. It has come to be controlled by

Note that 18 in the figure 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 operational data such as the 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 instructions to the driver of the truck mixer vehicle 5, etc. using a microphone.

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

When pouring ready-mixed concrete at a predetermined location using the concrete pump truck 1 of the present invention, after raising the boom 19 and arranging the feed pipe 20 to the site, the controller 7, the main switch S ₁ , and the ready-mixed concrete level Leveler switch S ₂ of detection device 3, concrete pump 4
Turn on the pumping switches _S3 in sequence. Then, the mixer drum 6 and the concrete pump 4 are automatically operated, and the pouring of ready-mixed concrete proceeds. To explain the situation of this automatic operation based on the waveform chart (time chart) in Fig. 4, first, when the main switch _S1 is turned on, a detection current flows through the electrode rods 8 and 9 of the ready-mixed concrete level detection device 3. . Next, when the leveler switch _S2 is turned on, there is no ready-mixed concrete in the hopper 2 and the ready-mixed concrete level l is in the ready-mixed concrete level range f, so the detection signals of the electrode rods 8 and 9 are cut off. From this state, the pumping switch
When _S3 is turned on, the oil pump 15 of the truck mixer vehicle 5 is started, the engine 17 is rotated at high speed (for example, 1000 rpm), and the mixer drum 6 starts discharging (throwing) fresh concrete into the hopper 2.
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 range d and reaches the ready-mixed concrete level range c, the electrode rod 9 detects this, and the control device 7 A signal to start the concrete pump 4 is output, and a signal to reduce the rotation speed γ of the engine 17 to a low speed (for example, 400 rpm) is output. When the engine 17 is decelerated to reduce the discharge speed of the ready-mixed concrete, and the concrete pump 4 is started to begin pumping 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, and the control device 7 sets the rotational speed γ of the engine 17 to a medium speed (for example, 700 rpm).
The amount of ready-mixed concrete discharged will increase. Accordingly, the ready-mixed concrete level l changes from the ready-mixed concrete level range to the ready-mixed concrete level range c again, and the electrode rod 9 detects this and changes the rotational speed γ of the engine 17 to a low speed. At this time, t ₂ seconds (for example, 1.5
When ready-mixed concrete is still detected even after 3 seconds), it is conveniently determined that the ready-mixed concrete level l is in the ready-mixed concrete level region b, and the oil pump 15 is stopped, and the discharge of ready-mixed concrete is stopped. Then, when the ready-mixed concrete level l returns to the ready-mixed concrete level range c, the oil pump 15 is started again and the engine 17 rotates at a 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 γ of the engine 17, etc. Note that when the number of strokes s of the concrete pump 4 increases (for example, 25 times or more), the concrete pump 4 is controlled by another control mode as described above. Furthermore, once the concrete pump 4 is stopped, the timing for starting it again is when the ready-mixed concrete level l reaches the ready-mixed concrete level range c.

Furthermore, as shown in FIG. 4, if the concrete pump 4 becomes clogged due to foreign matter, turn on the reverse switch _S4 , stop the oil pump 15,
Interrupt discharge of ready-mixed concrete.

Incidentally, in the above description, the case where fresh concrete is received 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.

As described above, in the concrete pump truck of the present invention, the concrete pump truck pumps the fresh concrete to the pouring site while putting the fresh concrete into the hopper using the mixer drum of a truck mixer truck. A ready-mixed concrete level detection device in which a plurality of electrode rods that flow a detection current through contact are arranged in a hopper at a predetermined distance from each other in the vertical direction and are electrically insulated from the hopper, and this ready-mixed concrete level detection device The system is equipped with a control device that controls the amount of fresh concrete input from the mixer drum to the hopper by changing the rotational speed of the mixer drum in multiple stages based on the level of fresh concrete detected in the hopper. It is possible to maintain optimal conditions and perform pouring work safely and easily.
This has the effect of making labor savings a reality.

[Brief explanation of drawings]

The figures show one embodiment of the present invention. Fig. 1 is an overall schematic diagram showing the state in which ready-mixed concrete is being poured by a concrete pump truck, Fig. 2 is a schematic block diagram, and Fig. 3 is a control mode diagram. The explanatory diagram, FIG. 4, is a waveform diagram showing a control example. 1... Concrete pump truck, 2... Hotsupa,
3... Fresh concrete level detection device, 4... Concrete pump, 5... Truck mixer vehicle, 6... Mixer drum, 7... Control device.

Claims (1)

[Claims] 1. In a concrete pump truck, which feeds fresh concrete from a mixer drum such as a truck mixer vehicle into a hopper and pumps the fresh concrete to the pouring site using a concrete pump, a plurality of electrode rods that send a detection current through contact with the fresh concrete are moved up and down. A ready-mixed concrete level detecting device is arranged in the hopper at a predetermined distance from each other in the direction and electrically insulated from the hopper, and the rotational speed of the mixer drum is determined based on the ready-mixed concrete level detected by the ready-mixed concrete level detecting device. A concrete pump truck characterized in that it is equipped with a control device that controls the amount of fresh concrete input from a mixer drum to a hopper in multiple stages.