JPH045648Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a device for detecting the level of ready-mixed concrete in a hopper for a concrete pump.

Generally, when pouring ready-mixed concrete (hereinafter referred to as "ready-mixed concrete") using a concrete mixer truck and a concrete pump truck, the ready-mixed concrete is poured from the concrete mixer truck into the hopper of the concrete pump truck, and at the same time, the concrete is poured into the hopper. The fresh concrete is pumped by a concrete pump through a feed pipe to the pouring site, 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. It seems so.

In other words, when the fresh concrete level in the hopper becomes lower than the opening of the ready-mixed concrete transfer cylinder that communicates with the hopper during pressure feeding of ready-mixed concrete, air will be sucked and pressure-fed together with the ready-mixed concrete, and this air will be pumped out from the discharge port of the feed pipe. The fresh concrete is discharged together with fresh concrete, or discharged into the hopper through the gap between the switching valve inside the hopper and the concrete cylinder, and the discharged air scatters the ready-mixed concrete into the surrounding area, causing damage to the pouring site and around the hopper of the concrete pump. This is a problem that is said to be dirty and dangerous. To prevent this phenomenon, it is necessary for workers to monitor the ready-mixed concrete level and take measures such as stopping the concrete pump at the same time as air is sucked in. However, this requires monitoring separately from workers at the pouring site. This poses a problem in terms of reducing the number of workers as it requires a worker to be attached to the side of the concrete pump truck. For this reason, devices have been developed that use sensors to detect abnormalities in the level of ready-mixed concrete in the hopper, and use this detection signal to automatically stop concrete pump operation or issue an alarm. This method has disadvantages in that it is not possible to accurately detect an abnormality in the level of ready-mixed concrete due to the effects of rippling of the ready-mixed concrete caused by the stirring device, and that accurate detection requires a complex device that is difficult to implement practically.

This device eliminates the possibility of inhaling air due to the effects of rippling in the ready-mixed concrete, and also makes it easy to tell if the concrete pump stops due to a drop in the level of ready-mixed concrete or a malfunction. The purpose of the present invention is to provide a ready-mixed concrete level detection device for a hopper for a concrete pump.

In order to achieve the above object, this invention includes a detection means for detecting whether or not the ready-mixed concrete in the hopper has reached a predetermined level; an amplifier means that closes the first contact means when detecting that the fresh concrete in the hopper is lower than a predetermined level; off-delay timer means connected in series, which closes the second contact means when the first contact means closes, and opens the second contact means when a set time elapses while the first contact means remains open; an operating switch and a reversing switch connected in parallel with each other, and a third contact means connected in series with the operating switch and connected in series with the second contact means when the operating switch is turned on;
A first relay means for rotating the concrete pump in the forward direction when the second contact means is closed is connected in series with the reversing switch, and when the reversing switch is turned on, the first relay means is connected in parallel to the second contact means and The fourth contact means connected in series to the third contact means is closed, and the fifth contact means connected in parallel to the second contact means and the third contact means is closed, and the operation switch is turned on. The structure includes a second relay means for reversing the concrete pump in case of a concrete pump.

This invention will be explained below with reference to the drawings.

1 to 3 show an embodiment of this invention, in which P is a conventional well-known device having a flow path switching valve 1 made of a bent pipe, a hopper 2, a pair of fresh concrete transfer cylinders 3 and 4, etc. concrete pump. The fresh concrete A put into the hopper 2 is sucked in and discharged alternately by the pair of cylinders 3 and 4, and the pair of cylinders 3,
4, the valve inlet 1a at one end of the flow path switching valve 1 is made to face the opening 3a of the cylinder 3 in which the suction operation has been completed by swinging as shown by the arrow A in FIG. The cylinder 3, which has completed the suction operation, is switched to the discharge operation to discharge the ready-mixed concrete A from the valve inlet 1a to the flow path switching valve 1 as shown in FIG. When the suction operation is completed, the valve inlet 1a of the flow path switching valve 1 is moved to face the opening 4a of the other cylinder 4 whose suction operation has already been completed by swinging as shown by arrow B in FIG. Similarly, by making the operation of this cylinder 4 into a discharge operation, the ready-mixed concrete A is discharged from the valve inlet 1a to the flow path switching valve 1, and the ready-mixed concrete A in the hopper 2 is transferred to the other end of the flow path switching valve 1. It is configured to be pumped to the driving site via a connected feed pipe 5. In addition, 6 in the figure is cylinder 3,
A suction guide pipe that communicates the openings 3a and 4a of 4 with the inside of the hopper 2 and guides the fresh concrete in the hopper 2 to the cylinders 3 and 4, 7 a hopper agitator that stirs the ready-mixed concrete, and 8 a flow path switching valve 1 and a suction guide pipe. 6 each shows a swing cylinder device for swinging the cylinder.

When the flow path switching valve 1 is swung by the swing cylinder 8, the hopper 2 is located above the suction port 6a of the suction guide pipe 6 which communicates with the openings 3a and 4a of the cylinders 3 and 4 on the suction side.
An electrode rod (electrode) 10 is mounted on the inner wall by a mounting bracket 11 almost horizontally with its tip facing toward the center of the hopper 2. As a result, the tip of the electrode 10 is placed at a predetermined distance from the inner wall of the hopper 2. The outer periphery of the electrode rod 10 except for the outer periphery of the tip thereof is covered with a protective cover 12 made of synthetic resin or other insulating material, so that the electrode rod 10 is electrically insulated from the hopper 2.

Further, the electrode rod 10 and the hopper 2 are connected to the lead wire 13.
a, 13b are respectively connected to an α amplifier 15, and this α amplifier 15 is connected to a positive power supply line 16 and a negative power supply line 17, and these lines 16,
17 and the first line 18 in parallel with the α amplifier 15.
, the second line 19 and the third line 20 are connected, and the off-delay timer T is connected to the first line 18.
and the normally open contact 13 of the α amplifier 15 are installed in series, a driving switch NSW and a relay R ₂ are installed in series in the second line 19, and a reversing switch RSW and a relay R ₁ are installed in the third line 20.
are installed in series. Note that the normally open contact 21 of the relay _R1 , the normally open contact 22 of the timer T, and the other normally open contact 24 of the relay _R1 are connected in parallel to the positive power supply line 16, and the contacts 21,
A normally open contact 23 of a relay R ₂ is connected in series to 22 . The normally open contacts 23 and 24 are connected to the control circuit of the concrete pump P, and the normally open contacts 2
3 closes, the concrete pump P rotates in the normal direction, and when the normally open contacts 23 and 24 close, the concrete pump P rotates in the reverse direction.

Next, the operation of this device configured as described above will be explained.

When ready-mixed concrete A is put into the hopper 2 and is brought into contact with the electrode 10, the α amplifier 15 is connected to the normally open contact 1.
3 is closed, the off-delay timer T operates and the normally open contact 22 is closed. Therefore, when the operation switch NSW is turned on here, relay _R2 closes the normally open contact 23, and the operation command is transmitted to the concrete pump P.

On the other hand, when fresh concrete A decreases and separates from the electrode 10, the α amplifier 15 turns off, so the normally open contact 13
becomes open. When the set time of the off-delay timer T elapses while the normally open contact 13 remains open, the off-delay timer T opens the normally open contact 22 and automatically starts the concrete pump P even if the operation switch NSW is on. Stop and prevent air intake. Note that when the level of ready-mixed concrete approaches the electrode 10, a phenomenon occurs in which the ready-mixed concrete A and the electrode 10 are momentarily separated due to the ripples caused by the stirring of the ready-mixed concrete A. However, the off-delay timer T
It will not operate unless the distance between the ready-mixed concrete A and the electrode 10 is continuous. Here, if the off-delay timer T is not provided, the concrete pump P will repeatedly stop and start due to separation and contact between the ready-mixed concrete A and the electrode 10 due to the rippling of the ready-mixed concrete A.
This makes it impossible for workers to work with peace of mind. In this regard, in this invention, the off-delay timer T is designed to prevent the above-mentioned repetition from occurring. In addition, since the electrode 10 is placed at a predetermined distance from the inner wall of the hopper 2, there is no risk of malfunction due to contact with the remaining ready-mixed concrete attached to the inner wall of the hopper 2, and the level of the ready-mixed concrete is reliably maintained. is detected.

When the fresh concrete level is low, it may be necessary to return the fresh concrete to the hopper 2 by reverse operation of the concrete pump P, but in this case, the normally open contact 2 connected in parallel with the normally open contact 22 of the off-delay timer T.
The concrete pump P can be reversed by closing the relay _R1 linked to the reversing switch RSW.

Furthermore, if the concrete pump P stops and you are concerned about whether the stoppage is due to a drop in the level of ready-mixed concrete or whether it has stopped due to a malfunction, please turn on the operation switch NSW and turn the reverse switch RSW. Turn on. If concrete pump P stops due to a drop in fresh concrete level rather than a malfunction, normally open contacts 21 and 24 of relay _R1 close by turning on reversing switch RSW, and concrete pump P reverses with commands from contacts 23 and 24. do. To stop the concrete pump P before operating the reverse switch RSW, use the normally open contact 22 of the timer T.
This is because the operation command from the normally open contact 23 is cut off when the normally open contact 23 opens, but the reverse rotation of the pump P
Needless to say, this is done regardless of whether 2 is opened or closed.

In the above embodiment, the electrode rod 10 serves as the detection means, the normally open contact 13 serves as the first contact means, and the normally open contact 2 serves as the first contact means.
2 is the second contact means, the normally open contact 23 is the third contact means, the normally open contact 21 is the fourth contact means, the normally open contact 24 is the fifth contact means, the α amplifier 15 is the amplifier means, and the relay R ₂ is the first relay means, relay R ₁
is the second relay means, off-delay (off-delay)
The timers T constitute off-delay timer means.

As explained above, this invention includes a detection means for detecting whether the ready-mixed concrete in the hopper has reached a predetermined level, and a detecting means that detects whether the ready-mixed concrete in the hopper has reached a predetermined level. Then the first
Amplifier means is connected in series with the first contact means and opens the first contact means when the detection means detects that the fresh concrete in the hopper has become lower than a predetermined level. off-delay timer means which closes the second contact means when the first contact means is closed and opens the second contact means when a set time elapses while the first contact means remains open; A run switch and a reverse switch are connected in series to the run switch, and when the run switch is turned on, a third contact means connected in series to the second contact means is closed, and the second contact means is closed. a first relay means that rotates the concrete pump in the normal direction when Closes the connected fourth contact means, closes the fifth contact means connected in parallel with the second contact means and the third contact means, and reverses the concrete pump when the operation switch is turned on. Since the structure is equipped with a second relay means, it is possible to accurately detect an abnormal drop state in which the level of ready-mixed concrete has reached the opening of the ready-mixed concrete transfer cylinder without being affected by the rippling of the ready-mixed concrete caused by the stirring device in the hopper. Furthermore, it is possible to prevent the concrete pump from sucking in and pumping air together with the ready-mixed concrete, and the ready-mixed concrete does not scatter around the pouring site or around the concrete pump due to air blowing out, and the surroundings do not get dirty.

Furthermore, if the concrete pump stops for a long time, by turning on the reverse switch, you can easily find out whether the stoppage is due to a failure, and this has the advantage of allowing you to quickly take measures such as continuing the work of pouring ready-mixed concrete.

Furthermore, in this design, if the operation switch is not turned on, the concrete pump will not reverse even if the reverse switch is turned on by mistake, so a changeover switch that switches between forward and reverse rotation with a single rotary knob is used. There is no risk of clumsiness such as inadvertently reversing the concrete pump and causing ready-mixed concrete to overflow from the hopper.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a perspective view, FIG. 2 is a sectional view, and FIG. 3 is a circuit diagram. P...Concrete pump, 1a...Valve inlet,
2...Hopper, 10...Electrode rod (electrode), A...
Ready-mixed concrete, T...timer, RSW...reverse switch.

Claims (1)

[Scope of utility model registration request] A detection means 10 detects whether the ready-mixed concrete in the hopper 2 has reached a predetermined level, and when the detection means 10 detects that the ready-mixed concrete in the hopper 2 has reached a predetermined level, a first contact means 13 An amplifier means 15 is connected in series with the first contact means 13 to close the first contact means 13 and to open the first contact means 13 when the detection means 10 detects that the fresh concrete in the hopper 2 has become lower than a predetermined level. off-delay timer means T which closes the second contact means 22 when the first contact means 13 is closed, and opens the second contact means 22 when a set time elapses while the first contact means 13 remains open; , a run switch NSW and a reverse switch RSW connected in parallel to each other, and a run switch connected in series to the above run switch NSW.
When the NSW is turned on, the third contact means 23 connected in series with the second contact means 22 is closed, and when the second contact means 22 is closed, the concrete pump P is rotated in the normal direction. relay means R ₂ ;
When the reversing switch RSW connected in series with the reversing switch RSW is turned on, the fourth contact means 21 connected in parallel to the second contact means 22 and in series with the third contact means 23 is closed. Second
The fifth contact means 24 connected in parallel with the contact means 22 and the third contact means 23 is closed, and the operation switch is turned on.
A ready-mixed concrete level detection device for a hopper for a concrete pump, characterized by comprising a second relay means _R1 for reversing the concrete pump P when the NSW is turned on.