JP2001009827A - Aggregate charging device for ready-mixed concrete plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate a load during charging of aggregates and manufacture a high-quality ready-mixed concrete in a short time by providing a fall energy buffering means for buffering the fall energy of aggregates during the flow-out of the weighed aggregates from a scale, when the ready-mixed concrete is manufactured using a variable speed mixer. SOLUTION: A ready-mixed concrete plant comprises storage bins 1 for storing various kneading materials such as sand, gravel and cement, a scale 2 for weighing each of the materials stored in the storage bins 1 respectively and charging chutes 4 for guiding the materials weighed by each of the scales 2 into the internal drum of a variable speed mixer 3, arranged in series. In this case, a fall energy buffering means 7 is provided which comprises a storage thank 5 for temporarily storing the gravel to be paid off from a scale 2G for gravel and a discharging means 6 for loading the gravel into the drum from the storage tank 5. Thus it is possible to cut down the fall energy of the gravel by about 70% and thereby, curtail the maximum load of the mixer 3 generated during charging the gravel by about 70%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregate loading device which is effective for loading aggregate into a mixer drum, particularly in a ready-mixed concrete plant equipped with a variable speed mixer.

[0002]

2. Description of the Related Art The present applicant has filed Japanese Patent Application Laid-Open Nos. 61-207764 and 8-196885 as proposals on mixers for kneading ready-mixed concrete. These proposals relate to a variable speed mixer that can increase or decrease the number of revolutions of the stirring blade, and in particular, have a feature in obtaining high quality ready-mixed concrete quickly and at low cost. according to it,
When kneading ready-mixed concrete by putting various kneading materials into the drum, first, water, cement, sand are mixed and kneaded with high-quality mortar, and then gravel is added to finish the ready-mixed concrete, In each process of mortar, ready-mixed concrete, and discharge, a suitable rotation speed (best stirring blade peripheral speed) is set. However, the load on the stirring blade temporarily increases when various kneading materials are charged, particularly when aggregates such as gravel and sand are charged. In this regard, FIG.
This will be described in detail with reference to FIG. Ready-mixed concrete plant
Sand, gravel, cement, kneading materials for ready-mixed concrete
.. a storage bin 1 for storing each material, a weighing device 2 for weighing the material in each storage bin, and the material weighed by each weighing device in the drum of the variable speed mixer 3 at an optimal timing. The introduction chutes 4 for guiding are arranged in series. Therefore, each material measured by the measuring device 2 is introduced into the drum of the variable speed mixer 3 by gravity via the chute 4.

In a general ready-mixed concrete plant equipped with a variable speed mixer capable of kneading 1.5 m ^{3 at a} time,
From the axis of the rotation shaft of the stirring blade of the variable speed mixer 3, the measuring device 2
The vertical distance to the top is about 4m, and the weight of aggregate put in at once is about 1200kg for sand and about 1500kg for gravel.
It is. Since the sand and the gravel are all charged in a short time of about 5 seconds, in the conventional aggregate input device including only the input chute 4, the impact force received by the stirring blades at the time of inputting the aggregate is considered. Since the aggregate supplied through the input chute 4 is piled up at one location, the load torque of the mixer is temporarily increased in order to uniformly disperse the aggregate in the drum. According to the proposal,
By responding quickly to this load and reducing the rotation speed of the stirring blade, the load can be handled.

[0004]

However, since the rotational speed of the mixer, even temporarily, is lower than the best peripheral speed of the stirring blade, the kneading time is increased. The present invention relates to producing ready-mixed concrete using a variable speed mixer,
The purpose of the present invention is to provide an aggregate input device for a ready-mixed concrete plant that reduces the temporary load generated during the input of the aggregate and kneads at the best stirring blade peripheral speed to produce a high-quality ready-mixed concrete in a shorter time. And

[0005]

SUMMARY OF THE INVENTION The present invention relates to an aggregate feeding device for introducing aggregate measured by a measuring instrument of a ready-mixed concrete plant having a variable speed mixer capable of increasing and decreasing the rotation speed of a stirring blade into a drum of the variable speed mixer. The apparatus according to any one of claims 1 to 3, further comprising a fall energy buffering means for buffering fall energy of the aggregate when the measured aggregate flows out of the measuring instrument. That is,
The fall energy buffering means buffers and attenuates the fall energy of the aggregate flowing out of the measuring instrument using physical means when the aggregate measured by the measuring instrument is charged into the variable speed mixer,
Further, the load on the variable speed mixer is reduced by dispersing the aggregate into the drum and charging the aggregate. Therefore, the stirring blade kneads the ready-mixed concrete at a rotation speed closer to the best stirring blade peripheral speed even when the aggregate is charged. This will be described in detail based on the explanatory diagram showing the load torque, electric power, and rotation speed of the variable speed mixer shown in FIG. For example, taking the second step as an example, when gravel as coarse aggregate is charged into a drum by a conventional aggregate input device, the load torque of the variable speed mixer becomes T in FIG.
As shown by a, the rotation speed of the stirring blade sharply decreases as shown by Na in the figure so as not to exceed the constant power value H1. The aggregate loading device of the present invention reduces the load of the variable speed mixer at the time of aggregate loading as shown by Tb in the figure,
The electric power of the motor is reduced from Ha to Hb, and the mixing speed of the stirring blades is kneaded in a state closer to the optimum rotation speed as indicated by Nb in the figure.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when producing ready-mixed concrete using a variable speed mixer, sand (fine aggregate), cement and water, which are mortar raw materials, are charged into a drum and the mortar is kneaded. This is an aggregate loading device that is particularly effective for charging the aggregate when kneading the ready-mixed concrete by charging the gravel (coarse aggregate) from the ground. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0007]

Embodiment 1 FIG. 2 shows a first embodiment of the present invention, and is a schematic view showing a measuring section and a mixer section of a ready-mixed concrete plant equipped with a variable speed mixer. The embodiment will explain the measurement and discharge of gravel as coarse aggregate. In FIG. 2, the fall energy buffering means 7 of the first embodiment includes a storage tank 5 for temporarily storing the gravel discharged from the gravel measuring device 2G, and a gravel stored in the storage tank at the lower end of the storage tank 5. And discharging means 6 for charging the drum into the drum. The storage tank 5 is disposed between the measuring instrument 2G and the mixer 3 and is as close to the mixer 3 as possible. With this storage tank 5, the gravel that had conventionally fallen from a height of about 3.5 m is dropped from a height of about 2.5 m, the fall energy of the gravel is reduced to about 70%, and the gravel input The occasional maximum load on the mixer is likewise reduced by about 70%. Further, since the discharging means 6 of the present embodiment is formed so that the bottom lid of the storage tank 5 is rotated around a pin, when the gravel stored in the storage tank is charged into the drum, the discharge means 6 is not used. The bottom lid of 5 rotates,
It is thrown into the drum through the space created by the bottom lid and the side wall of the storage tank. At this time, since the gravel also flows in the left and right directions of the bottom cover, the gravel is dispersed in the drum. Therefore, the load torque of the mixer when the gravel is charged is further reduced.

A conventional automatic weighing system in a ready-mixed concrete plant has been made as follows. That is, it is desirable to shorten the time from the start of kneading to the placing of the fresh concrete as much as possible, and it is necessary to minimize the kneading time from the start of kneading to the discharge. If the kneading is started at a point in time when the weighing is not completed due to a shortage of one of the kneading materials, the time until the remaining one weighing is completed and put into the mixer is a wasteful waste of the ready-mixed concrete.
In order to prevent this, kneading is started after all the materials are weighed, and each material is sequentially charged into the drum at the optimum timing.After all the materials have been charged into each measuring device, the next batch is weighed. It was a way to start. However, in this method, the measurement of the gravel can be started only after the release of the gravel in the second step is completed, so that the discharge in the third step is completed and the kneading of the next batch can be started. Even when the condition was reached, the gravel weighing was not completed, and there was a situation that kneading could not be started. However, the aggregate loading device of the present embodiment has a structure in which gravel measured by the measuring device 2G can be temporarily stored in the storage tank 5.
Immediately after the start of kneading, the gravel of the measuring device 2G can be discharged into the storage tank to start the measurement of the next batch, so that the cycle time of the measurement is greatly reduced. Therefore, the kneading cycle of the ready-mixed concrete plant can be shortened, and the shipping capacity can be greatly improved. In the present embodiment, the case of gravel as coarse aggregate has been described. However, when this means is used for a device for feeding sand as fine aggregate, the temporary load in the first step in FIG. Can be.

[0009]

Embodiment 2 FIG. 3 is a schematic view showing a falling energy buffer means of a second embodiment, in which only a portion corresponding to a portion for guiding the gravel in the gravel measuring device 2G of FIG. 2 into the drum is described. A falling energy buffer 7 is provided with a chute 8 for guiding the gravel discharged from the gravel measuring device 2G into the drum.
And a plurality of direction changing members 9 disposed on the chute to change the flow direction of the aggregate in the chute, and gravel flows between the lowermost direction changing member 9 and the lower end of the side wall of the chute 8. A space 10 is provided. Gravel measuring device 2G
Can be changed by the direction changing member 9 when sliding down the side wall of the chute 8 and the speed of sliding down is reduced. Further, the gravel is dispersed in the drum by the direction changing member 9 and the space 10.

[0010]

Embodiment 3 FIG. 4 shows a falling energy buffer means of a third embodiment, in which only a portion corresponding to a portion for guiding the gravel in the gravel measuring device 2G of FIG. 2 into the drum is described.
The fall energy buffering means 7 includes a chute 8 for guiding the gravel discharged from the gravel measuring device 2G into the drum, and a collision member disposed at the lower end of the chute to contact the aggregate flowing out from the lower end of the chute. 11 are formed. The gravel discharged from the gravel measuring device 2G slides down the side wall of the chute 8, and the gravel sliding down by the collision member 11 is temporarily received and the sliding speed is reduced. In this embodiment, since the collision member 11 is formed in a mountain shape, the gravel slides along the mountain shape and can be sufficiently dispersed.

[0011]

According to the first aspect, since the peak load at the time of introducing the aggregate can be reduced, the power consumption of the variable speed mixer can be reduced. In addition, even when the aggregate is charged, the stirring blades are kneaded at a rotation speed closer to the best stirring blade peripheral speed, so that high-quality ready-mixed concrete can be stably manufactured. Furthermore, it is possible to increase the peripheral speed of the stirring blades at the time of introducing the aggregate, as compared with the conventional case, to increase the aggregate dispersion efficiency immediately after the introduction of the aggregate, and to shorten the kneading time.

According to the second aspect of the present invention, since the aggregate input device has a structure capable of temporarily storing the aggregate flowing out of the measuring device, the fall distance of the aggregate is reduced by half, and the drop energy when the mixer is input is also large. To be reduced. Also, immediately after the aggregate weighing is completed, the aggregate in the measuring device can be discharged to the storage tank and the next batch weighing can be started immediately, and the shipping capacity of the ready-mixed concrete plant can be greatly improved. .

According to the third aspect of the present invention, since the falling energy of the aggregate flowing out of the chute is changed by changing the flowing direction thereof, the falling energy of the aggregate can be dispersed to each stirring blade. . Also, since the aggregate can be dispersed and supplied in the drum, the aggregate supplied after kneading the mortar is dispersed in the mortar in a shorter time, and the kneading efficiency of the ready-mixed concrete is improved. further,
Can be dealt with only by changing the chute, reducing the cost of changing

According to the fourth aspect of the present invention, since the aggregate flowing out of the chute is temporarily received and its falling energy is attenuated, the aggregate can be scattered and supplied into the drum.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing load torque, electric power, and rotation speed of a variable speed mixer.

FIG. 2 is a schematic view showing a fall energy buffering means of the first embodiment in a measuring section and a mixer section of the ready-mixed concrete plant.

FIG. 3 is a schematic view showing a falling energy buffer means according to a second embodiment.

FIG. 4 is a schematic view showing a fall energy buffering unit according to a third embodiment.

FIG. 5 is a schematic diagram showing a measuring section and a mixer section of a conventional ready-mixed concrete plant.

[Explanation of symbols]

 1, 1G storage bin 2, 2G weighing device 3, variable speed mixer 5, storage tank 6, discharge means 7, falling energy buffer means 8, chute 9, direction change member 11, Impact member

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F075 AA07 BB03 CA01 CA06 CD12 DA17 DA21 4G037 AA04 EA02 4G056 AA06 CB02 CB11 CC07 4G068 AA02 AB22 AC16 AD01 AE03

Claims (4)

[Claims] An aggregate feeding device for introducing aggregates measured by a measuring machine of a ready-mixed concrete plant equipped with a variable speed mixer capable of increasing and decreasing the rotation speed of a stirring blade into a drum of the variable speed mixer, wherein the measured aggregates are provided. An aggregate loading device for a ready-mixed concrete plant, comprising a fall energy buffer means for buffering the fall energy of the aggregate when the water flows out of the measuring instrument. 2. The ready-mixed concrete plant according to claim 1, wherein said falling energy buffering means comprises a storage tank for temporarily storing the aggregate flowing out of the measuring instrument, and a discharging means for gradually charging the once stored aggregate. Aggregate loading device. 3. The fall energy buffering means includes a chute for guiding the aggregate flowing out of the measuring instrument into the drum, and a chute disposed below the chute to change the flow direction of the aggregate flowing out of the chute and drop the chute. The aggregate input device for a ready-mixed concrete plant according to claim 1, further comprising a direction changing member that attenuates energy. 4. The fall energy buffering means includes a chute for guiding the aggregate flowing out of the measuring instrument into the drum, and an aggregate disposed below the chute and brought into contact with the aggregate flowing out of the chute. 2. The aggregate input device for a ready-mixed concrete plant according to claim 1, further comprising: a collision member that attenuates the aggregate.