JP6933917B2 - Concrete mixer and ready-mixed concrete manufacturing equipment in which it is used - Google Patents

Description

The present invention relates to a concrete mixer for kneading a plurality of types of materials, for example, in a batcher plant as a ready-mixed concrete manufacturing apparatus.

Conventionally, for example, a batcher plant as a ready-mixed concrete manufacturing apparatus manufactures ready-mixed concrete by kneading various materials such as gravel (coarse aggregate), sand (fine aggregate), cement, water, and an admixture. A concrete mixer for kneading each material is installed inside the batcher plant, and ready-mixed concrete is produced by kneading each material in the concrete mixer (see, for example, Patent Document 1). The generated ready-mixed concrete is put into an agitator truck or the like from the lower part of the concrete mixer and shipped as needed.

14 and 15 are views showing the internal configuration of a conventional concrete mixer, FIG. 14 is a front view, and FIG. 15 is a side view. The concrete mixer (hereinafter, simply referred to as “mixer”) 50 has a mixer main body 51 and two kneading shafts 52 rotatably provided in the mixer main body 51. The kneading shaft 52 is provided with a plurality of paddles 53 for kneading the above materials. Each paddle 53 includes an arm 54 connected to each kneading shaft 52 and a blade 55 provided at the tip of the arm 54. Further, a drive motor (not shown) for rotationally driving the kneading shaft 52 is provided outside the mixer body 51.

At the upper corner of the mixer body 51, a water distribution section 55 through which water supplied to the mixer body 51 flows is provided so as to extend in the extending direction of the mixer body 51. A plurality of injection pipes 56 are arranged on the outer surface of the water circulation unit 55.

In the above configuration, when the materials are kneaded, sand, gravel and cement are charged into the mixer 50, and water is ejected from the injection pipe 56 to charge water into the mixer 50. In this case, as shown by the dotted lines in FIGS. 14 and 15, the water from the injection pipe 56 is ejected in a straight line in a substantially downward direction, and reaches the material that is charged and stays on the bottom surface of the mixer body 51.

Since the water from the injection pipe 56 is ejected in a straight line, it penetrates into the retained material so as to locally pierce the material. Therefore, even if the material is kneaded by rotating the kneading shaft 52, there is a problem that it is difficult for water to permeate so as to spread over the entire material and it takes time to knead.

Further, since the water from the injection pipe 56 locally invades the entire material, so-called kneaded balls are likely to occur. Since the kneaded balls cause deterioration of the quality of ready-mixed concrete, it is necessary to suppress the generation of kneaded balls.

Further, the water ejected from the injection pipe 56 is mainly used for cleaning the insides of the kneading shaft 52, the paddle 53 and the mixer main body 51 at the end of the kneading step. However, as described above, since the water from the injection pipe 56 is ejected linearly, it is difficult to effectively clean the entire inside of the mixer body 51, and it is difficult to obtain a sufficient cleaning effect. be.

Japanese Unexamined Patent Publication No. 2008-21288

The present invention has been conceived under the above circumstances, and provides a concrete mixer capable of shortening the kneading time, suppressing the generation of kneaded balls, and further enhancing the cleaning effect inside the main body. That is the issue. Another object of the present invention is to provide a ready-mixed concrete manufacturing apparatus used for this concrete mixer.

Concrete mixer to a first aspect of the present invention, a plurality of types of materials are introduced into a hollow body, a concrete mixer to produce a raw concrete by kneading these materials, said body A substantially columnar kneading shaft provided inside the main body, which has a paddle for kneading the material and is rotatable, and extends in the extending direction of the main body in the upper corner of the main body. A water flow section provided and communicated with a water supply means for supplying water among the materials, and a kneading shaft attached to the outer surface of the water flow section and directed toward the kneading shaft inside the main body. With a plurality of nozzles that inject water supplied by the water supply means , the tip shape of the injection port is formed in a spiral shape, and the injection port is arranged so as to face the kneading axis. , Attached to the outer surface of the water flow section, injects water supplied by the water supply means toward the inside of the main body, the injection port is formed in a cylindrical shape, and the injection port is the said. A plurality of injection pipes arranged so as to face the kneading shaft are provided, and the plurality of nozzles are arranged on the outer surface of the water flow section at predetermined intervals, and the respective injection pipes are arranged at predetermined intervals. It is characterized in that it is arranged between the adjacent nozzles.

In the concrete mixer of the present invention, the base of the nozzle may be formed by a swivel mechanism.

In the concrete mixer of the present invention, the water supply means may mix the water supplied to the nozzle with an admixture that enhances the fluidity of the material during kneading.

In the concrete mixer of the present invention, it is preferable that the water supply means is provided with a water pressure increasing means for increasing the pressure of the supplied water.

The ready-mixed concrete manufacturing apparatus provided by the second aspect of the present invention is characterized by being provided with the concrete mixer provided by the first aspect of the present invention.

According to the concrete mixer of the present invention, since the tip shape of the nozzle for injecting water, which is one of the materials, is formed in a spiral shape, the water from the nozzle is ejected so as to spread in a spiral shape and a conical shape. Then, water is sprinkled so as to cover the entire surface of the material that is thrown into the main body and stays on the bottom surface of the mixer main body. Therefore, since water can permeate the entire inside of the material at the time of kneading the material, the fluidity of the material can be increased and the kneading time of the material can be shortened. Further, since water permeates the entire inside of the material when the material is kneaded, the generation of kneaded balls can be suppressed. Further, since the water from the nozzle is jetted so as to spread spirally and conically, the jetted water reaches the entire inside of the mixer, and the inside of the mixer can be effectively washed.

It is a figure which shows the schematic structure of the ready-mixed concrete manufacturing apparatus to which the concrete mixer which concerns on this invention is applied. It is an external side view of a concrete mixer. It is a side view which shows the internal structure of a concrete mixer. It is a top view which shows the internal structure of a concrete mixer. It is a front view which shows the internal structure of a concrete mixer. It is a figure which shows the mounting state of a spiral jet nozzle. It is a figure which shows the injection state of water from a spiral jet nozzle. It is a figure which shows the injection state of water from a spiral jet nozzle. It is a figure which shows the injection state of water from a spiral jet nozzle. This is experimental data comparing the kneading conditions of the spiral jet nozzle and the conventional pipe. This is experimental data comparing the kneading conditions of the spiral jet nozzle and the conventional pipe. This is experimental data comparing the kneading conditions of the spiral jet nozzle and the conventional pipe. This is experimental data comparing the kneading conditions of the spiral jet nozzle and the conventional pipe. It is a figure which shows the injection state of water from a conventional pipe. It is a figure which shows the injection state of water from a conventional pipe.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a ready-mixed concrete manufacturing apparatus to which the concrete mixer according to the present invention is applied.

The batcher plant 1 as this ready-mixed concrete manufacturing apparatus produces ready-mixed concrete by measuring and kneading a plurality of types of materials such as gravel (coarse aggregate), sand (fine aggregate), cement, water and admixture. It is a device for manufacturing. The batcher plant 1 includes a belt conveyor 2 for transporting aggregates such as sand and gravel from a storage silo (not shown) or the like. The aggregate carried by the belt conveyor 2 is distributed to the plurality of aggregate storage tanks 4 by the turn head 3. Cement is supplied from the cement silo to the cement storage tank 5 via an air transport device (all not shown) or the like.

The sand and gravel stored in the aggregate storage tank 4 are weighed by the aggregate measuring instrument 6 and charged into the concrete mixer (hereinafter, simply referred to as “mixer”) 8 via the aggregate input chute 7. The cement stored in the cement storage tank 5 is weighed by the cement measuring instrument 9 and charged into the mixer 8 via the cement charging chute 10.

Further, the water stored in the water storage tank (not shown) is mixed with the admixture in the water measuring instrument 11, the total amount of water and the admixture is measured by the water measuring instrument 11, and the water supply chute 12 and the water input are added. It is charged into the mixer 8 via the tube 13. There are various types of admixtures depending on their performance, but in the present embodiment, for example, those having the ability to improve the fluidity of the material at the time of kneading are used.

Materials such as gravel, sand, cement, water and admixtures charged into the mixer 8 are kneaded in the mixer 8 to become ready-mixed concrete. The ready-mixed concrete is transported to the construction site by an agitator truck (not shown) or the like via a concrete hopper 14 and a hopper gate 15 provided at the lower part of the mixer 8.

2 is an external side view of the mixer 8, FIGS. 3 to 5 are views showing the internal configuration of the mixer 8, FIG. 3 is a side view, FIG. 4 is a plan view, and FIG. 5 is a front view. Reference numeral 7 shown in FIG. 3 indicates an aggregate injection chute for sand, and reference numeral 7 shown in FIG. 5 indicates an aggregate injection chute using sand.

The mixer 8 has a mixer body 16 having a desired size. The inside of the mixer main body 16 is hollow in order to knead the above-mentioned materials, and the aggregate charging chute 7, the cement charging chute 10 and the water charging pipe 13 are connected to the outer surface of the mixer main body 16, respectively. There is.

The mixer body 16 has a curved bottom surface 17 when viewed from the front. The bottom surface portion 17 is formed substantially along a rotation locus of the kneading shaft 21, which will be described later. The bottom surface portion 17 is provided in accordance with the two kneading shafts 21, and is formed so that a portion in which the two bottom surface portions 17 are connected is raised. The raised portion 18 is provided with a gate (not shown) that can be opened and closed.

As shown in FIGS. 3 to 5, two kneading shafts 21 are rotatably provided inside the mixer main body 16. The two kneading shafts 21 extend in the extending direction of the mixer body 16 and are formed in substantially columnar shapes, and are rotated in directions opposite to each other. The shape of the kneading shaft 21 is not limited to a columnar shape, and may be, for example, a prismatic shape.

The two kneading shafts 21 are rotationally driven by two drive motors 22 (see FIG. 4) and a speed reducer (not shown) attached to the end faces of the mixer body 16. Each of these drive motors 22 serves as a drive source for the rotation of each kneading shaft 21. Each speed reducer is for changing the driving force of each driving motor 22.

The kneading shaft 21 is provided with a plurality of types of paddles 23 having different shapes. One of the paddles 23 includes a rod-shaped arm 24 connected to the kneading shaft 21 and, for example, a fan-shaped blade 25 connected to the arm 24, and the paddle 23 can mainly knead materials.

The water input pipe 13 described above is branched in the vicinity of the mixer body 16 (see FIG. 4), and the branched water input pipe 13 is connected to the upper side surface of the mixer body 16 as shown in FIG. There is. A pressurizing pump (not shown) for increasing the pressure of water may be interposed in the water input pipe 13. As a result, the pressure of the water jetted from the spiral jet nozzle 27, which will be described later, can be increased.

The water input pipe 13 communicates with the water distribution section 26 via the upper side surface of the mixer main body 16. The water flow section 26 is formed in a hollow box shape inside the mixer body 16. The water distribution unit 26 is not limited to the box shape, but may be formed in, for example, a cylindrical shape. As shown in FIG. 5, the water distribution unit 26 is located in the upper right corner and the upper left corner of the inside of the mixer body 16, respectively, and as shown in FIG. 3, the extension direction of the mixer body 16 (with the kneading shaft 21). Extends in the same direction).

A plurality of spiral jet nozzles (hereinafter, simply referred to as "spiral nozzles") 27 are arranged on the outer surface of the water distribution unit 26. The spiral nozzle 27 is for injecting water toward the inside of the mixer body 16. As shown in FIG. 6, the spiral nozzle 27 has a spiral tip shape, which is an injection port thereof. The spiral nozzle 27 is attached to a socket 28 provided in the opening of the water circulation section 26.

The spiral nozzle 27 can inject water in a spiral and conical shape due to the spiral tip shape. Therefore, the spiral nozzle 27 can sprinkle water over a wide range by injecting water.

As shown in FIG. 5, each spiral nozzle 27 is arranged so that its injection direction faces the kneading shaft 21 located on the front side of the spiral nozzle 27. Therefore, the water jetted from the spiral nozzle 27 spreads so as to cover the entire curved bottom surface portion 17 of the mixer body 16.

The plurality of spiral nozzles 27 are arranged at predetermined intervals (for example, about 256 mm) from one end to the other end of the mixer body 16. In the present embodiment, a total of 10 spiral nozzles 27 are arranged, 5 in 2 rows each.

Here, if the distance between the adjacent spiral nozzles 27 is extremely narrow, the water injected from the adjacent spiral nozzles 27 and spreading in a conical shape interferes with each other in the vicinity of the tip of the spiral nozzles 27, and the water is injected. It will hinder the momentum and spread of the water. Therefore, in the present embodiment, in consideration of the injection angle of the spiral nozzle 27, the size of the mixer body 16, and the like, the sprayed water is uniformly spread over the entire bottom surface 17 of the mixer body 16, or the material is used. Spiral nozzles 27 are arranged at predetermined intervals so as to spread uniformly over the entire surface of the material during kneading.

The water jetted from the spiral nozzle 27 is also used to wash the kneading shaft 21 while the material is being charged. Further, it is also used for cleaning the inside of the kneading shaft 21 and the mixer 8 after the material is kneaded and discharged. Therefore, when the injection direction of the spiral nozzle 27 is directed to the kneading shaft 21, for example, the kneaded material adhering to the kneading shaft 21 or the paddle 23 can be suitably peeled off.

Further, it is desirable that the diameter of the base of the spiral nozzle 27 is larger than, for example, about 20 to 25 mm, which is the particle size of gravel. For example, the water supplied to the spiral nozzle 27 may contain sludge water, and if the diameter of the spiral nozzle 27 is larger than the gravel contained in the sludge water, clogging in the spiral nozzle 27 is prevented. can.

Further, the base of the spiral nozzle 27 may be configured by a rotatable so-called swivel mechanism. As a result, the direction of the water ejected from the spiral nozzles 27 can be changed. For example, if the injection directions of the adjacent spiral nozzles 27 are set in a staggered pattern, the interference of the water ejected from each spiral nozzle 27 can be suppressed. can.

In the present embodiment, a cylindrical injection pipe 31 is arranged between adjacent spiral nozzles 27. Since the injection pipe 31 has a cylindrical ejection port, water is ejected in a straight line. The injection pipe 31 is provided mainly for removing deposits adhering to the kneading shaft 21 and the paddle 23, that is, for improving the cleaning effect.

Next, the operation of the spiral nozzle 27, which is a feature of the present embodiment, will be described.

When the material is kneaded in the mixer 8, the kneading shaft 21 is rotated, and water containing sand, cement and an admixture as the kneading material is poured into the mixer body 16 at almost the same time. That is, sand is charged into the mixer 8 via the aggregate charging chute (for sand) 7, cement is charged into the mixer 8 via the cement charging chute 10, and water containing the admixture is charged into the mixer 8 via the water charging chute 12 and the water charging pipe 13. Will be done. Then, a few seconds later, the gravel is thrown into the mixer 8 via the aggregate throwing chute 7 (using sand).

The water introduced through the water input pipe 13 is once supplied to the water distribution unit 26, and is injected from the water distribution unit 26 into the inside of the mixer main body 16 through the plurality of spiral nozzles 27. Since the tip portion of the spiral nozzle 27, which is a water injection port, is formed in a spiral shape, water is sprayed in a spiral shape and a conical shape. For example, as shown by the dotted line in FIG. 7, the water ejected from the spiral nozzle 27 is ejected from the center of the nozzle so as to spread in a conical shape toward the kneading shaft 21. Therefore, the water from the spiral nozzle 27 spreads so as to cover the paddle 23 (not shown in FIG. 7) of the kneading shaft 21, in other words, the curved bottom surface 17 of the mixer body 16.

Further, as shown by the dotted lines in FIGS. 8 and 9, the water jetted from the spiral nozzle 27 spreads in a conical shape, and although a part of the water jetted from the adjacent spiral nozzles 27 overlaps, the mixer body 16 It spreads so as to cover almost the entire surface of the bottom surface portion 17.

Therefore, the cement and sand that are added at almost the same time will be sprayed evenly and almost uniformly over the entire surface. During kneading, the kneading shaft 21 is rotated to stir the material, and as time elapses, water permeates the entire material volume. Therefore, the fluidity of the material is enhanced, and the kneading time can be shortened.

Here, since the water charged into the mixer body 16 contains an admixture, when the water is ejected from the spiral nozzle 27, the admixture is evenly diffused over the entire surface of the material. In the present embodiment, the admixture used has the ability to improve the fluidity of the material, and the admixture is diffused over the entire surface of the material to further enhance the fluidity of the material. Can be demonstrated.

Further, since the spiral nozzle 27 sprinkles water evenly and substantially uniformly on the entire surface of the material, unlike the injection pipe 56 shown in the background technology column, the water does not reach the material locally. It is possible to suppress the possibility of producing kneaded balls.

Further, at the time of washing after the kneading step is completed, water jetted from the spiral nozzle 27 is used. In this case, since the water from the spiral nozzle 27 is sprayed so as to spread spirally and conically, the sprayed water can reach the entire inside of the mixer body 16 and preferably peel off the deposits. The inside of the mixer body 16 can be effectively cleaned.

Next, the results of an experiment conducted by the applicant in order to confirm the effect of kneading the material due to the injection of water by the spiral nozzle 27 will be described.

FIG. 10 is a diagram showing experimental data comparing the kneading conditions when the spiral nozzle 27 according to the present embodiment and the injection pipe 56 (hereinafter referred to as “conventional pipe”) shown in the background technology column are used. Is.

In the figure, the horizontal axis shows time (unit is seconds), and the vertical axis shows current value (unit is ampere). Further, the solid line shows the current value at the time of kneading when the spiral nozzle 27 is used, and the dotted line shows the current value at the time of kneading when the conventional pipe is used. Here, the current value indicates the current value of the drive motor 22 when the kneading shaft 21 is rotationally driven, and the higher the current value, the more the driving force for rotating the kneading shaft 21 is required. Therefore, the current value is an index showing the degree of kneading of the material.

In the figure, the symbol t1 indicates the timing at which water containing sand, cement and an admixture is charged into the mixer body 16, and the symbol t2 indicates the timing at which gravel is charged. The ready-mixed concrete produced in this experiment is so-called ordinary concrete, and its composition is, for example, nominal strength = 27, slump = 18, maximum size of aggregate = 20, cement type = N.

According to the figure, the current value when the spiral nozzle 27 is used and the current value when the conventional pipe is used are almost the same in the period T1 until about 20 seconds after the material is charged. After that, in the period T2 until about 35 seconds later, the current value in the spiral nozzle 27 is lower than the current value in the conventional pipe, and the spiral nozzle 27 stabilizes the current value earlier than the conventional pipe. There is.

The above results are presumed to be due to the following reasons.

In the conventional pipe injection, water is injected linearly, so that the water reaches the material injected into the mixer body 16 so as to locally pierce the material and penetrates into the material as it is. On the other hand, in the injection by the spiral nozzle 27, the injected water spreads in a conical shape and is uniformly sprinkled on the surface of the material as shown in FIGS. 7 to 9. These waters remain on the surface of the material immediately after injection.

In the period T2, since water is locally ejected to the material in the conventional pipe injection, it takes time for the water to permeate the entire material even if the kneading shaft 21 is rotated. Therefore, the kneading is delayed.

On the other hand, in the injection by the spiral nozzle 27, water spreads over the entire surface of the material, so that the permeation into the entire material progresses with the passage of time, and it becomes possible to knead with a smaller kneading force than in the case of the conventional pipe. Therefore, it is presumed that the current value of the spiral nozzle 27 is lower than that of the conventional pipe.

In the injection by the spiral nozzle 27, water permeates the entire material quickly, so that the current value becomes stable faster than the injection by the conventional pipe. Specifically, as shown in FIG. 10, the injection by the spiral nozzle 27 becomes stable 2-3 seconds earlier than the conventional pipe. As described above, it was confirmed that the injection by the spiral nozzle 27 takes faster kneading time, in other words, the kneading time is faster.

As described above, when the spiral nozzle 27 is used, water is sprayed onto the entire material, so that the kneading time can be shortened, and thus the production time of ready-mixed concrete can be shortened.

11 to 13 are diagrams showing experimental data comparing the kneading conditions when the spiral nozzle 27 and the conventional pipe are used, as in FIG. 10. However, this experimental data is based on the case where so-called high-strength concrete is produced in which the composition of ready-mixed concrete is, for example, nominal strength = 48, slump = 21, maximum size of aggregate = 20, cement type = N. Is.

In the production of high-strength concrete, the timing at which gravel is added (see t2 in FIG. 11) is later than in the case where ordinary concrete is produced, and sand, cement, and water containing an admixture are kneaded before t2. So-called mortar is once generated. After that, gravel is added and kneaded to produce high-strength concrete.

According to FIG. 11, in the period T3 in which the mortar is generated from the start of kneading to about 70 seconds later, the current value in the spiral nozzle 27 is lower than the current value in the conventional pipe, and the current value in the spiral nozzle 27 is more stable. The time is getting earlier (about 5 seconds). In the subsequent period T4 until the end of kneading, the current value in the spiral nozzle 27 is low and the time when the current value stabilizes is earlier (about 8 seconds) as in the period T3.

In the period T3, since the mortar is produced in advance, the material capacity is small, and the material is actively moving immediately after the start of kneading. In this state, since water is sprayed onto the entire material by the spiral nozzle 27, it is presumed that the water permeates the mortar quickly and the admixture easily reacts.

In the period T4, the degree of kneading of the mortar in the period T3 is higher in the spiral nozzle 27 than in the conventional pipe, so that the state is continued even in the kneading after the gravel is added, and the spiral nozzle 27 has the current value as compared with the conventional pipe. Is presumed to stabilize quickly.

As described above, it was confirmed that the kneading using the spiral nozzle 27 has a faster kneading speed even in the production of high-strength concrete.

The scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the shape, size, quantity, and the like of the concrete mixer 1, the spiral nozzle 27, the paddle 23, the kneading shaft 21, and the like in the above embodiment are not limited to the above embodiment, and the design can be changed as appropriate. For example, in the above embodiment, the injection directions of the spiral nozzles 27 are the same, but the injection directions of the adjacent spiral nozzles 27 may be different. For example, the adjacent spiral nozzles 27 may be arranged so that the injection directions are staggered.

1 Batcher plant 8 Concrete mixer 13 Water input pipe 16 Mixer body 17 Bottom part 21 Kneading shaft 22 Drive motor 26 Water distribution part 27 Spiral jet nozzle

Claims (5)

A concrete mixer that produces ready-mixed concrete by putting multiple types of materials into a hollow body and kneading those materials.
A substantially columnar kneading shaft provided inside the main body, having a paddle for kneading the material, and rotating.
A water distribution unit that is provided inside the main body and extends in the extending direction of the main body in the upper corner of the main body and communicates with a water supply means for supplying water among the materials.
Attached to the outer surface of the water distribution unit, toward the kneading shaft in the interior of the body by injecting water supplied by said water supply means, formed tip shape is an injection port of that is spirally A plurality of nozzles that are arranged so that the injection port faces the kneading axis .
It is attached to the outer surface of the water flow section, injects water supplied by the water supply means toward the inside of the main body, the injection port is formed in a cylindrical shape, and the injection port is the mixture. Equipped with multiple injection pipes arranged to face the wrought shaft ,
The plurality of nozzles
It is arranged on the outer surface of the water distribution section at a predetermined interval.
Each of the injection pipes
A concrete mixer characterized in that it is arranged between the adjacent nozzles. The concrete mixer according to claim 1, wherein the base of the nozzle is configured by a swivel mechanism. The water supply means
The concrete mixer according to claim 1 or 2 , wherein an admixture that enhances the fluidity of the material during kneading is mixed with the water supplied to the nozzle. The water supply means is
The concrete mixer according to any one of claims 1 to 3 , further comprising a water pressure increasing means for increasing the pressure of the supplied water. A ready-mixed concrete manufacturing apparatus comprising the concrete mixer according to any one of claims 1 to 4.

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