JPS6087011A - Forced kneading mixer and method of kneading concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forced mixing remixer and a concrete mixing method using the mixer.

When kneading concrete, for example, a two-screw forced kneading remixer or a pan-type forced kneading mixer is used.

An example of a conventional two-shaft forced remixer will be explained with reference to FIGS. 1 and 2. Two parallel shafts 2, 2' are rotatably installed in a mixing pan 1, and the shafts 2, 2' is equipped with a feather m3.3' for crosstalk. In addition, induction type electric motors 4, 4' and reducers 5, 5' are installed on the outside of the side plate of the mixing pan L, and m 5, 5'
(1-digit belts 8, 8' are passed between the single-digit pulleys 7, 7', and the output shafts of the reducers 5, 5' are connected to the shafts 2, 2'. Left and right reducer 5.

A synchronized coupling 9 is disposed between the shafts 2 and 2' between the shafts 5', and the shafts 2 and 2' are rotated in synchronism by driving the electric motors 4 and 4', thereby driving the blades 3 and 3'. This makes it possible to mix concrete.

4/J4mM. ＃＋． m:MMfrh11SJ=JJ-
/7'l-Ishi11l10 As shown in FIG. A pulley 16.17 is attached to the output shaft of the motor 14 and an intermediate shaft 15, respectively, a belt 18 is passed between the boots 516.1, and the intermediate shaft 15 is connected to a deceleration JI.
It is connected to the input shaft of A12, and the blades 13 are rotated by an induction type electric motor 14 to mix concrete.

Figure 4 shows the relationship between output and time when mixing concrete using each of the above forced mixers.
It became clear that the output was not very high while supplying and mixing cement, but that a large output was required when adding gravel. In this way, when introducing gravel, a large output is required because, if the power of the induction electric motor is KW, the torque is T, the rotation speed is N, and the coefficient is α, then KW = αNT
This is because the rotation speed of the induction type electric motor is constant, and the rotation speed of the electric motor does not change even when the torque (load) increases. Therefore, the horsepower of the motor must be determined by the peak output of the graph shown in FIG. 4, which increases the size of the electric motor and increases equipment costs and operation and maintenance costs. In addition, when mixing water, cement, and sand, the higher the rotation speed (peripheral speed of the blade), the faster the concrete strength and the shorter the mixing time, but the rotation speed is suppressed when gravel is mixed, and the mixing time is The problem is that it cannot be shortened.

The present invention has been made to solve this problem, and its purpose is to make it possible to change the rotational speed of the drive device of the mixer for forced mixing in accordance with the load and the crosstalk conditions. be.

In the present invention, a drive source whose rotational speed can be controlled, such as a hydraulic motor or a DC motor, having a constant output range as shown in FIG. 5 is used, and the drive source is driven in a desired state by a control device. .

First, one of the drive modes is the forward-direction type, and in this case, the output characteristics of the drive source are shown in FIG.

That is, the capacity of the drive source is always pushed to nearly 100%.

When mixing water, cement, and sand (hereinafter referred to as mortar mixing)
The torque required for crosstalk may be small. Therefore, the fifth
When using the drive source with the constant torque characteristic shown in the figure, the number of rotations can be increased when driving in a low torque state.

Furthermore, when gravel is added and kneaded, the torque increases and the number of revolutions decreases. If the gravel is mixed at a high speed, the gravel and mortar will separate, so in order to obtain good quality concrete, the gravel must be mixed at a speed lower than the required speed. That is, if control is actively performed to increase the torque and decrease the rotational speed, the ability of the drive source can be fully exploited and high-quality concrete can be obtained.

As a result, mortar crosstalk time can be shortened and nearly 100% of the drive source's capacity can be utilized, improving crosstalk efficiency and AI.
4A efficiency can be improved. Furthermore, the capacity of the drive source can be made smaller than that of the conventional one.

Furthermore, other driving modes are possible with the present invention, and the second
This drive style ensures high quality and stability of concrete.

As shown in FIG. 7, this drive system rotates at high speed when mixing mortar and rotates at low speed when mixing gravel. Such a driving style can stabilize the quality of concrete.

Here, the concrete compressive strength σ when changing the mixer rotation speed (blade peripheral speed) when mortar is mixed,
, (ks/Li) variation results are shown below.

The test contents were the two types of compositions shown in Table 1, the blade peripheral speed R was R6 = 1 forceps/5ec R♂2111/SCC, the crosstalk time t was 30 seconds, and the number of tests was 3 under the same conditions. Six samples for strength measurement were taken from inside the mixer each time. was measured. The measurement results are shown in Table 2.

Table 1 (Composition) Note: W/Water C9 Shudori Portland Cement S: Sand Water absorption rate 1.42% Amount 2.65 Coarse particle ratio 2.68 G: Gravel Ad' water reducer, Hozolith L&+, 5 L Table 2 ( Test data) As is clear from the test data in Table 2 above, when the kneading time is the same and the blade peripheral speed is changed, the average strength of both soft and hard mortars is high under the condition of high blade peripheral speed R2. Good quality concrete with a small average standard deviation was obtained.

This tendency is observed even when the cross-contact time is 5Qsec, and it can be seen that the quality of concrete is influenced by the peripheral speed of the blade during mortar cross-contact.

It should be noted that the peripheral speed of the blade and the cross-circuit time during gravel cross-crossing may be such that the mortar and aggregate do not separate and the mortar adheres uniformly around the aggregate.

Moreover, there is a concrete quality improving type as a third driving style.

This detects the point at which the quality of the mortar has improved the most during mortar mixing, and at this point gravel is added to mix the concrete.

Regarding mortar, even if the mixing conditions are the same, the physical properties and fluidity of mortar will vary significantly if the surface water content of the sand changes. The point at which the quality of the mortar is most improved is the state when an outer shell of hard cement paste (capillary paste) is formed around the sand and the remaining space is filled with soft cement paste (slurry paste). This refers to the time when the concrete becomes capillary (called a shape), and when it becomes this capillary shape, concrete strength and concrete pumping performance are greatly improved.

The present inventor discovered that when the mortar becomes capillary-shaped during mortar mixing, the torque required for mixing becomes maximum, and the inventors monitored the mixer drive torque during mixing, detected the point at which the torque reached the maximum, and The concrete is cross-wired by adding gravel, and the output characteristics of the drive source in this case are shown in FIG.

There are various ways to drive the drive source to detect maximum torque, but one example is to install a torque detector in the drive source, drive the drive source at a constant rotation speed lower than the maximum rotation speed, and then use the torque detector to detect the maximum torque. One method is to find the maximum torque f1. If gravel is fed into the mixer and mixed with concrete in response to the maximum value detection signal from the torque detector, high-quality concrete can be obtained.

Note that capillary detection can be performed even when the maximum power consumption of the driving source is determined.

Further, in FIG. 8, after the gravel is added, the driving is focused on efficiency, and the ability of the driving source is fully demonstrated.

Although various drive styles can be obtained by controlling the drive source as described above, programs for various drive styles may be input into the control device in advance, and the operator may select the optimal drive style as appropriate depending on the situation.

Next, a drive device for performing the various drives described above will be explained with reference to FIG. 9.

In FIG. 9, 20 is an input device, 21 is a plant computer, 22 is a mixer control computer, and 23 is a mixer.
, a storage device 28, connected to a display device 29 and a recorder 30 such as a printer via an interface 24, and an opening/closing device 32 and a weighing device 33 for each bin in which sand, cement, etc. are stored, via an interface 25. A gate opening/closing device 34 for the 4-volume hopper is connected to the processor 27.

The mixer control computer 22 mainly consists of an interface 35, 36, a processor 37, and a storage device 38, and the processor 37 is connected to a mixer gate opening/closing device 39 and a mixer driving device 40 via the interface 36.
, a torque detector 41, and a rotation speed detector 42 are connected. Note that 43 is the mixer body.

Various data for inputting materials to the mixer 23 are input in advance to the storage device 28 of the n+1 plant computer.

One of the data is mixture data, that is, distribution rules P1 of each material as shown in Table 3 are created according to the required quality of concrete, and each mixture data is assigned a mixture number. Other examples include demota of material input data, ie, material input order, input interval, etc., which correspond to each formulation data (composition number).

Table 3 When the mixture No. and shipping amount (concrete cross-contamination amount) are input from the input device 20, the processor 27 searches the storage device 28 for various data matching the mixture No., and calculates the shipping amount from the various data. The input amount of each material is calculated accordingly, and when the measurement result by the scale 33 matches the calculated input amount, etc., a drive signal is issued to open and close the bin gate opening/closing device 32 and the hopper gate opening/closing device 34. Therefore, the material is fed into the mixer 23 at a predetermined time under the required conditions.

Further, the storage line 38 of the mixer control computer stores mixer driving conditions corresponding to each of the mixing data, namely mixing time, kneading rotation speed, final stage rotation speed (concrete υ [mixer rotation speed immediately before delivery), and kneading. The crosstalk time for each rotation speed when the rotation speed is changed, and also the above-mentioned figures 6, 7, and 8.
The driving pilot flame shown in the figure is inputted with the symbol (mixture) io, and the driving conditions corresponding to the blending number are determined from the storage device 38 by specifying the blending number from the ntJ input device 20 and specifying the shipping amount. The information is searched and further calculated in accordance with the shipping amount, and a start/stop signal 44 and a rotation speed setting signal 45 are input to the mixer drive device 40, and the drive source of the mixer is controlled according to the calculated driving conditions and the selected driving style. .

At this time, the rotation speed of the mixer drive line (or mixer blade rotating shaft) is fed back to the processor 37 from the rotation speed detector 42, and the rotation speed of the mixer drive source is maintained at the set rotation speed.

When the predetermined mixing time has elapsed, the mixer reaches the final stage rotational speed, and the mixer gate opening/closing device 39 opens the gate to discharge the mixed concrete.

In addition, when crosstalk is performed in the drive mode shown in FIG. detected,
The maximum value detection signal is input to the plant computer 21, and gravel is introduced into the mixer 22 based on the signal.

By using a drive source with a controllable rotation speed and appropriately selecting the preset drive conditions and driving style as described above, it is possible to cross-concrete with high efficiency and to achieve high-quality concrete. You can get concrete.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional two-shaft forced kneading remixer, Fig. 2 is a plan view of Fig. 1, Fig. 3 is an explanatory diagram of a partially broken conventional pan-type forced kneading mixer, and Fig. 4 is an explanatory diagram of a conventional two-shaft forced kneading remixer. A diagram showing the relationship between output and time when crosstalk is performed in a conventional forced mixer, FIG. 5 is a diagram showing the characteristics of the drive source used in the present invention, FIGS. 6 and 7, FIG. 8 is a diagram showing the output characteristics of the drive sources of various drive modes in the present invention, and FIG. 9 is a block diagram showing the apparatus of the present invention. 20 is an input device, 22 is a mixer control computer, 2
3 is a mixer, 37 is a processor, 38 is a storage device, 40
42 is a rotation speed detector, and 43 is a mixer main body. Patent Applicant Ishikawajima Harima Heavy Industries Co., Ltd. Patent Applicant Ishikawajima Construction Machinery Co., Ltd. Figure 7 Figure 8 VT Open - Figure 9 Continued from page 1 @ Inventor Otera Utaai Ishikawajima, 2-9-7 Yaesu, Chuo-ku, Tokyo Harima Heavy Industries Co., Ltd. Kyobashi Office

Claims (1)

[Claims] 1) A mixer main body having a drive source capable of controlling the number of rotations and a storage device in which various drive conditions are manually set, and the ml record fn is created by inputting a drive condition selection signal and a shipping amount designation signal.
: Select the required drive conditions from JIcFf, and drive the ll1I drive sources based on the drive conditions to match the shipping amount 4! A forced line remixer that is characterized by its newly developed features. 2) A concrete mixing method characterized by detecting load torque while kneading mortar at a constant speed, and adding gravel and kneading when the load torque becomes larger than the required (+Ir).