阅读说明：本技术 带怠速模式的混凝土振动器 (Concrete vibrator with idling mode ) 是由 铃木祯久 上田伸治 牛岛弘贵 山下和弘 铃木真辉 安藤友和 于 2018-04-27 设计创作，主要内容包括：本发明提供一种根据振动筒的状态能够自动地变更电动机的转速,从而能够适当地避免因电动机的过热状态及由此引起的故障的混凝土振动器。构成为在控制单元(8)的控制下,在将能够使电动机(2)以适合去除气泡作业的转速进行旋转的频率的驱动电力提供给电动机(2)的通常模式、或者将能够使电动机(2)以比通常模式要低的转速进行旋转的频率的驱动电力提供给电动机(2)的怠速模式下运行,控制单元(8)构成为每单位时间对输入至控制单元(8)或者电动机(2)的电流值进行测量并记录于存储器,并且将最新电流值与基于过去的测量值计算出的基准值进行比较,进一步将比较值的绝对值与阈值进行比较来掌握振动筒的状态,适当地切换运行模式。(The invention provides a concrete vibrator which can automatically change the rotating speed of a motor according to the state of a vibration cylinder, thereby properly avoiding the overheat state of the motor and the faults caused by the overheat state. The control unit (8) is configured to operate in a normal mode in which drive power of a frequency at which the motor (2) can be rotated at a rotation speed suitable for the operation of removing air bubbles is supplied to the motor (2) or an idle mode in which drive power of a frequency at which the motor (2) can be rotated at a rotation speed lower than that in the normal mode is supplied to the motor (2), under the control of the control unit (8), and the control unit (8) is configured to measure a current value input to the control unit (8) or the motor (2) per unit time and record the measured current value in a memory, compare the latest current value with a reference value calculated based on the past measured value, further compare the absolute value of the comparison value with a threshold value to grasp the state of the vibration cylinder, and appropriately switch the operation mode.)

1. A concrete vibrator is characterized in that,

comprises a vibration cylinder with a built-in motor and an eccentric weight, a power supply part for supplying driving power to the motor, a switch for switching the supply and stop of the driving power, a power supply cable for electrically connecting the vibration cylinder and the power supply part, and a control unit for controlling the driving power of the motor,

the control unit is configured to operate in a normal mode in which the motor is supplied with drive power having a frequency suitable for the bubble removal operation and a frequency suitable for the bubble removal operation, or in an idle mode in which the motor is supplied with drive power having a frequency lower than the normal mode,

the control means measures a current value input to the control means or the motor per unit time while the motor is driven, records the measured value in the memory, compares a latest current value input to the control means or the motor with a reference value calculated based on a past measured value to calculate a comparison value, and further compares an absolute value of the comparison value with a preset threshold value,

in the case of operation in the normal mode, when the absolute value of the comparison value is smaller than the threshold value, and the state continues and the duration exceeds the reference time, the operation mode is changed to the idle mode,

when the absolute value of the comparison value is larger than the threshold value in the case of operation in the idle mode, the operation mode is changed to the normal mode.

2. The concrete vibrator according to claim 1,

the latest measured value of the current input to the control unit or the motor and the average value of a plurality of measured values immediately before the latest measured value are taken as the latest current value,

an average value of the plurality of measurement values measured before the plurality of measurement values used for calculating the latest current value is taken as a first reference value,

an average value of the plurality of measurement values measured before the plurality of measurement values used for calculating the first reference value is taken as a second reference value,

comparing the latest current value with a first reference value to calculate a first comparison value, and comparing the latest current value with a second reference value to calculate a second comparison value,

the absolute value of the first comparison value and the absolute value of the second comparison value are compared with a preset threshold value respectively.

3. The concrete vibrator according to claim 1,

when operating in the idle mode, the motor is supplied with drive power at a frequency at which the motor is rotated at a rotation speed at which the motor does not overheat even if the motor is continuously driven in the air.

4. The concrete vibrator according to claim 1,

the threshold value is set to a value within the range of 0.3 to 2.0A.

5. The concrete vibrator according to claim 1,

in the case of operating in the normal mode, when a state in which the absolute value of the comparison value is larger than the threshold value continues and when the absolute value of the comparison value is temporarily smaller than the threshold value but the duration does not exceed the reference time, the normal mode continues,

in the case of operation in the idle mode, when the state in which the absolute value of the comparison value is smaller than the threshold value continues, the idle mode is continued.

Technical Field

The present invention relates to a concrete vibrator used for removing air bubbles from poured concrete, and more particularly to a concrete vibrator having the following structure: the operation can be performed in two modes, a "normal mode" and an "idle mode", and these operation modes are automatically switched under the control of the control unit.

Background

When concrete is poured in a construction site or the like, an operation of removing air bubbles from the concrete is performed using a concrete vibrator. The concrete vibrator has the following structure: the vibration cylinder is provided at the tip end with a built-in motor and eccentric weight, and by inserting the vibration cylinder into uncured concrete, vibration is applied to the concrete, and air bubbles present in the concrete can be lifted and removed.

When the motor built in the vibration cylinder is continuously rotated at a high speed, heat generated by friction heat, electric resistance, or the like is accumulated, and the motor may be overheated, but the motor is cooled by the surrounding concrete while the vibration cylinder is inserted into the concrete, and thus the motor does not get overheated even when the motor is continuously rotated at a high speed.

Disclosure of Invention

Technical problem to be solved by the invention

However, at a site where concrete pouring work is performed, since it takes a long time to pump concrete, the air bubble removal work cannot be continuously performed by the concrete vibrator, and therefore, there are cases where an intermittent operation (a time period during which the vibrating cylinder must be pulled out of concrete and held in air) occurs during the air bubble removal work. In such a gap of the air bubble removal work, when the switch of the concrete vibrator is not turned off and the high-speed rotation state of the motor is continued in the air for a long time, the vibration cylinder cannot be sufficiently cooled by only the ambient air, and there is a possibility that the motor is in an overheated state and malfunctions.

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a concrete vibrator capable of automatically changing the rotation speed of a motor according to the state of a vibration cylinder, thereby appropriately avoiding an overheat state of the motor and a malfunction caused by the overheat state.

Technical scheme for solving technical problem

The concrete vibrator according to the present invention is characterized by comprising a vibration cylinder having a motor and an eccentric weight built therein, a power supply unit for supplying driving power to the motor, a switch for switching supply and stop of the driving power, a power supply cable for electrically connecting the vibration cylinder and the power supply unit, and a control unit for controlling the driving power of the motor, and is configured to operate in a normal mode in which the driving power of a frequency at which the motor is rotated at a rotation speed suitable for a bubble removal operation is supplied to the motor or an idle mode in which the driving power of a frequency at which the motor is rotated at a rotation speed lower than that in the normal mode is supplied to the motor under the control of the control unit, wherein the control unit measures a current value input to the control unit or the motor per unit time during the driving of the motor and records the measured value in a memory, the control device compares the latest current value input to the control unit or the motor with a reference value calculated based on past measured values recorded in a memory to calculate a comparison value, and further compares the absolute value of the comparison value with a preset threshold value.

In the concrete vibrator, it is preferable that the latest measured value of the current input to the control unit or the motor and an average value of a plurality of measured values immediately before the latest measured value are set as the latest current value, the average value of the plurality of measured values measured immediately before the plurality of measured values for calculating the latest current value is set as a first reference value, the average value of the plurality of measured values measured immediately before the plurality of measured values for calculating the first reference value is set as a second reference value, the latest current value is compared with the first reference value to calculate a first comparison value, the latest current value is compared with the second reference value to calculate a second comparison value, an absolute value of the first comparison value and an absolute value of the second comparison value are compared with a threshold value set in advance, and when the concrete vibrator is operated in the idle mode, the motor is preferably operated at a rotation speed at which the motor is not overheated even if the motor is continuously driven in the air The driving power of the frequency of rotation is supplied to the motor.

Preferably, the threshold value to be compared with the absolute value of the comparison value is set to a value within a range of 0.3 to 2.0A in accordance with the size of the vibration cylinder (output of the motor), and the normal mode is continued when a state in which the absolute value of the comparison value is larger than the threshold value continues and when the absolute value of the comparison value is temporarily smaller than the threshold value but the duration time does not exceed the reference time in the case of operation in the normal mode, and the idle mode is continued when a state in which the absolute value of the comparison value is smaller than the threshold value continues in the case of operation in the idle mode.

Effects of the invention

The concrete vibrator according to the present invention is configured to automatically change to an operation mode in which the rotational speed of the motor is low when the vibration cylinder in which the motor is driven is pulled out of the concrete in a gap or the like in the air bubble removal work, and automatically return to a normal operation mode when the vibration cylinder is reinserted into the concrete, and when the air bubble removal work is interrupted, the motor can be appropriately prevented from being in an overheated state even when the vibration cylinder is pulled out of the concrete and kept in the air, and a malfunction due to overheating of the motor can be prevented from occurring.

Further, the concrete vibrator according to the present invention can suppress power consumption as a whole, and can expect an effect of contributing to energy saving. In addition, the concrete vibrator according to the present invention can accurately determine the state of the vibrating cylinder without being affected by individual differences.

Drawings

Fig. 1 is a block diagram showing a basic configuration of a concrete vibrator 1 according to a first embodiment of the present invention.

Detailed Description

Hereinafter, an embodiment of the "concrete vibrator" according to the present invention will be described. As shown in fig. 1, a concrete vibrator 1 according to the present embodiment is composed of: a vibration cylinder 4, the vibration cylinder 4 having a motor 2 and an eccentric weight 3 built therein; a power supply unit 5, the power supply unit 5 supplying driving power to the motor 2; a switch 6, the switch 6 switching supply and stop (on/off) of the driving power; a power supply cable 7, the power supply cable 7 electrically connecting the vibration cylinder 4 and the power supply unit 5; and a control unit 8, the control unit 8 controlling the driving power of the motor 2. The power supply cable 7 is covered and protected by a protective tube 9 between the vibration cylinder 4 and the switch 6.

The power supply unit 5 is connected to a commercial power supply (or another power supply) not shown, and converts input electric power into a current of an appropriate frequency through a built-in control unit 8 and a frequency conversion circuit 10 to output the current so that the motor 2 is driven at a desired rotation speed. The motor 2 in the vibration cylinder 4 is driven by receiving electric power output from the power supply unit 5 and supplied via the power supply cable 7, and the eccentric weight 3 rotates at a high speed, whereby the vibration cylinder 4 vibrates.

The concrete vibrator 1 is configured to operate in either a "normal mode" or an "idle mode" under the control of the control unit 8. The "normal mode" is an operation mode assuming that the vibration cylinder 4 is inserted into concrete and the air bubble removing work is performed, in which the driving power is adjusted to an appropriate frequency and supplied to the motor 2 so that the motor 2 is driven at a rotation speed suitable for the air bubble removing work. In the present embodiment, the power input to the power supply unit 5 is input to the driver of the control unit 8, the frequency is converted into 360Hz by the frequency conversion circuit 10, and the 360Hz is output from the driver of the control unit 8 and the power supply unit 5.

On the other hand, the "idle mode" is an operation mode in which the vibration cylinder 4 is extracted from the concrete into the air and the air bubble removal operation is interrupted, and in this mode, the driving power is adjusted to an appropriate frequency and supplied to the motor 2 so that the motor 2 is driven at a rotation speed at which the motor 2 is not in an overheated state even if continuously driven (a rotation speed lower than that in the "normal mode"). In the present embodiment, the power input to the power supply unit 5 is converted into a frequency of 250Hz by the driver of the control unit 8, and is output from the power supply unit 5.

Further, the control unit 8 is configured to: the operation mode is automatically changed from the "normal mode" to the "idle mode" or from the "idle mode" to the "normal mode" according to the state of the vibration cylinder 4 (inserted into concrete or held in air). Specifically, while the motor 2 is driven, the control unit 8 continuously monitors the current value input to the driver of the control unit 8, determines the state of the vibration cylinder 4 based on the magnitude of the change in the input current value, and appropriately selects and switches the operation mode according to the state of the vibration cylinder 4.

Here, a description will be given of a relationship between an input current value to the driver of the control unit 8 and a state of the vibration cylinder 4, and when the vibration cylinder 4 of the concrete vibrator 1 vibrates by driving the motor 2 by supplying driving power from the power supply unit 5 and rotating the eccentric weight 3, a continuous value of the current input to the driver of the control unit 8 in the power supply unit 5 has a waveform of a different form depending on whether the vibration cylinder 4 is inserted into concrete or the vibration cylinder 4 is held in the air.

Specifically, when the motor 2 is driven in a state where the vibration cylinder 4 is inserted into concrete, a large load is applied to the motor 2 by the concrete existing in the periphery, and therefore the input current value to the driver of the control unit 8 has a waveform with a relatively large amplitude. On the other hand, when the motor 2 is driven while the vibration cylinder 4 is kept in the air, the load due to the concrete is not applied, and therefore the input current value to the driver of the control unit 8 has a waveform with a smaller amplitude. Therefore, by continuously monitoring the input current value to the driver of the control unit 8 and grasping the magnitude of the change, it is possible to determine the state of the vibration cylinder 4, that is, whether the vibration cylinder 4 is inserted into concrete or the vibration cylinder 4 is held in the air.

The state of the vibration cylinder 4 may be determined by continuously monitoring the value of the current input to the motor 2 (i.e., the value of the current output from the driver of the control unit 8) and grasping the magnitude of the change in the input current value to the motor 2.

In the concrete vibrator 1 of the present embodiment, the following procedure is performed in order to determine the state of the vibration cylinder 4. First, in any operation mode while the motor 2 is driven, the driver of the control unit 8 measures the current value input to the driver of the control unit 8 per unit time (in the present embodiment, "0.1 second"), and records the measured value in the memory. In parallel with this, the driver of the control unit 8 compares the latest current value calculated based on the latest measured value of the current input to the driver of the control unit 8 or the like with the reference value calculated based on the past measured value already recorded in the memory (subtracts the reference value from the latest current value or subtracts the latest current value from the reference value) per unit time (in the present embodiment, "0.5 seconds").

In the present embodiment, the latest measured value of the current input to the driver of the control unit 8 and the average value of the plurality of measured values immediately before the latest measured value (for example, the average value from the measured value before 0.4 second to the latest measured value) are set as the latest current value, the average value of the plurality of measured values measured before the plurality of measured values used for calculating the latest current value (for example, the average value from the measured value before 0.9 second to the measured value before 0.5 second) is set as the first reference value, the average value of the plurality of measured values measured before the plurality of measured values used for calculating the first reference value (for example, the average value from the measured value before 1.4 second to the measured value before 1.0 second) is set as the second reference value, the latest current value and the first reference value are compared (the first comparison value is calculated), and the latest current value and the second reference value are compared (the second comparison value is calculated).

Then, the driver of the control unit 8 compares the absolute value of the comparison value (first comparison value and second comparison value) between the latest current value and the reference value (first reference value and second reference value) with a predetermined threshold value (in the present embodiment, "0.3A"). Here, when the absolute value of the comparison value (either the absolute value of the first comparison value or the absolute value of the second comparison value) is larger than the threshold value, the input current value to the driver of the control unit 8 changes with a large amplitude exceeding the threshold value, and when the absolute value of the comparison value (both the absolute value of the first comparison value and the absolute value of the second comparison value) is smaller than the threshold value, the change in the input current value to the driver of the control unit 8 is extremely small.

Therefore, when the absolute value of the comparison value (either the absolute value of the first comparison value or the absolute value of the second comparison value) is greater than the threshold value, the driver of the control unit 8 determines that "the vibration cylinder 4 is in the state of being inserted into the concrete". On the other hand, when the absolute value of the comparison value (the absolute value of the first comparison value and the absolute value of the second comparison value) is smaller than the threshold value, the driver of the control unit 8 determines that "the vibration cylinder 4 is likely to be held in the air", and further, when the state where the absolute value of the comparison value is smaller than the threshold value continues and the duration exceeds the reference time (in the present embodiment, "60 seconds"), the driver of the control unit 8 determines that "the vibration cylinder 4 is held in the air". Based on the determination result regarding the state of the vibration cylinder 4, the driver of the control unit 8 determines whether to change the current operation mode or to continue the current operation mode.

Specifically, when the concrete vibrator 1 is operated in the "normal mode", if the absolute value of the comparison value is smaller than the threshold value, and the state continues and the duration exceeds the reference time, it is determined that the vibration cylinder 4 is kept in the air, and the operation mode is changed to the "idle mode". On the other hand, when the concrete vibrator 1 is operated in the "normal mode", if a state in which the absolute value of the comparison value is larger than the threshold value continues and if the state is not continued (the duration time does not exceed the reference time) in which the absolute value of the comparison value is temporarily smaller than the threshold value, it is determined that the "state in which the vibration cylinder 4 is continuously or intermittently inserted into the concrete" continues, and the operation mode is not changed, and the "normal mode" continues.

When the concrete vibrator 1 is operated in the "idle mode", if the absolute value of the comparison value is greater than the threshold value, it is determined that "the vibration cylinder 4 is inserted into the concrete", and the operation mode is changed to the "normal mode". On the other hand, when the concrete vibrator 1 is operated in the "idle mode", if the state in which the absolute value of the comparison value is smaller than the threshold value continues, it is determined that "the vibration cylinder 4 is still held in the air", and the "idle mode" continues without changing the operation mode.

The concrete vibrator 1 according to the present invention is configured as described above, and when the vibration cylinder 4, which is driven by the motor 2, is pulled out from the concrete and kept in the air without turning off the switch 6 during a gap or the like in the air-bubble removal work, the driver of the control unit 8 determines that "the vibration cylinder 4 is kept in the air" at a time point when the state exceeds a reference time, and automatically changes the operation mode to the "idle mode".

In the "idle mode", the frequency of the drive power output from the power supply unit 5 is converted and supplied to the motor 2 so that the motor 2 is driven continuously at a rotation speed at which the motor 2 is not overheated (a rotation speed lower than that in the "normal mode"), and therefore, the motor 2 can be prevented from being overheated without disconnecting the switch 6, that is, without continuously rotating the motor 2, and a failure due to overheating of the motor 2 can be prevented.

In addition, when the vibration cylinder 4 held in the air is inserted into the concrete in order to restart the interrupted air bubble removal operation, the driver of the control unit 8 determines that "the vibration cylinder 4 is inserted into the concrete" and automatically changes the operation mode to the "normal mode".

Further, since the power consumption during the operation in the "idle mode" is smaller than the power consumption during the operation in the "normal mode", the operation mode is automatically switched to the "idle mode" in accordance with the state of the vibration drum 4, so that the power consumption can be suppressed as a whole and the energy saving can be facilitated. Further, the operator can operate the concrete vibrator without frequently switching the switch 6.

In addition, as a modification of the present invention, it is conceivable that when a concrete vibrator configured to operate in the "normal mode" satisfies a predetermined condition, the operation mode is automatically changed to the "stop mode" (that is, the switch 6 is automatically switched off) without being changed to the "idle mode", the driving power supplied to the motor is cut off to stop the motor, and from this state, the operator inserts the vibrating cylinder into the concrete, and the rotation of the motor is restarted by switching the switch 6 on.

In contrast, when the vibration tube 4 held in the air is inserted into the concrete as in the concrete vibrator 1 of the above embodiment, if the operation mode is configured to be automatically changed from the "idle mode" to the "normal mode", the width of change in the current before and after the change to the "normal mode" can be made small, and the load on the motor 2 can be reduced. After the switch to the "normal mode", the rotation speed of the motor 2 can be increased to a predetermined rotation speed (rotation speed suitable for the bubble removal operation) in a short time, and the operability for the operator is also good. This is similar to the case: the case where the vehicle is running at a low speed reaches the predetermined speed causes less load on the engine than the case where the vehicle is running at a stop and reaches the predetermined speed, and the time required to reach the predetermined speed is also shortened.

In addition, in a plurality of concrete vibrators 1 of the same model, even when the driving power is supplied to the motor 2 under the same condition, the current values actually input to the drivers of the respective control units 8 also cause individual differences, therefore, when the current value input to the driver of the control unit 8 is measured and the state of the vibration cylinder 4 is determined, as a reference value to be compared with the measured value, in the case where a fixed value set in advance is used, there is a possibility that an erroneous determination may occur due to the individual difference as described above, but in the present embodiment, as a reference value to be compared with the latest current value, since the average value calculated based on a plurality of measurement values in the concrete vibrator 1 immediately before is used, therefore, the state of the vibration cylinder 4 can be accurately determined without being affected by individual differences.

In the present embodiment, the frequency of the driving power of the motor 2 converted by the frequency conversion circuit 10 and the driver of the control unit 8 is set to "360 Hz" in the "normal mode" and "250 Hz" in the "idle mode", but the frequency is not limited to this frequency, and can be set to an appropriate value depending on the performance of the motor 2 to be used (for example, the frequency of the "normal mode" is set to "400 Hz", and the frequency of the "idle mode" is set to "300 Hz").

In the present embodiment, the interval (unit time) for measuring the input current value input to the driver of the control unit 8, which is executed by the driver of the control unit 8, is set to "0.1 second", but the measurement of the input current value may be executed at longer time intervals or at shorter time intervals. In the present embodiment, the interval (unit time) between the comparison of the latest current value and the reference value performed by the driver of the control unit 8 is set to "0.5 seconds", and the comparison of the latest current value and the reference value may be performed at longer time intervals or at shorter time intervals.

In the present embodiment, when determining the state of the vibration cylinder 4, the reference values (the first reference value and the second reference value) to be compared with the latest current value calculated based on the measured value of the current input to the driver of the control unit 8 and the like are "the average value from the measured value before 1.4 seconds to the measured value before 1.0 seconds" and "the average value from the measured value before 0.9 seconds to the measured value before 0.5 seconds", but the present invention is not limited to these, and the average value of the past measured values other than these may be used as the reference value. In the present embodiment, "the average value from the measurement value before 0.4 second to the latest measurement value" is used as the latest current value to be compared with the reference value, but the present invention is not limited to this, and other measurement values than these, that is, the average value of a plurality of measurement values updated from the measurement value used for calculating the reference value, or the latest measurement value itself may be used as the latest current value.

In the present embodiment, when determining the state of the vibration cylinder 4, the threshold value to be compared with the absolute value of the comparison value between the latest current value and the reference value may be set to "0.3A", or may be set to a larger or smaller value. In addition, when the state in which the absolute value of the comparison value between the latest current value and the reference value is smaller than the threshold value continues, the reference time of the duration of the condition for determining that "the vibration cylinder 4 is kept in the air" by the driver of the control unit 8 is set to "60 seconds", but may be set to a longer time or a shorter time. In addition, the reference time may be freely set by the user so as to be changeable.

Description of the reference symbols

1: concrete vibrator

2: electric motor

3: eccentric hammer

4: vibrating cylinder

5: power supply unit

6: switch with a switch body

7: power supply cable

8: control unit

9: protective tube

10: frequency conversion circuit