JP2821083B2 - Drive / control method and drive / control device for exciter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a rotary exciter for driving a pile and for controlling a vibrating function, and an apparatus therefor.

[0002]

2. Description of the Related Art In general, a vibration device used for civil engineering construction has a structure in which a plurality of pairs of rotating shafts each having an eccentric weight attached thereto are arranged in parallel. According to such a configuration, the centrifugal vibrating force of the eccentric weight rotating in the opposite direction can be added in a desired direction and can be offset in an unnecessary direction. FIG. 3 is a schematic explanatory view of this type of rotary type vibration exciter, in which four rotating shafts 2A, 2B, 2C, 2D are arranged for a case 1, and eccentric weights 3A, 3B, 3C and 3D are attached, and gears 4A, 4B, 4C and 4D are respectively attached and restrained so as to mesh with each other and rotate synchronously.

[0003]

When a pile driving operation is performed using the above-described exciter, prevention of vibration pollution and prevention of noise pollution are important issues. Next, a technical problem relating to vibration pollution will be described with reference to FIGS. 4 and 5, and noise pollution will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining vibration pollution in a pile driving operation. This figure shows a state in which the vibration device 6 is suspended by the crane boom 5, the upper end of the pile 7 is gripped by the chuck 6 a of the vibration device 6, and the pile 7 is vibrated and driven into the ground. Is drawn.

When the lower end of the pile 1 is brought into contact with the ground surface to start the pile driving operation, the vibration device 6 is fully operated from the beginning.
The surface wave a generated on the ground at the stakeout point reaches the nearby private house 8 with almost no attenuation, so that a problem of vibration pollution occurs.
Here, if the vibrating force of the vibrating device 6 can be adjusted arbitrarily, the pile driving operation is started while giving a slight vibration in addition to the weight of the pile 7, and after driving several meters, the vibration may be gradually increased. . If the sound source position corresponding to the lower end of the pile 7 is deepened, the underground wave b is attenuated on the way to the private house 8, so that the vibration pollution is negligible.

FIG. 5 is a table showing changes in the vibration frequency at the time of starting and stopping the operation of the vibration device. The horizontal axis represents time. Start of operation time t _0, between time t ₁ to reach the rated operating state, frequency rises sharply as shown by arrow c. During the above frequency rise, the natural frequency of the ground n ₁ and the natural frequency of the crane boom n ₂ are passed. However, it because revolutions increase time T ₁ at the start operation is generally short (e.g., about 3 seconds), the problem of resonance when the frequency of the vibration device matches the natural frequency of practically negligible it can. However, between the time t ₂ of stopping the energization of the motor of the vibrating device 6 (not shown) to the time t ₃ when the rotary shaft is stopped is gradually decelerated as indicated by the arrow d while continuing to rotate at a rotational axis of inertia . The above-mentioned rotation speed reduction period T
_{Since 2} is a relatively long time (for example, about 50 seconds), there is a possibility that the crane boom will resonate and be damaged when passing the natural frequency n ₂ of the crane boom on the way. Also, when passing through the natural frequency n ₂ of the ground, there is a possibility that vibration pollution may occur due to resonance of the ground. The time t
_{If the} motor could be de-energized in step ₂ and the vibrating device could change the rotational phase of the vibrating device's rotating weight to zero the vibrating force, it would be possible to prevent problems related to resonance during the operation of stopping the vibrating device. Can be.

Next, looking at the amount of energy supplied to the vibrating device, the vibrating device 6 from the time t ₀ to t ₁ described above.
If the speed is increased while the vibration is generated by the eccentric weight (not shown) of the vibration device while the rotation speed of the vibration device is increasing, a large-capacity motor or a large-capacity power supply facility is required to drive the vibration. . In this case, the operation is started in a state where the vibration force is reduced to zero by changing the rotation phase of the eccentric weight of the vibration device, and if the vibration force can be exerted after reaching the rated rotation speed,
It is economical because the motor capacity and power supply capacity can be reduced.
This is because, after reaching the rated rotation speed, there is no need to store any more rotational energy in the rotating member, and the operation can be continued by replenishing energy sufficient to compensate for the attenuation of vibration.

Next, reduction of gear noise will be described with reference to FIG. In order to rotate the vibrating mechanism composed of the eccentric weight shown in FIG. 3 described above, a structure in which _two motors M ₁ and M ₂ are generally synchronized via gears as shown in FIG. Used. 3E, 3F, 3G, 3H are each respectively eccentric weight, 4E, 4F, 4G, 4H are gears, 9I is a gear attached to the shaft of the motor M _1, 4J is attached to the shaft of the motor M ₂ Gears. Eccentric weights 3E, 3F via gears 9I, 4E, 4F
The gear 9I and the gear 9J are meshed with each other in order to synchronize the system that drives the eccentric weight with the system that drives the eccentric weights 3H and 3G via the gears 9J, 4H and 4G. . Now, as shown in FIG. 6 (B), without engaging the gear 9I and the gear 9J, one series consisting of the motor M ₁ and the eccentric weights 3E and 3F, and the motor M ₂ and the eccentric weight 3H, If one system consisting of 3G can be arranged in parallel, and if both systems can be synchronized by a method other than the forced synchronization by the meshing of the gears 9I and 9J, the same system as the gear 9I can be used.
The noise component generated by the engagement with J is completely prevented.

Further, as shown in FIG. 6 (C), the above-mentioned two series (hereinafter referred to as “exciting units” for convenience of explanation) are arranged as shown in FIG. If the phase difference can be controlled arbitrarily, the vibrating force can be adjusted from zero to the maximum, so that the vibration pollution described with reference to FIGS. 4 and 5 can be greatly reduced. The load on the drive motor and the transmission member (both not shown) can be significantly reduced.

Also, as shown in FIG.
When a pile chuck 12 is installed on the lower surface of the chuck 0 and the pile 7 is chucked, a vibrating pile driving is performed by installing an exciter / instep 11a and an exciter / part 11b on the chuck head 10. Then, in the prior art, the rotating members of both exciters had to be connected by some connecting member (for example, a gear train, a chain, a timing belt, a propeller shaft with a universal joint) 13, but both of the exciters had to be connected. If the phases of the motor shells 9a and 9b driving the respective shakers 11a and 11b can be controlled, the connecting member 13 can be omitted.

[0010] The present invention has been made in view of the above-mentioned circumstances, and rotates two motors for rotating each of the two series of vibrating units, as well as the phase between the two motors. And a device for controlling the same.

[0011]

FIGS. 2A and 2B are explanatory views of the basic principle of the present invention. FIG. 2
(A), (B) and FIG. 1 described later are schematically and simplified for easy understanding of the structure and function.
Devices such as an oil pressure gauge that can be appropriately disposed based on common technical knowledge are omitted. For further simplification of the figure, an exciter unit rotating a plurality of eccentric weights by an oil motor is represented as shown in FIG. 2 (C1), and an exciter unit provided with a rotary encoder is shown in FIG.
It is written as (C2). Reference numeral 14 denotes an oil motor, reference numeral 3 denotes an eccentric weight, and R / E denotes a rotary encoder.

As shown in FIG. 2A, a variable displacement oil pump (abbreviated as variable oil pump) A,
b is connected to the engine E, and both variable oil pumps are rotated at the same rotational speed. Then, the discharge pressure oil of both the variable oil pumps A 16a and 16b is equally supplied to the oil motor A 14a and the oil motor B 14b which are respectively driving the pair of vibrating units. Then, theoretically, the two oil motors 14a, 14a,
14b are rotated at equal rotational speeds. However, a. As a practical problem, a small difference in the adjustment state of the oil motor affects, so that the two oil motors shown in FIG.
It is not possible to expect complete synchronous rotation over a long period of time only with the above configuration, and a means for correcting this is required. B. Further, in order to intentionally control the phases of the two oil motors to arbitrarily increase or decrease the vibrating force, the two oil pumps are made into variable displacement oil pumps as shown in FIG. By controlling the variable oil pumps 16a and 16b. When the control mechanism as described above is configured to adjust the discharge amount of the variable oil pump / upper 16a to be larger than the discharge amount of the variable oil pump / b 16b, the oil motor / upper 14a becomes the same. The speed is increased compared to the second party 14b, and the phase advances. If it is too small, it will be slowed down and the phase will be delayed. Since the relative phases of the two oil motors can be controlled in this manner, it is possible to control the phase difference between the two series of vibrating units driven by both oil motors. 2
If the phase difference between the excitation units in the series can be arbitrarily adjusted, the total excitation force of the excitation units in the two series can be arbitrarily selected from the minimum value to the maximum value. If the two series of vibration units have the same capacity, the minimum value of the total vibration force can be set to zero. Similarly, it is possible to control a plurality of vibrating units.

[0013]

According to the above arrangement, by controlling the two variable oil pumps to adjust the discharge amount, the rotational speeds of the two oil motors that are drivingly rotating each of the two series of vibrating units are controlled. Can be changed to adjust the phase, and the synchronization state can be stably continued.

As described above, since the two oil motors are hydraulically synchronized without being mechanically connected, a transmission member for synchronization (for example, a gear, a belt, etc.) is not required, and this transmission member can reduce noise. Is prevented from occurring. Further, since the total excitation force can be adjusted by arbitrarily controlling the phase difference between the two excitation units, it is effective in preventing vibration pollution.

[0015]

FIG. 1 is an explanatory diagram of a hydraulic system and a control system showing an embodiment of a control / drive device configured to carry out a drive / control method of a vibration exciter according to the present invention. The two oil motors 14a and 14b shown in FIG. 1 correspond to the two oil motors 14a and 14b shown in FIG.
Similar or similar components are supplied with pressure oil by variable displacement oil pumps 16a, 16b. What has been described above with reference to FIG. 1 is the basic components described above with reference to FIG. Further, details of a specific configuration will be described. The variable oil pumps 16a and 16b are connected to a single shaft and are driven to rotate by the engine E. On the other hand, the two oil motors
4a and the oil motor / b 14b are each provided with a rotary encoder R / E. The output signals from these two rotary encoders R / E are
7, and the phase difference between the two oil motors is calculated. Specifically, a vibration unit driven by two oil motor uppers 14a and an oil motor
The phase difference with the vibration unit driven by the second party 14b is calculated, input to the operational amplifier 18 via the digital / analog converter D / A, and compared with the output of the eccentric moment control circuit. The above-described eccentric moment control circuit is a eccentric moment zero setting circuit 19 for outputting a signal for equalizing the phase difference between the two series of vibrating units by 180 °.
And an eccentric moment arbitrary setting circuit 20 that can arbitrarily adjust the phase difference, and is connected to the operational amplifier 18 via a changeover switch 28. The output signal of the operational amplifier 18 is supplied to a compensation circuit 21a,
21b, and voltage / current converters V / I 22a, 22b
Control the variable oil motors A and 14a, 14b through the control unit. Thereby, the phase difference between the two vibration generating units is adjusted as described above with reference to FIG. In cooperation with the phase difference control system described above with reference to FIG. 1, the vibration frequency of the vibration generating unit changes as described below. Therefore, the control system described below is a control system for the vibration frequency. The frequency setting circuit 27 includes a switch 2
9 and the delay circuit 24, and the V / I 22b, and is connected to the electromagnetic operating part of the variable oil pump 16b.

Next, an example in which the drive / control method according to the present invention is implemented using the drive / control device of the embodiment shown in FIG. 1 will be described. When the engine E is operated, the variable displacement oil pumps 16a and 16b rotate to send out pressure oil. The pressure oil sent out is the oil motor
a and 14b, and these oil motors are rotated at a rotational speed proportional to the flow rate of the supplied oil. Thus, the oil motor shell 1
4a and the oil motors 14b start rotating at the same rotational speed. As a result, each of the two series of vibrating units starts rotating. At this time, the changeover switch 28 is switched to the eccentric moment zero setting circuit 19. As a result, the phase difference between the two series of vibration units becomes 180 degrees, and the operation is started in a state where the total vibration force is zero. This operation is effective in preventing the vibration pollution described with reference to FIGS. 4 and 5 (described later in detail), and is advantageous because a large load is not applied to the driving motor and the transmission member. Press start button and relay R
1 is input, and the voltage set by the frequency setting circuit 27 gives a flow rate command to the variable displacement oil pump / b 16b. At this time, in order to prevent a shock at the time of rising of the set voltage, the set voltage is supplied via the delay circuit 24 and V /
It is given by voltage-to-current conversion by I22b. The eccentric moment is kept at zero until the rotation state of the oil motors 14a and 14b darkens, and a predetermined minute time (Δts)
The relay R2 is turned on with a delay, and the eccentric moment arbitrary setting circuit 20 adjusts the phase difference between the two series of vibrating units. In this manner, vibration pollution can be prevented by avoiding resonance with the ground described with reference to FIGS. 4 and 5, and damage to the crane boom can be prevented by avoiding resonance with the crane boom 5. To stop the operation, when the stop button is pressed, the relay R1 and the relay R2 are turned off at the same time, the eccentric moment zero setting circuit 19 is connected to the operational amplifier 18, and the operation of the variable oil pump / , Party 16a, 16
The discharge amount of b is set to zero, and the oil motor / A 14a and the oil motor / B 14b are stopped.

[0017]

As described above, when the drive / control method of the present invention is carried out using the drive / control device according to the present invention, the two series of vibration units are hydraulically linked without mechanical connection. At the very least, it can be rotated synchronously, and the phase difference can be arbitrarily adjusted. As a result, generation of noise due to the mechanical connecting member can be prevented, and vibration pollution during pile driving can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing one embodiment of a drive / control device of a vibration exciter according to the present invention.

2 (A) and 2 (B) are explanatory views of a basic principle of the present invention, (C1) is a symbol mark of a vibrating unit,
2) is a symbol mark of the vibration generating unit with a rotary encoder.

FIG. 3 is an explanatory view of a rotary type vibration exciter in which eccentric weights are attached to each of four rotating shafts.

FIG. 4 is an explanatory diagram showing transmission of ground waves and underground waves in a pile driving work using a vibration device.

FIG. 5 is a table showing time-rotation speed for explaining a resonance phenomenon in a vibrating pile driving work.

FIG. 6A is an explanatory diagram of a drive system of a conventional exciter,
(B), (C) is an explanatory view of a drive system in the present invention.

FIG. 7 is an explanatory diagram of a problem in a case where a pile driving operation is performed using two vibration exciters in the related art.

[Explanation of symbols]

1: Exciter case, 2A-2D: Rotating shaft, 3A-3H
... Eccentric weights, 4A-4H ... Transmission gears for synchronous rotation, 5 ...
Crane boom, 6… vibration device (vibrator), 7… pile, 8
... private houses, 9a, 9b ... motors, 9I, 9J ... gears, 10
... Chuck head, 11a ... Exciter / A, 11b ... Exciter / A, 12 ... Pile chuck, 14a ... Oil motor / A, 14b ... Oil motor / A, 15 ... Constant capacity oil pump, 16a, 16b ... Variable displacement oil pump, 17
... phase difference counter, 18 ... operational amplifier, 19 ... eccentric moment zero setting circuit, 20 ... eccentric moment arbitrary setting circuit, 21a, 21b ... compensation circuit, 22a, 22b ... voltage-current converter, 24 ... delay circuit, 27 ... frequency Setting circuit.

Claims (12)

(57) [Claims] 1. A plurality of vibrating units each composed of an eccentric weight are rotationally driven by one oil motor, and a discharge oil of one variable displacement oil pump is provided for each of the oil motors. Supply and
A method of driving and controlling a vibration exciter, comprising controlling each of the variable displacement pumps individually to synchronize a plurality of oil motors. 2. The method according to claim 1, wherein a rotational angle position of each of the oil motors is detected, a phase difference between the oil motors is calculated, and the variable displacement oil pump is controlled so as to equalize the phase difference to a predetermined value. The method for driving and controlling a vibration exciter according to claim 1, wherein: 3. The method according to claim 1, wherein the rotation is started in a state where the phase difference between two oil motors among the oil motors is zero, and then control is performed so as to maximize the vibrating force. 2. The method for driving and controlling the vibration exciter according to 2. 4. When stopping the operation of the vibration exciter by stopping the oil motor, the vibration force of the two series of eccentric weights rotationally driven by the two oil motors becomes zero. 4. The method according to claim 3, wherein after controlling the phase difference between the two oil motors, the discharge amount of the variable displacement oil pump is reduced to zero. 5. Two oil motors and two oil motors (14a) and (14b) for rotating and driving each of the two vibration units, and pressure oil is supplied to each of the two oil motors. A variable displacement oil pump (16a, 16b), and a mechanism for controlling the two variable displacement oil pumps so as to synchronize the two oil motors. Drive and control equipment. 6. The two oil motors (14a, 14a).
b) includes a means for detecting a rotational angle position, and a phase difference counter (17) which receives an output signal of the angular position detecting means and calculates a phase difference between the two oil motors. The drive / control device for a vibration exciter according to claim 5, wherein the drive / control device is provided. 7. The variable displacement oil pump (16a,
The drive / control device for an exciter according to claim 5, wherein 16b) has a function of changing a discharge amount in a stepless manner. 8. An output signal of a phase difference counter (17) for calculating the phase difference and an output signal of an eccentric moment control circuit, and the variable displacement oil pump ( The drive / control device for an exciter according to any one of claims 5 to 7, further comprising a flow rate adjusting circuit (21a, 21b) for controlling the exciter (16a, 16b). 9. The eccentric moment control circuit according to claim 1, wherein the eccentric moment zero setting circuit outputs a signal for reducing the eccentric moment amount to zero, and an eccentric moment arbitrary setting that can be adjusted to adjust an eccentric moment amount to an arbitrary amount. 9. The drive / control device for an exciter according to claim 8, wherein the drive / control device is configured to be able to switch between the circuit and the circuit. 10. The variable displacement oil pump (16)
a, 16b) is characterized in that the discharge amount of pressure oil is controlled by a frequency setting circuit (27).
A drive / control device for an exciter according to claim 9. 11. A delay circuit (24) is interposed between the frequency setting circuit (27) and the variable displacement oil pumps (16a, 16b).
A drive / control device for an exciter according to claim 10. 12. The two variable displacement oil pumps (1)
6a, 16b) are connected to the engine (E) in a single shaft and operated at the same rotational speed,
A drive / control device for an exciter according to claim 7.