JP2872880B2 - Drive and control method of the 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 type vibrator for pile driving and controlling a vibrating function.
It relates to the law.

[0002]

2. Description of the Related Art Generally, a vibration device used for civil engineering construction has a structure in which a plurality of pairs of rotating shafts having eccentric weights 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, technical problems 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 is
The state where 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. .

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, during the energization from the time t ₂ has stopped the motor of the vibrating device 6 (not shown), to the time t ₃ when the rotary shaft is stopped, gradually decelerated as shown by the arrow d while continuing to rotate at a rotational axis of inertia I do. Since the rotational speed decrease period T ₂ of the above is relatively long (e.g. about 50 seconds),
When passing through the natural frequency n ₂ of the crane boom on the way, the crane boom may resonate and suffer damage. Further, when passing through the natural frequency n ₁ 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 vibration phase could be reduced to zero by changing the rotational phase of the eccentric weight of the vibrating device, 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, if the vibrating device starts the operation in a state where the vibrating force is reduced to zero by changing the rotation phase of the eccentric weight, if the vibrating force can be exerted after reaching the rated number of operations,
It is economical because the motor capacity and power supply capacity can be reduced.
This is because, after reaching the rated operation number, 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 rotationally drives the shaft with the system that rotationally 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, the oil pump 1
5 is rotated by an engine (not shown), and the discharge pressure oil is equally supplied to an oil motor / a 14a and an oil motor / b 14b, which are rotatingly driving a pair of vibrating units, respectively. Specifically, the two oil motors 14a,
14b are rotated at equal rotational speeds. However, a. As a practical problem, the volume efficiency of the oil motor is affected by a small difference, 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, a control means shown in FIG. 2B is provided. That is, the oil discharged from the oil pump 15 is branched into two parts, and the divided oils are supplied to the oil motors A, B, and 14a and 14b via the control valves 23a and 23b. The above control valve 2
3a and 23b are flow control valves having a throttle function.
According to the above configuration, when the control valve 23a is slightly opened compared to the control valve 23b, the oil motor
The speed is increased compared to b, and the phase advances. Also, when the vehicle is almost closed, the speed is reduced and the phase is 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 of the series can be arbitrarily adjusted, the total excitation force of the excitation units of the two series can be arbitrarily selected from the minimum value to the maximum value. If the excitation force is zero,
You can also squeeze. Use this type of vibration control technology.
(See Fig. 5) to make the eccentric weight
Starts rotating by adjusting the phase difference, the natural frequency n _1, n with ₂
After passing through the vicinity, rotate at the rated speed. Exciting in the present invention
The zero force state means that the case of the exciter
This means that the pile does not give vertical vibration to the pile.

[0013]

According to the above arrangement, each of the two vibration generating units is rotationally driven by the oil pump.
Approximately equal amount of pressure oil is sent to the oil motors 14a and 14b to supply vibration energy while controlling the control valves 23a and 23b.
By manipulating 23b, its phase can be adjusted. As described above, since the two oil motors are hydraulically synchronized without being mechanically connected, a transmission member (for example, a gear or a belt) for synchronization is not required, and the transmission member generates noise. Is prevented. Furthermore, the phase difference between the two series of vibration units is arbitrarily controlled to adjust the total vibration force so that the vibration force is zero (the eccentric weight).
Vibration is not transmitted to the pile even if the
Condition, except for micro-vibration that does not cause vibration pile driving action.
And the rotation speed corresponding to the natural frequency of the ground,
Through the range of rotational speeds corresponding to the natural frequency of the
This is effective in preventing vibration pollution.

[0014]

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, and the pressure oil discharged from the variable displacement oil pump 16 is supplied by the control valves 23a and 23b in substantially equal halves. 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 oil pump 16 is connected to a single shaft and is driven to rotate by the engine E. On the other hand, the two oil motors A and 14b each have a rotary encoder R / E.
The output signals of these two rotary encoders R / E are input to a phase difference counter 17, and the phase difference between the two oil motors is calculated. More specifically, the phase difference between the vibration unit driven by the two oil motors A and the vibration unit driven by the oil motor B 14b is calculated, and the digital / analog converter D / A is calculated. Is input to the operational amplifier 18 through
This is compared with the output of the eccentric moment control circuit. The eccentric moment setting circuit includes an eccentric moment zero setting circuit 19 that outputs 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 compensation circuits 21a and 21b and a voltage / current converter V
The control valves 23a and 23b are controlled via / I22a and 22b. 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 29
And a delay circuit 24, and a V / I 22b, which are connected to an electromagnetic operating portion of the control valve 23b.

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 capacity oil pump 16 rotates to send out pressure oil. The delivered pressure oil is flow-controlled by the control valves 23a and 23b, and is supplied to oil motors A 14a and B 14b. These oil motors each have a rotational speed proportional to the flow rate of the supplied oil. Rotate with. In this way, the oil motor A 14a and the oil motor
14b starts 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 or the transmission member. When the start button is pressed, the relay R1 is turned on, and the voltage set by the frequency setting circuit 27 gives a flow command to the control valve 22b. At this time, in order to prevent a shock at the time of rising of the set voltage, the set voltage is applied via the delay circuit 24 and by voltage / current conversion by the V / I 22b. The eccentric moment is kept at zero until the rotation states of the oil motors 14a and 14b are stabilized, the relay R2 is turned on with a delay of a predetermined minute time (Δts), and the eccentric moment arbitrary setting circuit 20 generates the two series of vibrations. Adjust the phase difference between 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, press the stop button and the relay R
1 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 oil motor
a and the oil motor / b 14b stop.

[0017]

When carrying out the drive and control method of the Ku invention each described above, according to the present invention, it is possible for rotating synchronously with hydraulically interlocked allowed without mechanically connecting the vibration generating unit of the two series, moreover , caused by adjusting the phase difference arbitrarily
Increase or decrease the rotation speed at zero vibration, and
Resonance with the home position can be avoided . 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 illustrates a method of driving and controlling a vibration exciter according to the present invention.
FIG. 1 is a schematic system diagram showing one embodiment of a vibration and control device configured for the purpose.

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, and (C1)
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 and former, 11b ... Exciter and former, 12 ... Pile chuck, 14a ... Oil motor and former, 14b ... Oil motor and former, 15 ... Constant displacement oil pump, 16 ... Variable displacement Oil pump, 17: phase difference counter, 18: operational amplifier, 19: eccentric moment zero setting circuit, 20: eccentric moment arbitrary setting circuit, 21
a, 21b: compensation circuit, 22a, 22b: voltage-current converter, 23a, 23b: control valve, 24: delay circuit,
27: Frequency setting circuit.

Claims (2)

(57) [Claims] The method according to claim 1, wherein each of the vibration generating unit 2 sequence consisting of the eccentric weight, with rotationally driven by the respective one of the oil motor, individually controlled by a plurality of operating valves for excitation unit of the plurality of series Te case of synchronizing the two oil motors, detects the rotational angle position of each of the two oil motors
Te to calculate the phase difference of the two oil motors, said phase difference
Is controlled to a predetermined value, and the phase difference between the two oil motors is zero
After starting rotation in a state where
A method of driving and controlling a vibration exciter, characterized by controlling. 2. The method according to claim 1, wherein said oil motor is stopped to start said oil motor.
When suspending the operation of the shaker, use the two oil motors
Excitation force of two series of eccentric weights rotated by
Controlling the phase difference between the two oil motors so that
The method according to claim 1, wherein the discharge amount of the oil pump is reduced to zero after the operation.