JPH0411704B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a vibrator for compacting fresh concrete used in concrete placement work for construction work.

《Prior Art》 As is well known, in concrete pouring work for construction work, several layers of ready-mixed concrete are placed inside the assembled formwork in order to obtain a concrete structure that is solid and free of voids when solidified. Each time it is poured, the fresh concrete is vibrated to stabilize the distribution of the gravel, allowing the mortar and cement paste to spread around the gravel, expelling air bubbles, and compacting it.

In a conventional vibrator for compacting fresh concrete, a rod-shaped header containing a built-in vibrator is continuously and integrally attached to the tip of a thick captire cable. The above-mentioned captire cable has some flexibility so that it can absorb shock and the like and can be bent to some extent.

《Problem to be solved by the invention》 However, since the work must be carried out while holding the captire cable part by hand and controlling the position of the exciter header part, the captire cable is not very flexible. . It has considerable rigidity.
Therefore, not only the exciter part including the motor and the eccentric rotating body but also the captire cable are considerably heavy. Therefore, the entire vibrator is quite heavy, and the work of holding it by hand, inserting its tip through the opening at the upper end of the formwork, and vibrating the fresh concrete is labor intensive.

Further, with repeated use, the initially straight portion of the captire cable becomes curved and deformed, making it extremely difficult to handle, making it difficult to control the position of the tip.

Furthermore, when working from above, it was extremely difficult to appropriately control the insertion depth of the vibrator into each layer of poured fresh concrete, making uniform compaction impossible.

This invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a lightweight, easy-to-operate vibrator that can easily and uniformly compact fresh concrete.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention incorporates a vibrator in an envelope, and the specific gravity of the envelope and built-in components as a whole is equal to the specific gravity of ready-mixed concrete. first and second vibrating devices set smaller; a flexible connecting cord connecting the first and second vibrating devices; and a windable flexible cord tied to the first vibrating device. The second winding cord consists of a winding cord and a power supply line for the above-mentioned exciter included in these cords.
The eccentric weight is placed so that when the vibration device is suspended from the first vibration device by the connection cord, the center of the second vibration device is shifted with respect to the perpendicular line of the connection cord. 2, the second vibration device is provided with a switch means, and the switch means is in a state in which the second vibration device is placed in the formwork with the weight facing downward. The device is characterized in that it is installed so as to operate the vibrator in the second vibrating device when the vibrating device is suspended by the connecting cord.

<<Operation>> The first and second vibration devices are installed on the floor surface of the formwork in which fresh concrete is cast by stretching the winding cord. At this time, the switch in the second vibration device is in the reset state. When concrete is poured into the formwork and the exciter of the first vibrating device is activated at the same time, the first vibrating device uses its vibration to compact the surrounding ready-mixed concrete while also using its own buoyancy to compact the surrounding ready-mixed concrete. It comes to the surface. When the depth of the fresh concrete becomes greater than the length of the connecting cord, the second vibrating device is pulled and suspended by the connecting cord, and the second vibrating device is turned on and the second vibrating device is turned on. The second vibration device is activated. As a result, the second vibrating device floats while compacting the surrounding ready-mixed concrete similarly to the first vibrating device. Then, switch off the second vibration exciter,
By repeating the above operations, the fresh concrete is gradually compacted.

<<Example>> Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows the overall structure of a vibrator according to the present invention. This vibrator includes two parts, an upper vibration device 1 and a lower vibration device 2. Both vibration excitation devices 1 and 2 each house a vibrator 4 and a weight 3 in a substantially spherical envelope. Vibration device 1
There is a hollow part with an appropriate volume in the envelope 2, and the overall weight is adjusted by this hollow part and the weight 3, so that the specific gravity (weight/volume ratio) of the vibrating devices 1 and 2 is lower than the specific gravity of the fresh concrete. It's getting smaller.

The upper vibrator 1 and the lower vibrator 2 are connected by a flexible cord 8 of appropriate length. The cord 8 is fixed to the outer periphery of the upper vibrator 1 with a cord clip 5, and is connected to a cord reel 10 together with a flexible cord 9 tied to the upper vibrator 1 from there. Here, the cord reel 10 and the upper vibration device 1
9 is the cord connecting the upper vibration device 1 and the lower vibration device 2, and 8 is the cord connecting the upper vibration device 1 and the lower vibration device 2. code 8,9
includes a power supply line and a control line for driving the exciter 4 of both the excitation devices 1 and 2.

On the cord reel 10 side, there is a switch 11 for controlling the upper vibration device 1 on and off, a switch 11 for controlling the lower vibration device 2 on and off, and a limit switch 6.
a switch 12 that resets the
An operating lamp 13 is provided to indicate the operating state of the motor. These constitute one operating unit.

The upper vibration exciter 1 has a weight 3 and an exciter 4 disposed in the lower part thereof and a hollow part in the upper part in the hanging state by the cord 9 shown in FIG. This device 1
The rotational axis direction P of the exciter 4 in is orthogonal to the hanging axis of the device 1. The vibration device 1 includes a weight 3
Due to its weight, it maintains the attitude shown in Figure 1 even when floating through fresh concrete. In addition, the exciter 4
Even if a rotational force about the axis P is applied to the envelope of the vibrating device 1 due to the reaction force during its operation, it is almost never actually idling.

This is because the weight 3 and the envelope are asymmetrical with respect to the axis P, and therefore have a large rotational resistance.

In addition, the lower vibration exciter 2 has a weight 3 on one side in the lateral direction of the envelope and an exciter 4 having an axis R perpendicular to the direction of the weight 3 in a hanging state by the cord 8.
is arranged, and the other side in the lateral direction is a hollow part. Therefore, in the hanging state, due to the eccentric load caused by the weight 3 and the like, the rotation axis direction R of the exciter 4 in this device 2 forms an oblique (α°) angle with the hanging direction of the cord 8. When the vibrating device 2 floats in fresh concrete, the weight of the weight 3 causes the vibration excitation device 2 to
Keep the position facing downward and axis R vertical.

Note that since the weight 3 and the envelope are symmetrical with respect to the axis R, the moment of resistance is small, and therefore,
The reaction force of the vibrator 4 is the force that rotates the envelope around the axis R in the same direction as the hanging axis, which makes it much more likely to idle than the upper vibrator 1, causing problems such as twisting the cord 8. becomes. Therefore, in order to prevent the idling, a plurality of idling prevention fins 7 are formed on the envelope of the lower vibration excitation device 2. This slip prevention fin 7 comes into contact with fresh concrete and generates a large rotational resistance force.

Further, the lower vibration device 2 has a built-in limit switch 6 for automatically determining its operation timing during compaction work. This limit switch 6 determines whether the lower vibration device 2 is in an overturned state with respect to the direction of gravity (the hanging state in FIG. 1 or the state in FIG. 4C) or in an upright state (FIG. 4A,
It detects whether the robot is in state B, C, or D, and operates depending on its posture. The switch signal from the limit switch 6 is transmitted via the cord 8 to the above-mentioned operating unit.

FIG. 2 shows the configuration of the vibrator 4 of the upper vibrator 1. As shown in FIG. Further, FIG. 3 shows the configuration of the vibrator 4 in the lower vibration device 2. As shown in FIG. As shown in both figures, a high-frequency motor 42, which is the drive source of the exciter 4, is attached to the fuselage 41 with a fixture 46, and the motor 42
A rotating shaft 43 protruding from both ends is supported by the body 41 by bearings 44. Eccentric rotating bodies 45 are fixed to rotating shafts 43 protruding from both sides, respectively. Although the upper vibration device 1 and the lower vibration device 2 are different in the directions P and R in which the rotating shaft 43 of the vibration exciter 4 is disposed as described above, their basic structures are the same. When the motor 42 is driven to rotate, the eccentric rotating body 45 rotates together to generate large vibrations, which vibrate the entire device.

FIGS. 4A to 4E show the process of compacting fresh concrete using the vibrator configured as described above. First, as shown in A, formwork 1
Place the cord reel 10 above the concrete placement site assembled in step 4, stretch the cord 9, lower the vibrator into the formwork 14, and place both the upper vibration device 1 and the lower vibration device 2 on the floor. Put on. At this time, both vibration excitation devices 1 and 2 are in contact with the floor with their weights 3 facing down. In this state, the limit switch 6 of the lower vibration exciter 2 has been reset.

Next, as shown in B, fresh concrete 15 is poured into the formwork 14, and at the same time, the upper vibration device 1 and the vibrator 4 are operated by the switch 11. Then, the upper vibrating device 1 compacts the surrounding ready-mixed concrete by its vibration, but at this time, the ready-mixed concrete 15 around the device 1 liquefies, and the contact resistance between the device 1 and the ready-mixed concrete 15 becomes extremely small. As mentioned above, since the specific gravity (weight/volume ratio) of the vibrating device 1 is smaller than the specific gravity of the fresh concrete 15, the vibrating device 1 liquefies the surrounding fresh concrete 15 by its vibration. , and at the same time emerges by its own levitation. In other words, the operating vibration device 1 floats on the upper surface of the ready-mixed concrete 15 that is subsequently poured.

In this case, the floating vibration device 1 continues to vibrate and flattens the surface of the poured concrete 15.

Then, the ready-mixed concrete 15 is poured, and as shown in C, when the depth of the ready-mixed concrete 15 becomes larger than the length set by code 8,
The slack in the cord 8 is eliminated, and the lower vibration device 2 is pulled by the buoyancy of the upper vibration device 1. Then,
The lower vibration exciter 2, which was in an upright state, is raised by the cord 8, and temporarily falls over onto its side. At this time, the limit switch 6 is activated, and this signal activates the exciter 4 of the lower excitation device 2. When the vibrator 4 of the lower vibrating device 2 operates and vibrates, the device 2 liquefies the surrounding ready-mixed concrete, giving it a compaction effect and using buoyancy, just like the above-mentioned upper vibrating device 1. It comes to the surface. At this time, the vibration device 2 is in an upright position with the weight 3 facing down, as shown in D.

As shown in E, when the lower vibration device 2 also rises to the surface of the fresh concrete 15, this is confirmed and the switch 12 is turned off, and the exciter 4 of the lower vibration device 2 is stopped. Reset limit switch 6. Further, the loosened cord 9 is wound onto a cord reel 10.

From the state shown in E, the ready-mixed concrete 15 is poured again, and the same operations and actions as described above are repeated to pour the ready-mixed concrete into the formwork 14 in several layers. Compaction is performed sequentially using the shaking device 2.

Note that the operation lamp 13 lights up while the lower vibration excitation device 2 is in operation, so that the operation of the limit switch 6 can be confirmed. Further, the cord 8 connecting the two vibrating devices 1 and 2 can be adjusted as appropriate according to the pouring depth of fresh concrete.

<<Effects of the Invention>> As described above in detail, the vibrator for compacting fresh concrete according to the present invention is significantly smaller and lighter than conventional vibrators, and is easier to handle. Also, during actual compaction work,
The first upper vibrator and the second lower vibrator float in the fresh concrete by their own buoyancy, resulting in uniform and good compaction. Therefore,
There is no need to operate the vibrator with a large amount of force as in the past, making compaction work very easy and light. Moreover, it can be used in remote areas that conventional vibrators cannot reach. In addition, the two vibrating devices allow each layer of fresh concrete to be compacted evenly while checking the depth of the poured fresh concrete.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall configuration of the vibrator according to the present invention, FIG. 2 is a diagram showing the configuration of the vibrator of the upper vibration excitation device in FIG. 1, and FIG. FIG. 4 is a diagram showing the configuration of the vibrator in the apparatus, and is a diagram sequentially showing the compaction work process of fresh concrete performed using the same vibrator. 1...Top vibration device, 2...Bottom vibration device, 3
... Weight, 4 ... Exciter, 6 ... Limit switch, 7 ... Idling prevention fin, 8 ... Cord, 9 ...
Code, 10...Code reel, 14...Formwork,
15... Fresh concrete.

Claims (1)

[Claims] 1. First and second vibrating devices, each of which has a vibrator built into an envelope, and the specific gravity of the envelope and built-in components as a whole is set to be smaller than the specific gravity of fresh concrete. , a flexible connecting cord connecting the first and second vibration excitation devices, a flexible winding cord connected to the first vibration device and capable of being wound, and the vibration exciter included in these cords. when the second vibrating device is suspended from the first vibrating device by the connecting cord, the center of the second vibrating device is relative to the perpendicular line of the connecting cord. An eccentric weight is installed in the second vibration device, and the second vibration device is provided with a switch means, and the switch means is configured to cause the second vibration device to move the weight downward. Ready-mixed concrete is installed so as to operate the vibrator in the second vibrating device when suspended by the connecting cord from a state in which the concrete is placed in a formwork. vibrator for compaction. 2 A weight is installed in the first vibration device with the extension line of the winding cord and the connection cord as the mounting direction, and the rotating shaft of the vibrator in the first vibration device is aligned with the direction of the weight. The rotating shaft of the exciter in the second vibration exciter is arranged in a direction perpendicular to the mounting direction, and the rotation axis of the exciter in the second vibration exciter is arranged in the same direction as the mounting direction of the weight in the second vibration exciter. A vibrator for compacting fresh concrete according to claim 1, characterized in that: 3 An idler is provided on the outer periphery of the envelope in the second vibration exciter to prevent the envelope itself from rotating about the rotation axis in a direction opposite to the rotation direction of the vibration exciter. The vibrator for compacting fresh concrete according to claim 2, characterized in that a prevention fin is formed.