JP2976185B2 - Mold filling device for mortar specimen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold filling apparatus for obtaining a specimen for testing the strength of mortar (cement).

[0002]

2. Description of the Related Art Conventionally, a table supported via coil springs is provided at the upper four corners of a frame, and a pair of arms fixed to a shaft supported by a support member and extending downward are provided on the back surface of the table. A tester is known, in which a motor having an eccentric weight on a rotating shaft is attached to the lower ends of both arms and the table is vibrated in the vertical direction by rotation of the motor (Japanese Utility Model Publication No. 60-20028). Gazette).

[0003]

However, when using this tester to mount a mold on a table to obtain a mold-packed specimen, the mold filling state of the mortar greatly changes depending on the amplitude. Although the target value of the amplitude is in the range of 0.8 mm ± 0.05 mm, the aging of the amplitude must be taken into consideration, and therefore, the amplitude of the table is set to a constant value of 0.8 mm ± 0.0 mm.
I want to adjust it to the range of 10mm. However, the conventional vibration tester includes a plurality of eccentric weights (sector plates) provided on both sides of the electric motor, and changes the number of the eccentric weights, or changes the mounting angle between the plurality of eccentric weights. Since the amplitude is adjusted by changing the amplitude by adjusting, it is extremely difficult to keep the amplitude within a range of ± 0.010 mm with respect to a desired amplitude due to a processing error of the eccentric weight, an assembly error, and the like. is the current situation. The present invention is directed to an apparatus for molding mortar using a vibration tester as described above, so that the amplitude in a mold mounted on a table can be adjusted to a desired amplitude within a range of 10 microns. An object of the present invention is to provide a mold filling device for a specimen.

[0004]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a table is provided at four upper corners of a frame via elastic bodies, and a back surface of the table is provided. A pair of arms that are fixed to the horizontal axis and that extend downward, and that are provided with an electric motor having eccentric weights at the lower ends of both arms, supported by a shaft support provided at the upper ends thereof, and a part of the arms. Is provided with a slit along the length direction thereof, and a tightening means for tightening a portion of the arm provided with the slit in a direction in which the slit width decreases is provided, which can be easily tightened and fixed by the tightening means. It can be adjusted to a desired amplitude.

According to a second aspect of the present invention, in the first aspect of the invention, the elastic body is formed of a hollow cylindrical elastic rubber, and the elastic body projects upward from a frame in a hollow portion in a lower half portion of the elastic rubber. And a cylindrical body provided with the upper half of the elastic rubber on the lower surface of the table is covered by the pin. With such a configuration, lateral vibration can be further reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a frame, and 2 denotes a table supported at the upper four corners of the frame 1 via elastic members 3. On the lower surface of the table 2, bearing members 4 attached to both sides of the table 2 are provided. , 4 provided with a horizontal shaft 5 rotatably supported by the horizontal shaft 5.
A pair of arms 6, 6 that are fixed to and extend downward, are attached, and an electric motor 7 that rotates at a speed of about 2800 rpm is provided at the lower part of both arms 6 by being supported by a support part 8 provided at the upper end thereof.

The electric motor 7 is a double-shaft electric motor. Eccentric weights (not shown) are attached to both ends of a rotating shaft (not shown), and the motor 7 is driven to rotate the eccentric weights. The accompanying vibration was obtained. Therefore, this vibration is a circular vibration in a 360 ° direction about the rotation axis. However, as described above, the electric motor 7 is pivotally supported on the lower ends of the arms 6, 6 by the support portions 8 provided at the upper ends thereof. By attaching the arms 6, 6 to the horizontal shaft 5, which is rotatably supported by bearing members 4, 4, which are attached to both sides of the table 2, horizontal vibration of the eccentric weight can be released. 2
Only vertical vibrations are transmitted. The amplitude is determined by setting the number of the eccentric weights to be mounted or the mounting angle between the eccentric weights to a desired position.

In this case, the number of mounted eccentric weights or the mounting angle between the eccentric weights is the same at both ends of the rotating shaft. The configuration so far is not particularly different from those conventionally known. However, the setting of the amplitude by the eccentric weight alone includes an error with respect to the amplitude set as described above. In order to reduce this error as much as possible, a slit 9 is provided in a part of each arm 6 along its length direction, and a tightening means for tightening the slit 9 of each arm 6 in a direction in which the width of the slit 9 is reduced. 10 were provided.

To explain this, each arm 6 has a thickness of 30 m.
m, made of a metal rod having a width of about 65 mm. The arm 6 is attached to the shaft 5 by providing a shaft hole 6a at the upper end of the arms 6, 6 and inserting the shaft 5 through the shaft hole 6a. Tighten and fix with screws 11. And the slit 9 provided in the arm 6
Is provided at the upper end thereof so as to communicate with the shaft hole 6a so as to be located at the center in the width direction of each arm 6 over a length of about 80 mm downward from the shaft hole 6a. Slit 9
Is provided in the direction in which the width of the slit 9 is reduced. By tightening the portion in the direction in which the width of the slit 9 is reduced, the amplitude of the vertical vibration transmitted to the table 2 is reduced. Tweaked.

The fastening means 10 is provided with a slit 9 of the arm 6.
Screw hole 10a and screw hole 1 in one half of the portion provided with
0a and the bolt 1b provided on the other side.
0b is inserted into the through hole 10c, and the bolt 10b is screwed into the screw hole 10a through the through hole 10c, thereby tightening the arm 6 provided with the slit 9 in the direction in which the slit width decreases. I did it.

Thus, the amplitude of the vertical vibration of the table 2 can be finely adjusted according to the degree of tightening.

FIG. 3 shows this as an experimental value, and the amplitude increases from the initially set amplitude as the additional tightening torque increases until the additional tightening torque reaches a certain value. Decrease. Therefore, the amplitude before the retightening is set to be larger than 0.8 mm, and then the retightening can be performed so that the amplitude is within an allowable range. The elastic body 3
Has an inner diameter of 15 m at the center of a columnar elastic rubber made of chloroprene rubber having an outer diameter of 50 mm and a height of about 85 mm.
m, and a pin 12 having a length of about 25 mm protruding upward from the frame 1 is inserted into the lower half of the elastic rubber and the upper half of the elastic rubber. Was covered with a cylindrical body 13 having a depth of about 50 mm provided on the lower surface of the table 2, and the table 1 was supported on the frame 1 via the elastic body 3. In this way, even if vibration is transmitted to the table 1 in the lateral direction, the vibration can be absorbed by the portion and the durability of the elastic rubber can be secured. This is shown by the results of experiments. In the experiment, the elastic body 3 was attached to the upper four corners of the frame by the attachment means shown in FIG. 4 to support the table, and the amplitude was measured at each measurement position shown in FIGS. However, this data was measured before retightening. The results are as shown in Tables 1 to 5.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

[Table 4]

[0017]

[Table 5]

As is clear from Tables 1 and 2, when the upper and lower portions are covered with the cylindrical body 13 as shown by I and II in FIG. 4 , each amplitude becomes unstable. As is clear from Table 5, the ratio of the horizontal amplitude to the vertical amplitude is also large. In contrast, the lower surface of the table 1 in the upper half of the elastic body 3 while inserting the pins 12 projecting from the rack frame upward in the hollow portion of the lower half of the elastic body 3 shown in III of FIG. 4 In the case where the cylindrical body 13 provided in the above is covered, the amplitude is stable as is clear from Table 4, and the standard deviation of the amplitude in the mold is set to 0.
It can be a very small value of 001, Table 2
As is clear from Table 5, it was confirmed that the ratio of the lateral amplitude to the vertical amplitude was reduced. Then, when the durability test of the elastic body 3 used in the above experiment was performed 30,000 times with one cycle of operation for 2 minutes, it was found that it was within the target value as shown in FIG.

The frame 1 has a storage space for accommodating the electric motor 7 at the center. When the table 1 is supported at the upper four corners of the frame via the elastic members 3, the table 1 has a lower surface. The electric motor 7 supported via the arms 6, 6
From below.

Next, the filling of a mortar with a test sample by the present apparatus will be described. A mold 15 is attached to the upper surface of the center of the table 2 with a fastening jig 14, and the mortar kneaded to a predetermined hardness is filled into the mold 15 and the motor 7 is driven for 2 minutes to pack the mortar. This mold packing is performed by the electric motor 7.
The amplitude of the vibration given to table 2 by 0.8 mm
Use the device set in. The setting is the eccentric weight 7b
Is set so that its amplitude oscillates at the center of the formwork 15 with an amplitude slightly larger than 0.8 mm. By setting the amplitude closer to a desired value in the vertical direction of the table 2, the amplitude can be set within a range of ± 10 microns with respect to the set amplitude.

[0021]

According to the first aspect of the present invention, the table can be vibrated only up and down with a desired amplitude,
The structure is such that a part of an arm for suspending an electric motor having an eccentric weight is provided on a table with a slit along the length direction thereof, and a portion provided with the slit of the arm is tightened in a direction in which the slit width decreases. Since only the fastening means is provided, the structure is simple and the manufacture is easy.

According to the second aspect of the present invention, the lateral vibration can be reduced and the durability of the elastic body can be improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a characteristic curve diagram showing a relationship between additional tightening torque and decreasing amplitude.

FIG. 4 is a diagram showing a comparative example of how to attach an elastic body.

FIG. 5 is a diagram showing a measurement position of the amplitude of the one to which the elastic body of FIG. 4 is attached.

FIG. 6 is a diagram showing a result of a durability test of an elastic body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Frame 2 Table 3 Elastic body 5 Horizontal axis 6 Arm 7 Motor 8 Support part 9 Slit 10 Tightening means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 1/28

Claims (2)

(57) [Claims] 1. A table supported by elastic members at four upper corners of a frame, and a pair of arms fixed to a horizontal axis supported on the back surface of the table and extending downward are provided. A motor provided with an eccentric weight at the lower end thereof, supported by a shaft support provided at the upper end thereof, and a part of the arm provided with a slit along the length direction thereof and a part provided with the slit of the arm. A mortar specimen filling device, comprising a clamping means for clamping the mortar in a direction in which the slit width decreases. 2. The elastic body is made of a hollow cylindrical elastic rubber, and a pin protruding upward from a frame is inserted into a hollow portion of a lower half of the elastic rubber, and an upper half of the elastic rubber is inserted. 2. The mold filling apparatus for a mortar specimen according to claim 1, wherein a cylindrical body provided on a lower surface of the table is covered with the mold.