JPH04313422A - Stress relief-device for free access floor - Google Patents

Abstract

PURPOSE:To offer the stress relief device for eliminating strains d1-d25 of a free access floor F. CONSTITUTION:Plural lower cylinders L1-L25 having a linear gage 22, respectively are arranged so that linear gage 22 becomes upward, and also, conforms to a plane shape of a free access floor F, and fixed to the lower die 11, and the upper cylinders U1-U25 of the same number as the plural lower cylinder, having a load cell, respectively are placed opposingly in the lower part of the lower cylinders L1-L25 and fixed to the upper die 13 being freely ascendable and descendable.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strain relief device for removing strain on a raised floor.

0002

2. Description of the Related Art A raised floor, which is widely used in computer rooms and the like, generally has a flat upper surface and a ribbed lower surface. This floor is usually formed from aluminum alloy casting, but because it is not symmetrical in the vertical direction, it becomes distorted in the vertical direction during the cooling process after casting. This distortion occurs because the rib structure on the lower surface acts as a fin, so the rib surface cools faster and contracts during the solidification process.
Therefore, it is usually distorted in an upwardly convex manner. If this distorted floor is arranged on the floor of a building as it is, it will generate a rattling noise when people walk on the floor, which may worsen the quiet working environment.

[0003] The cast floor is then shipped after its distortions are corrected, and this correction work has conventionally been carried out as follows. That is, the floor is set in a press machine with battens interposed at the four corners if necessary, the center is pressed to remove distortion in the center, the floor is then turned upside down and placed on a surface plate, and each corner is pressed. were removed from the surface plate one by one and tapped on top with a mallet to remove distortions around the edges.

0004

[Problems to be Solved by the Invention] The above-mentioned conventional distortion correction work relies on human power, and in particular, the removal of distortion in the peripheral area relies on a ring. It was not possible to obtain a uniform product. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a strain relief device for eliminating strain on a raised floor.

[0005]

[Means for Solving the Problems] The present invention provides a lower mold by arranging a plurality of lower cylinders each having a linear gauge so that the linear gauges face upward and conforming to the planar shape of a raised floor. The above object is achieved by a strain relief device for a free access floor in which the same number of upper cylinders as the plurality of upper cylinders, each having a load cell, are arranged oppositely above the lower cylinders and fixed to an upper mold that can be raised and lowered freely. be.

[0006]

[Embodiment] An embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a front view showing an embodiment of the strain relief device according to the present invention, in which a lower mold 11 is fixed to a frame 10, and an upper mold 13 is guided by a guide rod 12 erected on the lower mold 11. is installed to be able to rise and fall freely, and the upper die 13 is driven up and down by a ball screw jack 14 attached to the frame 10, and the ball screw jack 14 is rotationally driven by a motor 16 via a clutch brake 15. .

As shown in FIG. 2, 25 lower cylinders L (L1 to L25) are fixed to the lower mold 11.
The five lower cylinders L are arranged to match the planar shape of the raised floor F whose distortion is to be removed. In this embodiment, since the floor F has a square planar shape, the 25 lower cylinders L are also arranged in a square shape. Further, the lower cylinders L are arranged in five columns and five rows so that the lower cylinders L are located at locations where the ribs of the floor F are formed. Each lower cylinder L is arranged so that its piston 20 faces upward, and a pad 21 is fixed to the upper surface of the piston 20. Each lower cylinder L is fixed to the lower mold 11 so that the upper surface of each pad 21 is on the same plane S when the piston 20 is raised to the maximum. This same plane S
is preferably a horizontal plane. Also, each lower cylinder L
is equipped with a linear gauge 22 so as to penetrate through its axis, and the upper end of the linear gauge 22 protrudes above the upper surface of the pad 21 and connects to the lower surface of the floor F placed on the pad 21. It is configured to be able to measure the distance between it and the top surface of the pad 21.

The upper die 13 also has 25 upper cylinders U (U
1 to U25) are fixed, and each upper cylinder U is arranged so that its piston 30 faces downward and so as to face each lower cylinder L. Furthermore, pads 32 are fixed to the lower surface of the piston 30 of the upper cylinder via springs 31, respectively. Each upper cylinder U
is fixed to the upper mold 13 so that the lower surfaces of the pads 32 are on the same plane when the piston 30 is raised to the maximum. This same plane is the pad 2 of the lower cylinder L.
The flatness does not need to be as high as that of the same plane S formed by the upper surface of 1. Each upper cylinder U is also equipped with a load cell (not shown).

The present embodiment is configured as described above.
The method of operating this strain relief device will be explained below. As shown in FIG. 3, the method of operating this strain relief device includes a step of measuring the load at the boundary between elastic deformation and plastic deformation, a step of creating a load-permanent strain diagram, and a strain relief step. Among these, the measurement process and load of the load at the boundary between elastic deformation and plastic deformation -
The process of creating a permanent distortion diagram is performed approximately once for each product type on each floor F, and the distortion removal process is performed for all floors F from which distortion is to be removed.

First, the process of measuring the load at the boundary between elastic deformation and plastic deformation will be explained with reference to FIG. , 5, 13, 21 and 25 cylinders L1, L5, L13, L21 and L25 are sufficiently lowered from this same plane S (FIG. 4a). Next, turn the free access floor F upside down, that is, place the lower cylinder L with the rib surface facing up.
The lower cylinders L1, L5, L1 are placed on the pads of
3.L21 and L25 linear gauge values h1X, h5
Measure X, h13X, h21X, and h25X, and find the average value hXm (same b). B-B in Figure 2 in this state
A schematic diagram in view of the arrows is shown in FIG. The floor F is normally warped upward by casting, and since it is placed upside down and placed on the pad 21, it becomes downward convex, and its center of gravity is approximately in the center. Therefore, the floor F is supported by the pads of about three lower cylinders L near the 13th lower cylinder L13, and as shown in the figure, the floor F is supported by the pads of the lower 2nd to 4th cylinders L2 to L4. are likely not in contact.

On the other hand, for the upper cylinder U, all the pistons 30 are raised to the highest level to keep the lower surfaces of their pads 32 on the same plane, and the ball screw jack 14 is operated so that any pad of the upper cylinder U is on the floor F. The upper die 13 is lowered until it reaches a position just before touching the upper die 13, and this is set as an initial state. After that, operate the ball screw jack to lower the upper die by 0.01 mm (Fig. 4c), and at that time, the upper cylinders U1, U5, U13, U21, and U25 The values P1, P5, P13, P21, and P25 of the load cells are measured, and the average value Pm is determined (d). Next, the upper mold is returned to the initial state and raised (e), and the linear gauge values h1, h5, h13, h21, and h25 of the lower cylinder at that time are measured, and the average value hm is determined (f). When this average value hm is about the same as the initial average value h Repeat the steps of lowering, measuring the load cell, returning and raising the upper mold, and measuring the linear gauge (same g). If the average value hm of the linear gauge does not reach the initial average value hXm when the upper die is raised, it means that the deformation of the floor F has entered the plastic deformation region and caused permanent strain. The average value Pm of the load cell can be adopted as the average value Pe of the minimum load for causing plastic deformation (h).

Note that the floor F is placed on the pad of the lower cylinder L with the rib side facing up, but there is a possibility that the floor F is distorted, and at the same time, there are some unevenness on the rib surface. there is a possibility. On the other hand, in the process of repeatedly raising and lowering while increasing the amount of elevation using a ball screw jack, when the amount of elevation is small, only a small number of the pads of the upper cylinder U are exposed to the rib surface, which may be distorted and may have irregularities. There is a possibility that the floor F will come into contact with it and press it, and therefore, there is a possibility that the floor F will move laterally to escape. Therefore, in this embodiment, a spring 31 is interposed between the pads of each upper cylinder U.
A large load is not applied to the floor F until many of the pads of the upper cylinders U come into contact with the ribs of the floor F, thereby preventing the floor F from moving in the lateral direction.

Next, the process of creating a load-permanent strain diagram will be explained. First, the pistons of all the lower cylinders L are raised to the highest level to keep the upper surfaces of their pads on the same plane S, and the floor F is placed on this pad with the rib surface facing upward. On the other hand, for the upper cylinder U, all the pistons are raised to the maximum and the lower surfaces of their pads are kept on the same plane, and one of the load cells exhibits the average value Pe of the minimum load for causing the plastic deformation. Lower the upper mold by operating the ball screw jack until it reaches the desired position.

After that, the piston of the lower first cylinder L1 is sufficiently lowered, and the value h1X of the linear gauge of the first cylinder and the value P1X of the load cell at that time are measured.
This is the initial state. A schematic diagram of this state is shown in FIG. Next, the load cell value P1 of the upper first cylinder is made larger than the initial value P1X by, for example, 1 kgf.
A load is applied to the upper first cylinder U1. Next, the piston of the first upper cylinder U1 is returned and raised until it reaches the initial value P1X. The state of return elevation is not necessarily the highest initial height. After returning and raising the piston of the upper first cylinder U1, the value h1 of the linear gauge of the lower first cylinder is measured, and d1=h for the load P1.
Plot 1X-h1.

Similarly, the load is increased so that the value P1 of the load cell of the upper first cylinder becomes larger than the initial value P1X by, for example, 2 kgf, and the piston of the upper first cylinder returns to the initial value P1X. and measure the value h1 of the linear gauge of the lower first cylinder to determine the load P.
Plot d1=h1X-h1 against 1. Similarly, the load to be increased from the initial value P1X is increased to, for example, 3 kgf, 4 kgf, and so on, and the above process is repeated. When the load cell value P1 reaches the same level as the average minimum load Pe for causing plastic deformation, the floor F
enters the plastic deformation region, and therefore the linear gauge value h1
becomes smaller than the initial value h1X. Both h1X and h1 are not the values when the load is removed, but they both have the same load P1
Since this is the value of the linear gauge when X is applied, h1
The difference between X and h1, d1=h1X-h1, can be considered as permanent distortion. An example of the load-plastic strain diagram at the first cylinder position obtained in this way is shown in FIG. Furthermore, the second ~
Similarly, a load-plastic strain diagram is created for the No. 25 cylinder.

Next, the distortion removing process will be explained. First, raise the pistons of all the lower cylinders to the highest level, keep the top surfaces of their pads on the same plane S, place the floor F on this pad with the rib side facing up, and calculate the values d1 to d25 of each linear gauge at that time. Measure. Figure 8 shows a schematic diagram of this state.
Shown below. Then, the pistons of all upper cylinders U are raised to the maximum, keeping the lower surfaces of their pads in the same plane, and the ball screw Operate the jack to lower the upper mold.

After that, the load P1 required to sufficiently lower the piston of the lower first cylinder L1 and remove the distortion d1 of the floor F at the first cylinder position is determined from FIG. A voltage is applied to the first cylinder U1, and then the piston of the upper first cylinder U1 is returned to its highest initial height, and the piston of the lower first cylinder L1 is also returned to its highest initial height and raised. The same upper and lower planes are formed by each pad. This eliminates the distortion d1 at the first cylinder position. Therefore, if the upper die is raised in this state, the vertically inverted lower surface of the floor F will be at about 4 points, including the 1st cylinder position and 3 points near the 13th cylinder position, as shown in Fig. 9. , are on the same plane S formed by the upper surfaces of the pads of the lower cylinder L.

Next, in the same manner, the piston of the lower second cylinder L2 is sufficiently lowered to find the load P2 necessary to remove the distortion d2 of the floor F at the second cylinder position.
This load P2 is applied to the upper second cylinder U2, the piston of the upper second cylinder U2 is returned and raised, and the piston of the lower first cylinder L1 is also returned and raised. This eliminates the distortion d2 at the second cylinder position. If the upper die is raised when the removal is finished, the floor F will be at the first cylinder position and the second cylinder position, as shown in FIG.
There are about five points on the same plane S, including the cylinder position and about three points near the 13th cylinder position. Similarly, the distortion d3 at the third cylinder position is removed and corrected as shown in FIG. 11, and the distortion d3 at the fourth cylinder position is corrected.
4 is removed and corrected as shown in FIG. With this removal, the distortion removal process for one free access floor F is completed.

[0019]

According to the present invention, a strain relief device for removing strain on a raised floor is provided.

[Brief explanation of drawings]

[Fig. 1] Front view of one embodiment of the present invention

[Fig. 2] Schematic view taken along arrow A-A in Fig. 1

[Fig. 3] Block diagram showing the operation method of the embodiment

[Figure 4
】Block diagram of the process of measuring the load at the boundary between elastic deformation and plastic deformation

[Fig. 5] Schematic diagram taken along arrow B-B in Fig. 2 showing the initial state of the load measurement process at the boundary between elastic deformation and plastic deformation.

[Figure 6] Schematic diagram showing the initial state of the process of creating a load-permanent strain diagram

[Figure 7] Example of load-permanent deformation diagram

[Figure 8] Schematic diagram of strain measurement in the strain removal process

[Figure 9
] Schematic diagram after removing distortion at the first cylinder position

[Figure 10] Schematic diagram after removing distortion at the second cylinder position

[Figure 11] Schematic diagram after removing distortion at the third cylinder position

[Figure 12] Schematic diagram after removing distortion at the fourth cylinder position

[Explanation of symbols]

F...Free access floor 10...Frame 11...Lower die 12...Guide rod 13...Upper die 14...Ball screw jack 15...Clutch brake 16...Motor L...Lower cylinder U...Upper cylinder
20, 30... Piston 21, 32... Pad 22... Linear gauge
31...Spring

Claims (2)

[Claims] 1. A plurality of lower cylinders, each having a linear gauge, are arranged and fixed to a lower mold so that the linear gauges face upward and conform to the planar shape of a raised floor, and each has a load cell. A strain relief device for a free access floor, in which the same number of upper cylinders as the plurality of upper cylinders are arranged oppositely above the lower cylinders and fixed to an upper mold that can be raised and lowered. 2. A strain relief device for a raised floor according to claim 1, wherein a spring is fixed to the lower surface of each of said upper cylinders.