JPH0754050B2 - Equalizer device having level return mechanism and tension device having the equalizer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applied to the case where a heavy object is lifted and laterally pulled through a tensioned member such as a plurality of wires or when stress is introduced to a plurality of PC wires. The present invention relates to an equalizer device and a tension device having a level return mechanism used.

[Prior Art] Conventionally, when stress is applied to a plurality of PC strands (wires), it is usually carried out by tensioning each PC strand while using a plurality of jacks.

Then, using the plurality of jacks, when tensioning each PC strand, the equalizer device absorbs the error in the length between the PC strands and equalizes the tension applied to each PC strand. used.

The structure of such an equalizer device is shown in FIG. 5, and the structure thereof will be described below with reference to FIG. 5. Reference numeral 1 is an equalizer main body, and the equalizer main body 1 has equalizer cylinders 2 and 3 arranged side by side. Has been done.

The pressure equalizing chambers 4 and 5 are provided inside the equalizer cylinders 2 and 3, and the pressure equalizing chambers 4 and 5 are connected to each other through a passage 6.

Further, a chuck case 9 in which chucks 7 and 8 are vertically movably fitted in the pressure balancing chambers 4 and 5 and
10 is mounted so that it can move up and down.

At the center of the equalizer cylinders 2 and 3, insertion holes 11 for PC strands 17 and 18 as tensioned members are formed.
And 12 are opened and chuck cases 9 and 1
0, the chucks 7 and 8 have insertion holes 13 and 1 respectively.
4. Open the through holes 15 and 16, and provide the inner peripheral surfaces of the through holes 15 and 16 of the chucks 7 and 8 with projections and depressions (not shown) for preventing slippage with the outer peripheral surfaces of the PC strands 17 and 18. It is composed by.

The pressure balancing chambers 4 and 5 are filled with hydraulic oil 19 through the passage 6 so as to be freely flowable.

In FIG. 5, the chuck cases 9 and 10 and the chucks 7 and 8 mounted in the equalizer cylinders 2 and 3 are equalizer cylinders 2 and 3, respectively.
A cylinder cap (not shown) is fitted on the upper side of the equalizer cylinders 2 and 3 so as not to separate from the inside.

Now, the operation of the equalizer device 20 having the above-described configuration will be described. The insertion holes 11 and 12 of the equalizer cylinders 2 and 3 of the equalizer body 1 are explained.
PC strands 17 and 18 via chucks 7 and 8
Then, the tension is applied to both PC strands 17 and 18 while pulling up the equalizer device 20 in the direction of an arrow 21 by a weighting means (not shown) to introduce stress.

However, when there is a difference in the slack between the PC strands 17 and 18, the pulling force is applied first to the PC strand having the lesser slack (for example, the PC strand 17). However, pressure is applied to the hydraulic fluid 19 in the pressure balancing chamber 4 on the chuck case 9 and the chuck 7 side that holds the PC strand 17, and the hydraulic fluid 19 in the pressure balancing chamber 4 passes through the passage 6 to the pressure balancing chamber 5 side. Flowing in to the pressure balancing chamber 5 side and pushing up the chuck case 10 on the side of the pressure balancing chamber 5, and the pulling force for the PC strand 18 is applied while being held by the chuck 8 so that the tension balance for both PC strands 17 and 18 can be maintained. Is configured.

[Problems to be Solved by the Invention] However, there is a limit to the amount of displacement of the pressure balancing chambers 4 and 5 in the equalizer device 20 having the above-described configuration.
For example, when the slack difference between the PC strands 17 and 18 at the time of setting is equal to or greater than the displacement amount of the pressure balancing chambers 4 and 5, the balancing action by the pressure balancing chambers 4 and 5 cannot be fully dealt with and the desired effect cannot be achieved. It has drawbacks.

Therefore, as a method to solve this drawback, both PCs
Pre-tension is applied to each of the strands 17 and 18 by a tensioning means different from the weighting means that operates the equalizer device 20,
Although there is a method of making the slack uniform, there is a drawback that the work of applying such pretension requires a very troublesome work.

Moreover, if the pull-in distance is long even if pre-tension is applied,
A biting error of the chucks 7 and 8 in the equalizer device 20 always occurs, and if this error exceeds the displacement amount of the pressure balancing chambers 4 and 5, tension imbalance occurs, and when the momentum tension difference becomes large, the tension is largely applied. Even the drawback of cutting PC strands 17 or 18 occurs.

Therefore, the present invention has been developed in view of the drawbacks of the conventional equalizer device, and is an equalizer device and a tension device that can exhibit a balancing action that can cope with a large slack error between a plurality of tensioned members. It is intended to be provided.

[Means for Solving the Problems] The equalizer device of the present invention is provided with a plurality of equalizer cylinders in the equalizer body, and a chuck case having a chuck for a tensioned member is movably mounted on each equalizer cylinder, and each equalizer cylinder is provided. In the equalizer device provided with the passages for communicating the respective pressure balance chambers provided in, the tension device having the equalizer device and the chuck in each of the equalizer cylinders and the returning means for the chuck case are provided. The equalizer body is provided with a plurality of equalizer cylinders, and each equalizer cylinder is movably attached with a chuck case having a chuck of a tensioned member, and each pressure provided on each equalizer cylinder. An equalizer device having a level return mechanism configured to provide a passage for communicating the balance chambers with each other and a return means for the chuck and the chuck case in each of the equalizer cylinders, a pressure jack for operating the equalizer device, and the equalizer device. Corresponding to a control circuit in which an operating circuit of a hydraulic piston as a returning means of a chuck and a chuck case in each equalizer cylinder is connected to a returning circuit of an operating circuit of the pressure jack, and a chuck and a chuck case provided in each equalizer cylinder of the equalizer device. It is composed of a plurality of exchanging chucks.

[Action]

Equalizer device of the present invention, by providing the chuck and chuck case return means in each equalizer cylinder, it is possible to always exert a balance action during the operation means of the equalizer device, absorb the slack error between the plurality of tensioned members. While being able to perform appropriate tension work.

Further, in the tensioning device of the present invention, the control circuit in which the operating circuit of the hydraulic piston as the returning means of the chuck and the chuck case in each equalizer cylinder of the equalizer device is connected to the returning circuit of the operating circuit of the pressure jack for operating the equalizer device. By providing the circuit, it is possible to perform the tensioning work while operating the returning means in the equalizer device in conjunction with the returning operation of the pressing jack, and the tensioning operation by the pressing jack and the operation of the returning means in the equalizer device are continuously performed. Then, it can operate smoothly and accurately.

[Examples] Examples of the equalizer device and the tension device of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1 to 3 show an embodiment of an equalizer device of the present invention, FIGS. 1 and 2 are schematic sectional views showing the essential parts, and FIG. FIG.

In FIGS. 1 and 2, the same components as those of the equalizer device 20 shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. Other components will be described below.

At the center of the equalizer body 1, a hydraulic piston 21 having a piston rod 22 mounted in a cylinder 46 so as to be vertically movable.
And a chuck lead-in plate 23 is attached to the end of the piston rod 22. Further, on both sides 23a, 23b of the chuck pull-in plate 23, openings 23c, 23d having a diameter smaller than the outer diameter of the chuck cases 9, 10 and larger than the outer diameter of the chucks 7, 8 are provided. Both sides of 23 23a, 23b
The means for returning the chuck cases 9 and 10 of the equalizer main body 1 is configured so that they can be engaged with the upper ends of the chuck cases 9 and 10 while directly abutting them.

Therefore, when the PC strands 17 and 18 are tensioned by the equalizer device 30 of the present invention having such a configuration, the PC strands 17 and 18 are similar to the case described in FIG.
Is set while being bitten by the chucks 7 and 8 of the equalizer cylinders 2 and 3, and an operating means (not shown) for operating the equalizer body 1 such as a fluid pressure jack (hereinafter simply referred to as a pressure jack) such as a pressure jack is used. The equalizer body 1 is pushed up in the direction of the arrow in FIG. 1 to apply tension to the PC strands 17 and 18.

It should be noted that when the pressure jack is pressed against the equalizer body, the hydraulic piston 21 is put into an inactive state so that the hydraulic circuit between the pressure balance chambers 4 and 5 is not affected by the pressing operation of the pressure jack.

Now, at the time of pushing up by the pressing jack, if there is slack on the PC strand 18 side at the time of setting, tension is applied to the PC strand 17 without slack (or little) as in the explanation of FIG.

As a result, as a result of the chuck case 9 on the side of the chuck 7 that holds the PC strand 17 descending in the equalizer cylinder 2, the hydraulic oil 19 on the side of the pressure balancing chamber 4 is associated.
Flows into the pressure balance chamber 5 side through the passage 6 to raise the chuck case 10 in the equalizer cylinder 3, and the PC strand 18 with a large amount of slack that is caught by the chuck 8
Can be pushed up to absorb the slack, so that the tension on the PC strands 17 and 18 by the pressing jack can be balanced (see FIG. 2).

However, the slack error between the two PC strands 17 and 18 cannot be absorbed by the one-stroke operation of the pressing jack, and when the PC strand 18 has slack, that is, as shown in FIG. The chuck case 9 that holds the strand 17 and fits the chuck 7 descends to the lowermost end in the equalizer cylinder 2, and the hydraulic oil 19 on the pressure balance chamber 4 side flows into the pressure balance chamber 5 side via the passage 6. However, the chuck case 10 into which the chuck 8 that holds the slack PC strand 18 fits is moved up in the equalizer cylinder 3, and even if this is raised to the uppermost end, the PC strand 18 still has slack. In this case, the tension due to the next stroke operation by the pressing jack against the equalizer body 1 is not evenly applied to both PC strands 17 and 18.

Therefore, in this state, when the pushing-up force by the pressure jack to the equalizer body 1 is continuously applied, the tension is applied only to the PC strand 17 side, which causes the PC strand 17 to be cut or the like.

Therefore, in the case of the embodiment of the present invention, the equalizer device 30 operates the hydraulic piston 21 as the returning means of the chuck and the chuck case to move the piston rod 22 downward before the second stroke operation of the pressing jack. By moving it, the chuck case 10 that engages with one end 23b of the chuck pull-in plate 23 becomes the equalizer cylinder 3.
Is lowered inside. And the chuck case 10
The hydraulic oil 19 in the pressure balancing chamber 5 flows into the pressure balancing chamber 4 via the passage 6 by the downward movement of the piston rod 22, and both chuck cases 9 and 10 are brought into the first state at the lower end of the piston rod 22. Will be restored.

In addition, prior to the backward movement of the piston rod when the pressure jack moves to the next stroke operation, both PC strands are
17, 18 are once chucked and held by a chuck (not shown) different from the chucks 7, 8 of the equalizer device 30, and under this state, the equalizer device 30
As the piston rod of the pressing jack moves backward, it itself descends in the direction opposite to the arrow shown in the second illustration, and at the time of this descending, the hydraulic piston 21 is operated and the chuck cases 9 and 10 are returned by the retracting plate 23. Both operations are performed
The chucks 7 and 8 are returned together with the returning operation of the chuck cases 9 and 10 without being affected by the gripping action of the chucks 7 and 8 on the PC strands 17 and 18.

The chuck cases 9 and 10 are returned to the state shown in the first illustration, and the chucks 7 and 8 of both cases 9 and 10 are used again to restore the both cases.
When the PC strands 17 and 18 are chucked and the chucks of both PC strands 17 and 18 that are chucked when the piston rod of the pressing jack is retracted are opened, the stroke operation of the second pressing jack is performed. , Apply tension to both PC strands 17 and 18.

Then, by the second stroke motion, the slack on the PC strand 18 side is again absorbed by the balancing action of the equalizer device 30.

If necessary, the above operation can be continuously performed to eliminate the slack error between the PC strands 17 and 18.

FIG. 3 shows the equalizer device 30 when the configuration of the equalizer device 30 of FIG. 1 is more specifically configured.
The same components as those of the equalizer device 30 in the figure are designated by the same reference numerals and the description thereof will be omitted.

Reference numerals 25 and 26 are equalizer pistons fixed to the lower portions of the chuck cases 9 and 10 of the equalizer cylinders 2 and 3, respectively.
The equalizing pipes 27 and 28 for the PC strands 17 and 18 are integrally formed, and the equalizing pipes 27 and 28 are slidably inserted into the through holes 11 and 12 of the equalizer cylinders 2 and 3 of the equalizer main body 1, respectively. The pistons 25 and 26 are mounted on the equalizer cylinders 2 and 3 so as to be vertically movable together with the chuck cases 9 and 10.

The equalizer cylinders 2 and 3 are watertightly sealed by caps 31 and 32 via seal members 33 and 34.

Also, the pipe 27 of the equalizer pistons 25 and 26 is
And 28 and through holes for equalizer cylinders 2 and 3
O-rings 36 and 37 are similarly interposed between 11 and 12.

Further, a supply port 38 for the hydraulic oil 19 is provided on the outer side of the equalizer cylinder 2.

Further, a cup-shaped tapered surface is provided inside the chuck cases 9 and 10, and the outer circumferences of the chucks 7 and 8 fitted inside the chuck cases 9 and 10 correspond to the tapered surfaces of the chuck cases 9 and 10. The chucks 7 and 8 are provided with a tapered surface and are slidable in the insertion direction (upward direction in FIG. 3) of the PC strands 17 and 18 inserted into the insertion holes 15 and 16 on the inner peripheral surfaces of the chucks 7 and 8. However, in the reverse direction (downward direction in FIG. 3), meshing blades (not shown) are formed in the circumferential direction so as to prevent the PC strands 17 and 18 from coming off.

Further, annular flanges 40 and 41 are attached to the upper ends of the chucks 7 and 8, and the springs 44 and 45 mounted elastically between the chuck caps 42 and 43 fitted in the chuck cases 9 and 10 are attached to the flanges 40 and 41. Due to the elasticity, the chucks 7 and 8 are constantly moved to the chuck case 9 and
10 It is configured by urging inward.

Further, in the hydraulic piston 21, a piston rod 22 is vertically movably fitted in a cylinder 46 provided in the central portion of the equalizer body 1, and hydraulic oil 47 is filled in the cylinder 46, and a chuck drawing plate 23 is provided in the chuck 22. It is fixed to the upper end of by a nut 48. 49 is an O-ring interposed between the piston rod 22 and the inside of the cylinder 46, and 50 is a cylinder
Reference numeral 51 denotes a cylinder cap fitted to the cylinder 46, and 51 denotes a hydraulic oil port for the cylinder 46 provided outside the equalizer cylinder 2.

The hydraulic oil port 51 is configured by connecting to a control circuit (not shown).

Now, as for the equalizer device 30 having the above configuration, as described above, when tension is applied to the PC strands 17 and 18 via the pressing jack, the PC strands are passed through the pipes 17 and 28 of the equalizer pistons 25 and 26. Insert 17,18 and chuck and 8 respectively
PC strand 17,1 on the equalizer device 30
Set 8.

Then, the equalizer main body 1 of the equalizer device 30 is pushed up in the pressing jack and tension is applied to the PC strands 17 and 18 to make them tension.

At this time, if there is slack in both of the PC strands 17 and 18 when they are set, the error between them is the chuck case of the chucks 7 and 8 that chuck both PC strands 17 and 18. It is absorbed by the hydraulic circuit between the pressure balance chambers 4 and 5 provided between 9 and 10 to eliminate the tension imbalance caused by the pressure jack, so that the tension from the pressure jack thereafter is evenly applied to both PC strands 17 and 18. What can be done is as described above.

If the slack error between the PC strands 17 and 18 cannot be completely absorbed by the equalizing device 30 during the one-stroke operation of the pressure jack, the hydraulic piston 21 is activated during the return operation of the pressure jack. Then, the chuck drawing plate 23 lowers the equalizer cylinder 3 while pressing the chuck case 10 in the second state, and the lowering of the chuck case 10 causes the hydraulic oil 19 in the pressure balancing chamber 5 to move. There is passage 6
And the chuck case 9 in the equalizer cylinder 2 rises and is returned to the first illustrated state.

Then, in this state, when the stroke operation of the pressing jack is performed again and the equalizer body 1 is pushed up, both PC strands 1 are operated by the same action as described above.
The slack error between 7 and 18 is absorbed, and thereafter, the tensioning action by the pressing jack acts between both PC strands 17 and 18 without imbalance, and the proper tensioning work can be performed.

Further, by repeating the return operation of the chuck cases 9 and 10 by the hydraulic piston 21 for each return operation of the pressure jack, the original purpose of the equalizer device 30 can always be properly performed during the press operation of the pressure jack. , Both
It is possible to prevent breakage between the PC strands 17 and 18 due to a slack error or the like.

The description of other operations is as described above.

(Second Embodiment) FIG. 4 is a vertical cross-sectional side view showing an embodiment of a PC strand tensioning device including the equalizer device of the first embodiment.

In the tension device 60, the pressing jacks 62 and 63 are installed on the lower frame 61a of the frame 61, and the rams 64 and 65 of the pressing jacks 62 and 63 are provided with the equalizer device 30 of the first embodiment. By fixing the equalizer body 1, the equalizer device 30 is held.

Further, the upper frame 61b of the frame 61 is made to correspond to the chucks 7 and 8 of the equalizer device 30, and the resize chuck 66 is provided.
And 67 are installed.

The refill chucks 66 and 67 fix the chuck bodies 68 and 69 to the upper frame 61b, and chucks 70 and 71 having a tapered surface corresponding to the cup-shaped tapered surface provided inside the chuck bodies 68 and 69. It is configured by fitting inside 68,69.

Further, insertion holes 72, 73, 74, 75 for PC strands are opened in the shaft centers of the chuck bodies 68, 69 and the chucks 70, 71, respectively.

The operation of the tensioning device 60 having the above-described configuration will be described below in the case where two PC strands 17 and 18 are simultaneously tensioned.

First, the two PC strands 17 and 18 are inserted from the lower side of the equalizer cylinders 2 and 3 of the equalizer device 30 through the through holes 11 and 12 into the chuck cases 9 and 10 and the through holes 13, 14, 15 of the chucks 7 and 8. And 16 through the upper side and then through the through holes 72 and 73 of the chuck bodies 68 and 69 of the reshuffling chucks 66 and 67 of the frame 61.
The holes 70 and 71 are inserted through the through holes 74 and 75, and the refill chucks 66 and 67 are penetrated and set on the upper side.

After the completion of such a set, the rams 64 and 65 are lifted by feeding oil to the upper side of the pressing jacks 62 and 63 to push up the equalizer device 30 and the two PC strands that are bitten by the chucks 7 and 8. 17 and 18 can be pulled upward by the stroke of the pressing jacks 62 and 63.

Then, by feeding oil to the return side of the pressing jacks 62 and 63, the equalizer device 30 descends downward and returns to its original position.At this time, the PC strands 17 and 18 are engaged with the refill chucks 66 and 67. It can be held and kept as it is.

Then, again, by feeding oil to the push-up side of the pressing jacks 62 and 63, the PC strands 17 and 18 can be pulled in, and by repeating the same operation as described above, the required PC strands 17 and 18 can be obtained. Can perform nervous work.

Now, when pulling in the two PC strands 17 and 18 during the tensioning operation, the chuck 7 that holds the PC strand with less slack of the two PC strands 17 and 18
Alternatively, the load is first applied to 8, and the load is transmitted to the equalizer piston 25 or 26 (see FIG. 3), so that the hydraulic oil 19 in the pressure balance chamber 4 or 5 passes through the passage 6 into the pressure balance chamber 5 or 4 Slackened between the two PC strands 17 and 18 by pushing up the equalizer piston 26 or 25 on the side with a large amount of slack and pushing up the chuck 8 or 7 via the equalizer piston 26 or 25. The error can be eliminated.

However, when the slack error of the two PC strands 17 and 18 cannot be eliminated by the operation of the equalizer device 30 once, the hydraulic piston 21 is operated and the chuck 7 or After returning 8 to the original position, by pulling in the PC strands 17 and 18, the slack error between the two can be eliminated. By repeating this operation, a large slack error between the two can be eliminated. Can also be resolved.

The hydraulic circuit of the pressure jacks 62 and 63 in the tension device 60 is connected to the hydraulic piston 21 in the equalizer device 30.
The hydraulic oil port 51 (see FIG. 3) for the cylinder 46 is controllably connected.

That is, the hydraulic oil port 51 is connected to the hydraulic circuits on the return side of the pressing jacks 62 and 63.

Therefore, during the above operation, the rams of the pressure jacks 62 and 63 are
When 64 and 65 return, the return side pressure rises and the hydraulic oil is transferred to the cylinder via the hydraulic oil port 51 of the hydraulic piston 21.
It flows into the inside (return side) 46, and the piston rod 22 descends to return to the state of FIG. 3, whereby the chuck pull-in plate 23 descends, and the chucks 7 and 8 can be returned to their original positions.

That is, the returning operation of the chucks 7 and 8 in the equalizer device 30 can be automatically performed in association with the tension operation of the PC strands 17 and 18 by the pressing jacks 62 and 63.

Therefore, with such a configuration, when the slack error of the PC strands 17 and 18 cannot be eliminated by one operation in the equalizer device 30, the repeated operation of the equalizer device 30 is performed by the operation of the pressing jacks 62 and 63, that is, the PC strand 17 and It can be carried out automatically in connection with the movement of the ten straining work, at the same time it means that the elimination of the large slack error between the PC strands 17 and 18 can be carried out automatically.
In the above description of the first and second embodiments, the PC strand was used as the tensioned member, but the stress introduced by other linear members or the weight supported by a plurality of hoisting wires or rod-shaped members. The same effect can be applied to hanging and horizontal pulling of objects.

Further, the chucks 7 and 8 and the reshuffling chucks 66 and 67 may be configured so as to appropriately obtain the desired biting action and non-biting action in accordance with the shape and configuration of the member to be tensioned. It is not limited to the configuration of the embodiment.

In addition, as for the configuration of the pressing jacks 62 and 63, instead of this, one jack, for example, a jack having a plurality of through holes for the tensioned members in its central portion, or the like can be applied.

[Effects of the Invention] As is apparent from the above description, according to the present invention, operations such as tension of a plurality of linear members or other linear or rod-shaped members for lifting or laterally pulling heavy objects are performed. It can be performed while eliminating any slack error between members, and it is possible to prevent accidents such as cutting due to overload on any of a plurality of tensioned members. It can improve safety.

Further, the pre-tensioning work for aligning the lengths of the plurality of members to be tensioned is unnecessary, the work can be simplified, and the tension error due to the biting error of each tension chuck can be eliminated.

[Brief description of drawings]

1 to 3 show a first embodiment of the equalizer device of the present invention, FIGS. 1 and 2 are schematic cross-sectional views showing a main part, and FIG. 3 is a part showing a concrete structure. FIG. 4 is a vertical sectional side view showing an embodiment of the tensioning device of the present invention, and FIG.
FIG. 1 is a sectional view showing a conventional equalizer device. 1 …… equalizer main body 2,3 …… equalizer cylinder 4,5 …… pressure balance chamber 6 …… passage 7,8 …… chuck 9,10 …… chuck case 11,12,13,14,15,16,… … Insertion hole 17,18 …… PC strand 19 …… Hydraulic fluid 20,30,60 …… Equalizer device 21 …… Hydraulic piston 22 …… Piston 23 …… Chuck drawing plate 25,26 …… Equalizer piston 27,28 ...... Pipe for insertion 31,32 ...... Cap 33,34 …… Seal member 36,37 …… O ring 38 …… Supply port 40,41 …… Flange 42,43 …… Chuck cap 44,45 …… Spring 46 …… Cylinder 47 …… Operating oil 48 …… Nut 49 …… O-ring 50 …… Cylinder cap 51 …… Operating oil port 60 …… Tensioner 61 …… Frame 62,63 …… Pressing jack 64,65 …… Ram 66,67 …… Replacement chuck 68,69 …… Main body 70,71 …… Chuck 72,73,74,75 …… Insert hole

Claims (4)

[Claims] 1. An equalizer body is provided with a plurality of equalizer cylinders, a chuck case having a chuck for a tensioned member is movably attached to each equalizer cylinder, and each pressure balance chamber provided in each equalizer cylinder is communicated with each other. An equalizer device having a level return mechanism, characterized in that the equalizer device is provided with a return path for the chuck and chuck case in each of the equalizer cylinders. 2. An equalizer body is provided with a plurality of equalizer cylinders, a chuck case having a chuck for a tensioned member is movably attached to each equalizer cylinder, and each pressure balance chamber provided in each equalizer cylinder is communicated with each other. And an equalizer device having a level return mechanism configured by providing a return means for the chuck and the chuck case in each of the equalizer cylinders, a pressure jack for operating the equalizer device, and a chuck in each equalizer cylinder of the equalizer device. And a control circuit in which an operation circuit of a hydraulic piston as a return means of the chuck case is connected to a return circuit of the operation circuit of the pressure jack, and a check circuit provided in each equalizer cylinder of the equalizer device. Tensioning device having an equalizer device comprising a level returning mechanism comprising a plurality of Morikawa chuck corresponding to click and the chuck case. 3. The level returning mechanism according to claim 1, wherein the returning means for the chuck and the chuck case in each of the equalizer cylinders is constituted by providing a return plate for the chuck case on a piston of a fluid cylinder. Equalizer device equipped with. 4. The pressing jack for operating the equalizer body is a jack (center hole jack-trademark) having an insertion hole at the center for inserting the plurality of tensioned members. A tensioning device having an equalizer device having the level return mechanism described.