JPH02240374A - Simultaneous stretching controller for pc steel wire - Google Patents

Abstract

PURPOSE:To attain safe, rapid and positive execution by automatically controlling the quantity of elongation and stretching force of a PC steel wire by a central control room computer while being compared and arithmetically operated to each deviation upper limit value and lower limit value. CONSTITUTION:A load cell 7 is installed to a jack 4, and stretching force applied to a PC steel wire 6 during a stretching process and after the completion of stretching can be measured while a displacement gage 8 is mounted and the quantity of elongation of the steel wire 6 can be measured. The load cell 7, the displacement gage 8 and the control unit 9 of a hydraulic pump 5 are connected to a personal computer 10. Design conditions are input to the personal computer 10, and the allowable deviation ranges of stretching force and the quantity of elongation are operated arithmetically, and displayed to a display 11. The pump 5 is controlled while checking a measured value, and the jack 4 is stopped automatically when the measured value reaches a desired value. Accordingly, execution can be conducted extremely safely and accurately and rapidly.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a PCH wire simultaneous tension management device that automatically controls the amount of elongation and tension of a PC steel wire during simultaneous tension in a central control room, and automatically creates a PC steel wire tension control chart.

[Conventional technology]

Prestressed concrete products that have been given compressive force so as to withstand tensile force are manufactured, for example, as bridge girders for slab construction, and the introduced tension force is specified in JIS. Manufacturers create control charts that record the PCgC strain status for each product and hand them to customers along with the products. The conventional method of creating such a PC steel wire tension management chart and managing simultaneous tensioning work is to temporarily tension a plurality of PCM wires one by one between the stationary post and the movable frame, and then A jack was operated to forcibly move the moving frame and simultaneous tension was applied to the final tension.The amount of elongation at this time was measured by a worker on site and plotted by hand on a graph. Also, calculate the calculated amount of elongation from the construction conditions, and check that the ΔPI constant value is generally within a 5% deviation range from the calculated elongation. If it exceeds the deviation range, Stop the equipment, investigate and eliminate the cause,
I was trying to get nervous again.

[Problem to be solved by the invention]

With the above-mentioned device, after the final tension is achieved, the fixing nut is tightened and the tension is transferred from the jack to the fixing nut. Due to the phenomenon that the tension bed as a whole shortens over time due to movement, the tension immediately before introduction is usually smaller than the final tension. However, since there was a lack of a means to detect the amount of decrease, it was currently treated as if the final tension had been introduced. In addition, because there were workers near the tensioning machine to take data, the PC steel wire during tensioning could come off or break due to a defect in the temporary tension fixing work or a defective PCFR4 wire, and the Pcm wire could not be used during the work. There was a potential risk of a serious accident resulting in a direct hit to someone. The problem to be solved by the present invention is to develop a device that can eliminate the inconveniences such as tilting. (confirmation within), detection of final tension, stop,
To provide a device capable of performing a series of operations such as maintaining tension and outputting results by operating a keyboard of a computer installed at a location away from the tensioning machine body.

[Means to solve the problem]

The present invention provides a tensioning device for a PC steel wire in which a jack attached to a movable frame presses a surface of a movable post to tension a plurality of PC steel wires stretched between a fixed side post and a movable frame.
By adopting the configuration shown in FIG. 1, the intended purpose has been achieved. That is, the load detection means (load cell) installed on the jack, the movable frame movement amount detection means (displacement meter), and the upper limit value that is the deviation range of the tension force and elongation of the Pcm line corresponding to the design condition input. A calculation means for calculating a lower limit value and a target tension force, and a calculation means that compares the measured values of the load cell and the displacement meter with the deviation range, and if it exceeds the deviation range, compares it with the degree of attainment of the target tension force, and calculates a predetermined degree of attainment. A tension-like operation that sends a jerk stop signal only when the tension reaches the target tension, compares the measured values of the load cell and displacement meter with the target tension, and issues a hydraulic pump stop signal when the target tension is reached. The apparatus is equipped with a signal generating means and a plotter for plotting a PC steel wire tension control diagram connected to the calculating means.

[For use]

The load cell, which is a load detection means directly incorporated into the jack, can detect the tension force not only during the tensioning process but also after the tensioning process is completed, which can be reflected in more accurate management. Relatively troublesome tension calculations can be quickly performed using a computer, and at the same time as the calculation results are output, the measurement process that ensures that the load is within the allowable range of elongation relative to the load index can be confirmed on the display. If the measured value deviates from the deviation range during measurement, and the tension at that time is, for example, 50% or more of the target tension, the jacking will be automatically stopped to prevent excessive tension due to input errors, etc. Safety is ensured by sensing. If it is below 50%, the method of coping will automatically change depending on whether it has reached 50%, such as continuing to maintain the tension.

【Example】

FIG. 4 shows an overall diagram of the PCFF4 line simultaneous tensioning device. A jack 4 attached to the movable frame 3 is a hydraulic pump 5
When the surface of the movable post 2 is pushed and extended by the hydraulic pressure sent from the fixed post 1 and the movable frame 3, the plurality of PC steel wires 6 stretched between the fixed post 1 and the movable frame 3 are tensed. In this respect, it is no different from the conventional tensioning machine itself. In addition, after the temporary tension fixing work in which the PC steel wires 6 are placed one by one between the fixed side boss 1 and the movable frame 3 by hand, and both ends of the wires are fixed, the simultaneous tension is applied by the movable frame 3. After tensioning is completed, reinforcing bars and formwork are assembled, concrete is poured, the concrete is then cured, and the next day when its strength is achieved, it is removed from the mold, and the movable frame 3 is returned to its original position and introduced. , P
There is no difference from the conventional method in terms of cutting the C steel wire and transporting the product. However, in the device of the present invention, the jack 4 is equipped with a rotor self, which is a load detection means, so that the tension force applied to the PC steel wire 6 during or after the tensioning process can be measured. It has become. In addition, movable frame 3
For example, a roll-in type displacement meter 8, which is a means for detecting the amount of movement of the movable frame, is provided between the work floor and the work floor to measure the amount of elongation of the PC steel wire 6. The load cell 7 and displacement meter 8 are connected to a personal computer 10 via an amplifier 14, 14 and an A/D conversion board 15, respectively, and the control unit 9 of the hydraulic pump 5 is connected to a personal computer 10 via an input/output board 16. has been done. In Figure 4, 11 is the display, 12
is a plotter, and 13 is a printer. Regarding the functions performed by the computer 10, the second
The explanation will be as follows according to the flowchart in the figure. The design conditions determined by the determination of the construction conditions are input into the personal computer 10 by operating the keyboard (step 21). The constants determined by determining the design conditions are the introduced tension force PI specified by JIS, and the PC1 given in the temporary tension work.
In addition to the temporary tension p per il wire, the cross-sectional area Ap of the PC steel wire used, the effective length 2 the elastic modulus Ep 1 the number N, the linear expansion coefficient α of the PC steel wire with respect to temperature, the maximum temperature TI during curing, Outside air temperature during stress T2. Temperature correction coefficient C, number NC of connectors, extraction tx and set loss ΔL
There is such a thing. These constants are manually entered into the personal computer 0 using the keyboard, and the arithmetic processing means performs calculations based on the following calculation formula (step 22). Pl-ΔL x Epx Ap/L. P2-αX EpX (Tl-T2) X CX Ap
. From Pt-Pl+ P2, the target tension force ΣP = (Pl+Pt) X N is also δ-(Pi+Pt) X L/^pXEp. From δc−NCXX, the total elongation amount −δ+δC is further calculated, and the upper limit value and lower limit value are calculated by setting the allowable value of the deviation range to, for example, 5%. When the above-mentioned calculation is completed, a deviation range graph is displayed on the display 11 (step 23), and a start signal is transmitted from the personal computer 10 to the control unit 9 of the hydraulic pump 5 to start the hydraulic pump 5 and adjust the jack 4. The main tensioning of the PC steel wire 6 is started by the movement of the moving frame 3 due to the operation of (step 24). During the main tensioning process, a check is made to see if the measured value exceeds the deviation range (step 25). If it does, it is checked to see if it has reached, for example, 50% of the target tension (step 26). ). If 50% of the target tension has been reached, a jack stop signal is transmitted from the computer 10 to the control unit 9 of the hydraulic pump 5 to interrupt oil supply and automatically stop the jack 4 (step 27). . 50
If the percentage has not been reached, continue to maintain tension. During the main tensioning process, a check is also made to see if the measured value has reached the target tension (two steps), and if the target tension has been reached, a stop signal is sent from the personal computer 10 to the control unit 9 of the hydraulic pump 5. is transmitted, and the hydraulic pump 5 and jack 4 are automatically stopped (step 29). and the fourth
A PCIC tension control chart is drawn using the plotter 12 in which the horizontal axis represents the amount of elongation and the vertical axis represents the tension force (step 30). FIG. 3 is an example of a PCMC strain management chart, in which two dotted lines indicate an upper limit and a lower limit, and a solid line indicates a total of 71111 M. Further, if necessary, a tension calculation statement can be created using the printer 13.

【Effect of the invention】

In this invention, since the load cell, which is a load detection means, is directly incorporated into the jack, it is possible to detect the tension force during the tensioning process and control using the detection result, as well as to detect the amount of decrease in tension force that occurs after the final tension is achieved. Based on this, more accurate management is possible. In addition, tension calculations and deviation range calculations can be quickly performed using a PC, and the total n1 process can be confirmed on the display. When the target tension is reached, the jacking is automatically stopped and a PC steel wire tension control chart is displayed. It can be created using a plotter. Furthermore, if the measured value deviates from the deviation range during measurement, the jacking will be automatically stopped depending on how much the tension force at that time is relative to the target tension force, and this will allow manual effort. It is possible to detect overstress due to mistakes, etc., thereby ensuring safety, and if it is still safe to continue tensioning, it is possible to increase operational efficiency by continuing to maintain tension. Moreover, since the series of operations after preliminary tensioning can be performed in a central control room that is separate from the main body of the tensioning machine, it is extremely effective in terms of safety measures, and this invention is extremely effective as a simultaneous tensioning control device for PC steel wire. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of the present invention, FIG. 2 is a flowchart, and FIG. 3 is an example of a PCM line tension management chart. FIG. 4 is an explanatory diagram of the entire simultaneous tension management device for PC steel wire. 1... Fixed side post, 2... Movable side post, 3... Movable frame, 4... Jacket, 6... PC steel wire, 7...
Load detection means, 8... Movable frame movement amount detection means, 12.
... Plotter, A... Calculating means, B... Tension machine operation signal generating means. Patent applicant: Tokiwa Kosan Co., Ltd. Agent: Yuki Omata
Male @2 ■ Flute diagram (middle; jg (mm)

Claims (1)

[Claims] 1. In a PC steel wire tensioning device, a jack attached to the movable frame presses the surface of the movable post to tension multiple PC steel wires stretched between the fixed side post and the movable frame. a load detecting means, a movable frame movement amount detecting means, and a calculating means for calculating the upper and lower limits of the deviation range of the tension and elongation of the PC steel wire and the target tension in response to the design condition input. and comparing the measured values of the weight detecting means and the movable frame movement amount detecting means with the deviation range, and if it exceeds the deviation range, checking the degree to which the target tension has been achieved,
A jack stop signal is sent only when the target tension has reached a predetermined degree, and the measured values of the weight detection means and the movable frame movement amount detection means are compared with the target tension, A simultaneous use of a PC steel wire, characterized in that it is equipped with a tensioning machine operation signal generating means that issues a hydraulic pump stop signal when a target tension is reached, and a plotter connected to the calculation means and plotting a PC steel wire tension control chart. Tension management device.