JPH0228410B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to
Precisely cut a large number of 100 to 200 m long PC steel wires so that the relative length error of each steel wire is within ±5 mm, including expansion and contraction due to environmental temperature changes and elongation due to constant tensile stress. This invention relates to a fixed length ultra-precision length cutting device.

[Conventional technology]

When building large structures, such as nuclear reactor domes, with prestressed concrete, many long pieces are used.
A PC tendon is used, which is a bundle of PC steel wires. Such a PC tendon is, for example, 7mmφ×163
It consists of a bundle of PC steel wires or 12.7 mmφ x 55 PC steel wires, and the length is determined by design and requires a long standard size ranging from 100 to 200 m.

After introducing prestress, the length of each PC steel wire must be exactly uniform so that the stress state of all the PC steel wires that make up the same PC tendon becomes uniform, and all of these It is required that the difference in the length of the PC steel wires be within ±5 mm.

Conventionally, such PC steel wires were measured and cut using a known length measuring method, but
For example, in the case of a PC steel wire of 500 mm, a difference in length of about 2.5 mm occurs due to thermal expansion due to a temperature change of 1° C., and a difference in length of about 10 mm occurs due to a uniform tensile stress of 1 Kg/mm ² .

It takes several hours to cut the large number of PC steel wires that make up the same PC tendon, and it is extremely difficult to accurately maintain a constant environmental temperature during this process. For example, the temperature inside a factory changes between morning and afternoon, and
Even at the same time, there are differences depending on location conditions. Therefore, for long PC steel wires that are measured and cut according to the conventional absolute length standard, the tolerance of the relative length of each PC steel wire within the same tendon at a length of 100 to 200 m is ±5 mm. It was virtually impossible to cut it to fit within this range. This is because it is extremely difficult to cut under exactly the same temperature and tension conditions.

[Problem to be solved by the invention]

In view of the above-mentioned circumstances, the present invention eliminates the element of relative length change of long PC steel wires due to the influence of environmental temperature changes, applies tensile force under the same constant conditions to the PC steel wires, and provides the same tendon. An object of the present invention is to provide a long PC steel wire cutting device that can keep the relative length error of a large number of long PC steel wires constituting the same within ±5 mm.

[Means to solve the problem]

The technical means of the present invention to solve the above problems is to provide a horizontal beam that can freely expand and contract according to temperature changes and has a cross section much larger than that of PC steel wire, so as to eliminate the influence of environmental temperature changes. A fixed point is set on this horizontal beam, and a fixed point is set between the fixed points of the horizontal beam.
Attach a PC steel wire to the same temperature, apply a certain tensile force to the PC steel wire in that state, standardize the temperature elongation and stress elongation, and cut the long PC steel wire into ultra-precise length dimensions. The device specifically has the following configuration.

(1) On this horizontal beam, one end of which is fixed to a fixed frame and stretched horizontally so as to be able to thermally expand and contract toward the other end, there is a continuous horizontal steel beam of approximately 200 m for mounting a prestressed steel wire. Equipped with a beam. It is preferable to include a guide plate to guide the PC steel wire.

(2) A long piece parallel to the longitudinal center line of the horizontal beam.
A feeding device is provided for feeding the PC steel wire onto the horizontal steel wire beam.

(3) Equipped with a stopper device that forms a fixed point to position the tip of the PC steel wire. This device is constructed so that it can be fixed to a desired position on the free end side of the horizontal beam.

(4) A clamp device is provided to fix the tip of the long PC steel wire aligned with the fixed point.

(5) A deviation detection device is provided to detect a deviation between the tip position of the clamped PC steel wire and a fixed point formed by the stopper. This deviation detection device may be, for example, a rotary encoder device.

(6) Equipped with a tensioning device that pulls the rear end of the long PC steel wire, whose tip is temporarily fixed, with a constant tension.

(7) Installed near the fixed end of the horizontal beam, and cutting a long length at a fixed cutting point set on the horizontal beam by increasing or decreasing the deviation of the tip position from the fixed point.
Equipped with a cutting device to cut PC steel wire.

(8) Note that it is preferable to include a controller that sequentially controls the operation of each of the above devices.

[Effect]

A continuous long horizontal steel beam made of a steel material with a much larger cross section than a PC steel wire expands and contracts depending on the environmental temperature. A long PC steel wire is placed on the horizontal beam to maintain the same temperature.
By comparing the long length dimensions based on two fixed points determined according to the design on the horizontal beam, the influence of expansion and contraction due to changes in environmental temperature when cutting each PC steel wire in the same tendon can be excluded. You can erase and adjust the length.

In addition, the holding and stretching state of the long PC steel wire is determined by feeding the PC steel wire under certain conditions on a certain horizontal beam.
After accurately positioning the tip of the PC steel wire, it is temporarily fixed, and the rear end of the PC steel wire is pulled with a constant tensile force, so that all the PC steel wires are maintained at a constant tensile condition.

Therefore, the length 100 that constitutes the same tendon
A large number of long PC steel wires of ~200 m can be temperature-corrected so that the relative length error is within ±5 mm, and can be cut reliably to the tensile-corrected ultra-precise length dimension.

〔Example〕

FIG. 1 shows the overall configuration of the device of the present invention, a, b
are respectively plan views, and c and d are side views, respectively.

The long PC steel wire 10 is fed from the left side in the figure, and is transferred to the horizontal beam 30 by the feeding device 20.
It is fed from above towards the right.

A stopper device 40 is fixed at a position of a predetermined length corresponding to the cutting length of the PC steel wire on the horizontal beam.

A tensioning device 50 that applies a constant tensile force to the feeding end of the PC steel wire and a PC steel wire cutting device 60 are provided. A controller (not shown) controls the feeding device 20, the stopper device 40, the tensioning device 50, and the cutting device 60.

The feeding device 20 includes a large number of pinch rollers 21 whose outer diameters are lined with rubber, etc., a cylinder 22 that presses the pinch rollers against the PC steel wire 10 with a constant compressive force, and a gear device for rotating the pinch rollers. 23, a motor 24 for driving this, a power transmission device 25, a speed reducer 26, etc., and the pinch roller 21 rotates while sandwiching the PC steel wire 10 from above and below, and applies a constant feeding thrust to the PC steel wire 10. and feed it onto the horizontal beam 30. The pinch roller 21 holds the PC steel wire 10 on the horizontal beam 30 on which the PC steel wire is placed.
It is designed to provide a propulsive force that can be slid over a predetermined length (100-200 m). The drive motor 24 is configured to be able to reduce the feeding speed of the PC steel wire to an extremely slow speed immediately before the feeding of the PC steel wire is stopped so that the PC steel wire can be stopped at a fixed position. This operation is controlled by an inverter. The horizontal beam 30 on which the PC steel wire is placed has one end fixed to the frame 11 at the PC steel wire feeding end, the other end as a free end, and the middle part thereof slidably supported on a number of frames 32. It is made of a long steel beam, for example, H steel 31. This steel horizontal beam 30 is made of a single continuous steel material with a required length of, for example, about 200 m, and slides on a pedestal 32, allowing it to expand and contract in response to temperature changes. The horizontal beam is made of a material whose coefficient of thermal expansion matches that of the PC steel wire, and has a much larger cross section than the PC steel wire.

Figure 2 shows a cross section of a horizontal steel beam. A PC steel wire guide hardware 33, such as a channel steel, is placed on the H steel 31 with its groove facing down, and guides the PC steel wire to be fed. This guide hardware 33 is laterally shifted on the H steel 31 by a shifter 35,
It also serves as a device for dispensing cut PC steel wire in the horizontal direction of the mounting beam. The paid-out PC steel wire is placed on the frame 70.
When the required number of data are collected, they are sent to another processing line and formed into tendons.

The stopper device 40 fixes the stopper frame 44 at a predetermined position on the free extension end side of the horizontal beam in accordance with the length of the PC steel wire determined according to the design of the PC tendon. Stopper device 40
These are a stopper hardware 41 against which the tip of the supplied PC steel wire comes into contact, a cylinder 42 that moves it horizontally and laterally, a clamp part 48 that fixes the vicinity of the tip of the PC steel wire, and the fixed PC steel wire. A measuring end 44a that measures the tip position of the line, and this measuring end 44a
It consists of a cylinder 45 that moves the motor forward and backward, and an encoder 47 that detects the amount of movement and compares it with a fixed point.

The stopper device 40 aligns and holds the tip of the PC steel wire with a fixed point on the loading line, and precisely measures the inevitable deviation between the fixed point and the tip of the PC steel wire.

Further, a detection device including a photoelectric device 36 and the like is provided to detect the proximity of the PC steel wire to the stopper device 40. Upon this detection, the speed of the aforementioned feeding device is reduced, and the PC steel wire is brought into contact with the stopper device slowly and quietly.

The tension device 50 is a clamp part 4 of the stopper device.
8 is a device that applies a constant tensile force to the PC steel wire 10 after fixing the PC steel wire.

This device includes a clamp 51 for clamping a PC steel wire on a clamp table consisting of a movable cart 53 mounted on a frame 11, and a cylinder 52 for crimping the clamp 51 to the PC steel wire. Movable trolley 53
move on a rail 58, and are connected to weights 55a and 55b that urge it to move in the backward direction. The weights 55a and 55b have a certain difference in weight, and the fixed force of that difference moves the movable trolley 53 to the PC steel wire 10.
Normally, a cylinder 57 supports this weight via a crank 56.

The PC steel wire cutting device 60 includes a parallel cutter 61, a cylinder 64 for moving the parallel cutter 61 forward and backward in the longitudinal direction of the PC steel wire, and an encoder 6 for measuring its forward and backward positions.
It consists of 3.

The encoder 63 receives a signal from the encoder 47 of the stopper device, that is, a signal indicating the difference between the tip of the PC steel wire and the fixed point, determines which device should cut the PC steel wire to the fixed point size, and issues a command to the cylinder 64. The cutter position is moved by applying a force to the cutter, the moved position is measured and confirmed, and cutting is performed using the cutter.

By this operation, the difference between fixed points on the loading line and the length of the PC steel wire can be kept within 1 mm.

The operation of the device of the invention is as follows.

The PC steel wire 10 is supplied from the left side in FIG. 1, and the feeding device 20 feeds it over the PC steel wire horizontal beam 30 toward the right side in FIG.

When the tip of the PC steel wire 10 passes the photoelectric device 36, the feeding device 20 reduces the feeding speed so that the PC steel wire 10
is controlled so that the tip thereof gently contacts the stopper metal fitting 41.

When the stopper hardware 41 detects contact with the tip of the PC steel wire, the feeding device 20 stops and the clamp part 48 closes.
Clamp the tip of the PC steel wire. The cylinder 42 then moves the stopper hardware 41 horizontally and laterally. After the clamp part 48 clamps the tip of the PC steel wire 10, the clamp 51 of the tensioning device 50
Clamp the rear part of the PC steel wire. At this time, the clamp truck 53 is located at the right end on the rail 58 in FIG. 1, and the cylinder 57 supports the weight 55a via the clamp 56. Clamp 51 is PC steel wire 1
After clamping the cylinder 57, the weight 55a
When the support is released, the clamp cart 53 is pulled to the left in the figure by a force equal to the difference in gravity between the weights 55a and 55b, and a constant tensile force is applied to the PC steel wire 10.

On the other hand, the cylinder 45 of the stopper device 40 is
Move the measurement end 44a forward to the tip of the steel wire 10, and
Measure the tip of the steel wire.

The encoder 47 transmits this measurement value to the encoder 63 of the cutting device 60, and the encoder 63
Move the parallel cutter 61 to the position of the predetermined cutting length of the PC steel wire 10, confirm the position, and
Cut the PC steel wire.

Next, the measurement end 44a is moved back and the clamp part 48
releases the clamp, and the shifter 55 moves to the guide hardware 3.
3 to move the PC steel wire onto the frame 70.

After the guide hardware 33 and the stopper hardware 41 return to their original positions and the clamp 51 is released, the feeding device 20 feeds the PC steel wire again, and the above operations are repeated.

The above operations are sequence-controlled by a control device (not shown).

〔Effect of the invention〕

Since the device of the present invention is configured as described above, it is possible to cut the PC steel wire for PC tendons within ±1 mm with respect to the length between fixed points on the loading line, and to cut the PC steel wire for the same tendons. Even if there are environmental temperature changes during long cutting operations, these
It is possible to reliably cut the PC steel wire within a relative length error of ±5 mm, and the stress distribution within the tendon can be strictly equalized, making it possible to cut prestressed wires that require extremely high safety, such as nuclear reactor domes. It has become possible to completely ensure the reliability of concrete structures.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIGS. 1a and 1b are plan views of both ends of the device, c and d are side views thereof, and FIG. 2 is a cross-sectional view of the intermediate portion of the device. 10...PC steel wire, 11...frame, 20...
... Feeding device, 21 ... Pinch roller, 22 ... Cylinder, 30 ... Horizontal beam, 31 ... H steel, 3
3... Guide hardware, 35... Shifter, 36... Photoelectric device, 40... Stopper device, 41... Stopper hardware, 42... Cylinder, 47... Encoder, 48... Clamp section, 50... Tension device ,5
1... Clamp, 52... Cylinder, 53... Dolly, 55a, 55b... Weight, 56... Crank, 60... Cutting device, 61... Parallel cutter, 63... Encoder, 64... Cylinder.

Claims (1)

[Scope of Claims] 1. A device that eliminates the influence of environmental temperature changes and applies a constant tensile force to cut a long PC steel wire into ultra-precise length dimensions, with one end fixed and the other end free. A continuous long horizontal steel beam with one end and a continuous long steel horizontal beam that freely expands and contracts toward the other end as the environmental temperature changes, and a long PC steel wire is fed parallel to the longitudinal center line of the beam onto the horizontal beam. A stopper device which can be fixed at a desired position on the free end side of the horizontal beam and forms a fixed point for positioning the tip of the PC steel wire; a clamp device that temporarily fixes a PC steel wire that is fixed to a set beam and has its tip aligned with the fixed point; a deviation detection device that detects a deviation of the tip of the clamped PC steel wire from the fixed point; The rear end of the long PC steel wire, which is temporarily fixed,
a tension device that tensions with a constant tensile force; and a tensioning device installed near the fixed end of the horizontal beam, the long length being set at a cutting point set on the horizontal beam at a cutting position that increases or decreases the deviation of the tip position from the fixed point.
A cutting device for cutting a PC steel wire; and an ultra-precision length cutting device for a long PC steel wire.