JPS59141338A - Construction of fixing part for pc steel stranded wire or the like - Google Patents

Abstract

PURPOSE:To reduce the size in a fixing part and to obtain the necessary strength in the fixing part by forming the outside circumferential surface of a fixing fitting press fixed to the bulging head part of a PC steel stranded wire in contact therewith and the inside circumferential surface of the fitting hole of a supporting plate fixing the fixing fitting into tapered shapes conforming to each other. CONSTITUTION:A bulging head part 2 is formed by heading at the terminal of a PC steel stranded wire 1. A compression sleeve 3 (fixing fitting) is press fixed via a triangular wire coil 6 which is a friction increasing material to the PC stranded wire near the part 2. The part 2 and the sleeve 3 are housed and fixed in the fitting hole 5 of a supporting plate 4. The tapers on the inside circumferential surface 5a of the hole 5 and the outside circumferential surface 3a of the sleeve 3 are formed to conform to each other so that the hole and the sleeve 3 are fixed by the same. The length of the sleeve 3 is thus made about 1/3- 1/4 of the length in the prior art.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anchoring part structure of PC steel wires suitable for pre-stressed concrete members of factory raw materials in which the anchorage is buried.

Conventionally, for factory-produced prestressed concrete members, such as centrifugal compaction pretensioned PC piles, which are buried without repeated use of fixing devices and used for one cycle, copper wire or steel rods are used as PC steel materials, and the ends of the Warm part (1
00-500°C), subthermal (500-800°C) -
Alternatively, by performing cold heading processing, a bulging portion that becomes a fixing portion that can be buried and used was formed. However, as the strength of the above-mentioned piles, etc. increases, PC steel materials are also required to have a larger diameter and higher strength.
There is a limit to increasing the diameter and strength of C steel wire, and P, C
There is also a limit to how high the strength of steel rods can be increased. On the other hand, PCqi
Wires can be easily made thicker and stronger than ll,
There is a demand for wires made from 1°C steel to be used in the above-mentioned piles because of their excellent economic efficiency, but there are the following problems in this case.

That is, as shown in Fig. 1, the conventional fixing means for general PC steel wires is to attach a fixing fitting such as a chuck or compression sleeve 16 directly to the end of the PC steel wire 1 or by attaching an abrasive material to the end of the wire. 16, and is fixed to the bearing pressure plate 14 using this metal fitting, but this makes the size of the fixing metal large and expensive, making it unsuitable for use in a buried state. In addition, attempts have been made to apply the above-mentioned hesoding fixing method to PC steel stranded wire, but
In this case, the strength of the bulging head was insufficient at 40 to 60% of the breaking strength of the PC steel crimp wire, and for this reason it had not been put into practical use.

In addition, as shown in FIG. 2, in the earlier application, Japanese Patent Application No. 56-210635, a bulging head 22 is provided at the end of the PC'A stranded wire 1 by heading processing, and a portion near the end of the PC steel stranded wire is provided. For example, a sleeve with a constant outer diameter along its entire length (
The fixing fitting) 26 is crimped through the friction material 26, and the sleeve 26 and the bulging head 22 share the entire fixing part strength corresponding to the breaking strength, so that the length of the fixing fitting can be shortened. However, in the case of using this method, if the bearing plate 24' is simply made of PC steel and has a flat plate shape with a tapered insertion hole 27, the sleeve 26 and the bulging portion 22 protrude outward from the bearing pressure plate 24'. To avoid this, all the recessed holes 28 are provided in the bearing pressure plate 24 as shown by solid lines in the same figure, and the recessed holes 28 (with the sleeve 26 If the structure is such that the bulging head 22 is inserted, there is a problem that the thickness T' of the bearing plate 24 must be considerably increased and the thickness T'' must be increased.

In view of these four concerns, the present invention has been developed to provide sufficient anchoring strength to match the breaking strength of PC steel stranded wire, and to significantly reduce the structure of the anchoring portion including the bearing plate. The present invention provides a constant temperature section structure for PC steel stranded wires, which is highly economical and suitable for burial use.

That is, the present invention provides a bulging head formed by heading at the end of the wire from PC steel, and the
[L is crimped near the end of the wire and the side end is on top 1.12
The swollen head V (close fixing metal fittings and the fixing metal fittings 1υ (
and a bearing pressure plate provided with a fitting hole to match,
The outer circumferential surface of the metal fitting and the inner circumferential surface of the fitting hole of the bearing pressure plate are formed into corresponding tapered shapes.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 8136 shows a specific example of the anchoring part structure of the present invention, in which 1 is a PC steel stranded wire, 2 is a bulged head formed at the end of the P'C steel stranded wire 1 by heading processing,
6 is a PC steel stranded wire IK crimped co/french 3-7-f9. The outer peripheral surface 6a of the combination sleeve 6 is formed in a tapered shape such that the end of the P wire 1 has a larger diameter and the other end has a smaller diameter than the PC steel. The length of the compression sleeve B, the end of which is in close contact with the bulging head 2, is determined based on the experimental data described below, and the structure is fixed with only a conventional sleeve (the structure shown in Figure 1). It is said to be 1/4 to 1/6 of the pleasure of being a woman.

Reference numeral 4 denotes a pressure bearing plate, and a fitting hole 5 into which a combination sleeve 6 is fitted is formed in the bearing pressure plates 4 and 4, and the inner circumference 1Ji15a of the fitting hole 5 is It is formed into a tapered shape corresponding to the outer circumferential surface groove a of the Hyakunosu leaf O.Then, the combination hole 7 sleeve 6 and the bulging portion 2ζ+S2 are housed in the fitting hole 5.
C%l,・I) With the stranded wire 1 led out from the small diameter side opening of the fitting hole 5, the bearing plate 4 is fixed 7 and P
By applying tension to the wire 1 from the C steel, the outer circumferential surface a of the compression sleeve B is compressed against the inner circumferential surface 5a of the mating hole 5.

Real hi! In one example, a steel wire coil 6 with a triangular cross-section is interposed between the inner circumferential surface of the combination sleeve B and the C steel stranded wire 1. 'j'61S]':"An example of a method for obtaining a θ structure, all shown in FIG. - As shown, the PC steel stranded wire 1 has already been inserted through the fitting hole 5V of the bearing plate 4.The end i'it+2' of this PC steel stranded wire 1 has an extra length (PC steel Stranded wire diameter 1.5~2 (iW Changqi,)
With the money in place, attach a triangular wire coil 6 as a friction material to the outer periphery of the PC steel gland 1. I White j: Deploy the taper sleeve 6' that forms the combination sleeve 3, and use a hydraulic press etc. to cut the tapered sleeve 76' with the arrow A.
Crimp wire 1 from base C. 1 In this case, if the entire outer circumferential surface of the sleeve B described in -H is made into a tapered shape, then P C%ji
When pressure is applied to line 1 from aj, a component force in the direction shown by the two-dot chain arrow will work, and there is a risk that the three-flow' or P CQiii will slip out of line 1. - Dog diameter of the outer periphery of the pro' (partially parallel part 3'b is provided at the 1111 end and the other part is tapered jfri 5
'a' is preferable.

After completing this crimping work, the heading die 8 of the heading machine is operated as shown by the arrow to head the end of the PCIA stranded wire 1, thereby forming the bulged head 2. Heading processing in this case may be carried out by the usual cold hesodinog method, but in the case of high-strength PC steel strands, it is done at a temperature of 200°C to 600'C at a temperature of 200°C to 600'C, at a temperature of 600'C to 900°C. It is also possible in the hot state. In particular, according to experimental results, 600°C ~ 900 ”
The shape of the bulged head 2 which was heso-dinda-processed in the hot process of C was good, and the strength as shown in the actual jW data described later was obtained.

In this way, the bulging head 2 and the compression sleeve 6 are integrated and formed, and then this part is fitted into the fitting hole 5 of the bearing pressure plate 4, as shown in FIG. An anchor structure is obtained.

In addition, the friction increasing material is not limited to triangular wire coil O.
Use an appropriate friction increasing material such as carboran cum, or P
The inner body of the wire 1 may be slightly threaded from C steel to increase the thickness.

In this fixing section structure, the load applied to the fixing section due to the tensile force of the wire 1 from the PC steel is shared between the bulging head 2 and the combination sleeve 6.
It will be ird. Moreover, compression three
'Since the fitting hole 5 of the support plate 4 fits into the fitting hole 5 of the pressure plate 4 at the corresponding tapered curve 6y5a, the tension U,
) + (f A clamping force is added to the wire 1 from the PC steel by the wedge action, increasing the constant strength.Here, the taper angle of the above-mentioned both surfaces 3a and 5a is 5'O~ as a result of the experiment. 15
If the taper angle becomes small, the compression sleeve 6 will be pulled out from the bearing plate 4, and if the taper angle becomes large, then the tightening force against the wire 1 will be sufficient? 4') I can't do it.

Thus, the length of the compression sleeve 6 required for VC in order to obtain the breaking strength of the line 1 from P C, /): jl shown in Figure 2.
, l, li, structure, it is shortened by the amount of tightening force added by the wedge action. In addition, the compression sleeve 6 and the bulging head 2 are accommodated within the pressure plate 4, resulting in a structure suitable for burial, and the thickness Tf of the pressure plate 4 is made thinner than that of the structure shown by the solid line in FIG. be able to. Furthermore, in the structure shown in FIG. 2, since it is necessary to provide a certain amount of pressure receiving area on one end surface of the sleeve 26, the wall thickness of the sleeve 26 is also increased, but according to the present invention, the outer circumferential tapered surface 6a of the compression sleeve 5 Since this serves as a pressure receiving surface, the wall thickness can be made thin, and it is preferable that the wall thickness be relatively thin in order to provide a tightening force due to a wedge action. Therefore, the entire fixing portion can be made smaller, and the fitting hole 5 can also be made smaller, so that a decrease in the strength of the bearing crusher 4 can be prevented.

Next, we will show some experimental data to confirm the effects of the present invention.

The following are the experimental results of examining the size of the fixing section to obtain the necessary fixing section strength for the conventional structure shown in Fig. 1 and the structure of the embodiment of the present invention shown in Fig. 6. It is shown in the table below.

In this experiment (d:, ]?C steel stranded wire with a diameter of 9-3 mrn and when a diameter of 12.7 am was used, the length of the anchoring part that satisfied the standard strength was obtained.'' , L', combresolution v-fu diameter D+D',
This is the result of an investigation into the following: Book 1] Light Structure - Compresin Sleeve Length - J 11. The length of the fixing portion means the length Ll of the sleeve in the conventional structure 1/(2), and the length L including the bulging head 2 and the combreso sleeve 6 in the structure of the present invention.

As is clear from this result, in the conventional structure shown in FIG.
? Unlike C steel, there is a sleeve length Ll that is about 6 to 4 times the wire outer diameter, but according to the structure of the present invention, the sleeve length Ll is pc
It is shortened to 1 to 1.5 times the outer diameter of the steel pre-wire, and the length L of the fixing part, which is the sum of the entire bulging head 2, is also smaller than PC steel to about twice the outer diameter of the wire.

In addition, using PC steel stranded wire with a diameter of 9.3 mm,
) Based on 3536-I 971, the tensile load of the PC steel stranded wire is set to a standard value f of 9050 Kg or more, and there are two cases: one where only a bulging head is formed at the end of the wire from the PC steel, and the other where the conventional structure shown in Fig. 2 is used. The fixing efficiency (ratio of the strength of the fixing part to the above standard value) was investigated for each case according to the structure of the present invention shown in No. 61-1. However, in the case of the structure of the present invention, the 9.3 mm shown in Table 1
The sleeve length was set to be the same (10+++i+) in the case of the conventional structure shown in FIG. 2 as in the case of the structure of the present invention. As a result, the fixing efficiency was about 60% in the case of only the bulging head, about 85% in the case of the conventional structure shown in FIG. 2, and about 105% in the case of the structure of the present invention. Therefore, according to the structure of the present invention, the fixing efficiency is greatly improved compared to the structure shown in FIG. Also, from this result, in the structure of the present invention, the share of fixing efficiency is approximately 60% due to the bulging head 2, approximately 25% of the initial fixing force due to the compression sleeve filter and the friction increaser 6, and +lYl due to the wedge action. It can be seen that 'fi' is the increase in the applied force or the increase in the fishing force.

As described above, according to the anchoring part structure of the present invention, the terminal bulging head of the ``°C steel wire'' and the combreso 7 consline (
The fixing force is shared between the fixing metal fittings), and the fixing force is shared between the
#11t due to wedge action during tension of line force ゛4 from 111tsuka
The fixing force is increased by applying the force.

Therefore, the length of the fixing section to obtain the necessary fixing strength can be significantly shortened compared to the conventional method, and a structure in which the constant slide portion can be accommodated in the bearing pressure plate can be obtained. It is suitable for killing purposes, and the thickness of the bearing plate and the compression sleeve can be made small, making it possible to significantly reduce the size of the entire unit, and improving economical efficiency.

[Brief explanation of the drawing]

211 is a sectional view showing an example of the conventional structure, FIG.
4 is a cross-sectional view showing a method of manufacturing this structure. 1 PC steel stranded wire, 2...Bulging head, 6 Co/Plenon Yo/Sleeve (fixed fitting), 6a Tapered outer peripheral surface, 4... Bearing plate, 5... Fitting hole, 5a Tapered shape The inner peripheral surface of the fitting hole. Applicant: Shinko Wire Industry Co., Ltd. No. 1
Figure 2

Claims (1)

[Claims] 1. A bulging head formed by heading at the end of the wire made of PC steel, a fixing metal fitting that is crimped near the end of the wire made of the PC steel and whose side ends are in close contact with the bulged head, and the fixing metal fitting. and a bearing pressure plate provided with a fitting hole into which the bearing plate is fitted, and is formed into a tapered shape that corresponds to the outer peripheral surface of the fitting and the inner peripheral surface of the fitting hole of the bearing pressure plate. C%
Fixed part structure of wire A from %j.