JPH0545680Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lock bolt used for supporting earth.

[Prior Art] Conventionally, the concept of self-boring and supporting the ground using hollow rock bolts is well known, but known rock bolts use deformed reinforcing bars as shown in Fig. 7.
Ribs a are provided in two rows symmetrically with respect to the diameter, approximately half the circumference, and V-threads are machined at both ends of the lock bolt. Therefore, in order to change the length to a desired length, it is necessary to cut, turn, and thread the ends, which poses a disadvantage in terms of work at the construction site. Furthermore, even after the hole is hardened with grout, there are no ribs around the entire circumference, which is disadvantageous for pull-out resistance, and the diameter of the hole is relatively large, so there is a large amount of grout on the outer periphery of the lock bolt after drilling. It was necessary to fill it with grout.

[Problems to be solved by the invention] The problems of the invention are that the diameter of the perforation is small and that it can be used by simply cutting it to any required length;
On the other hand, it is an object of the present invention to provide a lock bolt which can be easily added and embedded to a required length, and furthermore, can be easily and reliably filled with grout and has good work efficiency.

[Means to solve the problem] The means of the present invention are as follows.

A screw with a grout, high-pressure air, or high-pressure water injection hole penetrated through the center, and a rib with an arcuate curved groove formed on the surface over the entire length of the outer periphery, and the width of the spiral groove part of the screw is the same as the rib. width of 2 to 4
A hollow bolt body with a rib width approximately equal to the depth of the helical groove portion and a helical angle of the ribs of 6° to 10°, and a discharge port that is screwed into the tip and communicates with the injection hole. A rock bolt for shoring consisting of a drill head and a nut screwed into the end of the hollow bolt body.

[Operation] The proximal end of the hollow bolt body is fixed to a rotating body, and the drill head is used to drill a hole while rotating the body, and then the next hollow bolt body is connected with a coupling nut to continue drilling. In this case, high-pressure air or high-pressure water is injected through the injection hole of the hollow rock bolt to clean the rock powder or dirt generated by drilling and to cool the drill head. Then, place the restraining plate against the end of the hollow bolt body at a predetermined position, fix it with a nut, and inject grout from the mouth of the injection hole in the hollow bolt body. The grout is injected from the injection hole, through the communication port of the drill head, to the outer periphery of the bolt, and along the helical groove of the screw having ribs. After a predetermined period of time after filling with grout, the nut is tightened again to apply tension to the lock bolt body. Rotating the bolt after it is filled with grout is effective in making it firmly embedded in the grout and able to withstand large loads.

[Example] In the illustrated example, 1 is a hollow bolt body that penetrates grout, high pressure air, or high pressure water injection hole 2,
A spiral groove 3' is formed over the entire length of the outer periphery, forming a screw 3 with a rib 12 with a curved groove 12' formed on the surface, and the width of the spiral groove 3' of the screw 3 is equal to the width of the rib 12.
2 to 4 times the width of the rib 12, the width of the rib 12 is approximately equal to the depth of the spiral groove 3', and the helical angle of the rib is 6° to 10°.
It is. The hollow bolt body can be connected with a coupling nut 4. 4' is a stopper in the middle of the coupling nut.

A drill head 5 is screwed into the tip of the hollow bolt body 1. The drill head 5 has a communication hole 6 communicating with the injection hole 2 and a discharge port 7, and has six spherical boring tips 8 protruding from the tip surface. After drilling a predetermined length, grout is injected into the formed hole 9 from the injection hole 2 of the bolt body, and is sent to the hole 9 around the bolt body 1 through the communication hole 6 and the discharge port 7 to fill the hole. 10 is a restraining plate attached to the end of the hollow bolt body 1, and 11 is a nut.

[Effects of the invention] According to the invention, a thread having ribs uniformly over the entire length of the locking bolt is formed, so if a short locking bolt is required, it can be simply cut to the required length. , no other processing is required. In addition, by using a coupling nut, it is possible to add a thread without cutting the thread, making it easy to embed even a long excavation length. Furthermore, since the drilling head is attached to the tip, rock powder or dirt powder generated during the drilling process is carried away by the ribs of the screw, but the frictional resistance is small, reducing the power consumption required for drilling. This allows the excavated and battered rock to be smoothly transported with less power consumption.

These effects are achieved by the dimensional ratio between the rib and the groove of the thread with ribs selected at a helical angle of 6° to 8°, which shortens screw-in time and allows rapid adjustment, and reduces grouting. Even when two lock bolts are connected by a coupling nut, substances can pass from one lock bolt to the other through the groove, and the stability of conveyance by this rib depends on the depth of the thread of the rib. It is maintained by being smaller than the height.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view showing one embodiment of the rock bolt for shoring according to the present invention, Fig. 2 is a perspective view of the drill head attached to the tip, Fig. 3 is a sectional view of the coupling nut, and Fig. 4 is the main body. FIG. 5 is a longitudinal sectional side view showing the state of use of the invented lock bolt, FIG. 5 is a longitudinal sectional front view, FIG. 6 is an enlarged view of a part of the screw, and FIG. 1 is a side view, B is a plan view, and C is a sectional view taken along the line I-I' of FIG. 1...Hollow bolt body, 2...Injection hole, 3...
Left-hand thread, 3'... spiral groove, 5... drill head,
6... Communication hole, 7... Discharge port, 8... Boring tip, 11... Nut, 12... Rib, 12'
...curved groove.

Claims (1)

[Scope of utility model registration request] A screw with a grout, high-pressure air, or high-pressure water injection hole penetrated through the center, and a rib with an arcuate curved groove formed on the surface over the entire length of the outer periphery, and the width of the spiral groove part of the screw is the same as the rib. width of 2 to 4
A hollow bolt body with a rib width approximately equal to the depth of the helical groove portion and a helical angle of the ribs of 6° to 10°, and a discharge port that is screwed into the tip and communicates with the injection hole. A rock bolt for shoring consisting of a drill head and a nut screwed into the end of the hollow bolt body.