A hole enlarging drill bit

Abstract

The present invention discloses a hole-reaming drill bit. It comprises a hollow drill bit base connected to a drill rod, and at least three groups of open grooves are symmetrically arranged along the radial direction at the front end portion, and each open groove is provided with a movable cutting edge that moves radially along the drill bit base, and a push rod that can move axially along the drill bit base is arranged in the drill bit base; the top end surface of the push rod is a driving inclined surface that matches the pushing inclined surface of the rear end surface of the movable cutting edge to drive the movable cutting edge to move; the movable cutting edge is provided with a limiting protrusion that cooperates with the limiting groove arranged at the top of the push rod to limit the movement; the drill bit base is provided with a slide groove that limits the movement of the slide rod protrusion at the corresponding position on the movable cutting edge. The present invention performs hole-reaming drilling through a movable cutting edge with a variable diameter, and the drill bit comprises a drill bit base, a movable cutting edge and a push rod, and has a compact structure. Through the action of the push rod, the movable cutting edge is pushed outward, so as to achieve the effect of expanding the cutting area of ​​the drill bit; an enlarged grouting space is formed at the end of the drilling, and the pull-out resistance of the anchor system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of well drilling and exploratory engineering equipment design, in particular to the technical field of drill bit design in well drilling and exploratory engineering equipment, and particularly relates to a design technology of a hole enlarging drill bit used in civil engineering. Background Art

[0002] Anchor support is often required in slope support projects and tunnel excavation support projects. In broken and easily collapsed strata, drilling with pipes and inserting anchors are completed in the same process. After completion, grouting is injected and prestress is applied. The stability of the soil is enhanced by the implementation of anchors. At present, the anchoring effect is mainly formed by the friction between the anchor wall, slurry, and surrounding rock.

[0003] For some special stratum structures, the pull-out resistance of conventional drilling and anchor bolt structures cannot meet the needs, and a more stable and effective drilling drill bit, anchor bolt structure and construction method with stronger pull-out resistance are needed. Summary of the invention

[0004] The present invention discloses a hole enlarging drill bit in view of the deficiencies of the prior art. The present invention provides a drill bit design structure required for an anchor rod system that enhances the anchoring effect of the anchor rod end and improves the overall pull-out resistance. The hole enlarging operation is performed at the bottom of the hole, and the drilling can be completed in one go without replacing the drill rod and the drill bit during the construction process.

[0005] The present invention is achieved through the following technical solutions:

[0006] A reaming drill bit includes a drill bit base connected to a drill rod, and is characterized in that: the drill bit base is a hollow cylindrical structure, at least three groups of open grooves are symmetrically arranged along the radial direction of the cylinder at the front end, each open groove is provided with a movable cutting edge that moves radially along the drill bit base, and a push rod that can move axially along the drill bit base is arranged in the drill bit base; the top end surface of the push rod is a driving inclined surface that matches the pushing inclined surface of the rear end surface of the movable cutting edge to drive the movable cutting edge to move.

[0007] A limiting block with a convex structure is arranged on the inner wall of the end of the pushing inclined surface of the movable cutting edge, and a limiting groove which cooperates with the limiting block to limit movement is arranged on the outer side of the driving inclined surface of the top end surface of the push rod.

[0008] The movable cutting edge, the push rod and the drill base are a detachable set structure.

[0009] The drill bit base has an inclined sliding groove, and a sliding rod protrusion at a corresponding position on the movable cutting edge acts as a limiter to limit movement in the sliding groove. After the push rod pushes the movable cutting edge to the working position, the limiter plays a role to prevent the movable cutting edge from sliding outwards during operation.

[0010] The present invention uses a movable cutting edge for variable diameter hole enlarging to perform hole enlarging drilling. The drill bit includes a drill bit base, a movable cutting edge and a push rod, and has a compact structure. The movable cutting edge is pushed outward by the push rod to achieve the effect of expanding the cutting area of ​​the drill bit; an expanded grouting space is formed at the end of the drilling hole, thereby improving the pull-out resistance of the anchor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the drill bit of the present invention in a non-blade state;

[0012] Figure 2 yes Figure 1 Schematic diagram of the middle AA section;

[0013] Figure 3 It is a structural schematic diagram of the drill bit of the present invention in the state of cutting edge;

[0014] Figure 4 yes Figure 3 Schematic diagram of the middle BB section;

[0015] Figure 5 It is a schematic diagram of the structure of the push rod of the present invention;

[0016] Figure 6 It is a schematic diagram of the structure of the end portion of the drill base of the present invention;

[0017] Figure 7 yes Figure 6 Schematic diagram of the CC section;

[0018] Figure 8 yes Figure 6 Schematic diagram of the middle DD section;

[0019] Fig. 9 It is a schematic diagram of the side view structure of the movable cutting edge of the present invention;

[0020] Fig.10 It is a schematic diagram of the top view structure of the movable cutting edge of the present invention.

[0021] In the figure, 1 is the drill base, 2 is the movable cutting edge, 3 is the push rod, 21 is the cutting edge body, 22 is the pushing inclined surface, 23 is the limiting protrusion, 31 is the push rod body, 32 is the driving inclined surface, 33 is the limiting groove, 41 is the slide groove, and 42 is the slide rod protrusion. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific implementation methods. The specific implementation methods are further descriptions of the principles of the present invention and do not limit the present invention in any way. Technologies that are the same or similar to the present invention do not exceed the scope of protection of the present invention.

[0023] Combined with the attached pictures.

[0024] The reaming drill bit includes a drill base 1 connected to a drill rod, the drill base 1 is a hollow cylindrical structure, and at least three groups of open grooves are symmetrically arranged along the radial direction of the cylinder at the front end, and each open groove is provided with a movable cutting edge 2 that moves radially along the drill base 1. The drill base 1 is provided with a push rod 3 that can move axially along the drill base 1; the top end surface of the push rod 3 is a driving inclined surface 32 that matches the pushing inclined surface 22 on the rear end surface of the movable cutting edge 2 to drive the movable cutting edge 2 to move.

[0025] A limiting block 23 with a convex structure is arranged on the inner wall of the end of the pushing inclined surface 21 of the movable cutting edge 2, and a limiting groove 33 cooperating with the limiting block 23 for limiting movement is arranged on the outer side of the driving inclined surface 32 at the top end of the push rod 3.

[0026] The movable cutting edge 2, the push rod 3 and the drill base 1 are a detachable set structure.

[0027] The drill base 1 has an inclined slide groove 41, and a slide rod protrusion 42 is provided at a corresponding position on the movable cutting edge 2 as a limiter to limit movement in the slide groove 41. After the push rod 3 pushes the movable cutting edge 2 to the working position, the limiter works to prevent the movable cutting edge 2 from sliding outward during operation.

[0028] As shown in the figure, the drill base 1 is symmetrically provided with three grooves for mounting components, and it also has a cutting function. The movable cutting edge 2 is a movable metal component, which can expand the cutting area of ​​the drill under the drive of the push rod 3. A protrusion on the side wall of the movable cutting edge 2 serves as a limit convex block 23. The push rod 3 moves under pressure to push the movable cutting edge 2 outward, and stops pushing outward under the action of the limit convex block 23. The push rod 3 can be recovered after the construction is completed and reused.

[0029] like Figure 1 As shown, during the hole drilling process, the push rod 3 is in a retracted state, or the push rod 3 is not temporarily inserted into the drill pipe, the movable cutting edge 2 is in an initial state, and the drill bit system is in a general drilling state to perform hole drilling.

[0030] like Figure 2 As shown, when the hole expansion drilling is needed, the push rod 3 is installed and the work starts. The push rod 3 is a hollow metal rod, and the hollow part is the channel for drilling water. The push rod 3 is not fixed to the drill rod because the push rod 3 does not rotate; the push rod 3 is finally pushed to Figure 2 In the position shown, the movable cutting edge 2 has reached the hole reaming working position, and the limiting protrusion 23 on the movable cutting edge 2 serves as a limiter, cooperating with the limiting groove 33 provided on the push rod 3 to limit the falling of the push rod 3.

[0031] The drill bit installation and drilling steps of the present invention include:

[0032] Step 1: Install the movable cutting edge 2 on the drill base 1;

[0033] Step 2: The assembled drill bit is installed on a general drill rod;

[0034] Step 3, drilling;

[0035] Step 4: After drilling to the position where the hole needs to be expanded, install the push rod 3, and start pushing and expanding the hole under pressure;

[0036] Step 5: After the drilling is completed, the push rod 3 is taken out to perform grouting, hole sealing, stress application and other operations.

[0037] After the drilling is completed, a cavity with an enlarged bottom is formed, which becomes a strong anchoring end after grouting, enhancing the pull-out resistance of the anchor rod.

Claims

1. A reaming drill bit, comprising a drill bit base connected to a drill rod, characterized in that: The drill base is a hollow cylindrical structure, and at least three groups of open grooves are symmetrically arranged at the front end along the radial direction of the cylinder, and each open groove is provided with a movable cutting edge that moves radially along the drill base. The drill base is provided with a push rod that can move axially along the drill base; the top end surface of the push rod is a driving inclined surface that matches the pushing inclined surface of the rear end surface of the movable cutting edge to drive the movable cutting edge to move; A limiting block with a convex structure is arranged on the inner wall of the end of the push inclined surface of the movable cutting edge, and a limiting groove cooperating with the limiting block and limiting movement is arranged on the outer side of the driving inclined surface of the top end surface of the push rod; The drill base is provided with an inclined sliding groove, and a sliding rod protrusion is provided at a corresponding position on the movable cutting edge as a limiter to limit the movement in the sliding groove.

2. The reaming drill bit according to claim 1, characterized in that: The movable cutting edge, the push rod and the drill base are a detachable set structure.

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