Diameter expanding device for auger bit

Abstract

The utility model relates to a diameter expanding device for a spiral drill bit, and belongs to the technical field of building pile making tools. The expanding device structurally comprises an oil cylinder and an expanding body, the oil cylinder is of a hollow structure and located between a core pipe and an inner pipe of the spiral drill bit, and an oil cylinder body is fixed to the inner wall of the core pipe of the drill bit. The expanding body is positioned at the hole of the drill bit core tube and is hinged with the expanding body seat; the upper end of the expanding body far away from the hinge hole is connected with a piston rod of the oil cylinder through a link mechanism; two pistons and three chambers are arranged in a cylinder body of the oil cylinder; an annular table is arranged on the inner wall of the cylinder body and located in the middle cavity, and the inner diameter of the annular table is larger than the diameter of the upper rod body. According to the expanding device for the spiral bit, the hollow horizontal bar body double-stroke oil cylinder is adopted, the structure is compact and reasonable, the length of the spiral bit can be effectively shortened, and the manufacturing cost of the bit is reduced; a hollow hole of the oil cylinder facilitates installation of a concrete or slurry channel pipe of the spiral drill bit, and pouring smoothness during construction is guaranteed.

Description

Technical Field

[0001] The utility model relates to a diameter expanding device for a spiral drill bit, belonging to the technical field of building pile making tools. Background Art

[0002] In the construction of building pile foundation, the spiral expansion drill bit is a key component of the spiral drilling pressure-cast concrete different-diameter pile. The expansion device in the existing spiral expansion drill bit is mostly one expansion amount. The expanded diameter pile section formed after the expansion has the same outer diameter. The resulting pile shape is candied haws-shaped. The expanded diameter pile section has good end resistance and is an end-bearing pile. The pile section of the non-expanded part of the pile body still maintains the original column pile-soil friction resistance. This part of the friction resistance is relatively small, and the bearing potential of the soil around the pile is not brought into play, resulting in a waste of the bearing resources of the soil around the pile. In view of this situation, a spiral drill bit with two expansion amounts of expansion devices is proposed. The large expansion amount is used for the expansion construction of the pile section of the expanded diameter of the pile body, and the small expansion amount is used for the construction of the non-expanded diameter pile section of the pile body. The non-expanded diameter pile section of the pile body is constructed into a small outer diameter screw thread pile section, and the current column pile-soil friction resistance is changed into the shear stress of the soil around the screw thread pile section, releasing the bearing potential of the soil around the pile, and achieving a higher bearing capacity and more energy saving. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a diameter expansion device for a spiral drill bit. The diameter expansion device for the spiral drill bit adopts a hollow single-bar double-stroke oil cylinder with a compact and reasonable structure, which can effectively shorten the length of the spiral drill bit and reduce the manufacturing cost of the drill bit; the hollow hole of the oil cylinder is convenient for installing the concrete or slurry channel pipe of the spiral drill bit, ensuring the smoothness of the pouring during construction.

[0004] In order to solve the above problems, the specific technical scheme of the utility model is as follows: an expanding device for a spiral drill bit, comprising an oil cylinder and an expanding body; wherein the oil cylinder is a hollow structure and is located between the core tube and the inner tube of the spiral drill bit, and the oil cylinder body is fixed on the inner wall of the drill bit core tube; an opening is provided at a position corresponding to the drill bit core tube and the spiral blade, the expanding body is located at the opening, and the upper end of the expanding body is hinged to the expanding body seat at the upper end of the opening; the upper end of the expanding body is connected to the piston rod of the oil cylinder through a connecting rod mechanism away from the hinge hole; the oil cylinder is hollow and is located between the core tube and the inner tube of the spiral drill bit, and the oil cylinder body is fixed on the inner wall of the drill bit core tube; an opening is provided at a position corresponding to the core tube and the spiral blade, the expanding body is located at the opening, and the upper end of the expanding body is hinged to the expanding body seat at the upper end of the opening; the upper end of the expanding body is connected to the piston rod of the oil cylinder through a connecting rod mechanism away from the hinge hole; Two pistons and three chambers are arranged in the cylinder body of the cylinder, the two pistons are respectively an upper piston and a lower piston, the lower piston is respectively provided with an upper rod body and a lower rod body, a limit platform is arranged on the upper rod body, the upper sealing sleeve of the limit platform is connected to the inner cavity of the upper piston, an upper chamber is formed between the upper surface of the upper piston and the upper end surface of the cylinder body, a middle chamber is formed between the upper piston and the lower piston, and a lower chamber is formed between the lower piston and the lower end surface of the cylinder body; an annular platform is arranged on the inner wall of the cylinder body, the annular platform is located in the middle chamber, and the inner diameter of the annular platform is greater than the diameter of the upper rod body.

[0005] A connecting joint is provided at the bottom of the lower rod body. The connecting joint is an annular structure or a partial annular structure and is hinged to one end of a connecting plate on the circumference. The other end of the connecting plate is connected to the diameter-enlarging body.

[0006] The expanding body is composed of an expanding positioning body and an expanding cutting body. The expanding cutting body is vertically arranged and has an outward curved hook structure at the bottom. The outer surface is quenched or inlaid with cemented carbide. A positioning column is provided on the top of the expanding cutting body, and a hinged through hole connected to the expanding body seat is provided on the positioning column. The expanding positioning body is located at the upper end of the expanding cutting body and is connected to the vertical end face of the expanding cutting body by more than 90°. A hinged ear is provided at the outer end of the expanding positioning body, and the hinged ear is hinged to the connecting plate.

[0007] The diameter-expanding positioning body is in the shape of a ring, and its diameter is larger than the inner tube passing therein, and the hinged ear piece is located at an end away from the positioning column.

[0008] The diameter expansion positioning body is semicircular, and has two hinged ears, which are respectively located on the semicircular end faces of the diameter expansion positioning body; two connecting plates are symmetrically hinged on the connecting joint, and the two connecting plates are respectively connected to the hinged ears.

[0009] There is no diameter expansion positioning body on the top of the diameter expansion cutting body, and the hinged ear piece is directly arranged on the top of the diameter expansion cutting body.

[0010] The spiral drill bit expansion device of the present application adopts the above structure and has the following advantages:

[0011] 1. The cylinder of the diameter expansion device adopts a hollow single-bar double-stroke cylinder. Compared with two cylinders in series, it has a compact and reasonable structure, which can effectively shorten the length of the spiral drill bit and reduce the manufacturing cost of the drill bit; the hollow hole of the cylinder is convenient for installing the concrete or slurry channel pipe of the spiral drill bit, ensuring the smoothness of the pouring during construction.

[0012] 2. The oil cylinder is set in the annular cavity of the drill bit inner tube and the core tube, which has good airtightness. It neither affects the transmission of residual soil during construction drilling nor affects the construction pouring of pile materials, ensuring a good working environment for the oil cylinder and extending the service life of the oil cylinder.

[0013] 3. During construction, the maximum screwing out amount of the expander is used to complete the hole expansion of the expanded diameter section of the pile body, and the small screwing out amount of the expander is used to complete the formation of the small outer diameter thread groove of the non-expanded diameter section of the pile body. By expanding the diameter and pressurizing at the same time, a pile type is formed in which the pile body is composed of the expanded diameter section and the threaded section. The bearing capacity of the pile is improved, and the rich bearing potential of the soil around the pile is effectively utilized.

[0014] 4. For strata with negative friction around the pile, the expansion body is in a retracted state during construction to reasonably reduce the adverse effects of negative friction.

[0015] 5. The upper part of the expansion body is in the shape of a hollow ring or semi-circular ring, which is convenient for the inner tube of the drill to pass through and also increases the rotation torque of the expansion body.

[0016] 6. Two sets of expanding bodies can be set in the expanding device, which has high construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the expansion device in Example 1 (expanding body retracted state).

[0018] Figure 2 Schematic diagram of the expansion device of Example 1 (the expansion body is partially opened).

[0019] Figure 3 Schematic diagram of the expansion device in Example 1 (the expansion body is fully opened).

[0020] Figure 4 This is the state diagram of the cylinder at zero stroke.

[0021] Figure 5 This is the state diagram of the first stroke of the cylinder.

[0022] Figure 6 This is the state diagram of the cylinder's second stroke.

[0023] Figure 7 It is a front view of the expansion body of the first embodiment.

[0024] Figure 8 It is a top view of the enlarging body of the first embodiment.

[0025] Fig. 9 This is a schematic diagram of the diameter expansion device of Example 2 (the diameter expansion body is retracted).

[0026] Fig.10 It is a top view of the diameter-enlarging body of the second embodiment.

[0027] Fig.11 Schematic diagram of the diameter expansion device of Example 3 (the diameter expansion body is retracted).

[0028] Fig.12 It is a top view of the enlarged diameter body of the third embodiment.

[0029] Fig.13 This is a schematic diagram of the diameter expanding device in Example 3 in which the diameter expanding bodies are symmetrically arranged.

[0030] Fig.14 This is the application state diagram of the application structure. DETAILED DESCRIPTION Example

[0031] like Figures 1 to 6As shown, a diameter expansion device for a spiral drill bit includes a cylinder 100 and an expansion body 6; wherein the cylinder 100 is a hollow structure and is located between the core tube and the inner tube of the spiral drill bit, and the cylinder body is fixed on the inner wall of the drill bit core tube; an opening is provided at a position corresponding to the drill bit core tube and the spiral blade, the expansion body 6 is located at the opening, and the upper end of the expansion body 6 is hinged to the expansion body seat at the upper end of the opening; the upper end of the expansion body 6 is connected to the piston rod of the cylinder 100 through a connecting rod mechanism away from the hinge hole; two pistons and three chambers are provided in the cylinder body 105 of the cylinder 100, and the two pistons are an upper piston 102 and a lower piston 103, respectively. 103, the lower piston 103 is respectively provided with an upper rod body 101 and a lower rod body 104, a limit platform is provided on the upper rod body 101, the upper part of the limit platform is sealed and sleeved with the inner cavity of the upper piston 102, an upper chamber 201 is formed between the upper surface of the upper piston 102 and the upper end surface of the cylinder body 105, a middle chamber 202 is formed between the upper piston 102 and the lower piston 103, and a lower chamber 203 is formed between the lower piston 103 and the lower end surface of the cylinder body 105; an annular platform 106 is provided on the inner wall of the cylinder body 105, the annular platform 106 is located in the middle chamber 202, and the inner diameter of the annular platform 106 is greater than the diameter of the upper rod body 101.

[0032] like Figures 4 to 6 As shown, the working process of the oil cylinder 100 is as follows: the oil cylinder is provided with three oil inlet and outlet ports A, B, and C. When the pressure oil is supplied to the port A and communicated with the upper chamber 201, the upper piston 102 moves down to the upper end surface of the annular platform 106 of the cylinder body 105, and at the same time pushes the upper rod body 101 to move downward, so that the lower piston 103 and the lower rod body 104 move downward synchronously for the first stroke S1, and at the same time, the oil returns from the ports B and C. When the pressure oil is supplied to the port B of the oil cylinder 100 and communicated with the middle chamber 202, the upper piston 102 starts to move up, the lower piston 103 moves down, and drives the lower rod body 104 to continue to move downward to complete the second stroke S1+S2, and at the same time, the oil returns from the ports A and C. When the pressure oil supplied from port C is connected to the lower chamber 203, the lower piston 103 moves upward, synchronously driving the upper rod body 101 and the lower rod body 104 to move until the upper rod body 101 limit platform of the lower piston 103 contacts the lower end surface of the upper piston 102 to limit the oil cylinder to its zero stroke initial position reset, and at the same time, the oil returns from ports A and B.

[0033] A connecting joint 1 is provided at the bottom of the lower rod body 104 . The connecting joint 1 is an annular structure or a partial annular structure and is hinged to one end of a connecting plate 3 on the circumference. The other end of the connecting plate 3 is connected to the enlarged body 6 .

[0034] like Figure 7 and Figure 8As shown, the enlarged body 6 is composed of an enlarged positioning body 6-1 and an enlarged cutting body 6-2. The enlarged cutting body 6-2 is vertically arranged and has an outwardly curved hook structure at the bottom, and the outer surface is quenched or inlaid with hard alloy. A positioning column 6-3 is arranged on the top of the enlarged cutting body 6-2, and a hinged through hole 6-4 connected to the enlarged body seat is arranged on the positioning column 6-3. The enlarged positioning body 6-1 is located at the upper end of the enlarged cutting body 6-2, and has a diameter greater than the annular shape of the inner tube passing inside, and a hinged ear piece 6-5 is located at the end away from the positioning column 6-3. The enlarged positioning body 6-1 is connected to the vertical end face of the enlarged cutting body 6-2 by more than 90 degrees, and a hinged ear piece 6-5 is arranged at the outer end of the enlarged positioning body 6-1, and the hinged ear piece 6-5 is hinged to the connecting plate 3.

[0035] like Figures 1 to 3 As shown, the expansion process of the expansion body 6 is as follows: when the oil cylinder 100 is in the zero stroke state, the outer edge of the expansion cutting body 6-2 is on or within the maximum outer edge circumference of the spiral blade of the drill bit. When the oil cylinder 100 is in the first stroke, under the lever force of the connecting plate 3, the expansion body 6 rotates, and the expansion cutting body 6-2 is screwed out by an amount Q1. When the oil cylinder 100 is in the second stroke, the expansion body 6 continues to rotate, and the expansion cutting body 6-2 is screwed out by an amount Q2. Thus, by controlling the piston rod stroke of the oil cylinder 100, the extension amount of the expansion cutting body 6-2 is controlled. Example

[0036] like Fig. 9 and Fig.10 As shown, the enlarged diameter positioning body 6-1 of this embodiment is semicircular, and the number of hinged ears 6-5 is two, and they are respectively located on the semicircular end surface of the enlarged diameter positioning body 6-1; two connecting plates 3 are symmetrically hinged on the connecting joint 1, and the two connecting plates 3 are respectively connected to the hinged ears 6-5. The rest of the structure is the same as that of the first embodiment. Example

[0037] like Fig.11 and 12 As shown, in this embodiment, there is no expansion positioning body 6-1 on the top of the expansion cutting body 6-2, and the hinged ear piece 6-5 is directly arranged on the top of the expansion cutting body 6-2. Since this structure saves space, one expansion body 6 can be arranged on each side, such as Fig.13 The rest of the structure is the same as that of the first embodiment.

[0038] In summary, the spiral drill bit expansion device of the above embodiment is applied to the pile drilling tool, and plays the role of extending the expansion body 6 to complete the expansion when the diameter of a certain part of the pile body is increased according to actual needs, such as Fig.14 The expansion body is in the retracted state, which does not affect the normal drilling work. When expansion work is required, the two-speed stroke of the oil cylinder can be controlled to achieve two expansion diameters.

Claims

1. A diameter expansion device for a spiral drill bit, characterized in that: The invention comprises an oil cylinder (100) and an expansion body (6); wherein the oil cylinder (100) is a hollow structure and is located between the core tube and the inner tube of the spiral drill bit, and the oil cylinder body is fixed on the inner wall of the drill bit core tube; an opening is provided at a position corresponding to the drill bit core tube and the spiral blade, the expansion body (6) is located at the opening, and the upper end of the expansion body (6) is hinged to the expansion body seat at the upper end of the opening; the upper end of the expansion body (6) is connected to the piston rod of the oil cylinder (100) through a connecting rod mechanism away from the hinge hole; two pistons and three chambers are provided in the cylinder body (105) of the oil cylinder (100), the two pistons are respectively an upper piston (102) and a lower piston (103), and the lower piston (103) is respectively provided with An upper rod body (101) and a lower rod body (104) are provided on the upper rod body (101). The upper portion of the limit platform is sealed and sleeved with the inner cavity of the upper piston (102). An upper chamber (201) is formed between the upper surface of the upper piston (102) and the upper end surface of the cylinder body (105). A middle chamber (202) is formed between the upper piston (102) and the lower piston (103). A lower chamber (203) is formed between the lower piston (103) and the lower end surface of the cylinder body (105). An annular platform (106) is provided on the inner wall of the cylinder body (105). The annular platform (106) is located in the middle chamber (202). The inner diameter of the annular platform (106) is greater than the diameter of the upper rod body (101).

2. The spiral drill bit expansion device according to claim 1, characterized in that: The bottom of the lower rod body (104) is provided with a connecting joint (1), which is an annular structure or a partial annular structure and is hingedly connected to one end of a connecting plate (3) on the circumference, and the other end of the connecting plate (3) is connected to the diameter-enlarging body (6).

3. The spiral drill bit expansion device according to claim 2, characterized in that: The expanding body (6) is composed of an expanding positioning body (6-1) and an expanding cutting body (6-2). The expanding cutting body (6-2) is vertically arranged and has an outwardly curved hook structure at the bottom. The outer surface is quenched or inlaid with hard alloy. A positioning column (6-3) is provided on the top of the expanding cutting body (6-2). A hinged through hole (6-4) connected to the expanding body seat is provided on the positioning column (6-3). The expanding positioning body (6-1) is located at the upper end of the expanding cutting body (6-2) and is connected to the vertical end face of the expanding cutting body (6-2) at an angle greater than 90 degrees. A hinged ear piece (6-5) is provided at the outer end of the expanding positioning body (6-1). The hinged ear piece (6-5) is hinged to the connecting plate (3).

4. The spiral drill bit expansion device according to claim 3, characterized in that: The diameter-expanding positioning body (6-1) is annular and has a diameter larger than the inner tube passing therethrough. The hinged ear piece (6-5) is located at an end away from the positioning column (6-3).

5. The spiral drill bit expansion device according to claim 3, characterized in that: The diameter-expanding positioning body (6-1) is semicircular in shape, and the number of hinged ears (6-5) is two, and they are respectively located on the semicircular end surfaces of the diameter-expanding positioning body (6-1); two connecting plates (3) are symmetrically hinged on the connecting joint (1), and the two connecting plates (3) are respectively connected to the hinged ears (6-5).

6. The spiral drill bit expansion device according to claim 3, characterized in that: There is no diameter expansion positioning body (6-1) on the top of the diameter expansion cutting body (6-2), and the hinged ear piece (6-5) is directly arranged on the top of the diameter expansion cutting body (6-2).

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