Nut breaking tool

Abstract

A nut breaking tool (1) is provided with: a main body (2) having a hydraulic pump (9); a cylinder section (4) connected to the hydraulic pump (9); and a tool head (3) connected to the cylinder section (4). The tool head (3) is provided with: a jaw section (6a) and a jaw section (6b) which are rotatably connected to each other; a wedge part (7a) rotatably attached to the jaw part (6a) in a state in which the first shaft member (11) passes through and is axially supported; a wedge part (7b) rotatably attached to the jaw part (6b) in a state in which the first shaft member (11) passes through and is axially supported; and a spring (6c) that biases in the direction in which the distal end side of the jaw section (6a) and the distal end side of the jaw section (6b) are separated from each other. A hydraulic pump (9) is operated to supply hydraulic oil to a cylinder part (4), and a guide roller (5e) pressed by a piston (5b) slides on the rear end side of a jaw part (6a) and the rear end side of the jaw part (6b), so that a wedge part (7a) and a wedge part (7b) of a tool head (3) approach each other to break a nut (51).

Description

Technical Field

[0001] The present invention relates to a nut splitting tool. Background Art

[0002] In structures such as bridges and guide rails that are grounded and fixed, there is a known nut removal operation for removing nuts fixed to the structure. As an example, hundreds of nuts are provided at the bridge joint, and in regular maintenance operations, the old nuts are removed and replaced with new ones.

[0003] In the conventional nut removal operations using a high-speed grinding machine device and a gas fusing device, it takes 1 minute to 3 minutes to remove one nut. In recent years, an electric tool has been proposed that can significantly shorten the time required to remove one nut (Patent Document 1: Japanese Patent No. 7104102).

[0004] Prior art documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 7104102 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, when the space around the fixed nut is narrow, it is difficult for conventional tools to access the nut. Therefore, the problem to be solved by the present invention is to provide a nut splitting tool that can easily break the fixed nut.

[0009] Means for Solving the Problems

[0010] As a technical solution, the above-described problem is solved by the solution disclosed below.

[0011] The nut splitting tool of the present invention is characterized in that the nut splitting tool includes: a main body having a hydraulic pump; a cylinder portion connected to the hydraulic pump; and a tool head connected to the cylinder portion to operate. The cylinder portion has a piston and a pair of guide rollers mounted on the piston. The tool head has: a pair of jaws that are rotatably connected to each other; and a pair of rotatable wedges that are respectively mounted on the tip side of the jaws in a state of being pivotally supported by a first shaft member. The nut splitting tool operates the hydraulic pump to supply working oil to the cylinder portion, causing the piston to advance, and the guide rollers slide on the rear end side of the jaws, so that the wedges approach each other to break the nut.

[0012] According to this structure, the tool head can approach the fixed nut and clamp both sides of the nut with the wedge portion, bring the cutting edges of the wedge portion closer to each other to bite into the nut, and break the nut. Therefore, even if the space around the nut is narrow, it is possible to easily approach the nut and easily break the nut.

[0013] As an example, the structure is as follows: The tool head has a spring that applies a force in the direction of opening toward the tip side of the jaw portion. When the operation of the hydraulic pump stops, the piston retracts and the spring contracts, so that the tip side of the jaw portion opens. According to this structure, after the nut is broken, the tip side of the jaw portion opens due to the acting force of the spring, and it is possible to easily switch to the breaking operation of another nut.

[0014] As an example, the tool head is mounted on the cylinder portion in a state of being pivotally supported by a second shaft member. According to this structure, the tool head can be easily replaced. As an example, by preparing in advance a plurality of dedicated tool heads specialized for nuts of specific sizes and specific types of nuts, it is possible to easily disassemble the second shaft member from the cylinder portion, replace it with a desired tool head, and perform operations on site.

[0015] As an example, a pair of connecting plates are respectively mounted on the jaw portions in a state of being pivotally supported by a third shaft member, and the jaw portions are pivotally connected to each other by the third shaft member and the connecting plates. According to this structure, it is possible to easily make the tool have a high hinge strength, be small in size and high in power for the jaw portions.

[0016] As an example, a pair of protective plates are mounted on the jaw portions, and when the tip sides of the jaw portions are separated from each other, a state can be formed in which the nut can be surrounded by the protective plates and the tip sides of the jaw portions. According to this structure, the nut is broken in a state of surrounding the nut, so it is possible to prevent the fragments of the broken nut from flying.

[0017] As an example, the cylinder portion is connected to the main body, and the cylinder portion is connected to the hydraulic pump inside the main body. According to this structure, a compact and highly mobile structure can be achieved. As an example, the main body has a hydraulic pump for supplying working oil to the cylinder portion and an electric motor for driving the hydraulic pump, and the main body has a battery pack for supplying power to the electric motor and a mounting portion for mounting the battery pack. According to this structure, it can be easily carried to the work site, and the work range can be easily expanded. As an example, it is possible to make a nut cracking tool having a main body in the shape of a pistol, a gun, or a straight shape.

[0018] As an example, the cylinder part is connected to a hydraulic hose, and the cylinder part and the hydraulic pump are connected by means of the hydraulic hose. According to this structure, a structure with excellent freedom in the combination of the cylinder part and the main body can be achieved. As an example, the main body can be a known hydraulic pump device. As an example, a commercially available product can be applied to the hydraulic hose.

[0019] Effects of the Invention

[0020] According to the present invention, the tool head can approach from above the nut and clamp both sides of the nut with the wedge part, bring the cutting edges of the wedge part closer to each other to bite into the nut, and break the nut. Therefore, a nut cracking tool can be realized that can easily break a fixed nut even in a part where the space beside the nut is narrow and it is difficult for the existing tools to approach. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic front view showing a first example of the nut cracking tool of the present embodiment.

[0022] Figure 2 It is a schematic structural diagram showing the tool head of the nut cracking tool of the first example in an enlarged manner.

[0023] Figure 3 It is a schematic structural diagram showing the tool head of the first example when viewed from the side.

[0024] Figure 4 It is a schematic structural diagram showing the wedge part of the tool head of the first example when viewed from below, and is a view in a state where the wedge part approaches from above the nut.

[0025] Figure 5 It is a schematic structural diagram showing the wedge part of the tool head of the first example when viewed from below, and is a view in a state where the cutting edges of the wedge part are brought closer to each other to bite into the nut.

[0026] Figure 6 It is a schematic front view showing a second example of the nut cracking tool of the present embodiment.

[0027] Figure 7 It is a schematic structural diagram showing the tool head of the nut cracking tool of the second example in an enlarged manner.

[0028] Figure 8 It is a schematic structural diagram showing the tool head of the second example when viewed from the side.

[0029] Figure 9 It is a schematic structural diagram showing a third example of the nut cracking tool of the present embodiment.

[0030] Figure 10 It is a schematic structural diagram showing the tool head of the third example in an enlarged manner. Detailed Embodiments

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The nut splitting tool 1 of the present embodiment includes a main body 2, a cylinder portion 4, and a tool head 3. The main body 2 has a hydraulic pump 9. The nut splitting tool 1 of the present embodiment is a nut splitting tool 1 that breaks nuts fixed to structures such as bridges and guide rails. As an example, the size of the nut 51 used for bridges is M22 or M20 or more. These nuts 51 are fastened with high-tensile high-strength bolts, and the tensile strength after fastening is 1000 N / mm 2 Above. As an example, there are several hundred nuts provided at the bridge joint, and the minimum value of the nut interval is 34 mm.

[0032] First, the nut splitting tool 1A of the first example will be described.

[0033] [First Example]

[0034] Figure 1 is a schematic front view showing the nut splitting tool 1A of the first example. Figure 2 is a schematic structural diagram of the tool head 3A viewed from the front. Figure 3 is a schematic structural diagram of the tool head 3A viewed from the side. Among them, in order to easily explain the positional relationship of each part of the nut splitting tool 1A, the directions are indicated by the arrows X, Y, and Z in the figure. The nut splitting tool 1A works properly in any direction. In addition, in all the figures used to explain the embodiments, there are cases where components having the same function are labeled with the same reference numerals, and their repeated descriptions are omitted.

[0035] The nut splitting tool 1A includes: a main body 2A for the operator to hold; a cylinder portion 4A connected to the main body 2A; and a tool head 3A that performs nut splitting operations with the hydraulic pressure of the cylinder portion 4A. The first example is a structure in which the cylinder portion 4A is mounted on the main body 2A and the cylinder portion 4A is connected to the main body 2A. And the cylinder portion 4A and the hydraulic pump 9 are connected inside the main body 2A.

[0036] A guide roller 5e is connected to the piston 5b of the cylinder portion 4A. The hydraulic pump 9 supplies the working oil 9b to the cylinder portion 4A. The main body 2A has: a hydraulic pump 9; an electric motor 8 that drives the hydraulic pump 9; a controller 17 that drives and controls the electric motor 8; and a battery pack 19 that supplies power to the electric motor 8 and the controller 17.

[0037] The battery pack 19 is detachably connected to the mounting portion 18 provided on the main body 2A. Thus, a structure with excellent mobility is achieved. In addition to the above structure, there are cases where the battery pack 19 is built into the main body 2A or the battery pack 19 is connected by means of an adapter attached to the mounting portion 18. The battery pack 19 has a secondary battery and a sensor for detecting the state of the secondary battery. The secondary battery can be a lithium-ion battery, a nickel-metal hydride battery, or other known secondary batteries.

[0038] Along the first axis P1 passing through the main body 2A, a cylinder portion 4A, a hydraulic pump 9, a speed reducer 8a, and an electric motor 8 are arranged in sequence. The housing 21 is provided with a handle portion 21a for the operator to hold in a direction away from the first axis P1. The housing 21 is provided with a start switch 21b for starting the electric motor 8 at the handle portion 21a, and a return switch 21c is arranged above the start switch 21b. The operator operates the start switch 21b and the return switch 21c with the fingertips of the hand holding the handle portion 21a. The main body 2 is sequentially provided with a handle portion 21a, a mounting portion 18, and a battery pack 19. As an example, the nut splitting tool 1A has a main body 2A in the shape of a pistol, a gun, or a straight shape.

[0039] The tool head 3A is a structure that approaches from above the nut 51 and clamps both sides of the nut 51 with the wedge portion 7. The main component parts in the tool head 3A are arranged at positions symmetric with respect to the first axis P1 passing through the piston 5b. The tool head 3A has: a jaw portion 6a and a jaw portion 6b, which are rotatably connected to each other; a first shaft member 11; a wedge portion 7a, which is rotatably mounted on the tip side of the jaw portion 6a in a state of being penetrated by the first shaft member 11 and supported by the first shaft member 11; and a wedge portion 7b, which is mounted on the tip side of the jaw portion 6b.

[0040] The cylinder portion 4 is provided with a piston 5b in the cylinder chamber 5c, and a helical spring 5d is arranged along the outer periphery of the piston 5b so as to be concentric with the axis of the piston 5b. A cylindrical cover 5a is mounted on the tip side of the cylinder portion 4.

[0041] The tool head 3A has a spring 6c that applies a force in the direction of opening toward the tip sides of the pair of jaw portions 6a and 6b. The spring 6c is a tension helical spring. It is a structure in which the rear end sides of the jaw portion 6a and the jaw portion 6b extend in a direction away from the first axis P1, and as the piston 5b advances, the pair of guide rollers 5e slide on the rear end sides of the jaw portion 6a and the jaw portion 6b, so that the cutting edges 7c and 7d of the wedge portion 7 approach each other.

[0042] As an example, the wedge portions 7a and 7b are respectively formed with recesses, and auxiliary springs 7e and 7f that apply forces in the direction of making the tool tips 7c and 7d face each other in parallel are respectively disposed in the recesses. Thereby, it is possible to easily clamp both sides of the nut 51 with the wedge portions 7a and 7b. Both the auxiliary spring 7e and the auxiliary spring 7f are compression coil springs. The auxiliary spring 7e and the auxiliary spring 7f are optional and can be omitted.

[0043] The tool head 3A is mounted with a pair of connecting plates 14 in a state where the jaw portions 6a and 6b are respectively pivotally supported by the third shaft member 13. The jaw portions 6a and 6b are rotatably connected to each other by the third shaft member 13 and the connecting plates 14. The tool head 3A has protective plates 15 fixedly mounted on the respective connecting plates 14. When the tip sides of the jaw portion 6a and the jaw portion 6b are separated from each other, a state is formed in which the nut 51 can be surrounded by the respective protective plates 15, the tip side of the jaw portion 6a, and the tip side of the jaw portion 6b.

[0044] The first example is a structure in which the tool head 3A is pivotally supported by the second shaft member 12 in a state where the tool head 3A is mounted on the cylinder portion 4A. The tool head 3A is provided with a column portion 31 extending in the first axis P1 direction. The main body 2 is provided with a pair of support portions 16 extending in the first axis P1 direction. And, with the column portion 31 interposed between the pair of support portions 16, the second shaft member 12 is passed through a first through hole formed in each support portion 16 and a second through hole formed in the column portion 31, and the second nut is fastened to the second shaft member 12 to fix the second nut to the second shaft member 12. According to this structure, by preparing in advance a plurality of dedicated tool heads 3A specialized for a specific size range and a specific category of the nut 51 as an object to be broken, it is possible to easily remove the second shaft member 12 from the main body 2 at a work site or the like, replace it with a desired tool head, and perform the work.

[0045] Figure 4 It is a schematic configuration diagram of observing the wedge portions 7a and 7b from below, and is a diagram in a state where the wedge portions 7a and 7b are brought closer from above the nut 51 fastened and fixed to the bolt 52. The distance between the tool tip 7c of the wedge portion 7a and the tool tip 7d of the wedge portion 7b in a state where the tip side of the jaw portion 6a and the tip side of the jaw portion 6b are separated from each other is set as a first distance W1. As an example, the first distance W1 is 34 mm or more and 38 mm or less. As an example, the first distance W1 is 35 mm or more and 37 mm or less.

[0046] This is a view showing a state in which the cutting edge 7c of the wedge portion 7a and the cutting edge 7d of the wedge portion 7b are brought close to each other and bite into the nut 51. The interval between the cutting edge 7c of the wedge portion 7a and the cutting edge 7d of the wedge portion 7b in a state where the tip side of the jaw portion 6a and the tip side of the jaw portion 6b are brought close to each other is defined as the second interval W2. As an example, the second interval W2 is 21 mm or more and 24 mm or less. As an example, the second interval W2 is 19 mm or more and 21 mm or less.

[0047] For the nut cracking tool 1A, when the operator presses the start switch 21b, the electric motor 8 rotates, and the hydraulic pump 9 is operated by means of the speed reducer 8a. The hydraulic pump 9 supplies the working oil 9b stored in the oil tank 9a to the cylinder chamber 5c. When the working oil 9b is supplied to the cylinder chamber 5c, the hydraulic pressure in the cylinder chamber 5c increases. And, a pair of guide rollers 5e mounted on the piston 5b slide while pushing the rear end side of the jaw portion 6a and the rear end side of the jaw portion 6b, so that the cutting edge 7c of the wedge portion 7a and the cutting edge 7d of the wedge portion 7b are brought close to each other. And, by further sliding while a pair of guide rollers 5e push the rear end side of the jaw portion 6a and the rear end side of the jaw portion 6b, the cutting edges 7c and 7d bite into the nut 51, and the nut 51 is fractured.

[0048] After the nut 51 is fractured, the relief valve is opened at a specified pressure, and the pressure in the high-pressure stage is reduced (not shown). Next, when the operator presses the return switch 21c, the check valve is opened, and the piston 5b is pushed back due to the restoring force of the coil spring 5d, and the piston 5b returns to the initial position, and the working oil 9b returns to the oil tank 9a.

[0049] According to the present embodiment, the tool head 3A can approach from above the nut 51, clamp both sides of the nut 51 with the wedge portion 7a and the wedge portion 7b, bring the cutting edges 7c and 7d close to each other and bite into the nut 51, and fracture the nut 51. Therefore, for a portion where the space beside the nut is narrow and difficult to approach by the conventional tool, it is also possible to easily fracture the nut 51 fixed to the bolt 52.

[0050] Next, the nut cracking tool 1B of the second example will be described.

[0051] [Second Example]

[0052] Figure 6 This is a schematic front view showing the nut cracking tool 1B of the second example. Figure 7 This is a schematic structural view of the tool head 3B as viewed from the front. Figure 8 This is a schematic structural view of the tool head 3B as viewed from the side. The main body 2A in the second example has the same structure as that of the first example. In the second example, the description will be centered on the points different from the first example.

[0053] The second example is a structure in which the cylinder part 4A is attached to the main body 2A and the cylinder part 4A is connected to the main body 2A. Further, the cylinder part 4A and the hydraulic pump 9 are connected inside the main body 2A. The second example is a structure in which the tool head 3B is axially supported by the second shaft member 12 in a state where the tool head 3B is attached to the cylinder part 4A. Further, in the second example, the second shaft member 12 rotatably connects the jaw part 6a and the jaw part 6b to axially support the jaw part 6a and the jaw part 6b. Thereby, a simple structure with a reduced number of components can be achieved.

[0054] Next, the nut cracking tool 1C of the third example will be described.

[0055] [Third Example]

[0056] Figure 9 It is a schematic structural diagram showing the nut cracking tool 1C of the third example. Figure 10 It is a schematic structural diagram of the tool head 3B viewed from the front. The tool head 3A in the third example has the same structure as that of the first example. In the third example, the description will be centered on the points different from the first example.

[0057] The cylinder part 4B of the third example is separate from the main body 2B. The cylinder part 4B has a female connector 24b communicating with the cylinder chamber 5c. The third example has a hydraulic hose 23. The hydraulic hose 23 is a high-pressure-resistant and oil-resistant rubber hose, with a male connector 24a arranged on one end side and a joint 22c arranged on the other end side. The female connector 24b of the cylinder part 4B is connected to the male connector 24a of the hydraulic hose 23. The hydraulic hose 23 is connected to the joint 22c in the main body 2B. As a structure other than the above, there is a case where the cylinder part 4B has a male connector 24a and the hydraulic hose 23 has a female connector 24b.

[0058] The cylinder part 4B of the third example is connected to the hydraulic pump 9 via the hydraulic hose 23. As an example, the total length of the hydraulic hose 23 is 1 to 10 m. The third example is a structure in which the tool head 3A is axially supported by the second shaft member 12 in a state where the tool head 3A is attached to the cylinder part 4B. According to this structure, a structure with excellent freedom in the combination of the cylinder part 4B and the main body 2B can be achieved.

[0059] The main body 2B includes: a hydraulic pump 9; an electric motor 8 that drives the hydraulic pump 9; a controller 17 that drives and controls the electric motor 8; and a power supply unit 25 that supplies power to the electric motor 8 and the controller 17. As an example, the power supply unit 25 is connected to an external power source. As an example, the power supply unit 25 has a battery pack.

[0060] The housing 22 is provided with a handle portion 22a at the upper part for the operator to hold. As an example, a switch 22b for starting the electric motor 8 is arranged on the front side of the housing 22. As an example, the switch 22b is a toggle switch.

[0061] For the nut splitting tool 1C, if the operator raises the lever of the switch 22b, the electric motor 8 rotates, the hydraulic pump 9 operates, and the hydraulic pump 9 supplies the working oil 9b stored in the oil tank 9c to the cylinder chamber 5c. If the working oil 9b is supplied to the cylinder chamber 5c, the hydraulic pressure in the cylinder chamber 5c becomes higher. And, the guide rollers 5e mounted on the piston 5b slide while pressing the rear end sides of the jaw portion 6a and the jaw portion 6b, so that the cutting edges 7c of the wedge portion 7a and the cutting edges 7d of the wedge portion 7b approach each other. And, the pair of guide rollers 5e further slide while pressing the rear end sides of the jaw portion 6a and the jaw portion 6b, so that the cutting edges 7c and 7d bite into the nut 51 and break the nut 51.

[0062] After the nut 51 is broken, the relief valve is opened at a specified pressure, and the pressure in the high-pressure stage is reduced (not shown). Then, if the operator pulls down the lever of the switch 22b, the check valve is opened, and the piston 5b is pushed back due to the restoring force of the helical spring 5d, and the piston 5b returns to the initial position, and the working oil 9b returns to the oil tank 9c. In addition to the above structure, there is also a case where a remote control switch is provided on the main body 2B and a series of operations are performed using the remote control switch.

[0063] In the above-described embodiments, there are cases where the structure is provided with a built-in battery, a structure connected with a power cord connected to an external power source, and a structure combining these. The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

Claims

1. A nut breaking tool, characterized in that: The nut breaking tool comprises: a main body having a hydraulic pump; a cylinder connected to the hydraulic pump; and a tool head connected to the cylinder to work. The cylinder portion includes a piston and a pair of guide rollers mounted on the piston. The tool head comprises: a pair of jaws connected to each other so as to be rotatable; and a pair of rotatable wedges respectively mounted on the top ends of the jaws in a state of being axially supported by a first shaft member. The nut breaking tool is operated by the hydraulic pump to supply hydraulic oil to the cylinder portion, so that the piston moves forward and the guide roller slides on the rear end side of the jaw portion, so that the wedge portions approach each other and the nut is broken.

2. The nut breaking tool according to claim 1, characterized in that: The tool head has a spring that urges the jaw portion toward the tip end side to open. The tool head is mounted on the cylinder portion in a state of being axially supported by the second shaft member. The nut breaking tool is opened by stopping the operation of the hydraulic pump, causing the piston to retreat and the spring to contract.

3. The nut breaking tool according to claim 2, characterized in that: The jaws are each provided with a pair of connecting plates in a state of being axially supported by a third shaft member. The jaws are connected to each other rotatably by the third shaft member and the connecting plate.

4. The nut breaking tool according to claim 2, characterized in that: The jaw is equipped with a pair of protective plates. When the front ends of the jaws are spaced apart from each other, the nut can be surrounded by the protection plate and the front ends of the jaws.

5. The nut breaking tool according to any one of claims 1 to 4, characterized in that: The cylinder is connected to the main body. The cylinder portion and the hydraulic pump are connected inside the main body.

6. The nut breaking tool according to any one of claims 1 to 4, characterized in that: The cylinder is connected to a hydraulic hose. The cylinder portion and the hydraulic pump are connected via the hydraulic hose.

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