JPH0741462B2 - Hydraulically operated cutting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulically operated cutting device for cutting a reinforcing bar planted in concrete.

[Prior Art] Conventionally, as a hydraulically operated cutting device for cutting rebar, a pair of arm portions are provided on a cutting device book so as to project in a direction orthogonal to the main body, and cutting blades are provided at the tip portions of these arm portions, respectively. Things are known. These cutting blades are arranged linearly in the same direction as the protruding direction of the arms. Then, one of the cutting blades is hydraulically operated to mesh with the other cutting blade to cut the reinforcing bar.

[Problems to be Solved by the Invention]

By the way, in the above-mentioned conventional cutting device, since the cutting blade is attached in the same direction as the protruding direction of the arm portion arranged in the direction orthogonal to the main body, the rebar embedded in the concrete is cut. When attempting to bring the cutting blade closer to the concrete surface, the sides of the cutting device body and arms hit the concrete, and the rebar planted in the concrete could not be cut from its root. .

The present invention has been made to solve the above problems, and an object of the present invention is to provide a hydraulically operated cutting device capable of cutting a reinforcing bar, a round bar, or the like planted in concrete or the like from the root thereof. And

[Means for Solving the Problems]

In order to solve the above problems, the present invention provides a casing main body in which a hydraulic actuating mechanism for reciprocally driving a piston rod is provided, and a casing body formed at a tip end portion thereof, which is laterally offset from a center line of the piston rod. A jaw part having an upper protrusion at a position where there is no other component behind, and a jaw fixed to the upper protrusion of the jaw and orthogonal to the moving direction of the piston rod. Has a linear second cutting blade extending in the direction, and the second cutting blade is located at a position deviated from the center line of the piston rod and further in front of the front end surface of the upper protrusion of the jaw. The second cutting claw provided and one end of which is rotatably held by the jaw portion and the other end of which is rotatably connected to the tip end portion of the piston rod and which is connected to the center line of the piston rod from the center line. Upper protrusion of chin A rotating arm having a lower protruding portion provided at a position displaced in the same direction, and a front end of a lower protruding portion of the rotating arm at a position opposite to the piston rod with respect to a line connecting both ends of the rotating arm. A linear first attached to the rim and abutting the second cutting blade
And a first cutting claw provided at a position further forward than the front end edge of the lower projection portion.

[Action]

When the piston rod is moved forward by the hydraulic operating mechanism, the rotating arm connected to the tip of the piston rod is rotated, the second cutting blade is pressed against the first cutting blade, and the first and second cutting blades are pressed. The rebar or the like inserted between the two cutting blades is cut. Since the first and second cutting blades are arranged at the most distal end position of the casing body, it is possible to bring them close to the root portion of the reinforcing bar or the like.

〔Example〕

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

1 to 5 show a hydraulically operated cutting device according to the present invention. This cutting device includes an electric motor 11. The electric motor 11 is attached to the rear end of the casing body 13 with the motor shaft 12 inserted in the casing body 13. An oil tank 14 for storing oil is provided inside the casing body 13, and a pump mechanism 15 for pumping the oil in the oil tank 14 is further provided. The pump mechanism 15 includes a cam portion 16 formed at the tip of the motor shaft 12.
And a piston 17 reciprocated by the cam portion 16 via a needle bearing, and an opening / closing valve 18 disposed in the oil passage.The opening / closing valve 18 normally opens the oil passage by a spring 19. It is designed to be blocked. A cylinder chamber 20 is formed substantially in the center of the casing body 13,
The cylinder chamber oil tank 14 is partitioned by a vertical wall 21. The pressure oil generated by the pump mechanism 15 is
Through the oil supply passage 22 that penetrates through the cylinder chamber 20
It will be sent to.

A piston flange 23 is disposed in the cylinder chamber 20 in the axial direction, and a piston rod 24 is joined to the back surface of the piston flange 23. The piston rod 24 penetrates the front portion 13a of the casing body 13 that seals the cylinder chamber 20 and projects outside the casing body, and a U-shaped cutout portion 25 is formed at the tip thereof.

On the other hand, a jaw portion (arm portion) 13b is provided on the side of the piston rod 24 of the front portion 13a, and this jaw portion 13b includes
A rotating arm (arm portion) 27 is rotatably attached via a shaft 26. The other end of the rotating arm 27 is rotatably connected to the cutout portion 25 via an engaging pin 28. Then, when the piston rod 24 moves in the axial direction, the rotating arm 27 is rotated accordingly. A projecting portion 29 is formed at the tip of the rotating arm 27 so as to project in a direction orthogonal to the rotating surface of the rotating arm 27. This protrusion 29
A first cutting claw (tip portion) 30 is scribed on the cutting edge, and a linear first cutting blade 31 is formed at the tip of the cutting claw 30. On the other hand, like the protrusion 29, a protrusion 32 protruding in the front end direction is formed at the tip of the jaw 13b.
A second cutting claw (tip portion) 33 is provided on the protrusion 32, and a position of the cutting claw 33 facing the cutting blade 31 is
A linear second cutting blade 34 is formed. The first cutting blade 31 and the second cutting blade 34 are the piston rod 24
Are arranged in a direction orthogonal to the moving direction of the.

Further, as shown in FIG. 3, the protrusions 29, 32 are arranged in the casing body 13 at positions deviated from the center line, and the rebars to be cut are arranged in the longitudinal direction of the cutting device. The tip of the reinforcing bar is prevented from hitting the base portion of the rotating arm 27, the front portion 13a, and the like when gripped by the cutting blade 31 and the cutting blade 34.

An elastic member 36 is provided on a side surface 35 of the cutting claw 33 provided on the jaw portion 13b, which is opposed to the rotating arm 27. The elastic member 36 is made of urethane rubber and is provided so as to project toward the cutting claw 30 so that the rebar after cutting can be gripped.

A recess 5 is formed in the center of the rear end of the piston rod 24 in the axial direction, and a guide bar 8 extending in the axial direction from the vertical wall 21 is inserted into the recess 5 with a gap. A through hole 6 is provided at the center of the guide bar 8, and the recess 5 and the oil tank 14 communicate with each other through the through hole 6. A return valve 37 having a head portion that is larger than the diameter of the through hole 6 and abuts against the tip end portion of the guide bar 8 is inserted into the through hole 6. A spring 44 is provided at the rear end of the head of the return valve 37.
Is installed. This return valve 37 is generated in the cylinder chamber 20 while the piston flange 23 is moving to the left in the cylinder chamber 20, and is applied to the tip surface of the guide bar 8 by the hydraulic pressure exerted in the space 5. It abuts and serves to close the through hole 6.

A return spring 39 is provided between the piston flange 23 and the casing body 13 on the back side of the piston flange 23.
The backward movement (the rightward movement in FIG. 4) is caused. Such a mechanism for retreating the piston flange 23 is already known, and various types of return valves can be adopted. Also, the chin
A pressure buffer chamber 40 that communicates with the front end portion of the cylinder chamber 20 (the end portion on the opposite side of the vertical wall 21 with the piston flange 23 in between) by a communication passage is formed inside the cylinder 13b.
An air bag 41 that elastically deforms is disposed inside. Further, a return valve 42 is provided at the rear end of the cylinder chamber 20, and pressure oil on the rear side of the piston flange 23 is transferred to the oil tank 14.
It can be returned to. Reference numeral 43 is a handle for operating the return valve 42.

Next, the operation of this embodiment having such a configuration will be described with reference to FIGS. 4 to 7. First, the cutting blades 31 and 34 of the cutting device are positioned at the root of the reinforcing bar S planted in the concrete C. At this time, the cutting blades 31 and 34 are brought into contact with the surface of the concrete C in a parallel state. Next, when the electric motor 11 of the cutting device is turned on, the motor shaft
12 is driven to rotate, the cam 16 rotates, and the piston 17 reciprocates. As a result, the oil in the oil tank 14 is suction-compressed to generate pressure oil, which is pumped from the pump mechanism 15 into the cylinder chamber 20 through the oil supply passage 22. The pressure oil sent into the cylinder chamber 20 acts on the flange surface of the piston flange 23, and moves the piston flange 23 and the piston rod 24 against the return spring 39 to the left in FIG. Then, the engagement pin 28 at the tip of the piston rod 24 moves forward, and the rotating arm 27 rotates about the shaft 26. And the cutting blade 31
Approaches the cutting blade 34 and meshes with it. As a result, the reinforcing bar S is cut from its root. At this time, the rebar S to be cut
Is held by the elastic member 36 and the cutting claw 30 on the side of the rotating arm 27, so that bounce back due to cutting can be prevented.

In this way, when the piston flange 23 moves to the left and passes a predetermined position, the valve plate 38 mounted and fixed to the piston flange 23 abuts on the spring 44 mounted on the rear end of the return valve 37. ,spring
When 44 is compressed to a predetermined position, the spring force is applied to the guide bar 8 of the return valve 37 by the hydraulic pressure to cause the spring.
The elastic force of 44 becomes larger, and the return valve 37 momentarily separates from the tip surface of the guide bar 8. As a result, the through hole 6 is opened, and the cylinder chamber 20 on the high pressure side and the oil tank 14 communicate with each other through the recess 5 and the through hole 6. This allows the cylinder chamber
The pressure oil in 20 is returned to the oil tank 14, and the piston flange 23 is moved backward by the force of the return spring 39. And
The piston rod 24 and the piston flange 23 are again in the fourth position.
Returning to the position shown in the figure, the rotating arm 27 is rotated accordingly, and the cutting blade 31 and the cutting blade 34 are separated from each other.

As described above, in the cutting device according to the present embodiment, the linear cutting blades 31, 34 are at the tip position of the casing body 13,
Since the linear blade is provided in the direction orthogonal to the moving direction of the piston rod 24, even when the cutting blades 31 and 34 are brought close to the reinforcing bar S when the reinforcing bar S planted in the concrete C is cut. The sides of the rotating arm 27 and the jaw 13b do not hit concrete. As a result, the reinforcing bar planted in concrete can be cut from the root.

Further, at the tip end of the rotating arm 27 and the jaw 13b, a protrusion 29 is projected in a direction orthogonal to the rotating surface of the rotating arm 27.
Since 32 and 32 are provided, even if the rebar S having a long dimension is inserted between the cutting blades 31 and 34, the tip of the rebar S is rotated.
It does not hit the base part of 7 or the front part 13a.

Further, a return valve 42 is provided at the rear end of the cylinder chamber 20, and the return valve 42 allows the piston flange to pass through.
Since the pressure oil on the rear side of 23 can be returned to the oil tank 14, if the cutting blade bites into the rebar,
You can easily return the cutting blade to the open state and remove the reinforcing bar.

Further, since the elastic member 36 made of urethane rubber is provided on the side surface 35 of the cutting blade 33 facing the rotating arm 27,
The cut rebar S can be gripped together with the cutting blade 30 on the rotating arm 27 side. Therefore, when the reinforcing bar is cut, it is possible to prevent the reinforcing bar from rebounding, and it is possible to perform a safe work.

〔The invention's effect〕

As described above, according to the present invention, since the linear cutting blade is arranged at the most distal position of the casing body and the rotating arm in the direction orthogonal to the moving direction of the piston rod, it is planted in concrete. The installed rebar can be cut from its root.

Further, since the first cutting blade is a fixed blade, the cutting blade can be brought into contact with a cutting position such as a reinforcing bar for easy positioning, and stable cutting work can be performed.

Further, since the elastic member is provided between the jaw portion and the rotating arm, the reinforcing bar can be grasped at the time of cutting, and the reinforcing bar can be prevented from bouncing.

Furthermore, since the cutting blade is located laterally offset from the center line of the piston rod and there is no other component behind it, the tip of the rebar is cut even when cutting a long rebar. The part does not hit the front part of the casing body, the base part of the rotating arm, or the like.

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention, in which FIG. 1 is a plan view thereof, FIG. 2 is a view in the direction of arrow II in FIG. 1, and FIG. A front end view, FIG. 4 is a partially cutaway arrow view seen from the same direction as FIG. 2, and FIG. 5 is a sectional view taken along the line V-V in FIG. 4, FIG. 6 and FIG. The figure is a view showing a state in which the reinforcing bar is being cut by using the cutting device of this embodiment. 13b …… chin (arm), 27 …… rotating arm (arm), 3
0 …… First cutting claw (tip part), 31 …… First cutting blade, 3
3 …… Second cutting claw (tip), 34 …… Second cutting blade, 3
6 ... Elastic member.

Claims (1)

[Claims] 1. A casing body in which a hydraulic operating mechanism for reciprocally driving a piston rod is provided, and a position formed at a tip end portion of the casing body and laterally displaced from a center line of the piston rod. , A jaw portion provided with an upper protrusion portion at a position where no other component exists in the rear, and a linear shape fixed to the upper protrusion portion of the jaw portion and extending in a direction orthogonal to the moving direction of the piston rod. A second cutting blade, wherein the second cutting blade is arranged at a position deviated from the center line of the piston rod and further in front of the front end face of the upper protrusion of the jaw. 2 cutting claws, one end of which is rotatably held by the jaw portion and the other end of which is rotatably connected to the tip end portion of the piston rod, and the upper projection portion of the jaw portion from the center line of the piston rod. Deviated in the same direction as A rotating arm having a lower protruding portion provided on a lower end of the rotating arm at a position opposite to the piston rod with respect to a line connecting both ends of the rotating arm. A linear first that abuts the second cutting blade
A hydraulically operated cutting device comprising: a first cutting pawl, the first cutting blade being provided at a position further forward than a front end edge of the lower protrusion.