JP2805282B2 - Shearing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shearing machine, and more particularly to a shearing machine which can be used as a rebar cutter for cutting steel bars such as round bars or deformed bars.

[0002]

2. Description of the Related Art A steel shearing machine for cutting or punching a steel material is used in a steel material processing operation in building work or machine production. This type of shearing machine is configured to shear steel bars such as rebar mainly by a pair of fixed blades and movable blades, or to mainly punch a plate material such as a steel plate by a die and a punch. , A portable rebar cutter or a portable puncher (see, for example, JP-A-3-189022). Further, a so-called full-screw cutter provided with a fixed blade and a movable blade for cutting a full-screw bolt is known. The fixed blade and the movable blade of the full-screw cutter have a female screw corresponding to a male screw of a full-screw bolt. Further, in the above-mentioned rebar cutter, a configuration having a pair of left and right movable blades and a fixed blade that can be inserted between the movable blades is disclosed in Japanese Utility Model Application No. 58-42996 (Japanese Utility Model Application Laid-Open No. 59-148217). Is disclosed. This rebar cutter includes a main jaw member extending forward from the hydraulic cylinder device, and a movable jaw member guided by the main jaw member. One fixed blade is fixed to the distal end portion of the main jaw member bent downward, and a pair of left and right movable blades is fixed to the movable jaw member. The movable jaw member is fixed to the distal end of the piston rod of the hydraulic cylinder device, and moves forward or backward by expansion and contraction of the piston rod.

[0003]

However, in the rebar cutter having the above structure, a movable jaw member guided by the main jaw member and supporting two movable blades must be provided. It's getting more complicated. Also,
In many cases, such a cutting operation using a rebar cutter is performed with the portable portion or the portable handle portion facing upward and the jaws or jaws provided with fixed blades facing downward. Therefore, in many rebar cutting operations using the rebar cutter having the above-described configuration, the cutting operation must be started with the steel bar placed or positioned on one fixed blade in an unstable manner. Moreover, since the steel bar is punched on the side of the movable blade, the punched out broken material must be processed in the movable blade located above the steel bar. As described above, in the rebar cutter having the above-described configuration, not only is the mounting structure of the movable blade complicated, but also it is difficult to position the steel bar as a work on the fixed blade, and the broken material punched by the movable blade is discharged. For this reason, there arises a problem that a complicated broken material discharge structure must be provided at the tip of the piston rod. Further, the above-mentioned rebar cutter having the conventional structure cannot be used as a puncher or a full-screw cutter, and therefore has a drawback that it cannot cope with various kinds of work at a work site.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to enable a steel bar such as a round bar and a deformed bar to be easily and accurately positioned at a predetermined position of a shearing machine. Moreover, it is an object of the present invention to provide a shearing machine capable of simplifying a structure for supporting a movable blade and a structure for discharging broken material. Another object of the present invention is to provide a shearing machine that can be used not only as a rebar cutter but also as a puncher or a full-screw cutter.

[0005]

In order to achieve the above object, the present invention comprises a movable blade attached to a front end portion of a piston rod, and a fixed blade attached to a main body.
In a shearing machine configured to cut a steel bar such as a round bar or a deformed reinforcing bar by a movable blade and a fixed blade, the movable blade includes a cutting blade portion whose front end is pressed against the steel bar when the movable blade advances. And the fixed blade has left and right fixed blade portions,
A slit disposed between the fixed blade portions, wherein the fixed blade portion includes a concave portion having a shape substantially complementary to an outer shape of the steel bar, and the slit faces the cutting blade portion. The cutting blade portion is positioned at a position for accommodating the cutting blade portion when the cutting blade portion advances, and communicates with a broken material dropping hole formed in the shearing device main body to form a broken material discharge path; A concave portion of the portion having a smooth inner peripheral surface, the concave portion supports the steel bar on both sides of the movable blade, and the movable blade presses the steel bar between left and right fixed blade portions; A shearing machine, characterized in that the shearing machine is cut. According to the shearing machine having the above configuration, the fixed blade portion forms a fulcrum for supporting the bar at two points, and the movable blade presses the bar between the fulcrums. The steel bar is supported in a very stable manner, and the steel bar does not have any axial escape as seen in the case of cantilever support. Since the steel bars do not escape, irregularities, distortions, burrs, and the like hardly occur on the cut surface of the steel bars.

Further, the fixed blade has a concave portion having a smooth inner peripheral surface which is substantially complementary to the external shape of the steel bar, and positions a steel bar such as a round bar or a deformed reinforcing bar in the concave portion of the fixed blade. Accordingly, the steel bar can be positioned at a predetermined cutting position of the shearing machine, and the steel bar can be held at the cutting position in a relatively stable state. Furthermore, since the fixed blade is divided into two fixed blade portions and the slit of the fixed blade is connected to the broken material drop hole of the shears body, the punched broken material can be smoothly passed through the broken material discharge path. Is discharged outside the aircraft. In addition, by adopting such a structure of the fixed blade, the structure of attaching the movable blade to the piston rod is greatly simplified. This would allow, for example, the design of a support structure that is compatible with the movable blade and the punch, and would greatly increase the design flexibility. Preferably, the cutting edge portion has an arc-shaped depression provided with an inner peripheral surface that comes into contact with the outer periphery of the steel bar. The recess in the movable blade receives the bar on the opposite side of the fixed blade, abuts against the outer periphery of the bar and presses it against the fixed blade. Therefore, the pressing force for shearing is applied relatively evenly to the steel bar, and the steel bar is hardly subjected to a large shearing strain, and a good cut surface can be finished.

[0007] The present invention further provides the above-mentioned shearing machine, wherein the fixed blade and the movable blade are compatible with a puncher die and a punch, respectively.
Preferably, the fixed blade is designed to be compatible with a fixed blade for cutting a full screw bolt having an internal thread, and is used for cutting a bar steel such as a round bar and cutting a full screw bolt by the same shearing machine. Enable both tasks. In another preferred embodiment of the present invention, the fixed blade includes a hollow portion communicating with a pit of a broken material provided in the main body, and the hollow portion communicates with a bottom portion of the slit. The side wall that defines the slit is tapered, and the side wall forms a broken material discharge path that expands toward the hollow portion. According to this configuration, the broken material generated by the shearing operation can smoothly pass from the slit to the hollow portion and the pit, so that the previous broken material can be reliably prevented from remaining in the slit. Thus, the remaining broken material pushes and expands the slit by the subsequent shearing operation, thereby avoiding a crack near the bottom of the slit. More preferably, a small-diameter curved portion is provided at the intersection of the side wall and the bottom wall of the slit, whereby the occurrence of such cracks is reliably prevented.

[0008] In another embodiment of the present invention, the base of the fixed blade is formed in a cylindrical shape as a whole, and the end face of the base comes into contact with a shoulder formed in the pit, and during a shearing operation, Substantially all of the load acting on the fixed blade is supported by the reaction forces generated at the shoulder and the end face of the base.
According to such a configuration, breakage or damage of the collar or collar provided on the fixed blade can be avoided beforehand. In still another embodiment of the present invention, the portion of the side wall located between the exposed end face of the fixed blade and the bottom of the recess is not tapered and extends substantially parallel to each other. In another embodiment of the present invention, the clearance between the width of the slit and the cutting edge portion of the fixed blade is set to 0.3 to 0.8 mm, more preferably 0.4 mm to 0.7 mm. You. This prevents the cut surface of the bar to be cut from being distorted or stepped, and prevents the cut surface from having burrs. In addition, such a value of the clearance can be preferably adopted regardless of the material of the bar to be cut. In a preferred embodiment from a practical point of view of the present invention, the shearing machine is a shearing machine for mainly punching a steel material, and the movable blade and the fixed blade move a punch and a fixed die. The blade and the fixed blade have been replaced. Such a shearing machine allows two related operations to be performed by the same model, and in view of its practicality, is extremely high in added value and brings great convenience.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a shearing machine according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 is a longitudinal sectional view of a shearing machine according to an embodiment of the present invention. The shearing machine shown in FIG. 1 mainly functions as a so-called portable puncher for making a hole in a steel plate, a function as a full-screw cutter for cutting a full-screw bolt, and for cutting a bar steel such as a round bar or a deformed reinforcing bar. It also has the function of a rebar cutter.
The shearing machine 1 includes a portable handle 2, an electric motor 3 supported by the portable handle 2, a pump unit 4 connected to the electric motor 3, and a hydraulic cylinder unit 5 which constitutes a hydraulic operating mechanism together with the pump unit 4. And a jaw-type head or jaw 6 extending forward from the hydraulic cylinder section 5. The portable handle 2 includes a trigger switch 21 for manually controlling the operation of the electric motor 3 and a grip portion 22 that is held by the operator with fingers. Electric motor 3
Has an output shaft 30 extending into the pump section 4, and the output shaft 30 has a cam shaft 31 at a front end portion thereof. Camshaft 3
One central axis is slightly eccentric with respect to the rotation axis of the output shaft 30. On the outer periphery of the cam shaft 31, a needle bearing 32 is disposed concentrically with the cam shaft 31.

[0010] A housing 40 of the pump section 4 is connected to the electric motor 3, and an oil tank 42 for storing hydraulic oil is formed in the pump housing 40. Above the oil tank 42, a supply port 48 penetrating the housing 40 is formed, and a plug 49 is screwed into the supply port 48. A pump piston 41 constituting each pump unit 4 a of the pump unit 4 slides on the outer peripheral surface of the needle bearing 32.
The pump piston 41 is always held by a spring 44
In the figure, it is urged upward, that is, toward the needle bearing 32. An oil passage 43 communicating with the oil tank 42 is arranged adjacent to the lower end of the pump piston 41, and an on-off valve 45 is arranged in an oil passage 47 between the pump unit 4 and the hydraulic cylinder device 5. The on-off valve 45 is urged toward the pump piston 41 by a spring 46, and always closes the oil passage 47. The hydraulic cylinder device 5 includes a cylinder case 50, a piston 51 reciprocally arranged in the cylinder case 50,
Hydraulic chambers 52 and 53 defined on both sides of the vehicle 1 respectively. The hydraulic chamber 52 communicates with the oil passage 47 and can communicate with the release oil passage 54 when the release valve device 55 is opened. The release valve device 55 is opened when the piston 51 advances by a predetermined distance, and makes the hydraulic chamber 52 communicate with the release oil passage 54. Thereby, the hydraulic chamber 52
The working oil inside flows back to the oil tank 42 via the release oil passage 54.

An oil storage device is provided in the auxiliary handle 2a for absorbing or supplementing surplus hydraulic oil or insufficient hydraulic oil generated due to the difference in the volume change rate between the hydraulic chamber 52 and the hydraulic chamber 53. The oil device includes an oil storage chamber 55a that communicates with the hydraulic chamber 53 via an oil passage 56, and an air chamber 55b that is isolated from the oil storage chamber 55a by a flexible film 55c. The air chamber 55b is open to the atmosphere. Hydraulic chamber 5
A return spring 57 for urging the piston 51 rearward and a piston rod 58 extending forward from the piston 51 are arranged in the inside 3. The return spring 57
Normally, the piston 51 is held at the most retracted position. Further, the piston rod 58 penetrates the hydraulic chamber 53 and defines a jaw 6 defining a front end of the hydraulic chamber 53.
Through the cylinder connecting portion 60. The jaw 6 extends downward from the cylinder connecting portion 60 and extends forward in a substantially hook shape. When the shearing machine 1 is used as a rebar cutter for cutting a steel bar W (such as a round bar or deformed rebar)
The movable blade 10 is attached to the distal end of the piston rod 58, and the fixed blade 7 is moved to the jaw 6 so as to face the movable blade 10.
To the front end of the On the other hand, when the shearing machine 1 is used as a punching device for a steel plate, that is, as a puncher, a punch (not shown) is attached to the tip of the piston rod 58, and a fixed die (see FIG. (Not shown) is attached to the front end portion of the jaw 6. Furthermore, a shearing machine 1
Is used for cutting the full screw bolt, a fixed blade (FIG. 5) for cutting the entire screw described later is attached to the front end portion of the jaw 6 so as to face the movable blade 10. The fixed blade 7, the fixed blade for full-screw cutting, or the fixed die cooperates with the movable blade 10 or the punch when the movable blade 10 or the punch advances due to the extension of the piston rod 58, and the bar steel W or the steel plate is removed. Shearing is performed, and the steel bar W is cut at a substantially right angle to the axis thereof, or a steel plate is subjected to drilling.

FIGS. 2 to 4 are views showing a fixed blade and a movable blade according to an embodiment of the present invention, and FIGS.
FIG. 4 is a plan view and a longitudinal sectional view showing a structure around a fixed blade and a movable blade of the shearing machine. FIG. 4 is an elevation view of the fixed blade. FIG.
3, the base 12 of the movable blade 10 is inserted into the piston rod 58, and is integrally supported on the distal end of the piston rod 58 by the fixing screw 13. Cutting blade portion 11 of movable blade 10 protruding from piston rod 58
Is a substantially rectangular parallelepiped shape having a generally flat rectangular front end face, and the movable blade 10 embedded in the piston rod 58.
Are integrally supported by the base 12. The base 12
Has the same form as the base of the punch used for drilling a steel plate or the like, and the movable blade 10 is compatible with the punch. The base 12 is fixed to the distal end of the piston rod 58 by a fixing screw 13. An arc-shaped depression 10a is formed in the front end surface of the cutting edge portion 11, and the depression 10
The radius of curvature R ′ of “a” has a size equal to or slightly larger than the radius of the steel bar W, and is disposed at a position facing the steel bar W. More specifically, the radius of curvature R 'of the depression 10a is 1 /
It is set to be slightly larger than the radius of the 2 inch steel bar, not only for shearing 1/2 inch steel bars, but also for shearing 3/8 inch steel bars, and also for shearing steel bars with standard diameters of mm dimensions. Can also be shared. In addition, the width T of the cutting edge portion 11 in this example is:
It is set to 5.3 mm.

[0013] Fixed blade 7 arranged on the opposite side of movable blade 10
Has a base 74 formed in a generally cylindrical shape. The base 74 is inserted into a drop hole 62 formed in the jaw 6. An end face of the base 74 is in contact with a shoulder 64 formed in the pit 62. A peripheral groove 75 is formed on the outer surface of the base 74. The tip of a fixing screw (not shown) screwed into the jaw 6 engages with the circumferential groove 75, and the fixed blade 7 is held at a predetermined position of the jaw 6. Base 74
Has the same form as the base of the fixed die used for drilling a steel plate or the like, and the fixed blade 7 has compatibility with the fixed die. The fixed blade 7 includes a pair of left and right fixed blade portions 71, 71 integrally supported by a base 74. The fixed blade portions 71, 71 are spaced apart from each other by a predetermined distance, and a slit 72 extending vertically is formed between the fixed blade portions 71, 71. The slit 72 is positioned at a position exactly facing the cutting edge portion 11, and
The cutting blade part 11 is accommodated when 1 is advanced. Slit 7
2 has substantially the same width as the cutting edge portion 11 of the movable blade 10,
The left and right inner surfaces that define the slit 72 are the cutting edge portions 11.
At the time of forward movement, it comes into sliding contact with or close to each side surface of the cutting blade portion 11.

As shown in FIG. 3, each fixed blade portion 71 has a substantially semicircular concave portion 73, and the concave portion 73 is formed in a form complementary to the outer shape of the steel bar W. The concave portion 73 has an inner peripheral surface that is smoothly finished so as to be suitable for cutting a steel bar such as a round bar, and the inner peripheral surface of the concave portion 73 is entirely or partially formed on the outer peripheral surface of the steel bar W to be cut. Touch Further, as shown in FIG. 4, the perpendicular to the central axis of the concave portions 73, 73 is inclined at a predetermined angle γ with respect to the central line of the slit 72. Angle γ is preferably set to an angle of 3 ° to 5 °. As shown in FIG. 3, a hollow portion 76 is formed in the center of the base 74, and the hollow portion 76 is
And communicates with a slit 72 that divides the fixed blade 7 into right and left parts. The pit 62 and the hollow portion 76 are
A broken material discharge path for discharging the broken material punched by the movable blade 10 and the fixed blade 7 is configured. On both sides of a vertically extending slit 72, a pair of left and right fixed blade portions 71, 71 integrally supported by a base portion 74 are provided, and the fixed blade portions 71, 71 are separated from each other by a predetermined distance by the slit 72. They are separated by a distance. The slit 72 is movable blade 1
It is positioned exactly opposite the zero cutting edge portion 11 and houses the cutting edge portion 11 when the cutting edge portion 11 advances.

In use, the recess 7 of each fixed blade portion 71
The movable blade 10 comes into contact with the steel bar W positioned on the fixed blade 7 from the side opposite to the slit 72, with approximately half being accommodated in 3. The recess 10a of the movable blade 10 has its inner peripheral surface pressed by the steel bar W, and the left and right fixed blade portions 71, 71 support the pressing force of the movable blade 10 on both sides of the movable blade 10. Movable blade 1
0 and each fixed blade portion 71 cooperate to shear the steel bar W,
The portion of the steel bar W located in the slit 72 is punched, and the punched out material is discharged out of the machine through the slit 72, the hollow portion 76, and the pit 62. Both sides of the slit 72 are defined by first side walls 77, 77 and second side walls 78, 78. The first side walls 77, 77 extend substantially parallel from the exposed end face of the fixed blade 7 to the bottom of the recess 73, and the second side walls 78, 78 extend from the end portions 79, 79 of the first side walls 77, 77. It extends to the hollow part 76. The second side wall 78 forms an angle β with the first side wall 77, and the broken material discharge path formed by the second side walls 78, 78 is slightly widened toward the hollow portion 76. The end of the second side wall 78 is provided with a small radius R having a radius of about 1 mm, and the second side wall 78 smoothly transitions to the bottom wall 78a.

The fixed blade 7 can be replaced with a fixed screw cutting blade 8 shown in FIG. Like the fixed blade 7, the fixed blade 8 for full screw cutting includes a pair of left and right fixed blade portions 71.
The concave portion 73 of each fixed blade portion 71 is formed in a substantially semicircular shape so as to be substantially complementary to the outer shape of the full screw bolt, and the female screw corresponding to the male screw of the full screw bolt is formed in the inner peripheral portion. In preparation. The perpendicular to the central axis of the concave portions 73, 73 is inclined at a predetermined angle γ with respect to the central line of the slit 72, similarly to the fixed blade 7. Angle γ
Is preferably set to approximately 3 ° to 5 °, more preferably approximately the same as the lead angle of the female screw.
It is set to 0 '. Also, the first side wall 77 of the slit 72
Is close to the thread portion of the female thread, and the thread portion of the portion adjacent to the side wall surface 77 has a thickness of about half the width of the thread. Other structures, shapes and dimensions of the fixed blade 8 for cutting all screws are designed substantially the same as the fixed blade 7. Next, the operation of the shearing machine 1 will be described. By pulling the trigger switch 21 of the portable handle 2 with a finger, the shears 1 is started. The electric motor 3 is operated,
The output shaft 30 and the cam shaft 31 are rotated. The needle bearing 32 located on the outer periphery of the cam shaft 31 rolls, and the pump piston 4 slidingly contacts the outer periphery of the needle bearing 32.
1 is reciprocated. Thus, the pump section 4 supplies the hydraulic oil at a predetermined pressure to the hydraulic chamber 52 of the hydraulic cylinder device 5.

As the pressure in the hydraulic chamber 52 increases, the piston 51
Is moved forward (to the left in FIG. 1) while resisting the elastic force of the return spring 57. Thereby, the piston rod 58 and the movable blade 10 move forward, and the movable blade 10
Shears the steel bar W in cooperation with the fixed blade 7. Piston 5
When 1 moves forward by a predetermined distance, the release valve device 55 is opened, and the hydraulic chamber 52 communicates with the release oil passage 54. Hydraulic oil in the hydraulic chamber 52 flows through a release oil passage 54 through an oil tank 42.
Then, the piston 51 is retracted to the initial position shown in FIG. 1 by the return spring 57, whereby the release valve device 55 is closed. Since the basic operation mode of such a shearing machine is disclosed in detail in the above-mentioned Japanese Patent Application Laid-Open No. 3-189022, a further detailed description will be omitted by referring to the official gazette. Blade 1
The operation of the fixed blade 7 and the fixed blade 7 will be described in detail. The steel bar W to be cut is positioned in the concave portion 73 of the fixed blade 7,
A substantially half portion of the steel bar W is accommodated in the concave portion 73 of each fixed blade portion 71. As the movable blade 10 advances, the depression 10 a of the cutting blade portion 11 is pressed against the surface of the steel bar W. The left and right fixed blade portions 71, 71 support the pressing force of the movable blade 10 on both sides of the movable blade 10, so that the steel bar W is fixed to the fixed blade portions 71, 71.
The movable blade 10 presses the portion of the steel bar W located between the fulcrums toward the fixed blade 7. The movable blade 10 and each fixed blade portion 71 cooperate to shear the steel bar W and punch out a portion between the fulcrums of the steel bar W, that is, a portion of the steel bar W located in the slit 72. Thus, the steel bar W is cut along the left and right inner side surfaces of the slit 72, and substantially parallel cut surfaces are formed on the respective steel bar portions located on both sides of the movable blade 10.

Punched portion between both bar parts (fracture)
Are the slit 72, the hollow portion 76 of the base 74 and the jaw 6
Is discharged out of the machine through a broken material discharge passage formed by a trap hole 62. Generally, since the shearing machine 1 is used in a state where the grip portion 22 is directed upward and the tip of the jaw 6 is directed downward,
The broken material is smoothly discharged below the jaw 6 through the broken material discharge passage. Thus, the shearing machine 1 has a movable blade 10 compatible with a punch and a fixed blade 7 compatible with a die.
The cutting blade portion 11 of the movable blade 10 includes a fixed blade 7,
A pair of left and right fixed blade portions 71, 71, and a fixed blade portion 71,
And a slit 72 disposed between the slits 71. The slit 72 is positioned at a position exactly facing the cutting edge portion 11, and is in sliding contact with the cutting edge portion 11 when the cutting edge portion 11 advances. Or it has substantially the same width as the cutting edge portion 11 so as to accommodate it while being close to it. Such a shearing machine 1
According to this, the fixed blade portions 71, 71 constitute a fulcrum for supporting the steel bar W at two points, and the movable blade 10 is pressed against the steel bar W between the fulcrums. The steel bar W is supported in an extremely stable state,
No axial relief occurs in the steel bar W as seen in the case of the cantilever support structure. Therefore, irregularities, distortions, burrs, and the like hardly occur on the cut surface of the steel bar W.

Moreover, the concave portion 73 of the fixed blade 7 has a smooth inner peripheral surface which is substantially complementary to the outer shape of the steel bar W, and the steel bar such as a round bar or a deformed reinforcing bar is positioned in the concave portion 73. Is positioned at a predetermined cutting position of the shearing machine 1,
The cutting position is held in a relatively stable state. Furthermore,
The shearing machine 1 has a configuration in which the fixed blade 7 is divided into two fixed blade portions 71, 71, and the slit 72 of the fixed blade 7 is communicated with the broken-out hole 62 of the main body of the shearing machine 1. The broken material is divided into the slit 72, the hollow portion 76 and the pit 6
It is discharged smoothly outside the machine through the broken material discharge path consisting of 2 pieces. Moreover, by adopting such a structure of the fixed blade 7, the structure for mounting the movable blade 10 on the piston rod 58 is greatly simplified. Also, in actual work,
In many cases, the work of cutting the steel bar W is required in the workplace related to the work of cutting the full thread bolts and the work of drilling the steel plate. Since the shearing machine 1 of the above embodiment can use the fixed blade 8 for cutting all screws or the movable blade 10 and the fixed blade 7 which can be replaced with a punch and a die for puncher, it is very convenient for actual on-site work. Can respond. That is, the above-described shearing machine 1 having a main body common to a rebar cutter, a full-screw cutter and a puncher can be used for various kinds of applications by appropriately changing cutting tools. Related work can be performed,
In view of its practicality, it has extremely high added value and brings great convenience.

Further, in the above-mentioned shearing machine 1, an arc-shaped depression 10a having a radius of curvature equal to or slightly larger than the radius of the steel bar W is provided.
Is formed on the movable blade 10, and the inner peripheral surface of the recess 10 a contacts the outer periphery of the steel bar W and presses it toward the slit 72. Accordingly, since the pressing force applied by the movable blade 10 is relatively evenly applied to the steel bar W, a large shear distortion is hardly generated in the steel bar W, and a good finish of the cut surface can be realized. Further, in the shearing machine 1, the second side wall 78 defining the slit 72 is tapered, and the second side wall 78, 7
8 forms a broken material discharge path slightly expanded toward the hollow portion 76, so that the broken material generated by shearing can smoothly pass through the slit 72 to the hollow portion 76 and the drop hole 62. Thus, it is possible to reliably prevent the previous broken material from remaining in the slit 72. Therefore, the remaining broken material pushes and expands the slit 72 by the subsequent shearing operation, whereby the crack near the bottom wall 78a of the slit 72 is formed. Can be avoided beforehand. Moreover, the second side wall 78 and the bottom wall 7
Since a small-diameter R-attached portion is provided at the intersection with 8a, the induction of such cracks can be reliably prevented. In addition, the base 74 of the fixed blade 7 formed in a generally cylindrical shape
Does not have a collar or collar, the end face of which abuts the shoulder 64 of the pit 62, and substantially all the load acting on the fixed blade 7 during the shearing operation is the end face of the shoulder 64 and the base 74. Is supported by the reaction force generated. According to the fixed blade 7, it is possible to prevent a situation in which the collar or the collar is damaged or damaged due to the shear stress acting on the collar or the collar.

According to the knowledge of the present inventor, the value of the clearance between the fixed blade portion 71 and the cutting blade portion 11 of the movable blade 10 (slit width S−movable blade width T) is 0.3 to 0.1 mm. 8
By setting the thickness to 0.4 mm, preferably 0.4 mm to 0.7 mm, no distortion or step occurs on the cut surface of the steel bar W, and further, it is difficult to generate burrs on the cut surface. The value of the clearance is, even if the material of the bar to be cut is stainless steel or mild steel, as long as the value is within the above range, regardless of the material of the bar to be cut, the distortion or the step of the cut surface Also, burrs on the cut surface hardly occur. Thus, the clearance between the cutting edge portion 11 in the slit 72 is set to 0.3 to 0.8 mm, preferably 0.4 mm to 0.7 mm. Steps and burrs on the cut surface can be effectively eliminated. As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various modifications or changes can be made within the scope of the invention described in the claims. Needless to say, they are also included in the scope of the present invention. For example, the front end surface of the cutting blade portion may be formed as a completely flat front end surface without providing a recess in the cutting blade portion of the movable blade.

[0022]

According to the first aspect of the present invention, a bar steel such as a round bar and a deformed reinforcing bar can be easily and accurately positioned at a predetermined position of a shearing machine. A shearing machine capable of simplifying the structure and the structure for discharging broken material can be provided. According to the configuration of the present invention described in claim 2, the cutting edge portion has an arc-shaped depression provided with an inner peripheral surface that comes into contact with the outer periphery of a bar steel such as a round steel. Accept smoothly. According to the configuration of the present invention described in claim 3, the shearing machine of the present invention has both functions of a shearing machine for cutting steel bars (rebar cutter) and a shearing machine for punching steel materials (puncher), and is used for actual work. The ability to adapt very well to the process brings great convenience. Claim 4
According to the configuration of the present invention described in the above, the fixed blade is configured to be compatible with the fixed blade provided with an internal thread, and the cutting and cutting of steel bars (round bars, deformed reinforcing bars, etc.) by the same shearing machine. Enables cutting of all screw bolts. According to the configuration of the present invention described in claim 5, since the side wall defining the slit constitutes a broken material discharge path expanding toward the hollow portion, the previous broken material remains in the slit. Can be reliably prevented,
Thus, it is possible to prevent a crack from being generated near the bottom of the slit.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a shearing machine according to an embodiment of the present invention.

FIG. 2 is a plan view showing a structure around a fixed blade and a movable blade of the shearing machine according to the embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a structure around a fixed blade and a movable blade of the shearing machine shown in FIG. 2;

FIG. 4 is an elevation view of the fixed blade shown in FIGS. 2 and 3;

FIG. 5 is an elevation view of a fixed blade for cutting a full screw bolt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shearer 6 Jaw 7 Fixed blade 10 Movable blade 10a Depression 11 Cutting blade part 12 Base 58 Piston rod 71 Fixed blade part 72 Slit 73 Depression 74 Base W Steel bar

Claims (5)

(57) [Claims] A movable blade attached to a front end portion of a piston rod, and a fixed blade attached to a main body, wherein a bar steel such as a round bar or a deformed reinforcing bar is cut by the movable blade and the fixed blade. In the shearing machine, the movable blade has a cutting blade portion whose front end is pressed against the steel bar when the movable blade advances, and the fixed blade is provided between the left and right fixed blade portions and the fixed blade portion. And the fixed blade portion includes a concave portion having a shape substantially complementary to the outer shape of the steel bar, wherein the slit faces the cutting blade portion, and the cutting blade portion has It is positioned at the position for accommodating the cutting blade portion when it advances, and communicates with a broken material drop hole formed in the shearing device main body to constitute a broken material discharge path, and the concave portion of the fixed blade portion is smooth. Inner peripheral surface, and the concave portion is provided on both sides of the movable blade. A shearing machine for supporting the steel bar, wherein the movable blade presses the steel bar between left and right fixed blade portions to cut the steel bar. 2. The shearing machine according to claim 1, wherein the cutting edge portion has an arc-shaped depression having an inner peripheral surface abutting on an outer periphery of the steel bar. 3. The shearing machine according to claim 1, wherein the fixed blade and the movable blade are compatible with a puncher die and a punch, respectively. 4. A shearing machine according to claim 1, wherein said fixed blade is compatible with a fixed blade for cutting a full-thread bolt provided with an internal thread. 5. The fixed blade has a hollow portion communicating with a puncture hole of a broken material provided in a main body, the hollow portion communicating with a bottom portion of the slit, and a side wall defining the slit. The shearing machine according to any one of claims 1 to 4, wherein the taper is provided, and the side wall forms a fractured material discharge path which is expanded toward the hollow portion.