JPH0711857Y2 - Bar cutter - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rod cutter for cutting a metal rod by a movable blade provided on a piston rod of a hydraulic cylinder and a fixed blade fixed in position.

[0002]

2. Description of the Related Art (a) A main body frame, and (b) a hydraulic cylinder which is integrally provided on the main body frame and drives a piston rod in a straight line direction by hydraulic pressure,
(C) A movable blade fixed to the tip end portion of the piston rod, and (d) a fixed blade fixed to the main body frame, and the movable rod and the fixed blade are separated by the protrusion of the piston rod. A bar cutter for cutting metal bars such as reinforcing bars, steel bars and bolts is known.
The bar cutter disclosed in Japanese Utility Model Publication No. 53-47269 is an example.

[0003]

However, such a conventional rod cutter has a drawback that the piston rod escapes in a direction perpendicular to its axis due to the cutting resistance of the metal rod. Therefore, when cutting the bar material, the cutting surface of the bar material is inclined with the gap between the fixed blade and the movable blade open, for example, when the other bar material is butt-welded to the cut surface.
The work of grinding the cut surface at a right angle with a grinder or the like is troublesome and time-consuming. Further, since the double-edged tool will cut the bar material in an unreasonable posture, the force necessary for cutting is increased and the wear of the cutting edge is promoted,
When the sharpness of the cutting edge deteriorates and the sharpness of the piston rod increases, a vicious cycle occurs. Further, there is a disadvantage that twisting occurs at a fitting sliding portion between the piston rod and the cylinder body, and local wear progresses to shorten the useful life of the hydraulic cylinder or cause oil leakage.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the escape of the piston rod when the rod is cut.

[0005]

In order to achieve the above object, the present invention provides (a) a main body frame, (b) a hydraulic cylinder, (c) a movable blade, and (d) a fixed blade. A rod cutter for cutting a metal rod such as a reinforcing bar between a movable blade and a fixed blade by ejecting a piston rod of a hydraulic cylinder, wherein (e) a guide parallel to the axis of the piston rod. The body frame is provided with a surface, and the portion of the piston rod protruding from the hydraulic cylinder or the movable blade is brought into sliding contact with the guide surface thereof, so that the piston rod has its shaft when cutting the metal rod. It is characterized by having a backup that prevents it from escaping in a direction perpendicular to the heart.

[0006]

In such a bar cutter, a backup having a guide surface parallel to the axial center of the piston rod is provided in the main body frame, and the guide surface has a portion protruding from the hydraulic cylinder of the piston rod or By sliding the movable blade fixed to the piston rod, it is possible to prevent the piston rod from escaping in the direction perpendicular to the axis when cutting the rod material. There is no gap between the bar and the cutting surface of the bar material is almost at right angles to its axis, and even if butt welding is performed after that, it is easy to grind the cutting surface with a grinder, etc. Since the bar material can be reasonably cut with a relatively small force, wear of the cutting edge is reduced and the life of the cutting tool is extended. Further, since no twist is generated at the fitting sliding portion between the piston rod and the cylinder body, the service life of the hydraulic cylinder is not shortened or oil leaks due to local wear.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram showing the overall construction of a handy type bar cutter 10 which is an embodiment of the present invention. A grip portion 12 and a switch 14 provided on the grip portion 12 are pushed. While the pump driving electric motor 16 is turned on only while the electric motor 16 is rotating, a gear mechanism for transmitting the rotational force of the electric motor 16 and the like, a first housing 20 to which a tank 18 is attached, a hydraulic pump and valves are provided. Second housing 22 accommodated and hydraulic cylinder 2
4 and the cutting jig 26 are integrally provided.

In the first housing 20 and the second housing 22, the rotation of the output shaft 28 of the electric motor 16 is rotated by the gears 30, as shown in FIG.
A rotary shaft 34 transmitted via 32 is rotatably held, and a pump chamber 36 is provided in a direction orthogonal to the rotary shaft 34 so that a plunger 4 of a hydraulic pump 38 is provided.
0 is fitted so as to be movable in the axial direction. Plunger 4
0 is always rotated by the compression coil spring 44 inserted between the plug 42 forming the pump chamber 36 and the rotary shaft 3
The eccentric cam 46 provided on the rotating shaft 34 is urged to the 4 side and abuts against the eccentric cam 46 via a needle bearing 48. When the rotating shaft 34 is rotationally driven by the electric motor 16, it reciprocates in the axial direction. Pump room 3 moved
Increase or decrease the volume of 6. The pump chamber 36 allows the inflow of hydraulic oil into the pump chamber 36, but flows out, as is apparent from FIG. 4 showing the cross section of the second housing 22 and FIG. 5 showing the VV cross section of FIG. Is communicated with the intake oil passage 52 through a check valve 50 that blocks the discharge oil passage 56 through a check valve 54 that allows the hydraulic oil to flow out of the pump chamber 36 but blocks the inflow. Is in communication with
The hydraulic oil is sucked from the suction oil passage 52 and discharged to the discharge oil passage 56 as the volume of the plunger 40 increases and decreases due to the reciprocating movement of the plunger 40. The hydraulic pump 38 is configured as described above.

The intake oil passage 52 is opened to an oil storage chamber 58 shown in FIG. 3, and the oil storage chamber 58 is connected to the tank 18 via an oil passage 60.
The tank 18 has a bottomed cylindrical metal housing 62 having an opening screwed into the first housing 20, and is housed in the housing 62, and the opening is fixed to the inner wall surface of the housing 62 by a seal ring 64. And a rubber tank 66 having a bottomed cylindrical shape. The oil storage chamber 58 is communicated with the rubber tank 66. The rubber tank 66 is filled with hydraulic oil and is expanded or contracted according to the amount of the oil. A ventilation hole 68 is formed in the housing 62 to communicate the inside with the atmosphere.

On the other hand, the discharge oil passage 56 is shown in FIG.
It is communicated with the valve chamber 72 of the switching valve 70 shown in FIG. 6 which is a VI-VI cross section. The valve chamber 72 is
The opening of a bottomed circular hole formed in the second housing 22 is closed by a plug 74, and the discharge oil passage 56 is opened at the lower end of the valve chamber 72, that is, the end on the plug 74 side. . A main valve body 76 is fitted in the valve chamber 72 so as to be slidable in the axial direction, and the main valve body 76 is constantly urged toward the plug 74 by a compression coil spring 78. A circular hole 80 having a bottom is formed in the main valve body 76 from the end portion on the plug 74 side. The circular hole 80 is fitted to the protruding shaft 82 provided at the tip portion of the plug 74, and at the bottom portion of the circular hole 80. Is formed with a small circular hole, and a needle valve type auxiliary valve body 84 is disposed so as to be movable in the axial direction. The sub valve body 84 is always urged in a direction opposite to the plug 74, that is, a direction protruding from the main valve body 76 by a compression coil spring 86 interposed between the sub valve body 84 and the rear end portion. The collar portion provided on the abutment portion is brought into contact with the bottom portion of the circular hole 80 to prevent the protrusion of a certain amount or more. The spring force of the compression coil spring 86 is sufficiently weaker than that of the compression coil spring 78, and the main valve body 76 is operated via the sub valve body 84.
It is always moved to the plug 74 side against the biasing force of 6, and is fitted to the protruding shaft 82. Further, the oil supply / discharge passage 8 communicating with the hydraulic cylinder 24 is provided at an intermediate portion of the valve chamber 72.
8 is opened, a discharge oil passage 90 communicating with the oil storage chamber 58 is opened at the end opposite to the plug 74, and a plurality of passages are provided in the cylindrical portion of the main valve body 76. An oil hole 92 is provided. The sub-valve element 84 includes the plug 7
4 is moved in the opposite direction to the discharge oil passage 90.
Is to be seated in the opening of the valve and the discharge oil passage 90 is closed. In addition, FIG. 4 shows IV- in FIG.
It is a figure corresponding to a IV cross section.

The switching valve 70 thus constructed is
When the hydraulic pump 38 is operated by the electric motor 16 to supply hydraulic oil from the discharge oil passage 56 into the valve chamber 72, the hydraulic pressure causes the main valve body 76 to resist the urging force of the compression coil spring 78. The auxiliary valve element 8 is moved in a direction away from the plug 74, and as shown in FIG.
4 closes the opening of the discharge oil passage 90 according to the urging force of the compression coil spring 86, and the main valve body 76 is moved to a position where the protruding shaft 82 relatively comes out from the circular hole 80, and Gap with circular hole 80 and oil passage hole 9
The discharge oil passage 56 is communicated with the oil supply / discharge oil passage 88 via 2. As a result, the hydraulic oil pumped from the hydraulic pump 38 is supplied to the hydraulic cylinder 24. When the electric motor 16 is stopped and hydraulic oil is no longer supplied from the hydraulic pump 38, the main valve body 76 is moved to the plug 74 side according to the biasing force of the compression coil spring 78, as shown in FIG. As described above, the protruding shaft 82 is relatively fitted in the circular hole 80 of the main valve body 76, and the auxiliary valve body 84 resists the biasing force of the compression coil spring 86 as the main valve body 76 moves. Then, the discharge oil passage 90 is separated from the opening, and the discharge oil passage 90 and the supply / discharge oil passage 88 communicate with each other. This allows the hydraulic oil in the hydraulic cylinder 24 to return to the oil storage chamber 58 and further to the tank 18 via the oil supply / discharge oil passage 88 and the oil discharge passage 90. In addition, circular hole 8
0 is provided between the inner peripheral surface and the outer peripheral surface of the protruding shaft 82 so that the main valve body 76 can be returned to the position where the main valve body 76 abuts on the plug 74 by the working oil flowing through the gap. It has become.

A relief valve 94 is provided in the second housing 22 and is connected to the oil supply / discharge oil passage 88 via a branch oil passage 96. This relief valve 94
Is equipped with a relief valve 100 that always closes the opening of the branch oil passage 96 by a compression coil spring 98. When the hydraulic pressure in the oil supply / exhaust passage 88 becomes higher than necessary, the relief valve 100 is provided. Is pushed back against the biasing force of the compression coil spring 98, so that the opening of the branch oil passage 96 is opened and the hydraulic oil in the oil supply / discharge oil passage 88 is discharged.
To the oil storage chamber 58.

On the other hand, the hydraulic cylinder 24 and the cutting jig 26 are shown in detail in FIG. 8 which is a front view thereof, FIG. 1 which is a plan view thereof and FIG. 9 which is a IX-IX cross section of FIG. The hydraulic cylinder 24 includes a cylinder tube 112 fixed to the end surface of the second housing 22 by three bolts 110, and a body frame 1 of the cutting jig 26.
A cylinder cap portion 116 provided integrally with
A piston 118 slidably fitted in the cylinder tube 112. The cylinder tube 112 has a bottomed cylindrical shape, is fixed to the second housing 22 on the bottom portion 120 side, and the bottom portion 120 has an additional member formed between the piston 118 and the bottom portion 120. A communication hole 124 for communicating the pressure chamber 122 with the oil supply / discharge passage 88 is provided. Cylinder cap part 1
16 is provided with a female screw, which is screwed into a male screw provided on the outer peripheral surface of the cylinder tube 112,
The lock nut 126 is positioned at an arbitrary screwing position and is integrally connected to the cylinder tube 112.

The cylinder tube 112 is fixedly mounted on the second housing 22 in a predetermined posture around the axis thereof.
6, that is, the cylinder tube 11 of the body frame 114
The posture with respect to 2 is appropriately determined by the screwing amount, and in FIG.
1 and 8 are combined in a state in which the main body frame 114 is rotated by 90 ° around the axis of the cylinder tube 112 as compared with FIG. . The lock nut 126 is firmly brought into contact with the end surface of the cylinder cap portion 116 to position the body frame 114 and the cylinder tube 112 such that they cannot rotate relative to each other. Although illustration is omitted, the lock nut 126 is provided with a plurality of notches on the outer peripheral surface for locking the tightening tool.

Further, an insertion hole 132 is formed in the cylinder cap portion 116, a piston rod 134 integrally formed with the piston 118 is slidably inserted therein, and the scraper 13 is inserted in the insertion hole 132.
6 is installed. O-ring 13 on piston 118
8 is attached to the inner surface of the cylinder tube 112 to form an oil-tight seal, and hydraulic oil is supplied into the pressurizing chamber 122 so that the piston 118 moves to the left in FIGS. 1 and 8. That is, when the operation of the hydraulic pump 38 is stopped and the hydraulic pressure of the hydraulic oil is lowered while the piston rod 134 is moved in the direction of protruding, the piston 118 is inserted between the cylinder cap portion 116 and the cylinder cap portion 116. The hydraulic oil in the pressurizing chamber 122 is moved toward the bottom 120 side while being pushed out from the communication hole 124 according to the biasing force of the compression coil spring 140. When the hydraulic pump 38 stops, the switching valve 70 is switched to connect the oil supply / exhaust oil passage 88 and the oil discharge passage 90, so that the hydraulic oil in the pressurizing chamber 122 can be pushed out. The piston 118 and the cylinder cap 116
The space between and is communicated with the atmosphere via a vent hole (not shown) provided in the cylinder cap portion 116. The hydraulic cylinder 24 is configured as described above. FIG. 10 is a circuit diagram showing a series of hydraulic circuits provided in the rod cutter 10 of this embodiment.

Even when the piston rod 134 is pulled into the hydraulic cylinder 24, the tip end of the piston rod 134 protrudes from the cylinder cap portion 116 to the outside, and the tip end of the piston rod 134 is parallel to the shaft center. A mounting surface 142 is formed, and a receiving surface 144 facing the protruding direction of the piston rod 134 is provided, and the movable blade 146 includes the blade mounting surface 142 and the receiving surface 1.
It is fixed by two bolts in a state of being in surface contact with and closely contacting with 44. The movable blade 146 has a plate-like rectangular parallelepiped shape, and has four cutting edges 148a, 148b, 148c, 148d (hereinafter,
Unless otherwise specified, it is simply referred to as a cutting edge 148), and these cutting edges 148 are attached in a posture in which the cutting edges 148 are parallel to the tool attaching surface 142 and are substantially perpendicular to the axis of the piston rod 134. A cutting edge 148, in the figure, a cutting edge 148a at a position apart from the blade mounting surface 142 on the tip side of the piston rod 134, is used to cut the bar material 128. By inverting the movable blade 146 in the front-rear direction and the left-right direction in FIG. 8, any one of the four cutting edges 148 is used for cutting. In addition, FIG.
The length dimension of the movable blade 146 in the vertical direction is larger than the length dimension of the blade mounting surface 142, and the upper end portion and the lower end portion of the movable blade 146 extend vertically from the piston rod 134.

The body frame 114 of the cutting jig 26, which is integrally connected to the hydraulic cylinder 24 via the cylinder cap portion 116, has a tip end side in the axial direction of the hydraulic cylinder 24, that is, a direction in which the piston rod 134 projects. The fixed blade 150 for cutting the rod 128 is fixed between the movable blade 146 and the movable blade 146 when the piston rod 134 is projected. That is, at the tip of the body frame 114, the blade mounting surface 1 is parallel to the axis of the piston rod 134.
52 is formed and a receiving surface 154 facing the protruding direction of the piston rod 134 is provided, and the fixed cutting tool 150 has the cutting tool mounting surface 152 and the receiving surface 154.
It is fixed by two bolts in a state of being in surface contact with and in close contact with. The fixed blade 150 is the movable blade 146.
Similarly to the above, four cutting edges 156a, 156b, 15 each having a plate-like rectangular parallelepiped shape and each having a cutting edge angle of about 90 ° are formed.
6c and 156d (hereinafter, simply referred to as cutting edge 156 unless otherwise specified).
6 is parallel to the blade mounting surface 152 and the piston rod 13
The cutting edge 156, which is attached at a position substantially perpendicular to the shaft center of No. 4, on the hydraulic cylinder 24 side and apart from the blade attachment surface 152, is the cutting edge 156a in the figure.
It is used for cutting 28. Before and after the fixed blade 150 in FIG.
By turning left and right, the above four cutting edges 156
Any one of these will be subjected to cutting. Further, the portion of the main body frame 114 to which the fixed blade 150 is attached, and the piston rod 134 in a state where the piston rod 134 is drawn into the hydraulic cylinder 24.
A U-shaped notch 158 is formed in a portion between the blade and the tip of the rod, so that the bar member 128 can be relatively inserted between the blades 146 and 150.

The body frame 114 is also integrally provided with a pair of backups 160, 162 which are brought into surface contact with the upper end and the lower end of the movable blade 146 extending vertically in the piston rod 134 in FIG. . For the backup 160, 162, the fixed blade 1
Flat guide surfaces 164 and 166 are formed in parallel with the blade mounting surface 152 on which the movable blade 50 is mounted.
Among the above-mentioned upper end and lower end of 46, the blade mounting surface 142
The surfaces on the side to be closely attached to the guide surfaces 164, 1
By being brought into surface contact with 66, the movable blade 14
6 Furthermore, the piston rod 134 is the piston rod 13
The cutting edge 148 of the movable blade 146 around the axis of 4.
Is held in a constant posture in parallel with the cutting edge 156 of the fixed blade 150, and is guided in the axial direction of the piston rod 134. The guide surfaces 164, 1
The distance between the blade 66 and the blade mounting surface 152 in the direction perpendicular to these surfaces is substantially the same as or slightly larger than the total thickness of the blades 146 and 150.

A backup bolt 168 is screwed into the main body frame 114, and when the bar 128 is cut, the portion located on the fixed blade 150 side in the axial direction of the bar 128 is the hydraulic cylinder 24 side, that is, in FIG. Prevents escape to the right. This backup bolt 1
The screwing amount of 68 is changed according to the diameter dimension of the rod member 128, and is positioned by the lock nut 170.

Next, the operation of the rod cutter 10 having the above structure will be described.

First, if necessary, the screwing amount of the cylinder cap portion 116 into the cylinder tube 112 is changed depending on the posture of the rod member 128 to be cut, the preference of the operator, and the like.
The posture of the cutting jig 26 around the axis of the cylinder tube 112, in other words, the posture of the cutting jig 26 with respect to the grip portion 12 of the rod cutter 10 is adjusted, and the backup bolt is adjusted according to the diameter of the rod 128. 1
Adjust the screwing amount of 68. Next, the grip portion 12 of the bar cutter 10 is gripped, and the notch 15 of the cutting jig 26 is held.
The rod cutter 10 is moved so that the cutting portion of the rod 128 is located inside the rod 8, and the switch 14 is pushed in that state.

When the switch 14 is pushed in, the electric motor 16 is operated, hydraulic oil is pumped to the switching valve 70 by the hydraulic pump 38, and the switching valve 70 is connected to the discharge oil passage 56 by the hydraulic pressure of the hydraulic oil. The hydraulic fluid pumped from the hydraulic pump 38 is switched to connect the supply / discharge oil passage 88 and cut off the communication between the supply / discharge oil passage 88 and the discharge oil passage 90.
Flows in. As a result, the piston rod 134 of the hydraulic cylinder 24 is projected and the piston rod 13
The movable blade 146 fixed to the tip of the rod 4 and the fixed blade 150 fixed to the main body frame 114.
8 is cut. In this case, in this embodiment, since the movable blade 146 is guided by the backups 160 and 162, the piston rod 134 bends in the direction perpendicular to the axial center of the movable blade 146 due to cutting resistance or the like and the movable blade 146 is fixed. There is no danger of escaping from the blade 150, and the bar material 128 is satisfactorily cut by the two blades 146 and 150.

When the pushing operation of the switch 14 is released after the cutting of the rod 128, the operation of the electric motor 16 is stopped and the hydraulic oil is no longer supplied from the hydraulic pump 38 to the switching valve 70, the discharge oil passage 90 is formed. Since the supply / discharge oil passage 88 is communicated, the piston 118 of the hydraulic cylinder 24 is pushed back according to the urging force of the compression coil spring 140, and the working oil in the pressurizing chamber 122 is supplied / exhausted.
And the oil storage chamber 58 via the discharge oil passage 90, and further the tank 1
Returned to 8 As a result, the piston rod 134, to which the movable blade 146 is fixedly installed, is pulled back into the hydraulic cylinder 24, and a series of bar material cutting operations is completed. The pullback operation of the piston rod 134 is performed by the switch 14
It is performed at any time by releasing the pushing operation of. Further, when the pushing operation of the switch 14 is continued even after the piston rod 134 reaches the protruding end, the relief valve 94 is opened by the increase of the hydraulic pressure, and the hydraulic oil supplied from the hydraulic pump 38 is the branch oil. It is returned from the passage 96 into the tank 18 via the oil discharge passage 102.

As described above, in the bar cutter 10 of this embodiment, the movable blades 146 are backed up by the backups 160 and 162, and the bar cutters 10 are prevented from escaping in the direction away from the fixed blade 150 when the bar 128 is cut. . Therefore, the gap between the fixed blade 150 and the movable blade 146 does not open, and the cut surface of the rod 128 is always substantially perpendicular to the axial center of the rod 128. Even if butt welding such as gas pressure welding is performed thereafter, the grinder is used. It facilitates the work of grinding the cut surface by a tool such as
Since 8 can be cut without difficulty, wear of the cutting edges 148 and 156 is reduced, and the lives of the blades 146 and 150 are improved. Further, since no twisting is generated at the fitting sliding portion between the piston rod 134 and the insertion hole 132, the wear life of the hydraulic cylinder 24 is shortened due to local wear, and a double-acting cylinder is used as the hydraulic cylinder 24. There is no risk of oil leaks when adopted.

On the other hand, in this embodiment, a pair of backups 1
Since the upper and lower ends of the movable blade 146 are backed up by 60 and 162, it is easy to secure a large contact area as compared with the case where the piston rod 134 is backed up. Further, since the backups 160 and 162 restrict the rotation of the piston rod 134 around the axis, for example, a rotation-stop key is provided on the outer peripheral surface of the piston rod 134, and a key groove is provided in the insertion hole 132 so that the piston rod 134 is provided. It becomes unnecessary to perform detent of 134.

Further, in this embodiment, the cylinder tube 11 is used.
The main body frame 114 of the cutting jig 26 is screwed to the cutting jig 26.
The posture of the cutting jig 26 around the axis of 12 can be arbitrarily changed to improve the workability when cutting the bar 128, and compared with the case where both are integrally connected using a bolt. The bar cutter 10 is compact and lightweight. That is, between the cylinder tube 112 and the main body frame 114, a reaction force having substantially the same magnitude as the thrust of the piston 118, specifically, a large force required for cutting the rod 128 is applied in a direction in which they are separated from each other. Therefore, when connecting using bolts, it is necessary to dispose a large number of bolts around the entire circumference of the cylinder tube 112.

Further, in this embodiment, the single-acting hydraulic cylinder 24 is used, and the changeover valve 70 which is switched depending on the supply state of the hydraulic oil from the hydraulic pump 38 is adopted, and the hydraulic cylinder 24 is pushed by pushing the switch 14. While the piston rod 134 is pushed out, the piston rod 134 is pulled in by releasing the pushing operation, so compared with, for example, the one in which the operation stop of the hydraulic pump 38 and the switching of the valve need to be respectively switched by a switch or the like. Thus, the operation becomes easy, and particularly in the handy type bar cutter 10 of this embodiment, the burden on the operator is greatly reduced and the work efficiency is improved. The rod cutter disclosed in Japanese Utility Model Publication No. 53-47269 is designed to automatically return when the piston rod 134 reaches the protruding end.
While the piston rod 134 cannot be returned midway, in the present embodiment, the piston rod 134 can be returned at any time simply by releasing the pressing of the switch 14, so that, for example, the blades 146, 150 bite the rod 128. The piston rod 134 can be easily and quickly retracted even when the piston rod 134 does not move due to being caught or an obstacle is found during the projection of the piston rod 134.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the main body frame 114 of the cutting jig 26 is connected to the cylinder tube 112 so as not to rotate relative to it.
As shown in FIG. 5, a notch 172 is provided at the tip end of the cylinder cap portion 116 of the main body frame 114 with an arbitrary angular width, for example, an angular width of about 90 °, and the cylinder cap portion 116 is screwed. The engagement pin 174 is erected on the outer peripheral surface of the cylinder tube 112,
The engagement between the notch 172 and the engagement pin 174 may prevent the cylinder cap portion 116 from slipping out and allow relative rotation within an arbitrary angular range.

Further, as shown in FIG. 12, the tip end portion of the cylinder tube 112 is made thin by leaving the male screw portion on the outer peripheral side, and an engaging pin 180 is driven into the end surface of the step portion to be fixedly mounted. In the state where the cylinder cap portion 116 is provided with a screw hole 182 and the cylinder tube 112 and the cylinder cap portion 116 are screwed together, a hexagon socket screw 186 having an engaging projection 184 at the tip is attached to the screw hole 182. It is also possible to screw it in and to make the relative rotation of approximately 360 ° possible while preventing the cylinder cap portion 116 from slipping out by the engagement between the engagement protrusion 184 and the engagement pin 180. The screw 186 is a screw hole 18
2 and the lock screw 188 is screwed into the screw hole 182 later and is pressed against the rear end portion of the screw 186, so that the screw 186 cannot be rotated by the cylinder cap portion 116. Fixed to. Note that the engagement pin 180 may be directly provided upright on the tip surface of the cylinder tube 112 without thinning the tip portion of the cylinder tube 112.

Further, it is also possible to form a female screw on the cylinder tube 112 and provide a male screw on the cylinder cap portion 116 so as to screw them together. It should be noted that, as in the conventional case, a large number of bolts may be used to connect the two together.

Further, in the above embodiment, the pair of backups 160 and 162 are integrally provided on the main body frame 114, but the main body frame 11 is formed by using a backup member formed separately from the main body frame 114 by bolts or welding.
It may be fixed to No. 4.

Further, the backup may be a sliding contact with the piston rod 134, or may be a backup of the piston rod 134 via a sliding contact member fixed to the piston rod 134. In that case, it is also possible to use a backup having a curved arc-shaped guide surface corresponding to the outer peripheral surface of the piston rod 134. In that case, the rotation of the piston rod 134 can be stopped by a rotation stop key or the like. Become.

Further, in the above embodiment, the case where the present invention is applied to the handy type bar cutter 10 has been described, but the present invention can be similarly applied to the stationary bar cutter.

Further, in the switching valve 70 of the above embodiment, the compression coil spring 86 is inserted between the sub valve body 84 and the plug 74, but it is interposed between the main valve body 76 and the sub valve body 84. It does not matter if you insert it. Other switching valves such as an electromagnetic switching valve that is switched by a switch operation can be used, and a double-acting hydraulic cylinder in which a piston is reciprocally moved by hydraulic pressure can also be used.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

1 is a plan view showing a jig and a hydraulic cylinder for cutting the bar cutter of FIG. 2 which is an embodiment of the present invention.

FIG. 2 is a front view of a bar cutter that is an embodiment of the present invention.

FIG. 3 is a partial vertical cross-sectional view showing the vicinity of a hydraulic pump of the rod cutter of FIG.

4 is a cross-sectional view of a second housing portion of the bar cutter of FIG. 2 provided with a hydraulic pump, IV in FIG.
It is a figure corresponding to a IV cross section.

5 is a sectional view taken along line VV in FIG.

6 is a sectional view taken along line VI-VI in FIG.

7 is a cross-sectional view showing a state where the oil passage connection state of the switching valve shown in FIG. 6 is switched.

FIG. 8 is a front view in which a cutting jig and a hydraulic cylinder of the bar cutter of FIG. 2 are partially cut away.

9 is a sectional view taken along line IX-IX in FIG.

10 is a hydraulic circuit diagram of the bar cutter of FIG. 2. FIG.

FIG. 11 is a perspective view showing a main part of another embodiment of the present invention.

FIG. 12 is a view showing a main part of still another embodiment of the present invention,
FIG. 9 is a diagram corresponding to FIG. 8.

[Explanation of symbols]

 10: Rod Cutter 24: Hydraulic Cylinder 114: Body Frame 128: Bar Material 134: Piston Rod 146: Movable Blade 150: Fixed Blade 160, 162: Backup 164, 166: Guide Surface

Claims (1)

[Scope of utility model registration request] 1. A main body frame, a hydraulic cylinder integrally provided on the main body frame for driving a piston rod in a straight line direction by hydraulic pressure, a movable blade fixed to a tip end portion of the piston rod, and the main body. With a fixed blade fixed to the frame, in a rod cutter for cutting metal rods such as reinforcing bars between the movable blade and the fixed blade by protruding the piston rod,
The metal rod is provided on the main body frame with a guide surface parallel to the axis of the piston rod, and the portion of the piston rod protruding from the hydraulic cylinder or the movable blade is slidably contacted with the guide surface to make the metal frame. A bar cutter having a backup for preventing the piston rod from escaping in a direction perpendicular to the axis when the bar is cut.