JPS643579Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a torch attachment device for a cutter that mainly cuts steel bars such as reinforcing bars.

Generally, when cutting steel materials with gas, when it is required to minimize the roughness of the cut surface, for example, an automatic gas cutting machine that cuts by itself by attaching a torch to an electric trolley and running it at a constant speed is used. It is necessary to use

By the way, with this type of automatic gas cutting machine, if appropriate cutting conditions are selected using the precisely machined cutting tip, the cut surface of the workpiece will be 1/100.
It is possible to reduce the unevenness to about mm. Therefore, for example, if an automatic gas cutting machine is used for reinforcing steel,
When gas pressure welding is performed in a later process, it is preferable to do so because it facilitates the finishing process of the cut surface.

However, when this automatic gas cutting machine needs to cut steel bars such as reinforcing bars as necessary at construction sites, etc., it is necessary to prepare a power supply and the equipment is large-scale. There was a problem of not being able to handle the work.

On the other hand, when manually moving the torch of a gas cutting machine to cut reinforcing steel,
Due to instability in the holding angle and moving speed of the workpiece, the cut surface is not necessarily perpendicular to the reinforcing bar axis, the entire cut surface is not flat, and the depth of the dragline groove is also uncertain. This often results in deep grooves.

On the other hand, in gas pressure welding of reinforcing bars, for example, when two reinforcing bars are butted against each other, the gap between the end faces must be 3 mm or less, and the surfaces to be welded must be thoroughly ground to remove any rust or other deposits. It is required to remove the contact surface and make the pressure contact surface as flat as possible.

Therefore, until now, there has been a problem in that it is not easy in practice to grind manually gas-cut surfaces of reinforcing bars with a grinder so as to satisfy the above-mentioned requirements.

This invention solves the above problem by attaching a rotatable main shaft to the pliers, providing a torch and speed increasing mechanism on this main shaft, and providing a braking means on this speed increasing mechanism. The object of the present invention is to provide a torch attachment device for a cutter that can obtain a cut surface with the same degree of smoothness.

This invention will be explained in detail below based on the drawings.

1 to 5 show an embodiment of this invention, in which a reinforcing bar 2 is held at the tip of the pliers 1, and a base 1a attached to the upper part of the pliers 1 has a Torch 3 mounting part 4
is fixed with screws 6 or the like.

The pliers 1 have a well-known structure, and when the lever 1b is squeezed, the block 1c attached to the tip by an internal ratchet (not shown) can grip the reinforcing bar 2 with the required tightening force. It is configured as follows.

Further, the mounting portion 4 includes a casing 7 fixed on the base 1a, and a clamp 8 installed on the casing 7 to hold the torch 3 horizontally. As shown in FIGS. 4 and 5, the casing 7 includes a main shaft 9 and two driven shafts 10,
11, and a speed increasing mechanism A consisting of gears and the like that are pivotally attached to each of them. That is, the main shaft 9 has a gear 9a, and the driven shaft 10 has a gear 1.
0a and a pinion 10b that meshes with the gear 9a are coaxially provided, and a gear 11a is provided on the driven shaft 11.
and a pinion 11b that meshes with the gear 10a are coaxially provided. And this driven shaft 11
A braking means B consisting of a driven shaft 12 and a click 13 is connected to the drive shaft. That is, the driven shaft 12
A ratchet 12b and a pinion 12b that mesh with the gear 11a are coaxially provided. Furthermore, on this ratchet 12a, there is a substantially U-shaped click 13 that brings one of the claws 13c into contact with the teeth of the ratchet 12a.
It is installed so that it can swing freely in the horizontal direction around the center. This click shaft 13a is provided with an adjusting screw 13b for adjusting the rotation of the shaft 13a, that is, the swinging speed of the click 13.
3a at right angles. Note that the main shaft 9
The bearing includes a bushing 9b and a ball bearing 9.
Bushes 10c, 11c, and 12c are mounted on the bearings of the driven shafts 10, 11, and 12, respectively.

On the other hand, a clamp 8 for holding the torch 3 is attached on the casing 7 and coaxially with the main shaft 9.

As shown in FIG. 2, one leg of the clamp 8 is provided with a tightening lever 8c for fixing the torch 3 to the clamp 8, and the other side is provided with a tightening lever 8c.
In order to keep the rotation angle α of torch 3 to about 30°,
An arcuate long hole 8b is provided with a thumbscrew 8a attached thereto. That is, the elongated hole 8b is set to have a length of approximately 1/12 of a circular arc centered on the main shaft 9.
Since the torch 3 and the main shaft 9 are coaxially mounted, the torch 3 can rotate within an angle range of 30 degrees. Note that three blowholes 19 are provided at the rear end of the torch 3, and these blowholes 1
A rubber hose 20 for supplying oxygen and gas is connected to 9.

Further, a flat heat shield plate 21 is attached to the front part of the attachment part 4 to block heat during cutting.

Note that there are U-shaped handles 2 at both ends of the base 1a.
2 is installed.

Next, the operation of this torch 3 mounting device will be explained.

First, the part to be cut of the reinforcing bar 2 is the hole 3 of the torch 3.
Hold and fix the block 1c of the pliers 1 to the reinforcing bar 2 so that it is at approximately the same horizontal position as a. next,
The torch 3 is rotated to either side until it stops, and then the cutting is started while the torch 3 is manually rotated to the opposite side. In this case, since the torch 3 is rotated manually, it is difficult to rotate it at a constant speed and pulsation inevitably occurs.
This pulsation can be substantially suppressed by the braking means B and the braking means B. In other words, the rotation of the torch 3 is
The main shaft 9 rotates, and the driven shaft 1 sequentially starts from the gear 9a.
The transmission is increased to 0, 11, and 12, but gear 9
The number of teeth of a, 10a, and 11a are respectively Z ₉ a, Z ₁₀ a,
Z ₁₁ a, the number of teeth of the ratchet 12a is Z ₁₂ a, and the gears of pinions 10b, 11b, 12b are respectively
If Z ₁₀ b, Z ₁₁ b, Z ₁₂ b, then torch 3 is 1/12
(30°), the final stage ratchet 12
The rotation speed n of a is n=1・Z ₉ a・Z ₁₀ a・Z ₁₁ a /12・Z ₁₀ b・Z ₁₁ b・Z ₁₂ b. Here, for example, the number of teeth for each
Z ₉ a: 70, Z ₁₀ a: 63, Z ₁₁ a: 50, Z ₁₀ a: 19,
Z ₁₀ b, Z ₁₁ b, Z ₁₂ b: If each is 11, torch 3 is 1/
Even if it is rotated only by 12 (30 degrees), the ratchet 12a
is increased to approximately 14 rotations. However, click 1
The pawl 13c of No. 3 feeds the 266 teeth (14 rotations x 19 teeth) of the accelerated gear of the ratchet 12a minutely one tooth at a time. Therefore, even if there is pulsation in the rotation of the torch 3, the ratchet 12a of the driven shaft 12 and the click 13 act as a braking means B, suppressing the pulsation in the torch 3 and rotating the torch 3 at a smooth constant speed. I will let you do it.

In this way, the torch 3 can be rotated horizontally without pulsation even manually, so the cut surface of the reinforcing bar 2 can be perpendicular to the reinforcing bar axis and planar, and the desired smooth cut surface can be obtained. The grinding process for gas pressure welding in the subsequent process can be made extremely easy.

Once the reinforcing bars have been cut in the manner described above, the torch 3 may be reversed until it stops, and cutting may be started again.

Incidentally, since the rotation angle of the torch 3 is set to approximately 30 degrees by the thumbscrew 8a and the elongated hole 8b, no excessive tension is applied to the rubber hose 20 that supplies oxygen or gas.

In the above embodiment, the rotation angle of the torch 3 was set to approximately 30 degrees, but the rotation angle of the torch 3 may also be increased by lengthening the arc portion of the elongated hole 8b depending on the thickness of the reinforcing bar 2. good. In addition, in the illustrated example, the torch 3 is held in a horizontal state by the clamp 8, but in the case where the reinforcing bar 2 is to be cut diagonally rather than at right angles, the clamp 8 is held at the tip of the torch 3.
A configuration may be adopted in which a is moved up and down. Further, as the speed increasing mechanism A, a pulley and a belt, or a sprocket and a chain may be used. Further, instead of using the ratchet 12a and the click 13 as the control means B, the pulsation of the torch 3 can be suppressed by using a flywheel as the final stage rotary body.

As explained above, this invention has a main shaft rotatably attached to the pliers, a torch and a speed-increasing mechanism are installed on this main shaft, and a braking means is provided on this speed-increasing mechanism. It does not require large-scale equipment like a machine, and can be easily manufactured at low cost. In addition, the cutting range of reinforcing bars with this machine covers all the reinforcing bar diameters specified in the current JIS G 3112 (reinforcing bars that are actually pressure welded are generally D19 or more), and the cutting time is almost independent of the reinforcing bar diameter. , for an extremely short period of time. The resulting cut surface has a smooth surface with no drag lines, making it extremely easy to process the end faces of the reinforcing bars, which is required for gas pressure welding, and thus greatly improving the reliability of reinforcing bar joints. In addition to making a major contribution, it also shortens the work process and directly leads to lower costs. In addition, it has many features such as being small and lightweight, and does not use any electricity, making it highly mobile and applicable in a wide range of fields, and does not require skilled workers.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of this invention, with Figure 1 being a front view, Figure 2 being a plan view, Figure 3 being a left side view, and Figure 4 being a plan view of the casing. FIG. 5 is a sectional view of the casing. 1... Pliers, 2... Rebar, 3... Torch,
9...Main shaft, 10a, 11a...Gear, 10b,
11b, 12b...pinion, 12a...ratchet, 13...click, A...speed increasing mechanism, B...
...braking means.

Claims (1)

[Scope of utility model registration request] A main shaft is rotatably attached to pliers that grip the member to be cut, and a torch of a cutter for cutting the member to be cut is attached to the main shaft, and the speed is sequentially increased in conjunction with the rotation of the torch. Mounting of a torch in a cutter, characterized in that a speed increasing mechanism consisting of a plurality of rotating bodies is arranged in series, and a final stage of the rotating body of the speed increasing mechanism is provided with a braking means for suppressing pulsation of the torch. Device.