JPH0318110Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a centering device for a hollow circular object that is capable of centripeting, setting, and holding the central axis of a hollow circular object whose circumference is determined. It is something.

[Conventional technology]

For example, welding of doublers (reinforcing rings) in steel structures such as water gates and bridges has conventionally been performed by manual welding or semi-automatic welding. Generally, when performing fully automatic welding, it is necessary to determine the center for rotating the welding machine, but since the doubler is a hollow circular object, it has been difficult to determine the center. In other words, when centering a hollow circular object, conventionally, a hollow closing plate such as a plywood board is placed on the hollow part, a point bisecting the diameter of the circular object is copied onto the hollow closing plate, and then the centering point is placed at a position rotated 90 degrees. The center axis was set at the intersection with the bisected diameter.

[Problem that the invention attempts to solve]

Therefore, in the conventional method described above, (i) it takes time to determine the central axis by measurement;

(ii) In order to clearly indicate the central axis, a hollow closing plate such as a plywood board must be used, and the hollow closing plate must be processed each time, which is time-consuming.

(iii) Welding is unstable because the center shaft cannot be firmly fixed.

It had the following problems.

In view of these circumstances, the present invention has been devised to centripetalize, set, and hold the central axis of a hollow circular object without using measuring instruments or marking tools.

[Means for solving the problem] The present invention provides racks that can be slid in the radial direction at three equal positions in the circumferential direction on one side of the disk, and a claw is attached to the outer end of each rack in the radial direction. , and a pinion is engaged with each of the racks, and the shafts of the pinions are connected at a universal joint except for one location, and a first bevel gear is installed at the end of one pinion shaft located at the unconnected portion. and a second bevel gear meshing with the first bevel gear.
An operating shaft for operating the second bevel gear is rotatably protruded through the disk to the other side, a handle is provided at the protruding end of the operating shaft, and a center hole is provided in the center of the ground of the disk. It has a structure in which a block is fixedly installed.

[Effect]

When the handle is rotated, the rotational force is transmitted to each pinion shaft through the bevel gear mechanism, and the rotation of each pinion causes each rack to slide in the radial direction, displacing the position of each pawl simultaneously. When each claw touches the edge of the hollow circular object, the center hole of the block is set as the center of the hollow circular object.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in FIGS. 1 to 3, racks 2a, 2a, 2a, 2a, 3a, 3a, 4b, 3a, 3b, 4a, 5b, 3b, 3b, 3c, 4A, 3c, 3c, 3b, 3b, 3c, 3b, 3b, 3b, 3b, and 2a are shown in FIGS.
2b, 2c are provided so as to be slidable in the radial direction via guides 3a, 3b, 3c, and each rack 2
L-shaped claws 4 are provided at the outer ends of a, 2b, and 2c in the radial direction.
a, 4b, 4c, and each rack 2a,
2b, 2c are engaged with pinions 5a, 5b, 5c, and shafts 6a, 6b, 6c supporting the pinions 5a, 5b, 5c are supported by bearings 7a, 7b, 7c fixed to the disk 1, respectively, and axis 6
A and 6b are connected by a universal joint 8 and a connecting shaft 9, and shafts 6b and 6c are connected by a universal joint 10 and a connecting shaft 11, respectively, and a bevel gear 12 is provided at the unconnected end of the shaft 6a, The bevel gear 13 that meshes with the bevel gear 12 is connected to the disk 1.
be placed parallel to the Note that 20 is a bearing that supports the connecting shafts 9 and 11.

A bearing in an axle box 15 in which an operating shaft 14 for operating the bevel gear 13 penetrates the disk 1 from one side of the disk 1 and projects to the other side of the disk 1, and the protruding portion is fixed to the other side of the disk 1. An operating handle 17 is fixed to the protruding end of the operating shaft 14, and a center block 19 having a center hole 18 is fixed at the center of the other surface of the disk 1.

In such a configuration, when the handle 17 is rotated, the rotational force is transferred from the operating shaft 14 to the bevel gear 1.
3 and 12 to the shaft 6a, and the pinion 5a
Rotate. Thus, the shaft 6a is connected to the shaft 6b via the universal joint 8 and the connecting shaft 9, and the shaft 6b is connected to the shaft 6c via the universal joint 10 and the connecting shaft 11.
Pinions 5b and 5c also rotate at the same time as pinion 5a. When the pinions 5a, 5b, 5c rotate in this way, the racks 2a, 2b, 2c mesh with them.
slides in the radial direction along the guides 3a, 3b, 3c, causing the claws 4a, 4b, 4c to expand and contract.

Therefore, as shown in FIGS. 4 and 5, this device is placed in the circular hole 22 of the base material 21, and the handle 17 is
As described above, racks 2a, 2b,
The claws 4a, 4b, 4c are brought into contact with the edge of the circular hole 22 by sliding the claws 2c so as to protrude in the radial direction (see FIG. 2). After that, the doubler 23 is placed around the circular hole 22, and the center block 1 is further placed.
The rotation center shaft 25 of the doubler automatic welding machine 24 is fitted into the center hole 18 of 9. In addition, 26 is welding machine 2
4 is a torch, 27 is a rotary drive device, and 28 is a wire feeding device. By setting the torch 26 along the circumference of the doubler 23 and rotating the welding machine 24 about the rotating shaft 25, the doubler 23 is fillet welded to the base metal 21.

It should be noted that the present invention is not limited to the above embodiments, but can also be applied to, for example, installation, welding, and centering work of hollow circular objects such as pipes and manholes.

[Effect of idea]

As explained above, according to the hollow circular object centering device of the present invention, () Since the three claws are interlocked,
Centering, setting, and holding of hollow circular objects can be performed in a short time without using measuring instruments.

() Easy to operate as it has a single handle.

() Since the structure is simple, it is lightweight and has good workability.

() Can be applied to a wide range of sizes by changing the length of the nails.

() Can be widely applied to centering and welding of all hollow circular objects. It can produce excellent effects such as

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the device of the present invention, and Fig. 2 is an explanatory diagram of the device of the present invention.
Fig. 3 is a view taken from the - arrow in Fig. 1, Fig. 4 is a schematic cross-sectional side view of a doubler being automatically welded using the device of the present invention, and Fig. 5
The figure is a partial plan view of FIG. 4. 1 is a disk, 2a, 2b, 2c are racks, 4
a, 4b, 4c are pawls, 5a, 5b, 5c are pinions, 6a, 6b, 6c are shafts, 7a, 7b, 7c are bearings, 8, 10 are universal joints, 1
2 and 13 are bevel gears, 14 is an operating shaft, 17 is a handle, 18 is a center hole, and 19 is a center block.

Claims (1)

[Scope of utility model registration request] Racks are provided at three equal positions in the circumferential direction on one side of the disk so as to be slidable in the radial direction, and a pawl is attached to the outer end of each rack in the radial direction, and a pinion is engaged with each of the racks. A first bevel gear is attached to the end of one of the pinion shafts located in the non-connected part, and a second bevel gear meshes with the first bevel gear. an operating shaft for operating the second bevel gear rotatably protrudes through the other surface of the disk, a handle is provided at the protruding end of the operating shaft, and a center hole is provided at the center of the other surface of the disk. A centering device for hollow circular objects characterized by a fixed block.