JPH08206909A - Groove forming device - Google Patents

Abstract

PURPOSE: To provide a groove forming device which can automatically carry out the back chipping or bevel forming of the mutual joints of steel plates. CONSTITUTION: A groove forming device has a pair of guide rails 16, 18 which are arranged at fixed intervals and in parallel to each other, and a main spindle 50 having an attached side cutter 12 for forming a bevel by cutting, and moreover is equipped with a headstock 14 which is supported so as to be reciprocatable along the guide rails 16, 18. In the case of bevelling, the guide rails 16, 18 are fixed to a steel plate, and the headstock 14 is moved as the side cutter 12 is placed on the joint part of steel plates for automatically forming the bevel in the joint part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groove forming device,
In particular, the present invention relates to a groove forming device used for forming a groove and a groove on the back of a joint portion when butt welding of side plates such as an LNG (liquefied natural gas) tank and an LPG (liquefied petroleum gas) tank.

[0002]

2. Description of the Related Art Conventionally, in constructing a double low temperature tank such as an LNG tank, when the side plates of the inner tanks are butt-welded to each other, the joint between the inner tank side plates is welded from the outer surface side, and then the groove bottom is formed. In order to remove the incomplete welded part, the back side and the groove are formed from the inner surface side by arc air gouging. Then, after that, the joint portion between the side plates of the inner tank is generally welded from the inner surface side.

[0003]

However, gouging emits intense light, high-frequency sound, high heat, and fumes (smoke) to the surroundings. Further, after the gouging, a grinder is necessary, but when this grinder is used, a considerably large noise is emitted and the magnetic iron oxide powder is scattered. Therefore, the work environment for forming the groove is not good, and it is necessary to pay attention to alteration of the material due to high heat.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a groove forming device capable of automatically forming the back or the groove without performing manual gouging work. To do.

[0005]

In order to achieve the above object, a groove forming device according to the present invention comprises a pair of guide rails arranged in parallel with each other at a predetermined interval, and a groove formed by cutting. It has a main shaft to which a side cutter for forming is attached, and a headstock supported between the guide rails so as to be capable of reciprocating along the guide rails.

[0006]

In the groove forming device according to the present invention, the side cutter is attached to the spindle of the headstock and the headstock is movable along the guide rails. A desired groove can be formed by performing a cutting process along it.

[0007]

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

The groove forming device according to the present invention is shown in FIGS.
As shown in FIG. 2, a carriage 10 and a side cutter 12 for reciprocatingly attached to the carriage 10 for forming a groove.
Is attached to the headstock 14.

The carriage 10 has a pair of guide rails 16 and 18 arranged in parallel with each other at a predetermined interval, and a tie plate 20 horizontally extending between the ends of the guide rails 16 and 18. , 22. As described above, since the carriage 10 has the frame structure, it is relatively lightweight and portable.

The headstock 14 is arranged in a space surrounded by guide rails 16 and 18 and tie plates 20 and 22. The headstock 14 includes a headstock body 24 and a support unit 26 that supports the headstock body 24.

The support unit 26 includes a pair of side plates 28, 3 arranged in parallel with each other with a predetermined space.
0 and tie rods 32 and 34 connecting the ends of these side plates 28 and 30. Each side plate 28, 30 has a corresponding guide rail 16, 1.
8 are arranged adjacent to each other, and sliders 36 provided on the respective outer surfaces are slidably engaged with the adjacent guide rails 16 and 18. Also, one side rail 2
A female screw member 38 is provided at 8 and is screwed with a feed screw 40 extending along the guide rail 16. The feed screw 40 extends over the entire length of the guide rail 16, and the rotary shaft of a feed electric motor 42 is connected to one end of the feed screw 16 via an appropriate transmission mechanism 44 such as a timing belt. Therefore, by controlling the electric motor 42 and rotating the feed screw 40, the support unit 26 can be reciprocated along the guide rails 16 and 18.

A support shaft 46 for supporting the headstock main body 24 is attached between the side plates 28 and 30. The support shaft 46 extends substantially at right angles to the guide rails 16 and 18. The headstock body 24 is swingably supported about the support shaft 46. A well-known suitable swing mechanism (not shown) is provided inside the spindle stock main body 24. By controlling the swinging electric motor 48 fixed to the spindle stock main body 24, the spindle stock main body 24 is controlled.
Is reciprocated between the position shown by the solid line in FIG. 2 and the position shown by the chain double-dashed line.

A spindle 50 extending parallel to the support shaft 46 is rotatably attached to the spindle stock body 24. The spindle 50 is connected to a rotary shaft of a spindle electric motor 52 fixed to the outer surface of the spindle stock body 24 via an appropriate transmission / reduction mechanism 54 such as a timing belt. Spindle 5
One end of the side plate 2 from the side surface of the headstock main body 24.
It projects toward 8. This protruding portion serves as a cutter attachment portion to which the side cutter 12 is attached. It should be noted that this protruding portion is preferably made as short as possible in order to prevent shake during rotation.

As shown in FIGS. 4 to 6, the side cutter 1
Reference numeral 2 is a throw-away type, and cutter tips 56 and 58 are detachably attached around the cutter body 60. Although various materials can be considered for the cutter chips 56 and 58, for example, the inner tank side plate (9
%), A cemented carbide steel such as A30N or G10E is preferable when forming a groove.

Further, in this embodiment, as the cutter tip, as shown in FIG. 5, a first cutter tip 56 having a cutting edge formed on the leading edge and the left side edge and a leading edge and the right side edge as shown in FIG. Second cutter tip 5 with a cutting edge formed on
8 and 8 are used. These cutter tips 56,5
Each of the 8 is attached to the cutter body 60 in a direction for forming a substantially V-shaped groove, and the so-called staggered arrangement is applied to the cutter body 60 in consideration of chip dischargeability and reduction of cutting resistance. It is installed.

4 to 6, reference numeral 62 indicates a cutter tip mounting member. The member 62 has a wedge shape and is fixed by a screw 66 to a predetermined recess 64 formed around the cutter body 60. Cutter tip 56,
When mounting the 58, the cutter tips 56 and 58 are arranged between the inclined surface 68 of the wedge-shaped member 62 and the wall surface 70 of the recess 64 facing the wedge-shaped member 62, and the screw 66 is tightened to move the wedge-shaped member 62 in the radial direction. When the cutter tips 56 and 58 are moved toward one side, the cutter tips 56 and 58 are clamped by the wedge action between the wedge-shaped member 62 and the wall surface 70 of the recess 64, and are firmly fixed in that state. Reference numeral 72 is a parallel pin that supports the end surfaces of the ends of the cutter tips 56 and 58, and the radial length from the center point of the cutter body 60 to the tip of each of the cutter tips 56 and 58, that is, each cutter tip 56. , 58 to keep the height of the cutting edge constant.

When the side cutter 12 is attached to the cutter attachment portion of the spindle 50, the headstock main body 2
When 4 is in the position shown by the solid line in FIG. 2, side cutter 1
A part of 2 is a surface of the guide rails 16 and 18 (hereinafter, this surface is referred to as “front surface”, and the side of this surface is referred to as a front side) 74,
It projects forward by a predetermined amount from 76. Further, when the headstock main body 24 is in the position shown by the chain double-dashed line in FIG. 2, the entire side cutter 12 is in front of the guide rails 16 and 18.
It is arranged behind 4,76.

Next, using the groove forming device having the above-mentioned structure,
A procedure for forming the back and groove of the vertical joint (joint extending in the vertical direction) between the inner tank side plates of the LNG tank will be described.

First, the groove forming device is loaded into the inner tank of the tank. At this time, the headstock body 24 is at the position indicated by the chain double-dashed line in FIG. Then, with the guide rails 16 and 18 oriented substantially vertically, the groove forming device is arranged so that the center plane of the side cutter 12 is orthogonal to the vertical joint portion 3 of the inner tank side plates 1 and 2 to be back-hanged. Position. Then, while maintaining this state, the front surfaces 74, 76 of the guide rails 16, 18 are brought into contact with the inner surfaces of the inner tank side plates 1, 2, and the groove forming device is fixed to the inner tank side plates 1, 2 by appropriate means. . After that, the feed electric motor 42 is controlled to move the support unit 26 and the headstock main body 24 to the guide rails 16 and 18.
The side cutter 12 at the starting point of the groove formation.
To place.

Next, the spindle electric motor 52 is driven to rotate the spindle 50 and the side cutter 12, and the swing electric motor 48 is controlled to swing the headstock body 24 forward. As a result, the vertical joint portion 3 between the inner tank side plates 1 and 2
The starting point of the groove formation is cut by the side cutter 12.
When the depth of cut by the side cutter 12 reaches a predetermined value, the swing electric motor 48 is stopped while the feed electric motor 42 is controlled again to move the support unit 26 upward along the guide rails 16 and 18. Or move it downward. As a result, the side cutter 12 moves while cutting the vertical joint portion 3 between the inner tank side plates 1 and 2, and the back side is suspended and the groove is formed. The depth of the notch required for the back fishing is about half of the plate thickness of the steel plate, and in the case of a normal low temperature tank, for the inner tank side plates 1 and 2 with a plate thickness of 26 mm or less,
It is possible to carry out the back-hanging in a single cutting step, and for a plate having a thickness of 26 mm or more, cutting is performed in a plurality of steps. In this way, when the side cutter 12 reaches the end point of forming the groove, the electric motors 42 and 52 are stopped and the swing electric motor 48 is reversely rotated to return the headstock main body 24 to the initial position. After that, the groove forming device is removed from the inner tank side plates 1 and 2 to complete the hanging and groove forming of the back of the vertical joint portion 3.

In the above-mentioned embodiment, the back side of the vertical joint portion 3 between the inner tank side plates 1 and 2 and the groove formation are described, but the inner tank side plates vertically adjacent to each other are formed by using the groove forming device according to the present invention. It is also possible to groove the circumferential joint portion (joint portion extending in the horizontal direction) between them. In this case, the guide rail 1
6 and 18 extend in a straight line, but the circumferential joint is circular, which is a problem. However, since the radius of the inner tank of the LNG tank is as large as 30 m to 50 m, the circumferential joint portion should be regarded as a straight line within the range where the groove forming device can form the groove in one operation, for example, within the range of about 5 m. Therefore, the groove can be formed in substantially the same manner as in the case of the vertical joint portion 3 except that the guide rails 16 and 18 are horizontally oriented. It is also possible to adjust the depth of cut of the side cutter 12 by controlling the swing electric motor 48 in accordance with the movement of the headstock 14 to make the depth of the groove constant.

Further, the groove forming device of the present invention is particularly effective for the joint portion between the inner tank side plates of the LNG tank, but the application target is not limited to this, and the joint portion between the steel plates is opened. It can be widely used for preforming.

Further, in the above embodiment, the side cutter 12 is of the throw-away type, but it may be of a planting blade type.

[0024]

As described above, according to the present invention, the groove can be automatically formed by cutting the joint between the steel plates with the side cutter, and the work can be performed quickly. .

Further, since the arc air gouging and the grinder are not required, the working environment is improved and the worker can be freed from extreme labor.

[Brief description of drawings]

FIG. 1 is a rear view of a groove forming device according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a partial view showing an example of a side cutter applicable to the groove forming device of FIG. 1. FIG.

5 is a cross-sectional view taken along the line VV of FIG.

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

[Explanation of symbols]

10 ... carriage, 12 ... side cutter, 14 ... spindle head, 1
6, 18 ... Guide rail, 24 ... Headstock main body, 26 ... Support unit, 38 ... Female screw member, 40 ... Feed screw, 42
... electric motor for feeding, 48 ... electric motor for swinging, 50 ...
Spindle, 52 ... Spindle electric motor, 56, 58 ... Cutter tip, 60 ... Cutter body.

Claims (1)

[Claims] 1. A groove forming device for forming a groove in a joint between steel plates, wherein a pair of guide rails (16, 18) are arranged in parallel with each other at a predetermined interval,
Side cutter (12) for forming a groove by cutting
And a headstock (14) having a main shaft (50) to which is attached and reciprocally supported between the guide rails (16, 18) along the guide rails (16, 18). A groove forming device.