JP2810623B2 - Steel pipe clamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe clamping device. The steel pipe clamping device is a clamping mechanism used in a steel pipe cutting machine that cuts a steel pipe with a saw blade, presses a plurality of (for example, four) clamp segments against a pipe wall of a pipe to be cut, clamps the steel pipe, and passes the steel pipe. It has the function of holding at the center of the line.

[0002]

2. Description of the Related Art As an example of a conventional steel pipe clamping device,
There is one described in Japanese Utility Model Publication No. Sho 62-46499. This conventional example will be described with reference to the mechanism diagram of FIG. 9. Four clamp segments 101 are attached to four clamp heads 102, and the four clamp heads 102 are respectively provided by correspondingly provided clamp cylinders 103. The tube P is driven so as to approach and separate from the tube wall.
Each of the four clamp cylinders 103 operates simultaneously with the same cylinder stroke, and is configured to clamp the steel pipe P with the four clamp segments 101 sandwiching the pipe wall of the pipe P to be cut.

[0003]

The pipe to be cut P
There are various sizes, with both large and small outer diameters. When the size is changed from the large size to the small size, the stroke of the clamp cylinder 103 may be insufficient. In such a case, in the conventional steel pipe clamping apparatus, the clamp head 102 is replaced with the clamp segment 101 having an increased thickness to cover the shortage of the cylinder stroke. However, in the above case, it takes a lot of time (about 30 minutes) to replace the clamp segment 101, and during this time, the production line has to be stopped, so that the operation rate is reduced, the segment cost is high, and a large segment storage space is required. There was a problem that it became necessary and the factory space could not be used effectively. Further, when re-clamping the resized tube P,
Even if the upper, lower, left and right clamp cylinders 103 are simultaneously operated, there is no alignment function. Therefore, even if the clamp cylinder 103 can be clamped, the automatic centering for aligning the pipe P to be cut with the position corresponding to the pass line cannot always be performed.

[0004] In view of such circumstances, an object of the present invention is to provide a steel pipe clamping apparatus which does not require replacement of a clamp segment even when the size of a pipe to be cut changes. Another object of the present invention is to provide a steel pipe clamping device in which centering is automatically performed at the time of re-clamping even if the size of the pipe to be cut changes. Furthermore, the present invention prevents the lateral pulling of the time of clamping, and an object thereof is to provide a steel pipe clamping device can be clamped by exactly matching the pass line.

[0005]

According to a first aspect of the present invention, there is provided a steel pipe clamping apparatus, wherein a clamp unit for moving a clamp segment forward and backward by a clamp cylinder to clamp and unclampable faces four sides of a rectangular steel pipe to be cut. And a clamp device comprising four vertical and horizontal clamp units, and one of the four vertical clamp units and one of the left and right lateral clamp units. ,
An opposing clamp unit is constituted by one of the upper and lower vertical clamp units and the other of the left and right lateral clamp units. The reference clamp unit includes a clamp cylinder and a tube wall of a pipe to be cut. It consists of a moving means for moving the accessible spaced relative to the previous SL opposite side clamp unit, Kuranpushi
The clamp cylinder of the reference side clamp unit is provided with retraction preventing means for preventing the cylinder from retreating even when receiving a pressing force of each clamp cylinder of the opposite side clamp unit. And A second invention is characterized in that, in addition to the first invention, a side clamp unit of the opposing clamp units includes a preceding clamping means for clamping earlier than a vertical clamp unit.

[0006]

In the first aspect of the invention, when the size of the pipe to be cut changes from large to small, the reference side clamp unit can supplement the cylinder stroke of the clamp cylinder by moving the clamp cylinder closer to the pipe to be cut by the moving means. , Can be clamped without replacing the clamp segment. When the size of the pipe to be cut changes from small to large, the moving means may be moved in the opposite direction to increase the distance to the pipe to be cut. And since the clamp stroke of the opposing clamp unit is long, it is possible to cope with the large or small tube to be cut as it is. For this reason, in the first aspect of the present invention, since it is not necessary to replace the clamp segments, the line downtime is extremely short, and the operation rate is improved. When clamping a new size pipe to be cut, the reference side clamp unit is moved by a moving means to a position separated from the pipe wall of the pipe to be cut by the cylinder stroke of the clamp cylinder, and the opposite side clamp cylinder is set to the reference position. With a distance greater than the cylinder stroke of the side clamp cylinder, all clamp cylinders are simultaneously extended. In this case, the reference side clamp cylinder extends to the stroke end, and the clamp segment hits the pipe wall of the pipe to be cut and stops. This position is a reference position where the pipe to be cut coincides with the pass line. Next, the clamp cylinder on the opposite side comes into contact with the pipe wall of the pipe to be cut and stops, and the pipe to be cut is clamped from all sides. At this time, even if the pressure of the opposing side clamp cylinder acts on the reference side clamp cylinder, the reference side cylinder is not retreated by the retraction preventing means, so that the pipe to be cut is held in a state of being coincident with the pass line. Therefore, the first
According to the invention, centering at the time of clamping can be performed automatically.

According to the second aspect of the invention, at the time of the above clamping, the opposing side clamping unit can be clamped by the preceding clamping means before the opposing vertical clamping cylinder, so that the right and left direction of the pipe to be cut is clamped first. Then, the vertical direction can be clamped later. For this reason, if there is a horizontal bend that is likely to occur in the steel pipe, forcible horizontal pulling will occur if the vertical direction is clamped first and then the horizontal direction is clamped later. Pulling can be prevented. Therefore, centering can be performed accurately.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. Before explaining the steel pipe clamping apparatus of the present invention, a steel pipe cutting machine to which the apparatus is applied will be described with reference to FIG.
In FIG. 7, 1 is an entrance guide roller stand, 2 is a saw blade, 3 is an exit dragout stand, and the entrance guide roller stand 1 sandwiches a steel pipe P to be cut by a pair of upper and lower rollers 1a and 1b. The outlet drag-out stand 3 sandwiches the steel pipe P between a pair of upper and lower rollers 3a and 3b. A is a main clamp arranged between the saw blade 2 and the entrance guide roller stand 1, and B is a sub clamp arranged between the saw blade 2 and the exit drag out stand 3. The clamp device of the present invention is used as the main clamp A.

FIG. 1 is a front view of a clamp device according to an embodiment to which both the first invention and the second invention are applied, and FIG. 2 is a II-I of FIG.
FIG. 3 is a sectional view taken along line III-III in FIG. 1. In FIG. 1, reference numeral 4 denotes a pentagonal fixed frame,
An intermediate frame 5 for forming an opening through which the pipe to be cut P passes is provided, and four mounts 6, 7, 8, 9 are provided. Reference numeral 10 denotes an upper clamp unit, and reference numeral 20 denotes a right clamp unit. These constitute a reference-side clamp unit. Also, 3
Reference numeral 0 denotes a lower clamp unit, and reference numeral 40 denotes a left clamp unit. These constitute an opposing clamp unit. The upper clamp unit 10 and the lower clamp unit 30 correspond to a vertical clamp unit described in the claims, and the right clamp unit 20 and the left clamp unit 4
0 corresponds to the side clamp unit.

Worm jacks 50 and 60 as moving means are attached to the reference side clamp units 10 and 20, and a worm jack 70 as moving means is also attached to the left clamp unit 40 on the opposite side.
Only the lower clamp unit 30 on the opposite side has no moving means.

The upper clamp unit 10 will be described with reference to FIG. 2. Reference numeral 11 denotes a clamp cylinder, and two guide rods 13 are connected to the clamp cylinder 11 via a connecting plate 12; Is mounted with a segment base 14. This segment base 14 has a clamp segment 15 (see FIG. 1).
Is attached. The guide rod 13 is guided to slide in the axial direction by a cylindrical guide 16 fixed to the fixed frame 4.

A main body of a worm jack 50 is mounted on the mounting base 6 of the fixed frame 4, and an output shaft 51 thereof is connected to the clamp cylinder 11. The worm jack 50 is driven by the motor 52 shown in FIG. 1 so that the output shaft 51 advances and retreats in the axial direction. The advance and retreat position of the output shaft 51 is determined by an output signal from an encoder 53 connected to the worm of the worm jack 50. You can now know.

The lower clamp unit 30 includes a clamp cylinder 31, a connecting plate 32, a guide rod 33,
A clamp base 35 (see FIG. 1) is attached to the segment base 34. The guide rod 33 is guided to slide in the axial direction by a cylindrical guide 36 fixed to the fixed frame 4. In the lower clamp unit 30, a clamp cylinder 31 is fixed to the mount 8 of the fixed frame 4. No worm jack is installed.

Referring to FIG. 3, the right clamp unit 20
In the following, 21 is a clamp cylinder, and two guide rods 23 are connected to the clamp cylinder 21 via a connecting plate 22, and a segment base 24 is attached to the tip of the guide rod 23. A clamp segment 25 (see FIG. 1) is attached to the segment base 24. The guide rod 23 is guided in the axial direction by a cylindrical guide 26 fixed to the fixed frame 4.

The main body of the worm jack 60 is mounted on the mounting base 7 of the fixed frame 4, and its output shaft 61 is connected to the clamp cylinder 21. The worm jack 60 is driven by the motor 62 shown in FIG. 1 so that the output shaft 61 advances and retreats in the axial direction. The advance and retreat position of the output shaft 51 is determined by an output signal from an encoder 63 connected to the worm of the worm jack 60. You can now know.

The left clamp unit 40 includes a clamp cylinder 41, a connecting plate 42, a guide rod 43,
A clamp base 45 (see FIG. 1) is attached to the segment base 44. The guide rod 43 is guided to slide in the axial direction by a cylindrical guide rod 46 fixed to the fixed frame 4.

The main body of the worm jack 70 is mounted on the mounting base 9 of the fixed frame 4, and the output shaft 71 is connected to the clamp cylinder 41. The worm jack 70 is driven by the motor 72 shown in FIG. 1 so that the output shaft 71 advances and retreats in the axial direction. The advance and retreat position of the output shaft 71 is determined by an output signal from an encoder 73 connected to the worm of the worm jack 70. You can now know.

As shown in FIG. 4, the cylinder strokes and bore diameters of the clamp cylinders 11, 21, 31, 41 are set as follows. The cylinder strokes L1 and L2 of the reference side clamp cylinders 11 and 21 are shorter than those of clamp cylinders 31 and 41 described later, for example, set to 15 mm.
Is longer than the reference side clamp cylinders 11 and 21, for example, 20 mm or more, and the cylinder stroke L3 of the opposite side clamp cylinder 31 is set to the longest, for example, 120 mm or more. The cylinder stroke L of the worm jacks 50, 60, 70 and each of the clamp cylinders 11, 21, 41
1, L2 and L4, and the cylinder stroke L3 of the clamp cylinder 31.
Must be long enough to clamp and unclamp from the smallest sized tube to the largest sized tube.

The bore diameters d1 and d2 of the reference side clamp cylinders 11 and 21 are opposite to those of the opposed side clamp cylinders 31 and 41.
By setting them larger than the bore diameters d3 and d4, the retreat preventing means is constituted. That is, by increasing the pressure receiving area and the cylinder output by increasing the bore diameters d1 and d2 of the reference side clamp cylinders 11 and 21, the clamping cylinders 31 and
Even if it is pushed by 41, it does not retreat.

The retraction preventing means is not limited to the above example, and any means may be employed as long as it can prevent the reference side clamp cylinders 11 and 21 from retreating. Therefore, for example, as shown in FIG.
7, 27 may be used. That is, FIG.
, The check valves 17, 27 are connected to the clamp cylinder 11,
The hydraulic supply circuits 18 and 28 to the extension-side oil chamber 21 are interposed in the direction to prevent the discharge of the pressure oil, and the pilot lines 17a and 27a are connected to the hydraulic supply circuits 19 and 2 to the reduction-side oil chamber.
I'm leading from 9. According to such a configuration, when the clamp cylinders 11 and 21 are reduced by operating the hydraulic control valve (not shown), a reverse pressure is generated by the pilot pressure from the pilot lines 17a and 27a branched from the hydraulic pressure supply circuits 19 and 29. Since the stop valves 17 and 27 open, the clamp cylinder 1
1, 21 can be reduced, but depending on the pressing force of the opposing clamp cylinders 31, 41, the check valve 17,
Since the pressurized oil is prevented from being discharged by 27, the reference side clamp cylinders 11 and 21 do not contract. Therefore,
Retreat can be prevented.

Next, the clamping operation according to the above embodiment will be described with reference to FIG. When the size of the pipe P to be cut is large, the clamp units 10, 20, and 40 contract the clamp cylinders 11, 21, and 41, and at the same time, pull in the output shafts 51, 61, and 71 of the worm jacks 50, 60, and 70, respectively. The stroke clamp cylinder 30 is contracted. Thereby, the clamp segments 15, 35
Since the distance between them and the distance between 25 and 45 are widened, a large-sized tube P to be cut can be accommodated and clamped. When the size of the pipe to be cut P is small, the worm jack 5
When the output shafts 51, 61, 71 of 0, 60, 70 are extended, the clamp cylinders 11, 21, 41 approach the pipe P to be cut. Further, since the clamp cylinder 31 of the lower clamp unit 30 has a long cylinder stroke, the distance between the clamp segments 15 and 35 and between the clamp segments 25 and 45 is short, and the small-sized cut pipe P can be clamped without changing the clamp segment. Can be.

Next, the centering operation after the size change will be described. First, each of the clamp cylinders 11, 21, 3
1 and 41 are contracted by the full stroke, and then the clamp segments 1 of the reference side clamp units 10 and 20 are clamped.
The worm jacks 50 and 60 are driven and positioned at positions separated from the pipe wall of the pipe P to be cut by a distance (for example, 15 mm) corresponding to the cylinder stroke of the clamp cylinders 11 and 21. Then, the clamp segment 45 of the left clamp unit 40 on the opposite side is moved from the pipe wall of the pipe P to be cut by the clamp cylinders 11 and 21.
The worm jack 70 is driven and located at a position slightly longer (for example, 20 mm) than the separation distance of the worm jack 70. At this time, since the clamp cylinder 31 of the lower clamp unit 30 has the longest cylinder stroke, the clamp segment 35 is farther away than the left clamp cylinder 41. In this state, all the clamp cylinders 11, 21, 31, 41 are simultaneously extended. In this case, first, since the reference side clamp cylinders 11 and 21 have the shortest separation distance, when they extend to the stroke end, the clamp segments 15 and 25 come into contact with the pipe wall and stop. This position is the centering reference position. Next, since the separation distance of the left clamp cylinder 41 is the next shortest, the clamp segment 45 reaches the pipe wall by the extension operation, and the pipe P to be cut is laterally clamped by the right and left clamp units 20 and 40. Finally, the clamp segment 35 which is most separated is the clamp cylinder 3
The tube P reaches the pipe wall by the extension operation of 1 and the pipe P to be cut is vertically clamped by the upper and lower clamp units 10 and 30. When this clamping is completed, the reference side clamping cylinder 1
Since the reference numerals 1 and 21 do not retreat by the retraction preventing means, the center of the pipe P to be cut does not deviate from the pass line. Therefore, centering can be performed automatically.

The reason why the left and right clamps are provided before the upper and lower clamps as described above is as follows. FIG.
As shown in the figure, the steel pipe P cut by the saw blade 2 is supported by rollers 1a and 3a at the front and rear, and the amount of movement in the vertical direction is very small. As a result, the steel pipe P may be shifted from the pass line 0 as shown in FIG. In such a case, if the clamp is performed first in the vertical direction and then clamped in the horizontal direction, the steel pipe P
Is moved laterally against the clamping force in the vertical direction, so that accurate centering cannot be performed. Therefore, the steel pipe is first clamped in the horizontal direction, and the steel pipe is accurately centered in the horizontal direction without any resistance to the clamping operation, and then the vertical clamping is performed. Therefore, in this embodiment, centering can be performed accurately. The worm jack 70 of the opposing clamp unit 40 is provided for position adjustment for performing such a lateral clamp first.

Next, another embodiment of the present invention will be described. In the above embodiment, the preceding clamping means is replaced with the left clamping cylinder 4
The first cylinder stroke is realized by making the cylinder stroke shorter than the cylinder stroke of the lower clamp cylinder 31. However, the present invention is not limited to such a configuration. Any means can be employed without particular limitation. For example, as one example of such a clamp cylinder 4
There is a method of controlling the elongation speed of the 1,31. FIG. 6 shows an example thereof. The left clamp cylinder 41 is a long cylinder having the same cylinder stroke as that of the lower clamp cylinder 31 of the above-described embodiment, and does not include the moving means constituted by the worm jack 70. In addition, a flow control valve 80 is interposed in the hydraulic pressure supply circuit 38 to the extension-side oil chamber of the lower clamp cylinder 31. The flow control valve 80 is composed of a check valve that blocks supply and permits discharge, and a variable throttle valve.
The amount of pressurized oil supplied to the extension-side oil chamber can be limited. In this case, the pressure oil supply / discharge circuit 38, 3 of the clamp cylinder 31
Even if the expansion and contraction operation of the pressure oil supply / discharge circuits 48 and 49 of the clamp cylinder 9 and the clamp cylinder 41 is controlled by the same direction control valve, the left clamp cylinder 41 clamps first and the lower clamp cylinder 31 clamps later. The left clamp cylinder 41 may be clamped earlier than the lower clamp cylinder 31 by using a separate directional control valve and performing control with a temporal shift.

Further, in the above-described embodiment, the upper clamp unit 10 and the right clamp unit 20 are used as the reference side. However, the upper clamp unit 10 and the right clamp unit 20 may be arranged upside down or left and right as they are. Although the worm jack is used as the moving means in the above-described embodiment, any means may be used as long as the position of the clamp unit can be adjusted in the clamp / unclamp direction without being limited thereto. For example, a shim or a wedge may be used. May be adjusted using
Further, when a jack is used, various jacks can be used.

[0026]

According to the first aspect of the present invention, even if the size of the pipe to be cut changes, there is no need to replace the segment. Even if the size of the pipe to be cut changes, centering is automatically performed at the time of re-clamping. Further, according to the second aspect, lateral pulling at the time of clamping can be prevented, and accurate centering can be performed.

[Brief description of the drawings]

FIG. 1 is a front view of a clamp device according to an embodiment to which both the first invention and the second invention are applied.

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

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is an explanatory view of an example of a retraction preventing means of the clamp cylinders 11 and 21 of FIG. 1;

FIG. 5 is an explanatory view of another example of the retraction preventing means of the clamp cylinders 11 and 21 of FIG. 1;

FIG. 6 is a hydraulic circuit diagram showing another example of the preceding clamping means of the clamp cylinder 41.

FIG. 7 is an explanatory view of a steel pipe cutting machine using the clamp device of the present invention.

FIG. 8 is an explanatory view of a laterally bent state of the steel pipe P during cutting.

FIG. 9 is an explanatory view of a conventional steel pipe clamping device.

[Explanation of symbols]

10 upper clamp unit 20 right clamp unit 30 lower clamp unit 40 left clamp unit 11 clamp cylinder 21 clamp cylinder 31 clamp cylinder 41 clamp cylinder 15 clamp segment 25 clamp segment 35 clamp segment 45 clamp segment 50 worm jack 60 worm jack 70 worm jack

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23D 47/04 B23D 45/12 B23D 51/04 B23D 55/04 B23Q 3/06 303

Claims (7)

(57) [Claims] 1. A clamp device comprising four clamp units for moving a clamp segment forward and backward by a clamp cylinder to clamp and unclamp it in four vertical and horizontal directions, facing four side walls of a rectangular steel pipe to be cut. The reference side clamp unit is composed of one of the upper and lower vertical clamp units and one of the left and right side clamp units of the four clamp units, and the other one of the upper and lower vertical clamp units and the left and right Or the other side clamp unit constitutes an opposite side clamp unit, wherein the reference side clamp unit comprises a clamp cylinder and a moving means for moving the clamp cylinder so as to be able to approach and separate from the pipe wall of the pipe to be cut. becomes, the opposing side clamp unit, have a clamp cylinder
And has, on each clamping cylinder of the reference-side clamp unit, steel pipe, characterized in that the retraction preventing means that prevents receded by receiving the pressing force of the clamp cylinder on the opposite side clamp unit is provided Clamping device. 2. The steel pipe clamping apparatus according to claim 1, wherein a side clamp unit of said opposed side clamp unit is provided with preceding clamping means for clamping earlier than a vertical clamping unit. Wherein said preceding clamping means, claims cylinder stroke of the clamping cylinder on the opposite side lateral clamping unit is longer than the clamp cylinder reference side clamp unit, and is shorter than the clamping cylinder on the opposite side a vertical clamping unit 3. The steel pipe clamping device according to 2. 4. The steel pipe clamping apparatus according to claim 2, wherein said preceding clamping means comprises a hydraulic control circuit for making the extension speed of the opposed side clamp cylinder faster than the extension speed of the opposed vertical clamp cylinder. Wherein said moving means, a worm jack, the body of the worm jacks are mounted to the stationary frame, according to claim 1 Symbol mounting the output shaft is characterized in that it is connected to the clamping cylinder Steel pipe clamp device. 6. The steel pipe clamping apparatus according to claim 1, wherein said retraction preventing means sets the bore diameter of the clamp cylinder of the reference side clamp unit larger than the bore diameter of the clamp cylinder of the opposed side clamp unit. 7. The retraction preventing means is interposed in a hydraulic pressure supply circuit to a hydraulic oil supply circuit to an extension side oil chamber of a clamp cylinder of a reference side clamp unit in a direction for preventing discharge of pressurized oil. 2. The steel pipe clamping device according to claim 1, wherein the check valve is configured to be opened by a pilot pressure from a supply circuit.