JPH0231639B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is generally applicable to the work or processing of a long supported body while rotating it, which requires high accuracy. The present invention relates to a pedestal for supporting an object in which the attitude of the supporting part or its vicinity changes or goes out of order with respect to the whole. [Prior Art] In this type of pedestal, which simply uses a pair of rollers to place and support the supported object (for example, Japanese Utility Model Publication No. 12555/1983), the axial center position of the supported object is Since it is not fixed, it is not possible to perform highly accurate work such as attaching other objects using the axis of the supported body as a reference. In order to determine the axis of the supported object, it is sufficient to rotate it while chucking one end of the supported object, but if you do this, the supported object may not be a perfect circle, or the supported object may Due to warpage that is likely to occur due to the long length, the axis on the free end side of the supported member and the actual center of rotation may be misaligned. If the position is misaligned in this way, a large change in rotational resistance will occur for the supported object during its rotation, making it difficult for the rotational movement itself to be performed smoothly, which may impede work or damage the supported object itself. It may cause damage. Therefore, as a means for supporting the free end side of the supported body, a roller that elastically supports the supported body is used, and the elastic displacement of the roller allows the aforementioned axis of the supported body to be aligned with the center of rotation. It is not impossible to think of a structure that reduces sudden fluctuations in rotational resistance due to positional misalignment, but even in this case, even if the rotational resistance can be reduced to a certain extent depending on the degree of elasticity,
When the object to be supported is heavy, it is difficult to ensure sufficient elasticity, and in the end, it is difficult to ensure sufficient elasticity when the object to be supported is a heavy object. It was difficult to carry out the work. [Problems to be Solved by the Invention] An object of the present invention is to rotate the supported object while holding one end side of the supported object and fixing the reference axis, and perform the desired work. In this regard, misalignment between the shaft center and the center of rotation on the free end side due to some irregularities on the outer peripheral surface of the supported object or warpage of the supported object, etc.
Alternatively, even if there is an inclination of the axis line with respect to the rotation center line, the supporting force of the free end side support device can be maintained constant or almost constant at all times without causing large fluctuations in rotational resistance. It is in. [Means for Solving the Problems] In order to achieve the above object, the present invention fixes and holds one end of a long supported body in the radial direction, and holds the supported body with its longitudinal axis. In a pedestal comprising a proximal end support device that rotates around the proximal end support device and a free end support device that rotatably supports the other end side of the supported body, [A] the free end support device comprises a loading portion including a pair of loading rollers rotatable around an axis substantially parallel to the axis of the supported body, and a mounting portion supporting the loading portion. [B] Using fluid pressure, the mounting portion includes an idle rotation mechanism that allows the loaded portion to swing left and right around the vertical axis, and a left-right play sliding mechanism that allows the loaded portion to move laterally and laterally. In addition to supporting the above-mentioned loading section by the supporting action of the loading section, the loading section is combined with a vertical play sliding mechanism section that allows the loading section to move in the vertical direction due to changes in the load on the loading section. [C] The vertical play sliding mechanism is provided with a force adjusting mechanism section that adjusts the fluid pressure so as to maintain the supporting force in the loading section constant or almost constant. This device is equipped with the configurations described in [A] to [C] above, and thereby the following functions and effects can be obtained. [Function] One end of the supported body is fixed in the radial direction by the proximal end support device while being rotatably held around the axis, and the other end is rotatably supported. The desired work can be performed while rotating with the axis fixed. The vertical position fluctuation on the free end side of the supported body is
The vertical play sliding mechanism of the mounting part and the left and right position fluctuations are handled by the left and right play sliding mechanism, respectively.
It can be absorbed. If the axis at the free end of the supported body is inclined with respect to the rotational center line of the supported body due to warpage of the supported body, the loading part may not be swung horizontally around the vertical axis. The free rotation mechanism that allows movement is
The loading section is swung in a direction along the inclined axis of the supported body in a plan view, thereby smoothly rotating the loading roller with the axis aligned along the axis. I'm forced to do it. The vertical play sliding mechanism of the mounting section is provided with a force adjustment mechanism section that adjusts the fluid pressure to keep it constant according to fluctuations in the reaction force against the load on the loading section, so that it is not caused by mere elastic deformation. Compared to a device that changes the vertical position of the loading section, the fluctuation of the reaction force is minimized, and rotation can be performed with less change in rotational resistance. [Effects of the Invention] (a) Due to the above-mentioned effect, even though one end of the supported object is held and the reference axis is fixed, the rotation of the supported object does not cause distortion or distortion of the supported object. Changes in the radius of rotation on the free end side of the supported body due to warping or the like can be absorbed by changes in the vertical and horizontal positions of the loading portion of the free end side support device, thereby making it possible to reduce fluctuations in rotational resistance. (b) Due to the above-mentioned effect, even if the axial center line on the free end side of the supported body is inclined with respect to the rotation center line, the roller axial center of the loading section can be positioned along the inclined axial center line. This reduces the risk of fluctuations in rotational resistance due to unsmooth rotation of the roller, such as when the axis of the roller obliquely intersects the axis of the supported body in plan view. This allows for smoother rotation. (c) From the above-mentioned effect, even if the position of the loading part changes according to the rotation of the supported object, the supporting force is always kept constant or almost constant, and fluctuations in rotational resistance due to the rotation of the supported object are minimized. This has the effect of reducing and smoothing the rotation. [Examples] Examples of the present invention will be described below based on the drawings. FIG. 1 shows an automatic pipe welding apparatus to which the present invention is applied, and the schematic structure of this apparatus is as described in (a) to (f) and (i) to (vi) below. The supported body supported by the pedestal is called a drum or a main pipe. (B) Supporting device A for the drum or main pipe 2 to which the stud tube or branch pipe is temporarily attached; (B) Rotating device B for the supported drum or main pipe 2; (C) Robotic welding device C for the stud tube or branch pipe 1; ( D) Moving device D for the support device A; (E) Moving device E for the position sensor 3 of the stub tube or branch pipe 1; (F) The rotating device B, the robot welding device C, the moving device D, and the sensor moving device D. A control device F is provided which is connected to the welding point E, and the control device F (i) controls the rotating device B and the moving device D so that the stub tube or branch pipe 1 is positioned close to the welding point, and (ii) the sensor 3 Stud tube or branch pipe 1
(iii) the sensor exit/exit device E is controlled so that the stub tube or branch pipe 1 is located close to the sensor 3;
(iv) When the sensor 3 is connected to the stub tube or the branch pipe 1,
(v) Control the robot welding device C to weld one stub tube or branch pipe 1; (vi) After welding of one stub tube or branch pipe 1 is completed, The above-mentioned process (i) of controlling the rotating device B and the moving device D so that the next stub tube or branch pipe 1 is positioned close to the welding point in order to weld the next stub tube or branch pipe 1.
It is configured to have the function of returning to. The symbols (i) to (vi) in the above text correspond to those shown in FIG. The support device A includes a proximal support device 5 having a chuck 4 for one end of the drum or main pipe 2;
The free end support device 7 includes a pair of left and right rollers 11, 11 that receive the other end of the drum or main pipe 2 from below. Said rotating device B is for said chuck 4. The moving device D moves the proximal support device 5 equipped with the chuck 4. The free end support device 7 equipped with the pair of rollers 11, 11 is movable near and far with respect to the other proximal support device 5, and while supporting the drum or the main pipe 2, it does not support the drum or the main pipe 2. They move together through the This point should be kept in mind. Tubes etc. 1 are often temporarily attached with small pitches. It is necessary to enter the sensor 3 by passing between adjacent tubes 1, 1, etc. Therefore, the control device F controls the rotating device B and the moving device D to temporarily stop (roughly position) the tube etc. 1 so that the tube etc. 1 does not obstruct the entrance of the sensor 3. For this control, data regarding the rotation and feeding of the drum etc. 2 and the method of robot welding are stored in advance in the control device F in accordance with the arrangement pattern of the tubes etc. 1 installed. Its storage form and command form are numerical control (NC). Data for a suitable number of representative array patterns is input as a fixed (permanent) program into ROM or magnetic tape, but data for special or temporary array patterns can be input manually or by a created program. Input to RAM etc. as needed by teaching based on . The sensor 3 detects the position of the tube, etc. 1 in a direction along the rotation axis of the drum, etc. 2, and detects the position (phase) of the tube, etc. 1 around the axis. The control device F controls the rotating device B and the moving device D in the following three ways. (i) Rotation and feeding are performed simultaneously or in translation. (ii) Start the rotation and move on to the feed after it is completed. (iii) Advance the feed and move on to rotation after its completion. (i) is preferable for high efficiency. Of the support device A of the automatic pipe welding device, the free end support device 7 is configured such that the holder 12 of the rollers 11 and 11 can freely slide up and down, left and right, and can freely rotate around the vertical axis. do. In other words, as shown in Figure 2, when the drum or main pipe is warped and the drum, etc. 2 is rotated around its original axis O, movements such as Y, Z, and R occur, but the support corresponding to this movement occurs. This is to make them do the same thing.
The conditions are not to change the position of the original axis O and to keep the supporting force constant. Otherwise, defects will occur in the welding work. These matters will be explained in more detail as follows. (a) Depending on the material of the drum etc. 2, it may be necessary to preheat it before welding, but in that case, due to uneven expansion, the third
Bend downward as shown in Figure A. (b) When a tube etc. 1 is welded, shrinkage stress acts on that part. Therefore, as the welding process progresses along the length, the warpage due to shrinkage stress increases, and the wire bends upward as shown in FIG. 3B. (c) When warped as in (a) and (b) above, the support point changes vertically, and when rotating such a warped object, the support point changes vertically Z and horizontally Y. Furthermore, the directionality R of the roller pair also changes. To deal with this, it is possible to change the support point and the posture of the roller pair, but if the reaction force of the supporting part against the lifting part changes during this adjustment, the supporting force will also change, and the difference between before and after the adjustment will change. The balance will be disrupted. That is, although the original axial center position is maintained correctly, internal stress is generated in the drum etc. 2 due to the reaction force, which is undesirable, and there are problems such as stress being applied to the loading part and the chuck, shortening the service life. The present invention has been made in consideration of such problems. The free end support device 7 is composed of the loading section n and a mounting section m that supports the loading section n, and the mounting section m is constructed as follows. The mounting part m that supports the loading part n is (a) a mechanism part for free rotation around the vertical axis (hereinafter abbreviated as a), and (b) a sliding mechanism part for left-right play in the left-right direction (hereinafter abbreviated as b). (c) Vertical play sliding mechanism section (hereinafter sometimes abbreviated as c). The vertical play sliding mechanism section is provided with a force adjusting mechanism section (hereinafter sometimes abbreviated as d) that maintains the supporting force in the loading section (hereinafter sometimes abbreviated as n) constant or almost constant. There is. Next, we will provide a supplementary explanation of the above. (b) Table 1 summarizes the six cases in which the items indicated by the abbreviations a, b, and c in the above text are arranged in relation to those indicated by n. The closer a part is to n in terms of structure, the closer it is to n in terms of display.

[Table] (b) d is related to c and is structurally adjacent to c. The adjacent part is closer to n than c (dc)
There are two cases: and the side far from n (cd).
If c is farthest from n (nabc, nbac) and d is farthest from n than c (cd), then d
is interposed between c and the base member (frame, etc., floor, etc.). (c) We do not insist on the specific structure of each of a, b, c, d, and n. That is, it can be implemented in various forms. (d) Regarding the force adjustment mechanism part d, this is structurally divided into (i) a reaction force sensor, (ii) a drive part, (iii) a control part between (i) and (ii), and (iii) a control part between (i) and (ii). provides feedback as necessary. A pneumatic or hydraulic fluid pressure cylinder is used as the drive unit (ii), and a pressure-responsive relief valve is preferably used as the sensor (i). The sensor may be a strain gauge or other load cell. A more specific example of the free end side support device 7 is as follows:
Let's explain according to FIGS. 4 to 7. This corresponds to the form (nabcd). The loading section n has a pair of left and right idle rollers 11, 11 around the front and rear axes, and a holder 12 thereof. The free rotation mechanism part a around the vertical axis has a vertical shaft 13 and a vertical tube 15 into which the vertical shaft 13 is rotatably and slidably inserted via a collar 14 . The vertical shaft 13 is integrally connected to the holder 12. The left-right play sliding mechanism part b in the left-right direction has a horizontal tube 16 and a horizontal shaft 18 on which the horizontal tube 16 is slidably inserted via a thrust bearing 17 . The horizontal tube 16 is integrally connected to the vertical tube 15. Vertical play sliding mechanism part c in the vertical direction
has a pair of left and right vertical tubes 19, 19 and posts 21, 21 which are slidably inserted through thrust bearings 20, 20, respectively. The pair of vertical tubes 19, 19 are connected by overhanging frames 27, 27 and a frame 22 parallel to the horizontal axis 18. The frame 22 sandwiches the vertical tube 15 and the horizontal tube 1.
It is on the opposite side of 6. A cam follower 24 that rolls on an upper rail 23 of the frame 22 is supported by a holder 25 that is integrated with the vertical tube 15. The power adjusting mechanism part d has a pair of left and right air cylinders 2 in a vertical position.
6,26. Each cylinder 26, 26 is interposed between an overhang frame 27, 27 and a base 28. The base 28 has the posts 21, 21 erected thereon. The base 28 has wheels 29, 29 on the left and right front and back.
These are placed on rails 30, 30. The vertical cylinder 15 of the free rotation mechanism part a holds and connects a screw jack 32 via a support frame 31. The jack 32 is connected to and holds an electric motor (servo motor) 33 which is its driving source. The vertical and retractable shaft 34 of the jack 32 is connected to the free rotating roller 3 at its upper end.
5 is in contact with the lower surface of the vertical shaft 13 inside the vertical cylinder 15. The jack 32 and the motor 33 move up and down together with the frame 22, the vertical tube 15, the horizontal tube 16, etc.
The vertical shaft 13 is moved up and down relative to the vertical tube 15 by driving the motor 33, and the relative height of the rollers 11, 11 pair to the frame 22, the vertical tube 15, the horizontal tube 16, etc. is adjusted. This is because when the diameter of the supported object, such as a drum, etc. 2 is small, the roller pair is raised, and when the diameter is large, the roller pair is lowered, thereby keeping the axis of the drum, etc. 2 at a constant height. Keep it horizontal. When there is no need to deal with changes in the drum etc. 2, use the jack 32 and motor 33.
It is also possible to omit the above. 36 is a flexible electrical conduit (flexible hose) for the motor 33 and the solenoid valves of the cylinders 26, 26, 37 is a rail 30,
Scraper for 30. 38 is holder 12
The sensor bar hangs down from the base 28 and corresponds to a pair of upper and lower limit switches 39, 39 fixed to the side of the base 28. In other words, the lifting limit is detected. When the drum etc. 2 is warped as shown in Fig. 2,
When this is rotated, movements of X, Y, Z, and R occur, but these are caused by the rolling of the wheels 29 and 29, respectively.
and absorbed by each mechanism part c, b, a. Z
Although the reaction force against the supporting action changes depending on the movement in the direction, the supporting force is kept constant by the action of the relief valves attached to the air cylinders 26, 26. In other words, when the warped part goes down and the internal pressure becomes high, the relief valve works and the pressure escapes, and when the warped part goes up and the internal pressure becomes low, the compressor starts sending pressure and the relief valve works and the pressure becomes constant. . Now, with reference to this embodiment, the supplementary explanation from earlier will be continued. Since the displacement component X in the front-rear direction is extremely small, it is also good to ignore this component. Even when the problem cannot be ignored, it may be possible to allow relative sliding of the drums 2 by using drum rollers instead of the wheels 29, 29, for example, by using the pair of rollers 11, 11 as drum rollers. Alternatively, it may have the same configuration as the mechanical parts b and c. Instead of supporting the load received by the base 28 along with the weight of the base on the floor, it may be supported on the ceiling via a hanging tool. The purpose of use is not limited to automatic welding, and may be for any purpose.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a schematic configuration of an automatic pipe welding device to which the present invention is applied, Fig. 2 is an explanatory diagram of the movement of drums, etc., A and B are side views, C is a plan view, and Fig. 3 I. , B are explanatory diagrams of warped states of drums, etc., FIGS. 4 to 7 show the free end side support device, FIG. 4 is a plan view, FIG. 5 is a partially cutaway front view, and FIG. The figure is a front view with other parts cut away, and FIG. 7 is a side view with some parts cut away. n...Loading part, a...Idle rotation mechanism part, b...Right and left play sliding mechanism part, c...Vertical play sliding mechanism part, d
. . . Force adjusting mechanism section, m . . . Mounting portion, 2 . . . Supported body, 5 .

Claims (1)

[Scope of Claims] 1. A proximal support device 5 that fixes and holds one end of a long supported body 2 in the radial direction and rotates the supported body 2 around its longitudinal axis. and a free end support device 7 that rotatably supports the other end side of the supported body 2, [A] The free end support device 7 is It consists of a loading part n equipped with a pair of loading rollers 11, 11 that is rotatable around an axis substantially parallel to the axis of the body 2, and a mounting part m that supports the loading part n. . [B] An idling mechanism part a that allows the mounting part m to swing left and right about the vertical axis of the load part n;
A left-right play sliding mechanism part b that allows horizontal lateral movement of the loaded part n, supports the loaded part n by a supporting action using fluid pressure, and also moves the loaded part n up and down by changing the load on the loaded part n. It is composed of a combination with a vertical play sliding mechanism part c that allows movement in the direction. [C] The vertical play sliding mechanism c is provided with a force adjusting mechanism part d that adjusts the fluid pressure so as to maintain the supporting force in the loaded part n constant or almost constant. A pedestal characterized by having the configuration described in [A] to [C] above. 2. The cradle according to claim 1, wherein the load section n is directly installed on the idle rotation mechanism section a. 3. The cradle according to claim 1 or 2, wherein the idle rotation mechanism section a and the left-right idle slide mechanism section b are directly installed. 4. The cradle according to any one of claims 1 to 3, wherein the idle rotation mechanism part a is provided at a location closer to the load part n than the left-right free sliding mechanism part b. . 5. According to any one of claims 1 to 4, wherein the left-right free sliding mechanism part b is provided at a location closer to the load part n than the vertical free sliding mechanism part c. The mentioned cradle. 6. The pedestal according to claim 2, wherein the left-right free sliding mechanism section b is directly installed on the free rotation mechanism section a. 7. The cradle according to claim 1, which is constructed in the form of a trolley that can move freely back and forth with respect to the floor surface.