JPS59185596A - Positioning jig for cylindrical object to be welded - Google Patents

Abstract

PURPOSE:To improve the accuracy in positioning by inserting a cylindrical object to be welded onto a positioning shaft consisting of an outer shaft and an inner shaft, and fixing said object by the rotation of the inner shaft and by means of balls. CONSTITUTION:A positioning shaft 10 consisting of an outer shaft 21 and an inner shaft 22 is set on a supporting table 9, and an object 2 to be welded and a collar are fitted onto the shaft 10. A clearance delta/2 is provided between the object 2 and the outside wall surface of the shaft 21 in this stage. When the shaft 22 is rotated by rotating a handle 24, the cam member 27 fixed to the shaft 22 rotates and the balls 26 housed in the holes 25 of the shaft 21 are pressed by a cam surface 29, thus forcing the balls 26 to project from the outside wall surface of the shaft 21 and pressing the same to the inside wall surface of the object 2. The object 2 and a body 1 are welded in this state, by which the exact welding is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a positioning jig for a cylindrical workpiece to be welded to a main body.

Generally, when welding a cylindrical workpiece to a main body, for example, as shown in FIG. There are things that do. In this case, a pair of king pin bosses 2 are generally welded to the upper and lower parts of both ends of the axle center 1, and a king pin 3 is fitted into the king pin boss 2, and a wheel 5 is connected to the king pin 3 via a spindle 4. The king pin boss 2 functions as a bearing for the king pin 3. Therefore, when welding the king pin boss 2 to the axle center 1, it is necessary to position the king pin boss 2 with respect to the axle center 1, which has been positioned in advance, in order to set the axis of the king pin 3 at a predetermined position. I had to.

Therefore, conventionally, as shown in FIGS. 2 to 4, a positioning jig J has been used to position the above-mentioned king pin boss 2. It was attached to the positioning jig 6 of the center 1.

That is, the axle center 1 positioning jig 6 has a block 8 installed at a desired location on the base plate 7, and the axle center 1 is placed on this block 8 to position the axle center 1 with respect to the base plate 7. It is supposed to be done. On the other hand, the positioning jig J for the king pin boss 2 is provided on the base plate 7 corresponding to both ends of the positioning position of the axle center 1), and is fixed to the base plate 1 and has a horizontal support surface 9a. It consists of a stand 9 and a positioning shaft 10 which has a male threaded part 10a screwed into the female threaded part 9b of this support stand 9 and is erected on the support stand 9. and,
A pair of upper and lower king pin bosses 2 are fitted into the positioning shaft 10, and the axis of the king pin boss 2 is thereby positioned. In this case, the lower kingpin boss 2 is positioned in the vertical direction because its lower surface abuts the support surface of the support base 9, and the kinkbin boss 2 of the upper flu is located between the kingpin boss 2 of the lower flu. By interposing the collar 11 between the two, the collar 11 is positioned in the downward direction. When the axle center 1 and the king pin boss 2 are positioned in this manner, they are welded (arc welded) using a welding device not shown.

In such a conventional positioning jig for a cylindrical workpiece, the kingpin boss 2 as a cylindrical workpiece is fitted into one positioning shaft 10.
Since the structure was designed to position the positioning shaft with great precision, it was necessary to ensure a clearance C between the inner diameter of the king pin boss 2 and the outer diameter of the positioning shaft 10, and to set this clearance C small. . However, when welding the king pin boss 2, the king pin boss 2 is distorted due to the welding heat, so if the clearance C1 is set too small, the king pin boss 2
A situation occurs in which the heat b portion of the king pin boss 2 is pressed against the circumferential wall of the positioning shaft 1o, and the king pin boss 2 cannot be removed from the positioning shirt NO after welding. For this reason, the above-mentioned clearance Ck has to be set to a certain degree large, and as a result, the king pin boss 2 shakes against the positioning shirt NO, and the fineness of the king pin boss 2 slips from the axis of the positioning shaft. This results in poor positioning accuracy of the king pin boss 2.

The present invention has been made based on the above points. Its purpose is to completely improve the positioning accuracy of a cylindrical workpiece, and also to make it possible to remove the cylindrical workpiece after welding without being affected by thermal distortion during welding. An object of the present invention is to provide a positioning jig for a cylindrical workpiece.

The gist of the present invention is that a positioning shaft that stands up on a support base is fitted into a sleeve-shaped outer shaft having an outer diameter smaller than the inner diameter of the cylindrical workpiece and this outer shunt. and an inner shaft that rotates relative to the outer shaft with a constant rotating shaft metal, and the cylindrical welded object is mounted on the peripheral wall of the outer shaft corresponding to the installation position of the cylindrical object to be welded. A centering member is provided facing the inner wall surface of the outer shaft and protruding and retracting from the outer surface of the peripheral wall of the outer shaft, and a cam member gold-plated plate that engages with the centering member is provided on the inner shaft corresponding to the centering member, and a cam member gold-plated plate that engages with the centering member is provided on the inner shaft corresponding to the centering member. A positioning tool for a cylindrical workpiece, in which the centering member is placed in a recessed position and a protruding position for centering the cylindrical workpiece, depending on the relative rotational positional relationship between the member and the centering part A3. It's in the ingredients.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

In the embodiments shown in FIGS. 5 to 9, a positioning jig J for a king pin boss 2 as a cylindrical workpiece is shown, and the basic configuration of this positioning jig J is as follows: The support stand 9 to be fixed and this support stand 9
It consists of a positioning shaft 10 that is installed upright.

In this embodiment 51j, the support stand 9 has a horizontal support surface 9ae on its upper surface, and a bearing hole 20 is formed in the center thereof in a direction orthogonal to the base plate I.

Further, the positioning shaft 10 is composed of a sleeve-shaped outer shaft 21 and an inner shaft 22 that is inserted into the outer shaft 21. The outer shaft 21 is formed with a metal having an outer diameter smaller than the inner diameters of the king pin boss 2 and the collar 11, and the support base 9
It is integrally formed with the support base 9 surrounding the bearing hole 20 of the support base 9 . On the other hand, a rotating shaft portion 23 is formed at the lower end of the inner shaft 22, and this rotating shaft portion 23 rotatably fits into the bearing hole 20, and the tip of the rotating shaft portion 23 is placed on the upper surface of the base plate I. When brought into contact with each other, the inner shaft 22 rotates within the outer shaft 21 with a fixed rotation axis 0. A handle 24 for rotating the inner shaft 22 is attached to the upper end of the inner shaft 22.

Further, on the peripheral wall of the outer shaft 21, a portion corresponding to the arrangement position of the king pin boss 2 is shown in @5 and 6.
In the workpiece 9 shown in the figure, for example, four ball accommodation holes 25 are provided in a row in the axial direction at intervals of a predetermined angle +Ht, and each ball accommodation hole 25 has a ball 26 as a centering member. are accommodated respectively. That is, the ball accommodation hole 2
5 is inclined diagonally downward from the outer wall surface to the inner wall surface of the outer shaft 21 as shown in FIG. A stopper portion 31 is formed to restrict movement of the ball 26 in the direction. The ball 26 is normally accommodated and held in the ball accommodation hole 25 and placed in a recessed position relative to the outer wall surface of the outer shaft 21, but can move in a radially outward direction of the outer shaft 21. It looks like this.

Furthermore, a cam member 27 is fixed to a portion of the inner shaft 22 corresponding to the position where the ball 26 is disposed concentrically with the inner shirt 22- through a pin 28, and each cam member 2T has four cam surfaces 29 of the same shape on its circumferential surface, and each cam surface 29 is configured so that the radius becomes larger sequentially along the direction shown by arrow A, and the adjacent cam surface 29 It is continuous with 30 steps. The inner end of each ball 26 is always in contact with each cam v129 of the cam member 2T, and the inner end of each ball 26 is in contact with the radius 11 portion 29a near the minimum radius of each cam surface 29. Each ball 26 when in contact
is housed in the ball housing hole 25.

Therefore, according to the positioning jig according to this embodiment, when setting the king pin boss 2 to the positioning shaft 10, after rotating the handle 24 in a predetermined direction and setting the inner shaft 22 to the set position, Positioning shaft 10 Niking bin boss 2 and collar 11f? c.
Just fit it in. At this time, the cam member 27 rotates as the inner shaft 22 rotates, and when the inner shaft 22 reaches the set position, the radius 11 portion 29a of the cam surface 29 comes into contact with the balls 26, and each ball 26 It is configured to be set at a recessed position from the outer wall surface of the outer shaft 21.

Therefore, there are no protrusions on the outer wall surface of the outer shaft 21, and the king pin boss 2 and collar 11 fit smoothly with the outer wall surface of the outer shaft 21 with a clearance δ. .

After this, when positioning the king pin boss 2, it is sufficient to rotate the handle 24 in the opposite direction to the center position and set the inner shaft 22 at the position. At this time, the cam member 21 together with the inner shaft 22
When the inch shaft 22 rotates and reaches the positioning position, a portion 29b of the radius 11 near the maximum radius of the cam surface 29 comes into contact with the ball 26, as shown in FIG. In this state, each ball 26 is pushed out in the radial direction while slidingly contacting the respective cam surface 29, and each ball 26 is set at a position protruding from the outer wall surface of the outer shaft 21, and the ball 26 is placed in a position protruding from the outer wall surface of the outer shaft 21. Still in contact with the inner wall surface. In this case, since each ball 26 moves concentrically with respect to the rotation axis O of the inner shaft 220, the king pin boss 2 moves self-centripetally while being restrained by each ball 26, and the axis of the king pin boss 2 The centering state is set such that the center and the axis of the inner shaft 22, that is, the rotational axis O coincide with each other.

In this state, the positional relationship between the pre-positioned axle center 1 and the king pin boss 2 is determined 9, and welding between the two is performed by a welding device not shown. At this time, the king pin boss 2 is attached to each ball 26.
Since the movement of the king pin boss 2 is restricted, even if the king pin boss 2 is distorted due to welding heat, the axis of the king pin boss 2 is unlikely to be displaced, and the axle center 1 of the king pin boss 2 is The position relative to is maintained at a predetermined value.

After that, when welding of both is completed, the positioning jig J will remove the king pin boss 2. In this case, rotate the handle 24 in a predetermined direction and return the inner shaft 22 to the center position. After setting, the king pin boss 2 and collar 11 may be removed from the actuator shaft 21. At this time, the inner shaft 22
When returning to the center position, the cam surface 29 that holds the valley balls 26 in the protruding position moves, so each ball
6 retreats from the inclined protruding position of the ball accommodation hole 25 and returns to the retracted position, and no protrusion is present on the outer wall surface of the outer shaft 21. Therefore, the king pin boss 2 and collar 11 can be easily removed with a clearance δ between them and the outer wall surface of the outer shaft 21. In this case, the king pin boss 2 is distorted due to welding heat, but if the clearance δ is set to a certain degree, the king pin boss 2
This has no effect on the separation from the outer shaft 21.

Furthermore, in this embodiment, the ball 26 is used as the centering member, and the structure is such that the ball 26 is simply fitted into the ball accommodation hole 25 of the outer shaft 210, so that the outer shaft 21 of the centering member In addition, the ball 26 accommodated in the ball accommodation hole 25 is easily attached to the stopper part 3 due to the inclination of the ball accommodation hole 25.
1, so there is no concern that the ball 26 will fall unnecessarily.

Incidentally, in the above embodiment, the outer shaft 21 is fixed and the inner shaft 22 is rotated.
The inner shaft 22 may be completely fixed and the outer shaft 21 may be rotated.

Further, the number and arrangement of the balls 26 as the centering member are not limited to those shown in the above embodiments, and the design may be changed as appropriate, and the balls 26 are not necessarily used as the centering member. It is not necessary, and for example, two or more ronds that protrude and retract in the radially outward direction of the outer shaft 21 may be provided. Further, in the above embodiment, the separate cam member 27 is attached to the inner shaft 22, but the cam member 21 may be formed integrally with the inner shaft 22. Furthermore, the specific structure of the cam member 21 is not limited to that shown in the above embodiments, and it goes without saying that the design can be modified as appropriate depending on the number and arrangement of centering members. Further, in the above embodiment, the kingpin boss 2 is used as an example of the cylindrical object to be welded, but it goes without saying that the present invention can be applied to positioning jigs for other cylindrical objects to be welded. In this case, the number of cylindrical objects to be welded to be positioned with one positioning jig is not necessarily two as shown in the embodiment, but may be one, three or more.

As explained above, according to the positioning jig for a cylindrical workpiece according to the present invention, the positioning shaft erected on the support base is connected to a sleeve having an outer diameter smaller than the inner diameter of the cylindrical workpiece. The outer shaft is composed of a shaped outer shaft, and an inner shaft that is inserted into the outer shaft and rotates relative to the outer shaft with a fixed rotation axis, and the outer shaft corresponds to the installation position of the cylindrical workpiece. A centering member is provided on the peripheral wall of the shaft so as to face the inner wall surface of the cylindrical object to be welded and can freely protrude and retract from the outer surface of the peripheral wall of the actor shaft, while an inner shaft corresponding to the centering member is provided with a centering member. A cam member that engages is provided, and ρ is determined by the relative rotational positional relationship between the cam member and the centering member.
Since the centering member is placed in the recessed position and the protruding position for centering the cylindrical workpiece, when the centering member is placed in the protrusion position, the cylindrical workpiece is centered. This centering condition will be maintained without being affected by thermal distortion during welding.
Accordingly, the positioning accuracy of the cylindrical workpiece can be improved. When the centering member is placed in the retracted position, there is sufficient clearance between the cylindrical workpiece and the positioning shaft. 71i that balance is secured
:,! l) Accordingly, the cylindrical workpiece can be easily removed from the positioning shaft without being affected by thermal distortion during welding.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a main body and a cylindrical workpiece, Fig. 2 is a front view showing a conventional positioning jig for the main body and a cylindrical workpiece, and Fig. 3 is a plan view thereof. FIG. 4 is a cross-sectional view of main parts showing details of a conventional positioning jig for a cylindrical workpiece, and FIG. 5 is a cross-sectional view showing an embodiment of the positioning jig for a cylindrical workpiece according to the present invention. Figures 6 and 7 show the state of the centering member when the cylindrical workpiece is centered.
In the figure, a sectional view taken along the line Vl-W and an enlarged view of part ■, and Figs. 8 and 9 are explanatory views corresponding to Figs. 6 and 7 showing the state of the centering member when positioning the cylindrical workpiece. It is. J...Positioning jig 1...Axle center (main body) 2...King pin boss (cylindrical welded object) 9...Support stand 10...Positioning shaft 21...
Outer shaft 22... Inner shaft 25...
Pole accommodation hole 26...Ball (centering member) 2T...Cam member Patent applicant: Nissan Motor Co., Ltd. Representative Patent Attorney Hao Tsuchibashi 4C Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] A cylindrical workpiece having a positioning shaft erected on a support base, the cylindrical workpiece to be welded to the main body being fitted into the positioning shaft to position the cylindrical workpiece. In the positioning jig, the positioning shaft has a sleeve-shaped outer shaft having an outer diameter smaller than the inner diameter of the cylindrical workpiece, and a sleeve-shaped outer shaft that is inserted into the outer shaft and has a constant rotation axis with respect to the outer shaft. The peripheral wall of the outer shaft, which is intersected by the relatively rotating inner shaft and corresponds to the installation position of the cylindrical object to be welded, faces the inner wall surface of the cylindrical object to be welded and has an outer surface of the peripheral wall of the actuator shaft. The centering member gold film can be freely retracted from the centering member, and the inner shaft corresponding to the centering member is provided with a cam member that engages with the centering member, and the relative rotational positional relationship between the cam member and the centering member is adjusted. A positioning jig for a cylindrical workpiece, characterized in that the centering member is arranged at a retracted position and a protruding position for centering the cylindrical workpiece.