JPH074722B2 - Manufacturing method of spherical node for joining structural members - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a spherical node for joining structural members,
More specifically, the present invention relates to a method for machining a spherical work in which a spherical node that joins a plurality of structural members forming a truss is machined from a spherical work with high dimensional accuracy to form a joint screw hole for the structural member.

[Conventional technology]

There are flat plates, mountain shapes, ridges, arches and domes in the frame shapes such as ceilings and beams for construction. When constructing them with a truss structure, screw structures are joined to both ends of many long steel pipes. A structural member to which the device is attached and a spherical node connecting it are used.

In such a three-dimensional frame structure, as shown in FIG. 6, a large number of structural members 18 are connected to the upper and lower sides of the spherical node 17 and to the front, rear, left, and right through a joining device 19, but the structural members 18 are sequentially assembled. Then, the position of the joint screw hole 16 formed in the spherical node 17 as shown in FIG. 7 and the direction of the hole are uniquely defined, and in some cases, the joint screw hole to be finally connected is A situation occurs in which the direction of the structural member connected to it does not match.

FIG. 8 shows the state exaggeratedly.
When the joining of a is incomplete, the joining screw 20a is bent, or the compressive load acts on the structural member 18a, the tip end surface of the joining device 19a and the spherical node 1 with which it abuts.
It happens that the joint surface 15a of 7 comes into partial contact.

Around the spherical node 17, for example, 10 to 18 joining surfaces 15
The joint screw holes 16 are formed in the center of each, but the position and direction of the joint screw holes 16 are set so that the frame work can be performed smoothly and completely so that the above-mentioned situation does not occur. It is desired that it be accurate.

Therefore, in the production of the spherical node 17, as shown in FIG. 9, the spherical work 1 which is the material thereof is attached to the center of the work fixing base 2 of the machining center 22 and the milling cutter or the drill 9B which is a tool is used. The joint surface 15 and the joint screw hole 16 (see FIG. 7) are formed.

The machining center 22 is a spherical work piece 1 with one installation.
It is a numerically controlled machine tool equipped with an automatic tool changer that can perform various operations such as milling, drilling, and thread cutting on several surfaces of the machine. The ratio of time and labor-saving effect are increased, and the time required for work is shortened to further enhance the effect of numerical control.

In such a machining center 22, first, a spherical workpiece 1 whose one surface is previously chamfered so as to form the machining reference surface 10 is brought in, and the machining reference screw hole 5 formed in the machining reference surface 10 is The spherical work 1 is mounted on the work fixing base 2 which is screwed with the fixing bolt 4 and rotates horizontally and vertically.

For example, the surface on the opposite side of the machining reference surface 10 is cut by a milling cutter to form a joint surface 15, and a drill 9B is placed at the center of the joint surface 15.
Prepare a pilot hole with and tap to thread. When the work on one joint surface is completed, the work fixing base 2 is rotated about the vertical axis in the direction of arrow 6 and, if necessary, about the horizontal axis in the direction of arrow 7. The relative positional relationship between the tool 9 and the spherical work 1 is set as desired as shown in the plan view of FIG. 10, and the same processing as above is performed.

In this way, the bonding surface 15
And the joining screw hole 16 are formed, but in some cases, the hemispherical surface on the side of the processing reference surface 10 is also processed. In that case, the joining surface 15b that has been machined first is used as a new machining reference surface, and is mounted on the workpiece fixing base 2 with a fixing bolt that matches the joining screw hole 16.

When there are many joining screw holes 16, 18 are also formed as described above, but their mutual positions are not always fixed or symmetrical, and differ depending on the frame position where the spherical node is used. Although the predetermined position can be easily obtained by the numerical control of the machining center, the spherical work 1 is rotated together with the tool 9 during the machining, and the rotational deviation between the spherical work 1 and the work fixing base 2 is caused. Occurs,
An error will occur in the subsequent processing position.

[Problems to be Solved by the Invention]

By the way, when the spherical workpiece 1 is processed, only the fastening bolt 4 is used to hold the spherical workpiece 1 in the mounted state. Therefore, the rotational deviation of the spherical work 1 is prevented by the frictional force between the seat pad 2B and the machining reference surface 10 of the spherical work 1 constituting the workpiece fixing base 2 shown in FIG. 9 and the fixing bolt 4 and the machining reference screw. It only depends on the force of engagement with the hole 5.

As a result, when the rotational force of the tool 9 acts in the direction opposite to the screwing rotation direction of the fixing bolt 4, the fixing bolt 4
Therefore, the posture of the spherical work 1 is deviated, or seriously, the spherical work 1 is loosened in the mounted state.

In order to reduce this deviation, conventionally, for example, the spherical work 2 is supported from below by a support member 23 as shown by a chain double-dashed line, or is supported by support members 24 and 25 from the left and right as shown in FIG. There is. However, since any of the supporting members depends on the frictional force, it is not possible to completely suppress even minute deviations, and there is no choice but to allow some error.

On the other hand, as shown by the broken line in FIG. 10, the position of the tool 9 (for example, milling cutter 9A) with respect to the spherical work 1 is the machining reference plane.
When the hemispherical surface is extended to the 10 side, the spindle 8 to which the tool 9 is attached or the tool itself may interfere with the work fixing base 2 and the machining can no longer be performed.

In that case, after removing the spherical work 1 from the work fixing base 2 and reversing it to make it possible to reproduce the attachment position by marking it, the joining surface 15b that was first machined is used as the machining reference surface, and the joining screw It will be attached to the work fixing base 2 with the fixing bolts matching the holes 16.

In this case, since there is no reference for the mounting angle of the spherical work 1, it is a manual operation of the operator, and it is not easy to set accurately without rotation deviation. Therefore, the spherical node
If the joint surface with the correct angle and the joint screw hole in the correct direction are not formed on the surface of 17, the connection state of the structural member with one-sided contact or backlash as shown in Fig. 8 will result, and the fixing will be incomplete. And the rust will occur at the spots on each side.

When the joining device 19 has a watertight structure, watertightness at the joining surface 15 cannot be obtained, and corrosive vapor enters the joining screw 20 in the joining device 19 or the inner surface of the structural member 18. As a result, problems such as a reduction in the durability of the truss occur.

As one of means for solving the above problem, for example,
Two locating pins can be employed as described in 62-29238. When the work is attached to the work fixing base using such positioning pins, it is possible to restore the original attachment state after, for example, removing the partially processed work and processing the other parts.

The diameters of the two positioning pins may be the same as each other when the workpiece has irregularities and the original posture can be easily grasped. However, when the work is a spherical node for joining a number of structural members, there is a situation in which it is difficult to distinguish front, back, left, and right except for the machining reference plane because the work is spherical, which is a problem in machining work. Is difficult to handle.

On the other hand, at the truss construction site, the structural members that make up the truss are not only symmetrically joined to the nodes, but also at an angle that at first glance it is not possible to see that the posture is slightly deviated from the symmetrical shape. It may be joined. Even if you can grasp the posture of the node from the two pin holes of the same diameter, you can not immediately grasp whether it should be arranged backward, for example, which means that truss construction work There is a drawback that it takes time.

The present invention has been made to solve the above problems,
The purpose is to be able to accurately machine a large number of joint surfaces and joint screw holes formed on spherical nodes to the desired angle and direction, and to exert a predetermined strength when the structural members are assembled as a truss structure. It is an object of the present invention to provide a method for manufacturing a spherical node for joining structural members, which enables reliable joining.

[Means for Solving the Problems]

According to the present invention, a machining reference surface is formed in at least one place of a spherical work which becomes a spherical node, and a fixing bolt is screwed into a machining reference screw hole provided in the machining reference surface, thereby a work fixing table is provided. The spherical work is mounted and applied to a method for manufacturing a spherical node in which a tool is used to form a joining screw hole of a truss-forming structural member on the spherical work.

As for the feature, referring to FIG. 1 and FIG. 2, the machining reference plane 10 at a position distant from the machining reference screw hole 5 is shown.
, Two pin holes 11 and 12 having different hole diameters are provided in a straight line with the machining reference screw hole 5 sandwiched between them, and fixing pins 13 and 14 corresponding to the above hole diameters are planted on the work fixing base 2. Fixing pin 1
That is, the pins 3 and 14 can be engaged with the pin holes 11 and 12.

[Action]

The machining reference surface 10 of the spherical work 1 is engraved with a machining reference screw hole 5 for mounting on the workpiece fixing base 2, and the machining reference surface 10 at a position distant from the machining reference screw hole 5 is Two pin holes 11 and 12 having different hole diameters are formed. Then, the two pin holes 11 and 12 are arranged in a straight line with the machining reference screw hole 5 interposed therebetween.

The work fixing base 2 has a pin hole 1 on the mounting surface of the spherical work 1.
Fixing pins 13 and 14 having a size corresponding to the hole diameters of the pin holes 11 and 12 are implanted at positions facing the 1 and 12, respectively. Its fixing pin 1
After engaging 3,14 with the pin holes 11,12, the fixing bolt 4
Then, the spherical work 1 is fixed to the work fixing base 2.

The posture of the work fixing base 2 is changed, and a plurality of points are machined from a desired direction. When the joint surface 15 and the joint screw hole 16 are formed by the tool 9, the rotation of the spherical work 1 accompanying the rotation of the tool 9 is prevented by the fixing pins 13 and 14, and the spherical work 1 is fixed on the work fixing base 2. On the other hand, there is no rotational deviation.

Further, when the processed spherical node 17 is processed again, the pin holes 11 and 12 and the fixing pin 1 on the work fixing base 2 side.
If 3 and 14 are re-engaged according to the hole diameter, the posture of the machining state is completely reproduced, the machining reference of the spherical work 1 is always secured, and the occurrence of dimensional error in the additional machining is avoided. It

In this way, when the two pin holes 11 and 12 having different hole diameters are arranged in a straight line with the machining reference screw hole 5 interposed therebetween, the arrangement direction of the pin holes 11 and 12 is set in the truss structure X, If the Y-axis and the Z-axis are made to coincide with each other in advance, the mounting posture of the node during the construction of the truss can be naturally grasped, and the occurrence of joint failure of the structural members can be avoided.

〔The invention's effect〕

According to the present invention, by using two pin holes having different hole diameters provided on the machining reference surface sandwiching the machining reference screw hole, the mounting posture of the spherical work is always fixedly held and removed. When processing a spherical work again, it is possible to reliably reproduce the posture before removal and mount it on the work fixing base. Therefore, it is not necessary to employ a supporting member or to support and adjust the spherical workpiece, and a large number of joint surfaces and joint screw holes formed on the spherical workpiece can be accurately and efficiently machined in a desired angle and direction. With this, when the structural members are assembled using the spherical nodes, it is possible to provide a truss structure that realizes a reliable connection that exhibits a predetermined strength.

〔Example〕

Hereinafter, the present invention will be described in detail based on its embodiments with reference to the drawings.

FIG. 1 is a mounting view of a spherical work 1 on a work fixing base 2 in a state where the method for manufacturing a spherical node for joining structural members of the present invention is applied. Work fixing base 2 is fixed base 2A
And a seat pad 2B attached to the front surface thereof, and its fixed base 2A is attached to a machining center 22 which is a processing machine via a fixing jig 3.

The spherical work 1 is provided with a bolt mounting hole penetrating through the center between the fixing base 2A and the seat pad 2B so that the spherical work 1 can be mounted in the center of the work fixing base 2 and fixed through the bolt mounting hole. The spherical work 1 is fixed to the seat pad 2B by the bolts 4 for use.

The diameter of the shaft part 4m of the fixing bolt 4 is set to be approximately the same as the hole diameter so that it does not rattle in the bolt mounting hole.
A screw portion 4n that is screwed into the processing reference screw hole 5 formed in the spherical work 1 is formed at the tip of 4m. The seat pad 2B may be integrated with the fixed base 2A in advance,
When replacing the spherical work 1 according to the dimensions,
As shown in the figure, the fixed base 2A may be provided separately from the fixed base 2A so as to prevent rotational deviation from occurring with the fixed base 2A via the protrusion 2a.

The workpiece fixing base 2 is capable of two-dimensional displacement in a horizontal plane, rotation in the direction of arrow 6 around the vertical axis, and rotation in the direction of arrow 7 around the horizontal axis, and is attached to the spindle 8. In addition to the vertical displacement of the tool 9, displacement and rotation of five axes are possible.

The spherical work 1 which is a material to be manufactured in the spherical node 17 (see FIG. 7) is, for example, a forged product, and the machining reference surface 10 is formed at least at one location of the spherical work 1, and the machining reference surface 10 has the above-mentioned structure. The machined reference screw hole 5 is previously engraved.

In such a spherical work 1, two pin holes 11 and 12 having different hole diameters are formed on the machining reference surface 10 at positions as far as possible from the machining reference screw holes 5. The two pin holes 11 and 12 are arranged in a straight line with the machining reference screw hole 5 interposed therebetween, and the pin hole 12 having a large diameter is, for example, on the minus side of the Y axis, as shown in FIG. 11 is located on the plus side.

The above Y axis is the vertical axis in Fig. 2, and the X axis intersecting with it is the horizontal axis. Both X and Y axes are, for example, the left and right and front and rear directions when the truss structure is viewed in plan. Selected to make. Although not shown, the Z axis perpendicular to the ground is given perpendicular to the plane of the drawing.

On the other hand, two fixing pins 13 and 14 are planted on the front surface of the seat pad 2B so as to face the pin holes 11 and 12 in a size corresponding to the respective hole diameters. Then, the fixing pins 13 and 14 are engaged with the pin holes 11 and 12, so that the spherical work 1 does not shift in the rotational direction with respect to the work fixing base 2 during processing by the tool 9.

Since the diameter of each fixing pin is accurately defined so that it can be fitted into each pin hole, the spherical work 1 can be reliably mounted on the work fixing base 2 without displacement.

Next, a procedure for machining the spherical work 1 will be described. The spherical workpiece 1 having the machining reference screw hole 5 formed at the center of the machining reference surface 10 faces the seat pad 2B of the workpiece fixing base 2, and the two fixing pins 13 and 14 planted are spherical workpieces. 1 to engage with the pin holes 11 and 12.

At this time, the pin hole 12 having a large hole diameter is fitted so as to be on the lower side of the seat pad 2B in the initial posture, and the two pins 11 and 12 prevent the spherical work 1 from falling off. The fixing bolt 4 thus inserted is inserted into the bolt mounting hole of the work fixing base 2, and the threaded portion 4n at the tip thereof is screwed into the machining reference screw hole 5.

Since the rotation of the spherical work 1 is blocked by the fixing pins 13 and 14, if the fixing bolt 4 is rotated, the spherical work is stopped when the head of the fixing bolt 4 comes into contact with the back surface of the work fixing base 2. 1 is completely fixed to the work fixing base 2.

Rotate the work fixing base 2 around the vertical axis and the horizontal axis,
The spherical work 1 is adjusted so that the predetermined position is in the direction of the tool 9. When the work fixing base 2 is moved forward, machining is performed by the rotating tool 9.

First, as shown in FIG. 3 (a), the spindle 8 having the milling cutter 9A attached thereto is rotated to make the surface of the spherical work 1 a flat joint surface 15. The workpiece fixing base 2 is slightly retracted, the milling cutter 9A is separated, the multi-axis head (not shown) is rotated, and the drill 9B is placed at the processing position. A prepared hole is made at the center of the joint surface 15 shown in FIG. 3 (b), the opening 9c having the next largest diameter is chamfered by the drill 9C, and finally the tap 9D is used to make the third hole. Figure (d)
Threading is done as shown in.

When one joint surface 15 and its joint screw hole 16 are formed, the posture of the workpiece fixing base 2 is changed and the above-mentioned processing is performed from a desired direction at a plurality of places, and the spherical node 17 shown in FIG. To be done. When the joining surface 15 and the joining screw hole 16 are formed by the tool 9, the spherical work 1 is prevented from turning along with the rotation of the tool 9 along with the fixing pins 13 and 14 (see FIG. 1), and the spherical shape is obtained. The work 1 does not rotate relative to the work fixing base 2.

Further, when it is necessary to process the processed spherical node 17 again, if the pin holes 11 and 12 and the fixing pins 13 and 14 on the work fixing base 2 side are engaged with each other, the previously processed state can be obtained. Posture is completely reproduced, spherical work 1 or spherical node
17 machining standards are always ensured, and dimensional errors in additional machining are avoided.

By the way, the machining reference screw hole 5 on the machining reference surface 10
Is used as a roof member, used as a hanging hole for electric lights, or a connecting screw hole when connecting a structural member 18.
Processed to be 20.

Of course, since the hole diameters of the pin holes 11 and 12 are different, when the spherical work 1 which has been once removed is mounted on the work fixing base 2 again, the pin holes 11 and 12 are not mistaken for up and down. For example, when the joining surface 15 and the joining screw hole 16 are formed on the hemispherical surface of the spherical workpiece 1 on the working reference surface 10 side, as shown in FIG. 4, the joining formed on the opposite side of the working reference surface 10 is performed. Face 15
If the pin holes 11a and 12a having different hole diameters described above are formed in b,
The joining surface 15b can be attached to the work fixing base 2 by facing the seat pad 2B with the processing reference surface.

Therefore, when the spherical work 1 is brought close to the tool 9, as shown by the broken line in FIG. 10, even if the tool 9 or the spindle 8 hits the work fixing base 2 as shown by the broken line in FIG. As long as 1 is reversed, the desired position can be processed. At that time, pin hole 11
Since the a and 12a are accurately positioned by the machining center 22, the mounting posture after reversal does not deviate from the mounting posture before reversal.

Of course, the mounting posture of the spherical workpiece 1 can be completely reproduced even when returning to the state before the reversal, as described above. By the way, in the spherical node 17 manufactured in this way,
For example, the structural member 18 is connected by the joining device 19 as shown in FIG.

The structural member 18 is composed of a steel pipe 26 and a stub cone 27 welded to both ends thereof, and the joining screw 20 of the joining device 19 inserted through the holes provided therein and attached to the joining screw hole 16 of the spherical node 17. It is screwed. The joint screw 20 is advanced by the rotation of the hexagonal sleeve 29 that fits into the hexagonal boss 28 integrally formed in the middle portion of the joint screw 20 and slides relatively in the axial direction. 29 is a joining screw
Cover 20 completely.

In the case of such a joining device 19, if the tip end surface of the joining device is brought into close contact with the joining surface 15 of the spherical node 17 and the sealing material 30 and the like are interposed, a watertight structure can be obtained.

As can be seen from the above description, according to the above-described spherical node manufacturing method, the mounting posture of the spherical work is always fixedly held, and when the detached spherical work is processed again, Since it can be reproduced and mounted on the work fixing table, it is not necessary to use support members or support adjustment work for spherical workpieces, and many joint surfaces and joint screw holes formed on the spherical workpiece can Accurate and efficient processing in the direction.

Furthermore, since the diameter of the pin hole is changed, it does not cause up / down and left / right confusion when it is mounted on the work fixing base again.
When the direction of the joint screw hole is correct, a reliable connection is achieved so as to exert a predetermined strength when the truss structure is assembled by using the structural member and the spherical node.

As shown in FIG. 2, connect the two pin holes 11 and 12 to Y, for example.
When the truss structure is arranged on the axis and the Y axis is aligned with, for example, the front-back direction when the truss structure is viewed in plan, a single node or a structure in which several structural members are connected via a node or When a subassembly truss that is partially or planarly assembled is brought into the truss structure being constructed by a crane or the like, in any case, just check the size and direction of the pin holes 11 and 12 of the node, It is possible to realize a planar layout that matches the drawings, and to significantly facilitate the truss construction work.

[Brief description of drawings]

FIG. 1 is a front view of a spherical work to which a method for manufacturing a spherical node for joining structural members according to the present invention is mounted on a work fixing base, and FIG. 2 is a side view of the spherical work taken along the line II-II in FIG. FIGS. 3 (a) to 3 (d) are process diagrams of a spherical work, and FIG. 4 is a mounting of a spherical work having a joint surface corresponding to the machining reference surface and a pin hole on the opposite side of the machining reference surface. FIG. 5 is a cross-sectional view showing an example of a connection state between a structural member and a spherical node by a joining device, FIG. 6 is a truss structure diagram formed by structural members connected by a spherical node, and FIG. 7 is a spherical node FIG. 8 is a joint view exaggeratingly showing that the finally connected structural member is not accurately fixed to the spherical node, and FIG. 9 shows a processing state of a conventional spherical workpiece. The front view and FIG. 10 are the planes at the locations corresponding to the line XX in FIG. It is. 1 ... Spherical work, 2 ... Work fixing base, 4 ... Fixing bolt, 5 ... Machining reference screw hole, 9,9A to 9D ... Tool, 10 ... Machining reference surface, 11, 11a ... Pin hole with small hole diameter, 12, 12a ... Pin hole with large hole diameter, 13,14 ... Fixing pin, 16 ... Joining screw hole, 17 ... Spherical node, 18 ... Structural member.

Claims (1)

[Claims] 1. A work fixing base is formed by forming a machining reference surface on at least one location of a spherical work serving as a spherical node, and screwing a fixing bolt into a machining reference screw hole formed on the machining reference surface. In the method for manufacturing a spherical node in which the spherical work is mounted, and the joining screw hole of the truss-forming structural member is processed into a spherical work by the tool, in the processing reference surface at a position apart from the processing reference screw hole,
Two pin holes with different hole diameters are provided in a straight line across the machining reference screw hole, and a fixing pin corresponding to the hole diameter is planted on the work fixing base, and the fixing pin is used as the pin hole. A method for manufacturing a spherical node for joining structural members, characterized in that it can be engaged with