RU2555263C1 - Method of riveting of curvilinear panels at drilling-riveting machine - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: surface of curvilinear panel is levelled up in the riveting zones by its orientation at right angle to axis of the force head of the drilling-riveting machine. At that three levelling sensors are used to measure distance from them to the panel surface. The sensors are located on casing of the power head with making of the equilateral triangle by their parallel axis upon crossing the perpendicular plane. At middle of the altitude of the triangle the plane crosses the axis of the power head creating value that is parameter determining distance between levelling sensors. During the sensors installation this value is set depending on tolerance for misalignment of the rivet axis relatively to the panel surface. The panel orientation is made until equality of the distances to it measured by the sensors. Liner movement of the drilling-riveting machine over the riveting zones of the panel is performed to value determined as per the specified equation.

EFFECT: higher accuracy of riveting.

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Description

The invention relates to mechanical engineering and can be used for riveting curvilinear panels on a drilling and riveting machine when it is moved to the riveting step while leveling the surface of the curvilinear panels relative to the axis of the riveting during their automatic riveting, as well as for programming the riveting route.

There are two known methods of programming the positioning process and the route of automatic riveting of curved panels used in domestic and foreign assembly and riveting industries. In the first method, a program for positioning (orienting) a drilling and riveting machine to the riveting step while simultaneously aligning the panel normal to the riveting axis is developed by removing the initial information from the standard of the assembled panel, and the panel with guide holes in the stringers determining the position of the rivet axes is used as a reference (riveting points) on the surface of the panel (Belyanin PN Production of wide-body aircraft. Publisher: M., Mashinostroenie, 1979. - 298 p). The manufacture of the panel standard includes the steps of performing section cross-sections of the panel, followed by the manufacture of templates for the production of tooling, with the help of which stringers are formed and drilled into them, guide panels are assembled in the assembly device, which leads to a significant increase in the complexity and cost of the automatic riveting process.

Along with this, the accuracy of the location of the axis of the rivets on the surface of the panel decreases due to errors at the stages of size transfer: drawing-plasma-template-tooling-part-assembly fixture-standard-panel and the production preparation time is increased due to the need to produce a set of standard-panels on product when changing the object of production.

In the second method, information for programming positioning (orientation) on the riveting step t (segment [i; i + 1]) is taken from the panel drawing (Fig. 1), which shows the coordinates of the intersection of the axis of the rivets with the surface of the panel (riveting points) (Ershov V.I. Automation of assembly and technological design.Tutorial, 2T. Publisher: M., MAI. - 1998. - 153 p.) Thus, the coordinates x _{i of the} riveting step t in the riveting plane XOY are the coordinates x _i and y _i , and along a number of riveting - coordinates z _i . In this case, with the help of sensors, the panel or power head (SKA) is aligned to achieve perpendicularity of the riveting axis O _i O _i to the surface of the panel in the riveting area. During the alignment process, it is necessary to correct the positioning parameters x _i y _i and z _i due to the inconsistency of the radius of curvature of the panel R _i in the plane of the ZOX riveting. This complicates and makes the process of programming the positioning parameters x _i , y _i and z _i more time consuming. At the same time, the low rigidity of the assembled panel and the errors of its preliminary assembly lead to deviations of its real geometric parameters from the theoretical ones in the OZYX coordinate space.

The above-mentioned causes of errors reduce the accuracy of parameter positioning during automatic riveting of curved panels, and the stage of programming the riveting route is difficult and time-consuming, and in some cases practically impossible.

To align the surface of the panel normal to the axis of the riveting (axis of the power head of the boring-riveting machine), automatic alignment devices are used - rangefinder sensors (laser, tactile, etc.) mounted on the case of the power head of the boring-riveting machine.

There are many known methods, constructive and functional schemes using these sensors, one of which is the “Method for measuring deviations from straightness” (AS No. 1523890, G01B 5/28, authors L. Zeitman and Yu.P. Timofeev) in which the base of the measuring device is moved normal to the plane by rotating it along one constant support perpendicular to the measured surface until the remaining base supports are sequentially positioned on the profile line of the measured surface, and segments are selected as chords direct, and further, by trigonometric transformations, the measured deviation from straightness is obtained.

However, this method has significant drawbacks when it is used to control the positioning process while aligning the surface of the panel with respect to the riveting axis during automatic riveting:

1) in the method, deviations from straightness are measured, and when aligning the panel, it is necessary to have the values of the deviation parameters of the curvilinearity of the panel surface from its theoretical values, presenting curved sections through the chords, which leads to additional labor-intensive operations for calculating and programming positioning (orientation) parameters;

2) low efficiency and productivity when implementing this method using control sensors, because it provides for additional rotational movements for measuring deviations from straightness;

3) additional recalculation of each measured deviation value is required using trigonometric transformations, which greatly complicates and makes time-consuming programming of the positioning process along the riveting route.

The closest in technical essence to the proposed invention and taken as a prototype is the "Method of riveting curved panels on a drilling and riveting machine" (AS No. 912392, B21J 15/28, BI No. 10, authors: Baranova GA, Novikova AD et al. In this case, the principle of controlling the process of alignment of panels with their help remains the same regardless of their design, its essence lies in the fact that the surface of the panel is considered to be level, that is, the condition for perpendicularity of the surface to they are not relative to the axis of riveting in the riveting zone, with equal distance from it fixing the removal of sensor elements or leveling devices This principle underlies the functioning of domestic and foreign drilling and riveting machines and installations and is presented in the considered analogues.

Its disadvantage is the low accuracy of the riveting method of the drilling and riveting machine when it is moved to the riveting step with simultaneous alignment of the surface perpendicular to the riveting axis due to the lack of connections between the measurement parameters of the sensors and alignment devices, their relative position relative to each other in the riveting area and the panel geometry, namely, its curvature in the plane of the riveting row, which has different meanings when positioning (orientation) on the riveting step. This makes it difficult, and sometimes makes it impossible to correct the coordinates x _i and y _i when moving the drilling and riveting machine by the riveting step (Fig. 1), which also reduces productivity, and therefore overall efficiency, when implementing this method using control sensors.

The object of the invention is to increase the productivity and accuracy of automatic riveting of curved panels by determining the relationships between the parameters of measuring the position of the surface of the panel relative to the axis and plane of the riveting and its curvature in the riveting area using adjustable sensors, followed by the calculation of positioning (orientation) parameters and programming the automatic riveting route by drilling riveting machine.

The technical result from the use of the invention is the creation of an effective and accurate method for riveting curved panels on a drilling and riveting machine in the process of moving to the step of riveting while aligning the surface of the panel relative to the axis of the riveting along the riveting route, as well as programming this route.

The technical result is achieved by the fact that in the Method for riveting curved panels on a drilling and riveting machine, comprising aligning the surface of the curved panel in the riveting zones, installing rivets in the riveting areas of the rivets and moving the drilling and riveting machine with the power head along the riveting zones of the curved panel, according to the invention alignment of the surface of the curved panel in the riveting zones is carried out by orienting it normal to the axis of the power head of the drilling-riveting machine with using three alignment sensors, by means of which they measure the distance from them to the surface of the curved panel, while alignment sensors are placed on the body of the power head with the formation of their parallel axes at the intersection with the plane of an equilateral triangle perpendicular to them with a height of 2b, in the middle of which the plane intersects the axis power head to obtain a value of b, which is a parameter that determines the distance between the alignment sensors, while the location of the sensors For alignment, the value of b is adjusted depending on the tolerance on the non-perpendicularity of the rivet axis to the surface of the curved panel, and the aforementioned orientation of the curved panel is carried out to the equality of the distances measured by the sensors, installation of rivets in the riveting zones and linear movement of the drilling and riveting machine with the power head along the riveting zones of the curved panel by q, which is determined by the following formula:

t is the riveting pitch;

a - the distance measured by the alignment sensors of the riveting plane tangent to the surface of the curved panel at the point of intersection of the axis of the power head of the riveting and drilling machine and located perpendicular to the axis from the surface of the curved panel at points corresponding to the alignment sensors, and enter this displacement value into the program automatic riveting route with its further implementation in automatic riveting mode.

To clarify the technical nature of the method, consider figures 1, 2, 3, 4, 5, 6.

The figure 1 shows a diagram of the designation of coordinates (riveting points) on the surface of the assembled panel in its coordinate space OZYX.

The figure 2 shows a schematic diagram of the positioning of a drilling and riveting machine with automatic riveting of a curved panel.

The figure 3 presents the layout of the alignment sensors in the plane of the row of riveting.

The figure 4 shows a diagram for determining the pitch of the riveting and the corresponding parameter of the linear positioning of the drilling-riveting machine.

The figure 5 presents a diagram for determining the value of stepwise positioning.

Figure 6 shows the riveting zone with alignment sensors and the power head of the GEMCOR 5013TTX / G86 drilling and riveting machine for automatic riveting of curved panels.

Where: 1 - processed panel; 2 - frame support-leveling device; 3 - power head; 4, 5, 6 - alignment sensors; 7, 8 - drives vertical movement and rotation; 9 - power head drilling and riveting machine; 1 - supporting sleeve; 11 - sheathing of the assembled panel; 12 - shelf stringer; 13 - rivet.

Consider the work of the proposed systems in statics (Fig. 2, 3, 4, 5, 6).

The panel 1 to be machined is fixed on the frame 2 of the supporting-leveling device of the drilling and riveting machine in its OZOX coordinate space with the possibility of two-way vertical movement along the OZ axis and rotation relative to the axis of symmetry of frame 2 to orient any point on its surface perpendicular to the axis O ₁ O _{1 of the} power head 3 drilling and riveting machine, performed using alignment sensors 4, 5 and 6, controlling the drives of vertical movement and rotation 7 and 8 of frame 2 (Fig. 2).

Sensors 4, 5 and 6 are located on the housing 9 of the power head 3 in such a way that their parallel axes, when intersecting with the plane equidistant and perpendicular to them, form an equilateral triangle with a height of 2b on the latter, and the axis O ₁ O _{1 of the} power head 3 of the drilling-riveting the automaton intersects this plane in the middle of the height of this triangle b. In this case, the value of b is a tuning parameter and determines the size of the distance between the sensors 4, 5 and 6. The axis O ₁ O _{1 of the} power head 3 (riveting axis) intersects the surface of the panel 1 being assembled at the point C _i formed by this surface and tangent to it a plane M perpendicular to the axis O ₁ O ₁ (Fig. 3). The plane M is aligned with the working surface of the support sleeve 10 of the drilling and riveting machine, designed to compress the package from the skin 11 of the assembled panel 1 and the shelf of the stringer 12 when installing the rivet 13 (Fig. 3).

Rivets 13 are located in a row of rivets with a step t equal to the length of the arc between the points of intersection of their axes with the surface of the panel (riveting points) (Fig. 4).

Consider the work of the proposed systems in dynamics: Sensors 4, 5 and 6 measure the distance to the surface of the processed panel 1, respectively, LC, KD ′ and GE and send a command to the tracking drives 7, 8 of the support-leveling device. In this case, the working frame 2 with the processed panel 1, moving up and down in the coordinate OZ, rotates relative to the axis OY by angle β and, at the same time, rotates around its axis parallel to the axis OX by angle α. Thus, the panel 1 is oriented normal to the axis O ₁ O _{1 of the} power head 2 of the drilling and riveting machine and is considered aligned at the moment when the distances to it measured by each sensor are equal, i.e., the condition:

LC = KD ′ = GE = l, where:

points L, K, and G are reference points of the distance to the surface of the processed panel 1. On the surface of panel 1, a zone of perpendicularity Ω with boundaries CD′E is formed, in which the condition of perpendicularity of the axis O ₁ O ₁ to the surface of the assembled panel 1 is fulfilled (alignment condition). A rivet is installed in this zone, and its axis intersects the surface of the panel at the point C _i , as does the axis O ₁ O _{1 of the} power head 3 of the boring-riveting machine.

Connecting the points C, D ′ and E after the alignment condition for panel 1 is fulfilled, we obtain an equilateral triangle CD′E in a plane parallel to the riveting plane M, and the removal of its vertices corresponds to the distance l to the panel surface measured by sensors 4, 5 and 6 at a distance between them defined by parameter 2b, and the riveting plane M is thus removed from the panel surface at points C, D by a distance a (Fig. 3).

The movement of a drilling and riveting machine with a power head 3 along the OX axis by the riveting step t with a variable radius of curvature by the value of this step leads to a positioning error Δt, because the riveting step value t is defined in riveted aircraft structures as the arc length C ₂ C _i and the riveting machine moves along the rectilinear component and its value when positioned on the riveting step t is equal to the value of the arc chord length C ₂ C _i (Fig. 4) . We determine the value of this displacement.

To do this, consider the section of the row of riveting CD between the points of intersection of the axes of the sensors 4 and 5, 6 with the surface of the assembled panel 1. It is an arc CD lying in a plane parallel to ZOX (Fig. 3).

We draw a tangent AB lying in the plane of the riveting M, at the point of setting the rivet C _i . Then, from the condition that the riveting axis is O ₁ O ₁ perpendicular, the distances from the tangent to the arc CD at points C and D will be equal, i.e., AC = BD = a. This means that the arc CD of the riveting row between the sensors 4 and 5, with the riveting axis O ₁ O ₁ normal to the surface of the panel 1, has a constant radius of curvature R with a certain error. The magnitude of this error, depending on the deviation of the theoretical values of the variable radius of curvature of the panel in the riveting zone Ω from the value of R, is controlled by the distance b between the sensors 4, 5 and 6 so that the deviation of the normal to the surface of the panel 1 at the riveting point from the riveting axis is O ₁ O ₁ did not exceed the tolerance on the position of the rivet axis.

This tolerance is the main factor determining the boundaries of the zone Ω and, accordingly, the settings of the sensors 2b and l. Find the relationship between these parameters and the radius R of the curvature of the panel in the riveting zone Ω.

We determine the value of R of the arc CD between the sensors 4, 5 and 6, knowing their settings l and b. In the isosceles ΔCQ ₁ C _i, we _{draw the} height OC ₁ to the chord CC _i . The segment OC ₁ is the bisector of the angle CO ₁ C _i . Triangles ΔCC ₁ S and ΔCC ₁ O ₁ - are similar, like triangles with mutually perpendicular sides. Therefore, the equality ∠SCC _i = ∠CO ₁ C ₁ holds.

From ΔCC _i S we find the value of the angle α

where: a and b are the settings for sensors 4 and 5.

Next, from ΔCSO ₁ we find R:

Let the riveting step be equal to the length of the arc t = C ₂ C _i and when positioning on this value, point C _{2 will be} combined with point C _i . With a constant R, you can determine the value of t through the value of R:

From here we find the value of α ′:

Substituting R from expression (2) into the last equality, we have:

Define the value of the segment C ₂ C _i in ΔO ₁ C ₂ C _i (Fig. 5):

We substitute the value of α 'from expression (5) and the value of R in relation (2) into expression (6) and determine the value of moving the SKA at a given step t (segment C ₂ C _i ):

where: t is the riveting pitch;

a and b are the adjusting and tuning parameters of the alignment sensors 4, 5 and 6 of panel 1, and a is the derivative of the value of the parameter l (Fig. 2).

Thus, knowing the tolerance on the non-perpendicularity of the axis of the rivet to the surface of panel 1, the setting sets the parameters b and l of the alignment sensors 4, 5 and 6 and calculates, according to formula (7), the displacements q of the drilling and riveting machine for each riveting step t along the riveting zones panel 1, after which it is programmed the route of its riveting in the machine as a whole and is realized in the process of sequential positioning at the riveting step by linearly moving the drilling and riveting machine along the axis OX by the calculated value q, The appropriate step size riveting t, with simultaneous alignment of the panel 1 along the normal to the axis of the riveting and the subsequent implementation of the rivet setting cycle in the automatic mode.

Example

To confirm the technical result of the claimed technical solution, automatic riveting of experimental panels pre-assembled on technological bolts with a surface of arbitrary curvature was performed on a GEMCOR 5013TTX - 128 / G86 installation. Positioning for a given riveting step t = (20 ± 0.5) mm was performed in manual and program modes by a number of rivets between the technological bolts connecting the stringer 12 without guide holes with an L-shaped section of the profile to the inner surface of the sheathing sheet 11 of panel 1 (see Fig. 6). In this case, the technological bolts are located at a distance multiple of twenty values of the riveting pitch t and equal to (400 ± 0.5) mm along the arc PQ on the outer surface of the panel 1 lying in the plane of the row of rivets ZOX.

The movement q of the G86 drilling and riveting machine GEMCOR 5013ТТХ - 128 / G86 for its positioning at the riveting step t = (20 ± 0.5) mm is previously determined by formula (7) based on the measurement parameters of the distance sensors 4, 5 and 6 to the surface of panel 1 and the distance between them. Moreover, these parameters, both in the design of the considered model of equipment for automatic riveting, and in other models have a constant unregulated value and determine the possibility of riveting panels whose curvature lies in a certain range of its values. Therefore, the values of the radii of curvature of the experimental panels are within the curvature of the fuselage panels of the TU-204 aircraft, the automatic riveting of which is performed on the above equipment.

In the process of manual positioning (orientation) at the riveting step t, the operator set the displacement value q from the control panel and, accordingly, the drilling and riveting machine moved to this value along the OX axis while automatically leveling the surface of panel 1 using sensors 4, 5 and 6 relative to the axis riveting O ₁ O ₁ , after which operations were performed cycle automatic riveting. In program mode, this process is implemented using the GE FANUC CNC of the GEMCOR 5013ТТХ - 128 / G86 installation.

After riveting, between the technological bolts, the distances between the axes of the rivets along the arc of the row of rivets PQ were measured and the positioning (orientation) error on the riveting step was determined. At the same time, its values did not exceed the tolerance values of ± 0.5 mm per riveting step, which is practical confirmation of the theoretical laws and basic technical principles inherent in the method of riveting curved panels on a boring-riveting machine.

Thus, the technological process of automatic riveting was practically implemented without using the standards of panels and the theoretical coordinates of the axis of the rivets for positioning the riveting route when the drilling and riveting machine is moved to the riveting step, in the considered analogues and in modern assembly plants for automatic riveting of curved panels, and the riveting route programming process is performed using the basic principles of the riveting method of curved panels n and a riveting machine.

The proposed method of riveting curvilinear panels on a drilling and riveting machine allows to obtain an economic effect when used, which consists in refusing to design, manufacture and store reference panels for programming a route of automatic riveting and laborious input of a large array of coordinates of riveting points on the surface of assembled panels in the route program automatic riveting in the presence of theoretical models of panels with subsequent adjustments to the values of the latter in the process of automatic epki due to the low stiffness panel. Using the calculated parameters of the automatic riveting method of the present invention makes the process of programming the riveting route of the machine simple and low-labor when fulfilling all the technical requirements of positioning (orientation) accuracy along the riveting route. Thus, due to the above reasons and conclusions, the use of the method of riveting curved panels on a boring-riveting machine significantly reduces the complexity and preparation time of their production while maintaining the required quality and accuracy parameters, making the inventive riveting method effective.

Claims (1)

A method for riveting curvilinear panels on a drilling and riveting machine, including aligning the surface of the curvilinear panel in the riveting zones, installing rivets in the riveting areas of the curved panel, moving the boring and riveting machine with the power head over the said riveting zones, characterized in that the alignment of the surface of the curvilinear panel in the zones riveting is carried out by orienting it normal to the axis of the power head of a drilling and riveting machine using three alignment sensors, by They measure the distance from them to the surface of the curvilinear panel, while alignment sensors are placed on the body of the power head with the formation of their parallel axes when they intersect with the plane of an equilateral triangle with a height of 2b, in the middle of which the said plane crosses the axis of the power head with the value b , which is a parameter that determines the distance between the alignment sensors, and when the alignment sensors are located, the value of b is adjusted depending on start perpendicularity to the axis of the rivet to the surface of the curved panel and the curved panel is performed before orientation equal distances measured by the sensors before it, a linear displacement of drilling-riveting machine with a power head for riveting curved panel zones to produce a value q, which is defined by the following formula:
$$q=\frac{2b\sin [\frac{t\cdot {90}^{\circ }\sin 2\left(arctg\frac{a}{b}\right)}{\pi b}]}{\sin 2\left(arctg\frac{a}{b}\right)}$$

,
where t is the riveting pitch;
a - the distance measured by the alignment sensors of the riveting plane tangent to the surface of the curvilinear panel at the point of intersection of the axis of the power head of the riveting-drilling machine and located perpendicular to the axis from the surface of the curvilinear panel at points corresponding to the alignment sensors, while the value of the specified value q is entered into the program of the riveting route of a drilling and riveting machine, which is used for riveting in automatic mode.

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