JP3288518B2 - Automatic parts assembly method and automatic parts assembly device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic component assembling method and an automatic component assembling apparatus for automatically fitting and inserting components requiring shaft alignment and phase alignment.

[0002]

2. Description of the Related Art FIGS. 27 to 33 are views showing a conventional automatic parts assembling apparatus, FIG. 27 is a front view showing the basic structure of the automatic parts assembling apparatus, FIG. 28 is a partially enlarged view of FIG.
29 is a perspective view showing the parts to be assembled, FIG. 30 is a cross-sectional view showing the parts to be assembled and the positioning or supply of the parts, FIG. 31 is a front view for explaining the operation of the conventional automatic parts assembling apparatus, and FIG. FIG. 33 is a plan view showing an assembled state of the parts to be assembled.

In FIG. 27, reference numeral 7 denotes a chuck mechanism for gripping a component, 8 denotes a horizontal movement along a horizontal orthogonal axis X, Y, a vertical movement along a vertical axis Z, and a vertical axis generally called a scalar robot. 4 of wrist horizontal rotation θ around Z
A robot 9 having a degree of freedom is a connection mechanism for connecting the chuck mechanism 7 to the tip 8a of the wrist of the robot 8 (that is, the work tool mounting portion).

As shown in FIG. 28, the connecting mechanism 9 is provided with an RCC (REMOTE CENTER COMPLIA) for absorbing a minute axis and angular deviation of a component to be assembled.
NCE) 11 and a Z-axis compliance mechanism 12.

The Z-axis compliance mechanism 1
2 is a plate 16 attached to the wrist tip 8a of the robot 8.
And a plate 17 attached to the RCC 11, a guide 13 for allowing the plate 17 to slide only in the Z-axis direction (up-down direction) of the robot 8 with respect to the plate 16, a plate 16 and the plate 17
And a proximity switch 15 that detects an approach of the detection member 15a and turns on an output signal when the amount of deflection of the compression coil spring 14 exceeds a predetermined value. It comprises a load sensor 18 for measuring the force in the insertion direction. Here, Guide 1
3. The compression coil spring 14, the plate 16 and the plate 17 constitute a float mechanism for causing the chuck mechanism 7 to float in the direction opposite to the component insertion direction.

In FIG. 29, reference numeral 1 denotes a keyed hole 1a.
The first part 2 provided with a key is a second part provided with a keyed shaft part 2a in which the keyed hole part 1a is fitted.
In FIG. 30, reference numeral 3 denotes a positioning mechanism for positioning and holding the first component 1, and 4 denotes a component supply mechanism for supplying the second component 2 to the apparatus.

The robot 8 is automatically controlled by, for example, a teaching playback system by a controller (not shown), and the first part 1 is attached to the shaft 2 a of the second part 2.
The operation of fitting the hole 1a is performed. When the output of the proximity switch 15 is turned on, the robot 8
The operation program and the like of the controller are set so as to make the emergency stop.

Next, the operation will be described. First, the robot 8 moves, and the chuck mechanism 7 grips the second component 2 supplied by the component supply mechanism 4. Then, the robot 8 is moved to position the second component 2 above the first component 1 positioned by the positioning mechanism 3 as shown in FIG. 31 and then lowered to fit the first component 1. Let it.

At this time, if the axis and phase are precisely adjusted by using a means such as a CCD camera not shown in advance, the shaft 2a of the second component 2 is inserted into the hole of the first component 1. 1a, the fitting is smoothly realized.

However, when the axis and the phase are not accurately adjusted in advance or when it is difficult to adjust the phase, the second component 2 is usually attached to the first component 1 in the process of lowering the second component 2. On the other hand, the axis is slightly off,
First, the chamfer at the lower end of the shaft portion 2 a of the second component 2 comes into contact with the upper end of the hole 1 a of the first component 1. Therefore, as shown in FIG. 32, a force F acts on the second component 2 in the direction of the arrow. This force F deforms the RCC 11 to passively absorb the axial misalignment.

Even if the axes of the second component 2 and the first component 1 are aligned as described above, the phase is usually slightly out of phase, so that the wrist tip 8a of the robot 8 is rotated about the θ axis. To adjust the phase. That is, the wrist tip 8a of the robot 8 is slowly rotated around the θ axis, and the robot 8 is stopped at a position where the value of the load sensor 18 has become equal to or less than a certain value. In this state, if the second component 2 is pressed against the first component 1, the fitting is smoothly realized unless the components 1 and 2 are twisted.

The second part 2 and the first part 2 are
After aligning the axis of the part 1 of the
Even if a is rotated around the θ axis and the phases are matched, if the rotation axis of the wrist tip 8a of the robot 8 and the rotation axis of the second part 2 moved by the RCC 11 are greatly shifted, the second part 2 is tilted by the clearance of the first component 1 to form a so-called twisting state, and even if the RCC 11 is flexible, a smooth fitting cannot be performed, or in the worst case, the fitting cannot be performed. When the fitting becomes impossible, the chuck mechanism 7 does not follow the descent of the wrist tip 8a of the robot 8, so that the compression coil spring 14 contracts and the plates 16 and 17 move in a direction approaching each other. Te, it is possible to prevent the overload applied to the robot 8, and finally the proximity switch 15 is turned on, the robot 8 is urgently stopped by receiving an oN signal from the proximity switch 15.

[0013] Also, when the shaft center and the phase are measured and fitted using a means such as a CCD camera in advance, the fitting cannot be performed if the measurement is difficult due to the shape of the component.

Further, in the case of inserting a square part having a chamfered part, when the wrist tip 8a of the robot 8 is rotated about the θ axis by aligning the axes by the RCC 11, and the phases are matched, the direction in which the phase shift can be eliminated is as follows. Because there is only one direction,
If the direction cannot be determined, fitting cannot be performed.
The reason will be described with reference to FIG.

In FIG. 33, reference numeral 5 denotes a first part provided with a hole 5a having a square chamfer, and reference numeral 6 denotes a second part provided with a square shaft 6a. Chuck mechanism 7 of robot 8
When the user grips the second component 6 and tries to fit the shaft portion 6a of the component into the hole 5a of the first component 5, the second component 6 is moved in the direction A as shown in FIG. Rotate to match the phase. However, when the second component 6 is to be rotated in the direction B, the second component 6 is moved along the square chamfer of the first component 5.
Is moved in the direction opposite to the fitting / inserting direction. Therefore, in order to eliminate such a phase shift,
It is necessary to rotate the second part 6 in the direction of A.

[0016]

Since the conventional automatic parts assembling method and the conventional automatic parts assembling apparatus are constructed as described above, the second part is fitted to the first part with its axis and phase aligned. For insertion, the axis and phase are measured in advance using a means such as a CCD camera, or the axis of the second component 2 and the first component 1 are aligned with the RC C11 , It is necessary to adjust the phase by rotating the wrist tip 8a of the robot 8 around the θ axis.

However, in actuality, even if a means such as a CCD camera is used, it may be difficult to detect the axis and phase depending on the shape of the component, which makes automatic assembly of the component uncertain.
Or two more second parts RC C11 first component 1
The combined shaft centers, if phase matching by rotating the wrist front end 8a of the robot 8 to θ axis, rotation of the second part 2 which has moved more to the rotary shaft and RC C11 wrist tip 8a of the robot 8 If the axis is greatly displaced,
Parts products 2 becomes an amount corresponding inclined by prying status of clearance between the first part article 1, there is a problem such components automated assembly becomes impossible.

Further, the conventional component automated assembly device, when phase matching by rotating the wrist front end 8a of the robot 8 to θ axis, because the robot 8 no means for detecting the moment of θ axis If the parts are torn,
Will be chucking mechanism 7 does not follow the θ around the axis rotation of the wrist front end 8a of the robot 8, RC C11 Oh Ru <br/> physician a problem, such as to destroy the worst case robot 8 Was.

Further, in the conventional automatic parts assembling apparatus, when the phase of a square part having a chamfer is adjusted by rotating the tip 8a of the wrist of the robot 8 around the θ axis, there is no function of detecting the direction in which the phase is adjusted. Was.

It is another object of the present invention to provide a method for automatically assembling a component which can be reliably and automatically assembled by adjusting the axis and phase of the component.

It is an object of the present invention to provide a component automatic assembling apparatus capable of assembling components reliably and smoothly by adjusting the axes and phases of components.

[0022]

According to a first aspect of the present invention, there is provided an automatic component assembling method, wherein a second component is pressed against the positioned first component in an assembling direction, and the second component is placed in the first component. Calculating the moving direction and the moving amount of the second part necessary to make the component force orthogonal to the assembling direction received from the part to be substantially zero, moving the second part in the moving direction, and Is made substantially zero and the pressing force in the assembling direction is moved so as to be smaller than a predetermined value, and then the second component is moved in the assembling direction with respect to the first component.

According to a second aspect of the present invention, there is provided an automatic component assembling method, wherein the second component is pressed against the first component and then separated, and after the shaft is aligned, the second component is pressed against the first component again. Is performed repeatedly.

According to a third aspect of the present invention, in the method for automatically assembling a part, the phase of the second part and the first part are adjusted.
A rotation direction and a rotation amount required to make the moment reaction force around the axis in the assembling direction received by the second component from the first component substantially zero are calculated, and the second component is rotated by the rotation amount. .

According to a fourth aspect of the present invention, there is provided an automatic component assembling method for determining a direction in which the phase of a second component is changed as a function of a moment reaction force about an axis in the assembling direction.

According to a fifth aspect of the present invention, there is provided a component automatic assembling method, wherein during the phase adjustment of the second component and the first component, when a moment reaction force about an axis in the assembly direction becomes larger than a predetermined value. The phase adjustment process is immediately stopped.

According to a sixth aspect of the present invention, there is provided an automatic parts assembling apparatus, comprising a robot and a positioning mechanism which relatively move in X, Y, and Z axis directions orthogonal to each other and in a θ axis direction rotating about the Z axis. A compliance mechanism and a four-axis force sensor are provided on one of them, a pressing step of pressing the second part against the first part, a calculating step of calculating an error correction amount, and the second step by the error correction amount. A controller for sequentially executing an axis alignment step of moving the part, a phase alignment step of rotating the second part, and an insertion step of moving the second part in the assembly direction with respect to the first part. .

According to a seventh aspect of the present invention, in the component automatic assembling apparatus, the controller separates the second component from the first component after pressing the second component against the first component, and separates the second component again after the shaft alignment. It has a function of repeatedly executing pressing on a part.

The motor component automatic assembling apparatus according to the invention of claim 8, wherein the controller, the second component after the phase match the the first part, which is measured by 4-axis force sensor
It has a function of calculating a correction amount Δθ of the error due to the overshoot in the rotation direction about the θ axis as a function of the element Mz, and executing a rotation step of rotating the θ axis by Δθ.

According to a ninth aspect of the present invention, in the automatic component assembling apparatus, the controller is configured to determine the θ based on the moment Mz about the θ axis measured by a four- axis force sensor.
It has a function of determining the direction of rotation about the axis.

According to a tenth aspect of the present invention, in the automatic component assembling apparatus, when the moment around the θ-axis becomes larger than a predetermined value while the controller is adjusting the phase of the second component to the first component, It has a function of immediately stopping the rotation about the θ axis.

[0032]

According to a first aspect of the present invention, there is provided an automatic component assembling method, wherein a second component is pressed against a first component by a predetermined force in a fitting / inserting direction, and the second component receives the first component from the first component. By measuring the direction and amount of movement of the robot required to make the component force in the direction perpendicular to the insertion direction almost zero,
There is no need to adjust the axis and phase in advance, and automatic assembly can be performed reliably and smoothly.

According to a second aspect of the present invention, there is provided an automatic component assembling method, in which a second component is pressed against a first component to calculate an amount of axis deviation, and thereafter, the second component is pulled from the first component. After moving in the direction of axis alignment after separating, pressing the second part against the first part again is repeated without damaging the part. Automatic assembly is possible.

According to a third aspect of the present invention, in the method for automatically assembling a part, the second part is moved so that a moment reaction force received from the first part around the axis in the assembling direction is made substantially zero. It is possible to prevent the part from inclining by the amount of the clearance with the first part and twisting to make it impossible to fit.

According to a fourth aspect of the present invention, there is provided a method for automatically assembling a part, wherein the direction of changing the phase of the second part as a function of a moment reaction force about an axis in the mounting direction received by the second part from the first part. Is determined, automatic assembly can be performed reliably.

According to a fifth aspect of the present invention, in the automatic component assembling method, if the moment reaction force around the assembly direction axis increases during the phase adjustment of the second component and the first component, the phase adjustment is immediately performed. Stopping does not damage the parts.

In the four-axis force sensor according to the sixth aspect of the present invention, the moving direction necessary for making the component force received by the second component from the first component in a direction orthogonal to the fitting and inserting direction substantially zero. And the amount of movement, and the controller replaces the second part with
By moving by the moving amount in the above-mentioned measured moving direction so that the above-mentioned component force becomes almost zero, there is no need to preliminarily adjust the axis and the phase by another means such as a CCD camera, so that automatic assembly can be performed reliably and smoothly. Can be.

According to a seventh aspect of the present invention, the controller separates the second component after pressing the second component against the first component,
By repeatedly pressing the second component against the first component after the axis alignment, it is not necessary to previously align the axis and the phase, and it is possible to reduce the axis alignment error.

In the controller according to the eighth aspect, after the second component is phase-aligned with the first component, the controller adjusts the rotation direction about the θ axis as a function of the moment Mz measured by the four-axis force sensor. By calculating the correction amount Δθ of the error due to the overshoot and rotating the θ axis by this Δθ, it is possible to prevent the first component and the second component from being in a twisted state and being unable to be assembled.

According to a ninth aspect of the present invention, the controller according to the ninth aspect is a motor around the θ axis measured by the four- axis force sensor.
By determining the rotation direction about the θ axis based on the element Mz, the assembly can be performed reliably and smoothly.

According to a tenth aspect of the present invention, the controller stops the phase adjustment immediately when the moment about the θ-axis becomes larger than a predetermined value during the phase adjustment of the second component to the first component. Parts and devices can be prevented from being damaged.

[0042]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a basic structure of an apparatus according to claim 6 for implementing the automatic parts assembling method according to claims 1 to 5, and FIG. 2 is a partially enlarged view of FIG. The same parts as those described above are denoted by the same reference numerals, and redundant description will be omitted. 1 and 2, reference numeral 10 denotes a four-axis force sensor. The four-axis force sensor 10 is a wrist tip 8 of the robot 8.
a and the Z-axis compliance mechanism 12. This provides a four-axis force sensor 10 and a six-degree-of-freedom compliance mechanism. This is because the RCC 11 is a compliance mechanism having five degrees of freedom in positions and postures other than the fitting / inserting direction, and when used together with the Z-axis compliance mechanism 12, it becomes a compliance mechanism having six degrees of freedom.

FIG. 3 is a perspective view showing parts to be assembled.
In FIG. 3, reference numeral 19 denotes a first component having a square hole 19a, and reference numeral 20 denotes a second component having a shaft portion 20a having a square chamfered portion into which the square hole 19a fits.

FIG. 4 is a sectional view showing a part to be assembled and its positioning or part supply.
A positioning mechanism 22 for positioning and holding the second component 20 is a component supply mechanism for supplying the second component 20 to the apparatus.

FIG. 5 is a diagram showing a configuration of a transmission system of a measurement signal of the four-axis force sensor 10.
Measured in the X, Y, and Z directions Fx, Fy, Fz, and θ
Enter the axis of the moment Mz, the respective force and Mome
Calculator such as a microcomputer for converting the cement movement amount [Delta] X, [Delta] Y, the ΔZ and [Delta] [theta], 52 in response to the movement amount from the computing unit 51, relative to the first part 19 and second part 20 This is a robot controller that moves the moving amounts ΔX, ΔY, ΔZ, and Δθ.

Next, the operation of the first embodiment will be described. First, the robot 8 is operated, and the second component 20 supplied by the component supply mechanism 22 is gripped by the chuck mechanism 7. Then, the robot 8 is moved as shown in FIG.
Is positioned above the first component 19 positioned by the positioning mechanism 21. Next, the wrist 8a of the robot 8 is lowered to convert the second part 20 into the first part 19,
Due to the action of the RCC 11, the pressing is performed with a force equal to or greater than the pressing force at which the axes match.

Then, in the process of lowering the second component 20, the second component 20 is usually slightly off-axis with respect to the first component 19. A part of the chamfer at the lower end of the shaft contacts the upper end of the hole of the first component 19. For this reason, as shown in FIG.
A force F1 acts on the component 20 in the direction of the arrow. The RCC 11 acts by the force F1, and the second component 20 moves in the direction of aligning the axes. As described above, by using the force sensor 10 and the RCC 11 together, as shown in FIG.
By detecting the force F2 by the force sensor 10, not only the direction of the axis misalignment but also the axis misalignment amount can be detected. Therefore, the second component 20 is moved by the RCC 11 in the direction where the axes are aligned, but since the wrist tip of the robot 8 is not moved, the robot 8 is moved horizontally as shown in FIG. The axis of the second component 20 can be aligned with the axis of the tip of the wrist of the robot.

Even if the axes of the second component 20 and the first component 19 are aligned, the phases are usually slightly shifted. For this reason,
As shown in FIG. 10, a moment M indicated by an arrow acts on the second component 20. Phase adjustment is force sensor 1
0, the same direction as this moment M detected is determined, and the wrist 8 of the robot 8 is oriented in that direction as shown in FIG.
is rotated, and the robot 8 is stopped at a position where the force in the Z-axis direction is rapidly changed by the force sensor 10. As described above, by using the force sensor 10 and the RCC 11 together, the shaft center and the phase can be matched, and the fitting is realized at high speed and smoothly.

Here, the method of axis alignment using both the force sensor 10 and the RCC 11 will be described in detail with reference to FIGS. In FIG. 12, reference numeral 26 denotes a first component having a hole 26a having a chamfered portion, and reference numeral 27 denotes a second component including a shaft 27a into which the hole 26a is fitted.

Assume that the second component 27 is gripped by the chuck mechanism 7 of the robot 8 and fitted to the first component 26 positioned by the positioning mechanism 19. At this time, in order to align the axes of the second component 27 and the first component 26, a method using only the force sensor 10 and a method using the force sensor 10 and the RCC1
1 will be described. Here, F is the force that presses the second component 27 against the first component 26, N is the reaction force that the second component 27 receives from the first component 26, θ is the angle of chamfering the first component 26, The length of the chamfered slope of the first component 26 is L, and the friction coefficient is μ.

First, a method of aligning the axes with the force sensor 10 alone will be described. As shown in FIG. 12, even when the first component 26 is in the state A or the state B, the equation of the balance in the vertical direction is as follows: μN sin θ + N cos θ−F = 0 N = F / (μ sin θ + cos θ) .

Therefore, the direction of the axial misalignment depends on the direction of the second component 2.
7 can be detected by measuring the direction of the reaction force N received from the first component 26 by the force sensor 10. On the other hand, regarding the amount of axial misalignment, the magnitude of the reaction force N received by the second component 27 from the first component 26 is determined by the angle of the chamfer and the friction coefficient regardless of the state A or the state B. Even if the sensor 10 is used, the amount of axial misalignment cannot be detected.

Therefore, when the axis is aligned only by the force sensor 10, the direction in which the axis is shifted is detected by the force sensor 10 and the second component 27 is moved little by little in the direction. Will be combined.

Next, a method of aligning the axes using the force sensor 10 and the RCC 11 will be described. Due to the operation of the RCC 11, the second component 27 is in the state C in which the axes are aligned irrespective of the initial position in the state A and the state B as shown in FIG.
Go to Therefore, if the horizontal reaction force generated on the second component 27 in the state where the axes are aligned is Fx, the amount of axis misalignment is Δx, and the horizontal spring constant of the RCC 11 is K, Fx = KΔx Holds.

That is, the horizontal component force Fx generated with respect to the second component 27 can be measured by the force sensor 10, and the axial misalignment Δx can be calculated as follows: Δx = Fx / K.

Therefore, when the force sensor 10 and the RCC 11 are used together and the axes are aligned, only the second component 27 is brought into contact with the first component 26 once. The amount can be detected, and the axis can be aligned faster than in the case of only the force sensor 10 that can detect only the direction of the axis deviation.

Next, when the force sensor 10 and the RCC 11 are used together and the axes are aligned, the second component 27 is connected to the first component 2.
The pressing force when pressing against No. 6 will be described. When the pressing force F is small, the action of RCC11 causes
As shown in FIG. 4, the second component 27 moves along the chamfered portion of the first component 26, but does not move to a position where the axes are aligned. For this reason, in order to align the axes by the action of the RCC 11, a certain or more pressing force is required.

The equation for the balance in the vertical direction in FIG. 14 is μNsin θ + Ncos θ−F = 0 (1) as in the case of FIG. Further, the equation for the balance in the horizontal direction is as follows: −μNcos θ + Nsin θ−KΔx = 0 (2) From Equations (1) and (2), the pressing force F is as follows. F = (μtan θ + 1) / (− μ + tanθ) * KΔx (3)

Here, the maximum horizontal movement amount ΔXmax by which the second part 27 moves along the chamfer of the first part 26 by the action of the RCC 11 is determined by the angle θ of the chamfer and the length L of the slope of the chamfer. ΔXmax = L * cos θ, and when this is substituted into equation (3), RCC11
The maximum pressing force Fma required to align the shaft cores
x is determined as follows. Fmax = (μtan θ + 1) / (− μ + tanθ) * KL cos θ

Therefore, in order to align the shaft center by the action of the RCC 11 irrespective of the shaft center misalignment position of the second component 27, the pressing force must be equal to or greater than the maximum pressing force Fmax.

Embodiment 2 FIG. In the first embodiment, the second component 20 is kept pressed against the first component 19 in order to align the axis, but the maximum pressing force Fmax is equal to the second pressing force Fmax.
If the force is large enough to damage the part 20 or the first part 19, the pressing force needs to be the maximum force that does not damage the part. For this reason, if the shaft center is displaced beyond a certain range, the shaft center will not completely match just by pressing once.

In such a case, the second component 20 is first pressed against the first component 19 with the maximum force that does not damage the component, and the displacement measured by the four-axis force sensor 10 is stored in the memory means (not shown). After storage, the second part 20 is replaced with the first part 1
9 is moved in the horizontal direction in order to correct the axis deviation by the deviation read out from the memory means, and then pressed against the first component 19 again, whereby the axis can be aligned. .

Embodiment 3 FIG. In the first or second embodiment, the phase is matched by rotating the wrist tip 8a of the robot 8 around the θ axis, and the robot 8 is moved in the fitting / inserting direction in that state. In the third embodiment, the robot overshoot caused by the problem of the responsiveness when stopping the robot 8 is detected by the force sensor 10 to detect the moment Mz around the θ axis, and then to calculate the overshoot amount. Only the wrist tip 8a of the robot 8
Is rotated about the θ axis to correct the overshoot, thereby preventing a prying state that may be caused by the overshoot of the robot 8.

Embodiment 4 FIG. FIGS. 15 to 23 are explanatory views showing the fourth embodiment, and FIG. 15 is a perspective view showing three basic parts of a speed reducer called a harmonic drive. In FIG. 15, reference numeral 23 denotes a cup-shaped flexible component (flex spline) having teeth 23a on the outer periphery, 24 denotes an elliptical rotor (wave generator), and 25 denotes a ring-shaped component (circular spline) having inner peripheral teeth 25a. is there.

As shown in FIG. 16, the assembling work in the fourth embodiment is to insert the circular spline 25 into the flexspline 23 which is deformed into an elliptical shape with the axis and phase aligned. In the case of assembling, if a circular spline is forcibly inserted in a state where there is no shaft center or phase, deformation of the flexspline causes a defective assembly, a so-called dead-idal state.

Next, the operation of the fourth embodiment will be described.
First, the robot 8 is operated, and the circular spline 25 supplied by the component supply mechanism by the chuck mechanism 7 is operated.
To grip. Then, as shown in FIG. 17, the robot 8 is moved to position the circular spline 25 held by the chuck mechanism 7 above the flexspline 23 positioned by the positioning mechanism 21. Next, the robot 8 is lowered, and the circular spline 25 is pressed against the flexspline 23 by the action of the RCC 11 with a predetermined force equal to or greater than the pressing force at which the axes are aligned.

Then, in the process of lowering the circular spline 25, usually, the circular spline 25
Since the axis is slightly deviated from the axis of the flexspline 23, the ring-shaped chamfer of the circular spline 25 first contacts the chamfer of the flexspline 23. Therefore, as shown in FIG. 18, a force F1 indicated by an arrow acts on the circular spline 25. As in the case of the first embodiment, the RCC 11 acts by this force, and moves in the direction of aligning the axes as shown in FIG.

However, unlike the case of the first embodiment, if the axis is shifted beyond a certain range, the axis is not completely aligned, and as shown in FIG. The tooth of the part gets stuck and the movement stops. This is because the flexspline 23, which is a flexible component, is slightly deformed by the pressing force.

In the case of the fourth embodiment, if the axis is shifted by more than a certain range, the axis cannot be passively aligned only by the RCC 11, so that the robot with the circular spline 25 pressed against the flexspline 23. No matter how much is moved, the axes do not align. Therefore, it is essential that the force sensor 10 actively separates the circular spline 25 once and then aligns the axes. Further, in this case, assuming that the forces in the X-axis direction and the Y-axis direction measured by the force sensor 10 are Fx and Fy, the correction amounts Δx and Δy in the X-axis direction and the Y-axis direction are Δx = (1 / K + Cx) * FxΔy = (1 / K + Cy) * Fy, and unlike the case of the first embodiment, Cx and Cy have coefficients that take into account the slight misalignment of the axis.

Therefore, in the fourth embodiment, as shown in FIG. 21, the circular spline 25 is raised to a predetermined height of the Z axis, the robot is moved in the horizontal direction, and the axis of the circular spline 25 and the wrist of the robot are moved. The axis of the tip was aligned. Thereafter, as shown in FIG. 22, the circular spline 25 is pressed again by the predetermined force on the flexspline 23 to align the axes.

Even if the axes of the circular spline 25 and the flexspline 23 are aligned, the phases are usually out of phase as shown in FIG. For this reason, with the axes aligned,
By rotating the circular spline 25 around the θ axis and detecting the force Fz in the Z-axis direction by the force sensor 10, the teeth 25 a on the inner circumference of the circular spline 25 and the teeth 23 a on the outer circumference of the flexspline 23 are normally engaged. Detect that. Further, by detecting the moment Mz about the θ axis, it is determined whether the teeth 25a on the inner circumference of the circular spline 25 and the teeth on the outer circumference of the flexspline 23 are not meshed with each other.
When z becomes larger than a predetermined value, the rotation of the robot 8 around the θ axis is immediately stopped. If the circular spline 25 is pressed with the phases adjusted by this method, a slight axis shift, phase shift, and posture error can be reduced by R
Can be absorbed by CC11, and the teeth 23a and 25
a engages normally and the assembly is completed.

Embodiment 5 FIG. In each of the above embodiments, the case where the force sensor 10 and the RCC 11 are provided on the wrist 8a side of the robot 8 is illustrated. However, as shown in FIG.
0, the RCC 11 and the Z-axis compliance mechanism 12 are provided on the positioning mechanism 19 side. Alternatively, as shown in FIG. 25, the force sensor 10 is placed on the wrist 8a side of the robot 8 by RCC.
11 and Z-axis compliance mechanism 12 for positioning mechanism 1
9 or as shown in FIG.
The RCC 11 and the Z-axis compliance mechanism 12 may be provided on the wrist 8a side of the robot 8 on the positioning mechanism 19 side. In particular, when the second component is pressed against the first component, the wrist 8a side of the robot 8 and the positioning mechanism 19 side are integrated, and as shown in FIGS.
Even if the force sensor 10 and the RCC 11 are disposed separately from each other, the bending force of the RCC 11 can be accurately and reliably detected by the force sensor 10.

[0073]

As described above, according to the first aspect of the present invention, the second component is pressed against the first component by a predetermined force in the fitting / inserting direction, and the second component is pressed by the first component. Since it is configured to measure the moving direction and the moving amount of the robot necessary to make the component force in the direction orthogonal to the fitting and inserting direction received from the robot almost zero, there is no need to previously align the axis and phase. is there.

According to the second aspect of the present invention, the second component is pressed against the first component in the fitting / inserting direction by a predetermined force, and the second component receives the fitting / inserting direction from the first component. After measuring the moving direction and the moving amount of the robot necessary to make the component force in the orthogonal direction substantially zero, the second part is once separated from the first part, and the second part is separated from the first part. Since the robot is moved so that the component force in the direction orthogonal to the fitting insertion direction received from the robot becomes substantially zero, the second component is pressed again against the first component with a predetermined force. Even if the pressing force cannot be increased due to the possibility of damaging the shaft, or even if the axis is not aligned just once from the contact state of the components, the automatic assembly can be performed reliably and smoothly.

According to the third aspect of the present invention, the phase of the second component is changed until the pressing force of the second component against the first component in the fitting and inserting direction becomes smaller than a predetermined magnitude. Measuring the direction and amount of movement of the robot necessary to make the moment reaction force around the insertion axis received by the second part from the first part substantially zero, and moving the robot by the measured amount of movement. Because it was configured to move,
The second component is inclined by the clearance between the first component and the first component, so that it is difficult for a twisting state to occur, and the automatic assembly can be performed reliably and smoothly.

According to the fourth aspect of the present invention, when the phase of the second component is changed until the pressing force of the second component on the first component in the fitting / inserting direction becomes smaller than a predetermined magnitude, Since the second component is configured to determine the direction in which the phase of the second component is changed as a function of the moment reaction force about the fitting insertion axis received from the first component, the automatic assembly can be reliably performed. .

According to the fifth aspect of the present invention, while the phase of the second component is changed until the pressing force of the second component on the first component in the fitting / inserting direction becomes smaller than a predetermined magnitude. In addition, when the magnitude of the moment reaction force around the insertion shaft received from the first component becomes larger than a predetermined magnitude, the operation of the robot is immediately stopped, so that damage to the component is prevented. Can be.

According to the sixth aspect of the present invention, the second component is pressed against the first component by a predetermined force in the fitting and inserting direction.
The axial force sensor measures the moving direction and the moving amount of the robot necessary to make the component force in the direction orthogonal to the fitting and inserting direction received by the second component from the first component substantially zero. Since the robot is configured to move the component so that the component force received from the first component in the direction orthogonal to the fitting and insertion direction is substantially zero, the component automatic assembling apparatus does not need to previously align the axis and phase. There is an effect that can be obtained.

According to the seventh aspect of the present invention, after the second component is pressed against the first component by a predetermined force in the fitting and inserting direction, the second component is once separated from the first component, and Second
Is moved so that the component force in the direction orthogonal to the fitting / insertion direction received by the first component from the first component becomes substantially zero, and the second component is again fitted to the first component by a predetermined force in the fitting / inserting direction. Because it is configured to press again, there is a possibility that parts may be damaged, so even if the pressing force can not be increased, or even if the axis is not aligned just once by contacting the parts from the contact state, it is sure and smooth. Has the effect that it can be automatically assembled.

According to the eighth aspect of the present invention, the phase of the second component is changed until the pressing force of the second component against the first component in the fitting / inserting direction becomes smaller than a predetermined magnitude. Measuring the direction and amount of movement of the robot necessary to make the moment reaction force around the insertion axis received by the second part from the first part substantially zero, and moving the robot by the measured amount of movement. Because it was configured to move,
This has the effect of preventing the second component from being tilted and twisted by the clearance of the first component and becoming unfittable.

According to the ninth aspect of the present invention, when the phase of the second component is changed until the pressing force of the second component on the first component in the fitting and inserting direction becomes smaller than a predetermined magnitude, The second component is configured to determine the direction in which the phase of the second component is changed as a function of the moment reaction force about the fitting insertion axis received from the first component, so that the second component can be securely fitted. effective.

According to the tenth aspect, while the phase of the second component is changed until the pressing force of the second component against the first component in the fitting / inserting direction becomes smaller than a predetermined magnitude. In addition, when the magnitude of the moment reaction force around the fitting / insertion axis received from the first component is greater than a predetermined magnitude, the operation of the robot is immediately stopped. There is an effect that a part can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a front view showing a basic structure of an automatic parts assembling apparatus according to an embodiment of the invention as set forth in claim 6, which implements the automatic parts assembling method according to claims 1 to 5;

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a perspective view showing a component to be assembled.

FIG. 4 is a sectional view showing positioning of a component to be assembled and supply of the component.

FIG. 5 is a configuration diagram of a transmission system of a measurement signal of the four-axis force sensor.

FIG. 6 is a front view for explaining an automatic component assembling method according to an embodiment of the present invention.

FIG. 7 is a front view illustrating an automatic component assembling method according to an embodiment of the present invention.

FIG. 8 is a front view for explaining an automatic component assembling method according to an embodiment of the present invention.

FIG. 9 is a front view illustrating an automatic component assembling method according to an embodiment of the present invention.

FIG. 10 is a plan view illustrating an automatic component assembling method according to an embodiment of the present invention.

FIG. 11 is a front view for explaining an automatic component assembling method according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram of axis alignment using a 4-axis force sensor and an RCC together.

FIG. 13 is an explanatory diagram of axis alignment using a four-axis force sensor and an RCC together.

FIG. 14 is an explanatory diagram of axis alignment using a 4-axis force sensor and an RCC together.

FIG. 15 is a perspective view showing a component to be assembled.

FIG. 16 is a perspective view showing an assembled state of a component to be assembled.

FIG. 17 is a front view for explaining the operation of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 18 is a front view for explaining the operation of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 19 is a front view for explaining the operation of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 20 is a plan view showing a slight axial misalignment of a component to be assembled.

FIG. 21 is a front view for explaining the operation of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 22 is a front view for explaining the operation of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 23 is a plan view showing a phase shift of a component to be assembled.

FIG. 24 is a schematic diagram showing another basic configuration of the automatic parts assembling apparatus according to one embodiment of the present invention.

FIG. 25 is a schematic diagram showing still another basic configuration of the automatic parts assembling apparatus in one embodiment of the present invention.

FIG. 26 is a schematic diagram showing still another basic configuration of the automatic parts assembling apparatus in one embodiment of the present invention.

FIG. 27 is a front view showing a basic configuration of a conventional automatic assembling apparatus.

FIG. 28 is a partially enlarged view of FIG. 27;

FIG. 29 is a perspective view showing a component to be assembled.

FIG. 30 is a sectional view showing positioning of a component to be assembled and supply of the component.

FIG. 31 is a front view illustrating the operation of a conventional automatic assembling apparatus.

FIG. 32 is a side sectional view for explaining the operation of the conventional automatic assembling apparatus.

FIG. 33 is a plan view for explaining the operation of a conventional automatic assembly device.

[Explanation of symbols]

 5, 19, 26 First component 6, 20, 27 Second component 7 Chuck mechanism 8 Robot 9 Connecting mechanism 10 Force sensor 11 RCC 21 Positioning mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-236487 (JP, A) JP-A-4-354629 (JP, A) JP-A-7-1260 (JP, A) JP-A-7-260 75922 (JP, A) JP-A-63-185540 (JP, A) JP-A-7-1369 (JP, A) JP-A-3-19683 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23P 19/02

Claims (10)

(57) [Claims] A positioning step of positioning a first component; a pressing step of moving a second component with respect to the first component to press the first component in a fitting / inserting direction; A calculating step of calculating a moving direction and a moving amount of the second part necessary for making a component force orthogonal to the fitting and inserting direction received by the second part from the first part substantially zero; (2) moving the second component in the calculated movement direction to make the component force orthogonal to the fitting and inserting direction received from the first component substantially zero; and moving the second component to the first component. A phase adjustment step of moving the pressing force in the fitting and inserting direction received from a component to be smaller than a predetermined value; and an inserting step of moving the second component in the fitting and inserting direction with respect to the first component. Are performed sequentially. 2. A separating step of separating the second component from the first component after the calculating step, and the fitting of the second component to the first component after the axis aligning step. 2. The automatic component assembling method according to claim 1, further comprising the step of: pressing again with a predetermined force in the insertion direction. 3. After the phasing step, a rotation direction and a rotation amount of the second component necessary for making a moment reaction force around the fitting insertion axis received from the first component substantially zero are calculated. 3. The component automatic assembling method according to claim 1, further comprising the steps of: rotating the second component by the calculated rotation amount. 4. A method for determining a direction in which a phase of the second component changes as a function of a moment reaction force about the fitting insertion axis received by the second component from the first component. The method for automatically assembling a part according to claim 1. 5. When the moment reaction force around the fitting insertion axis becomes larger than a predetermined value during the phase matching step,
5. The method for automatically assembling a part according to claim 1, wherein the phase matching step is immediately stopped. 6. A Z-axis direction coinciding with the fitting and inserting direction, an X-axis direction orthogonal to the Z-axis direction, a Y-axis direction orthogonal to the Z-axis direction and the X-axis direction, and a rotation about the Z-axis direction. Robot that moves relatively in four directions in the θ-axis direction
A positioning mechanism for positioning the parts, either provided on one of the robot and positioning mechanism, the six degrees of freedom of the position and orientation of the vicinity of the tip portion of the second part chucked by Chi jack mechanism and the compliance center A four-axis force sense that measures a compliance mechanism having compliance and forces Fx, Fy, Fz in the X-axis direction, Y-axis direction, and Z-axis direction acting on the compliance mechanism and a moment Mz about the θ-axis. A sensor and a second component gripped by the chuck mechanism are moved relative to the positioned first component, and the second component is moved so that the force Fz measured by the four-axis force sensor falls within a predetermined range. A pressing step of pressing the second component against the first component, and a relation between the forces Fx and Fy measured by the four-axis force sensor. As, X direction of the robot,
A calculating step of calculating the error correction amounts Δx, Δy in the Y direction, an axis alignment step of moving the robot by the error correction amounts Δx, Δy, and measuring the θ axis of the robot by the four-axis force sensor. A component automatic assembling apparatus comprising: a controller that sequentially executes a phase matching step of rotating the force until the force Fz becomes sufficiently small and an insertion step of moving the robot in the Z direction and inserting the second component into the first component. . 7. The controller, after the calculating step,
A separating step of moving the chuck mechanism in the Z direction to separate the second component from the first component; and, after the axis aligning step, moving the chuck mechanism in the Z direction to remove the second component from the first component.
A re-pressing step of sequentially pressing the second component against the first component so that the force Fz measured by the axial force sensor falls within a predetermined range. The automatic parts assembling apparatus according to claim 6, wherein 8. The controller calculates, after the phase matching step, a correction amount Δθ of an error due to an overshoot in a rotation direction around the θ axis of the robot as a function of a moment Mz measured by the four-axis force sensor. 7. A function for executing a rotation step of rotating the θ axis of the robot by Δθ.
Or an automatic parts assembling apparatus according to 7. 9. The controller according to claim 6, wherein the controller measures a moment M about the θ-axis in the Z direction measured by the four-axis force sensor.
9. The automatic parts assembling apparatus according to claim 6, further comprising a function of determining a rotation direction of the robot about the θ axis based on z . 10. The controller according to claim 6, wherein, during the phase matching step, when the moment Mz about the θ axis measured by the four-axis force sensor becomes larger than a predetermined value, the controller rotates the robot about the θ axis. 10. The automatic parts assembling apparatus according to claim 6, further comprising a function of immediately stopping the parts.