JPS6119523A - Fitting device - Google Patents

Abstract

PURPOSE:To make the fitting of a member not chamfered easy by so constituting a device for fitting a shaft or the like to a hole as to insert a part into the hole making it stand up after putting it to the edge of the hole detecting the state of contact in the directions of three dimensions with it put to the hole on the slant. CONSTITUTION:A part 6 is made to contact with a point A1 on a workpiece 8 on the slant against the hole of the workpiece and is made to move toward a point A2 keeping the contact to search a hole 7. And when finding the hole 7 by repeating the above movement changing the start point from A5-A7, the circumferencial surface of part 6 in the moving direction is made to contact with the point A12 of the interior of the hole 7 in the moving direction. After that, the end of part 6 is put together with the hole 7 making the part 6 stand up inserting it into the hole 7. These operations are controlled by a computer not shown in the drawing according to a specified program detecting the state of three dimentional contact. Due to this constitution, members not chamfered can be fitted with each other aligning each center with a small insert force.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a fitting device for fitting a shaft or the like into a hole.

(Technical Background of the Invention and Problems thereof) Generally, various fitting devices have been proposed with the automation of various operations in recent years.

For example, some fitting devices for fitting a part such as a bottle to a workpiece are formed by simply moving the part to a pre-planned position and then simply pushing the part.

However, in this fitting device, the part is fitted by simply pushing it into the hole, so the eccentricity between the part and the hole to be fitted is determined by the chamfer provided at the part insertion end and the opening end of the hole. In addition, if the part is pushed in without being accurately aligned, the pushing force will be considerably large, and if the fitting clearance between the part and the hole is small, it may be difficult to pry the part. There were inconveniences such as parts being inserted and getting jammed, making it impossible to insert and remove them.

Therefore, conventional fitting devices as shown in FIGS. 14 to 16 have been proposed.

This device is formed by a fitting mechanism 1 called a remote center compliance, which supports a translation mechanism 3 via a flexible part 2 so as to be movable in the translation direction a, and supports the translation mechanism 3 via a flexible part 4. The rotating device 4% 5 is supported so as to be movable in the rotating direction about the center of rotation O. This rotating mechanism 5 has a shaft-shaped component 6 at its tip.
It is designed so that it can be grasped.

The fitting of the component 6 using the fitting device thus formed is carried out as follows.

For example, as shown in Figure 15, the neutral position (dotted line in the figure)
If the component 6 located in the hole 7 is eccentric from the hole 7 to be fitted, the translation mechanism 3 is moved via the flexible component 2 in the direction C that eliminates the eccentricity, and then the component 6 is inserted into the hole 7. I'm going to push it into.

Furthermore, as shown in FIG. 16, when the axis of the hole 7 is inclined to the axis of the component 6 in the neutral position, the flexible component 4
After the rotating mechanism 5 is rotated in the direction d that eliminates the deviation in the inclination direction to align the axes, the component 6 is pushed into the hole 7.

However, in the conventional example shown in FIGS. 14 to 16, the component 6 and the hole 7 are not forced together or clogged due to the action of the flexible components 2 and 4, but the component 6 is simply inserted into the hole. Since it is a push-in method, it has the same drawbacks as the conventional method.

[Purpose of the invention]

The present invention has been made in view of these points, and it is possible to fit the parts in a self-aligning manner without limiting the eccentricity between the parts to be fitted and the hole. It is also possible to easily fit parts without chamfers,
Moreover, it can be fitted securely with a small insertion force.
Another object of the present invention is to provide a fitting device that can perform various detections such as detecting excess or insufficient fitting clearance, detecting parts that are inappropriately fitted, detecting forgotten hole machining, and detecting hole position.

[Summary of the invention]

The fitting device of the present invention includes a gripping mechanism that grips a component to be fitted into a hole, a component drive mechanism that moves the component in a three-dimensional direction and supports the component so as to be tiltable with respect to the axis of the hole; a detection mechanism that detects a contact state in the three-dimensional direction between the workpiece in which the hole is drilled and the component;
A control means for instructing the component driving mechanism to move the component, the component being first tilted with respect to the axis and pressed against the workpiece with an appropriate contact force, and then being controlled by the detection mechanism. While detecting the contact state between the part and the workpiece, a part of the outer circumferential surface of the part in the direction of movement is brought into contact with the edge on the far side of the hole, and then a movement command is issued to raise the part and insert it into the hole. and a control means for sending a signal to the component drive mechanism.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 13.

FIG. 1 shows the entirety of this embodiment.

In the figure, reference numeral 20 is a component drive mechanism consisting of a robot-like arm. This component drive mechanism 20 has a gripping mechanism 28 formed of a grip or the like that grips a component 6 to be fitted, such as a shaft, at its tip, and moves the component 6 in three-dimensional directions of X, Y, and Z. At the same time, it is supported so as to be tiltable in the axial direction of the hole 7 of the workpiece 8 to be fitted (direction 7 in the figure).

The component drive mechanism 20 has several stages of detection mechanisms that detect the contact state of the component 6 and the workpiece 8 in the three-dimensional directions of X, Y, and Z, and the reference numeral 36 in the figure indicates X, Y.

It is a displacement sensor interface that takes out displacement signals in seven directions, and numeral 37 is a load cell interface that takes out contact loads in each direction. In this embodiment, the state of contact between the component 6 and the workpiece 8 is recognized by receiving signals from each interface 36 and 37, and a command is sent to the servo driver 38 that drives the component drive mechanism 20 to drive the component 6. A control means 39, such as a computer, is provided which automatically inserts the hole 7 into the hole 7. This control means 39 fits the component 6 into the hole 7 through the steps shown in FIGS. 5 to 12, for example, in accordance with the flowcharts shown in FIGS. 13a and 13b.

Further, each part will be explained in detail.

As shown in FIGS. 1 to 3, the gripping mechanism 28 is a piston that is slidably provided in a cylinder chamber 22 of a cylindrical cylinder 21 attached to the tip of a component drive mechanism 20 consisting of a robot-like arm. 3 flexible parts 2 at the tip of 23
6 and a movable plate 27 so as to be tiltable. The piston 23 is provided through a spline 24 so as not to rotate, and is prevented from protruding excessively by a stopper 25.

The detection mechanism is formed as follows.

As shown in FIGS. 2 and 3, a predetermined number of three or more minute spot light sources 29 are provided on the movable plate 27, and a two-dimensional light receiving element 30 for receiving the spot light is provided at each part It! The displacement signal of the movable plate 27 which is attached to the inner surface of the cylinder 21 and which receives light from each dimension light receiving element 30 is expressed as X,
A displacement sensor interface 36 is provided for converting displacement signals in the Y and Z directions.
It is formed as follows to detect the contact force.

That is, air is supplied and discharged into the cylinder chamber 22 from an air source through an air duplex 31 provided with a release valve 35, a solenoid 34, and a load cell 33 in this order. The relief valve 35 adjusts the supplied air pressure, and the load cell 33 measures the force acting on the piston 32 attached to the air tube 31 to determine the air pressure. The qP-docell 33 is connected to the load cell interface 37 that converts the output signal of the load cell 33 into a load acting on the gripping mechanism 28, as described above.

In this embodiment, the signal contents of each interface 36 and 37 and the contact state between the component 6 and the workpiece 8 are classified as shown in FIG. That is, the signals in the Y, Z directions α of the displacement sensor interface 36 are
Y, SZ, and the signal of the load cell interface 37 is SL, and the sensor lower limit signal and upper limit signal are divided and displayed as follows.

First, a non-contact area where the part 6 and the workpiece 8 are not in contact is located in the center between the upper limit value and the lower limit value (the upper and lower boundary values are SXO
, -8XO, SYO, -8YO.

SZO, -8ZO, -8LO'>t# ke, contact permissible sections on both outer sides of sono (boundary value is SX1.-8XI).

SYl, -8Y1. SZl; -871, -8L1) is provided on both sides of the excess contact section (boundary value is SX2.-8
X2', SY2. -8Y2. SZ2゜-8Z2. -3L
2), with breakage risk zones on both sides.

Next, the fitting operation according to this embodiment will be explained.

First, the movement of the component 6 will be explained with reference to FIGS. 5 to 12.

As shown in FIG. 5, any point A1°A2.
For the area enclosed by A3 and A4, the part 6 is tilted by an angle θ from the axis of the hole 7 by each flexible part 26,26. Thereafter, the part 6 is brought close to the workpiece 8 from a suitable point AO (FIG. 6), and first the tip of the part 6 is brought into contact with the point A1 with a predetermined contact force (FIG. 7). Thereafter, the part 6 is moved from point A1 to point A2 while maintaining contact with the workpiece 8 to search for the hole 7. If there is no hole 7,
At point A2, the part 6 is separated from the workpiece 8 and guided to point A5, and then the hole 7 is searched from point A5 to point 0 in the same manner as the search was made from point A1 to point A2. If hole 7 is found while repeating such a search, for example, if hole 7 is found while searching from point A7, point A8°A'9. Pass through intermediate points such as AI O, A11 (Fig. 8), and place a part of the outer circumferential surface of the part 6 in the direction of travel to point A12, which is the edge of the hole 7 on the back side in the direction of travel of the part 6. (Figure 9). Thereafter, while inserting the part 6 into the hole 7, the tip of the part 6 is aligned with the hole 7 while increasing the inclination angle (Fig. 10), and the part 6 is fitted into the hole 7 (first
Figures 1 and 12).

Next, the procedure for fitting the component 6 will be explained based on the flowcharts of FIGS. 13a and 13b showing the order of operation of the three control means.

First, as shown in FIG. 13a, when a first command is issued, the tip of the component 6 moves to point AO according to step 40, and then, according to step 41, the component 6 is tilted by an angle θ.

Thereafter, the part 6 is moved in seven directions in order to come into contact with the workpiece 8 according to steps 42 and 43. And part 6
When the part 6 comes into contact with the workpiece 8, it is determined whether the part 6 is inside or outside the hole 7 according to step 44. This determination is made by comparing the height of the tip of the component 6 and the height of the top surface of the workpiece 8.

In this case, if the part 6 is outside the hole 7, the hole 7 is searched according to step 45 from point A1 to point A2 in FIG.
Alternatively, the part 6 is moved in the -X direction from point A5 to point 6 or from point A7 to point A8. During this search, it is always determined in step 46 whether the component 6 is in the hole 7 or not. This judgment is made if the SX or SZ signal is 18XO≦Sx SXO or -5ZO≦SZ
This is done by detecting that the component 6 is not in contact with the workpiece 8 due to SZO, and detecting that the component 6 is in the hole 7 at the point 8 in FIG. Thereafter, according to step 47, the part 6 is moved by A7 in order to bring it into contact with the edge of the hole 7. Then, according to step 718, SX, SZ,
SL double signal S, XO x Sx SX1 or -S71≦S
By becoming Z≦-5ZO or -8L1-SL,
It is determined that the part 6 and the edge of the hole 7 are in proper contact. Thereafter, in order to make the outer surface of the component 6 in the -X direction reach the innermost edge A12 of the hole 7, point A9 is moved in the Y direction and the -X direction. A10. Steps 49 to 64 are performed to move in the order of A11°A11. In other words, ■ stage 4
9 to 52, the deviation in the Y direction is calculated by multiplying the signal by SY.
Make sure that YO≦SY≦SYO. Also, ■Code 53
At sx and 54, it is confirmed that the tip of the component 6 is in the hole 7 in FIG. 5 and has not reached the point AI2.
, sz times signal. Thereafter, in step 55, the part 6 is moved in the -X direction, and in steps 56, 57, and 58, the part 6 is moved so as to correct the misalignment of the part 6 with the hole 7 in the Y-axis direction.

These steps 53 and 57 are repeated as necessary. After that, according to steps 59, 60, and 61, when the component 6 is moved by ΔX in the -X direction to indicate that the component 6 has reached the edge A12 of the hole 7 in FIG. 5, an SX or Sz signal excessive contact state occurs. In step 64, it is determined that the contact state at point A12 in FIG. 5 has become the solid line state in FIG. On the other hand, in steps 62 and 63,
Hole 7 is at point AI, A2. It is determined from the coordinates of the part 6 that it cannot be detected within the area surrounded by A3 and A4.

Thereafter, as shown in FIG. 13b, in step 65, the inclination angle θ is reduced by A6 degrees in order to raise the part 6. Thereafter, according to steps 66 to 69, the component 6 is moved up and down in the Z-axis direction so that the signals SL, SZ, and Sx are adjusted to appropriate amounts. Thereafter, in steps 70 and 71, the amount of insertion between the tip of the component 6 and the hole 7 is determined. After that, in Step 72, it is determined whether the inclination angle θ of the part 6 is O or not. If θ~0, the operation from Step 65 is repeated, and if θ-〇, Step 7
In step 3, it is determined whether or not the part 6 and the hole 7 are fitted by the required amount for fitting and are in the state shown in FIG. This process 73
If the determination is "no", it is determined in step 74 that insertion is not possible, and if "yes", the component 6 is inserted into the hole 7 by ΔZ according to step 75. At this time,
X by signals SX and SY in steps 76 and 77.

The eccentricity between the component 6 and the hole 7 in the Y direction is within the allowable range -SXO<
It is determined whether SX<SXO, -3YO<SY<SYO, and if it is not within the allowable range, the eccentricity is set to O in step 78.79.

Then, if the amount of eccentricity is within the allowable range, step 80
In this step, it is determined whether the insertion force of the component 6 into the hole 7 is appropriate or not based on the fact that the signal SE satisfies -SE1≦SE and that the signal SL of the load cell 33 is appropriate. If the determination in step 80 is "no", a determination is made in step 82 that insertion is not possible. On the other hand, if the answer is "Yes", it is determined in step 81 whether the insertion amount of the component 6 into the hole 7 is a predetermined depth. ”, step 75
The process returns to , and the same operation is repeated.

The operation of this embodiment will be further explained with reference to FIG.

Interference when fitting the component 6 inclined by an angle θ into the hole 7 will be explained. In the figure, part 6 centered on point C1
The outer diameter circle Oa is centered on the point C, and the intersection point D1 between the outer diameter inner ob of the part 6, which passes through the dot, and the parallel line of the center line of the part 6 and the outer diameter inner 9b, is a vertical line centered on the dot. The point rotated until it becomes D2 is defined as a circle Qc that passes through this point D2 and has point C as its center.

First, the distance between point C and point C1 of part 6! ! In the case of 1tj=O, the tip point A13 of the component 9 coincides with the edge A12 of the entrance of the hole 7 when the inclination angle θ=O, so the component 6 cannot be inserted into the hole 7.

On the other hand, in the case of an appropriate amount of 1', the following clearance is required. In other words, at the tip of the component 6, there is a gap between a point B3, which is approximately vertically lowered from the point B, and a point B2, which is the tip position of the component 6 at an inclination angle θ-〇, and a gap between the component 6 and the tip at the point. In order to avoid interference with the hole 7, it is necessary to fill both the inner diameter and the gap between the hole 7 with a circle OC that is slightly larger than the inside Qa of the outer diameter of the component 6.

Further, to explain the operation of the load cell 330, air at a predetermined pressure is supplied into the cylinder 22 via the relief valve 35, the solenoid 34 is closed, and then the operation is performed according to the steps shown in FIGS. 13a and 13b. The best fitting can be achieved while controlling the inclination angle θ and the insertion adjustment length ρ so as to minimize interference between the component 6 and the hole 7 during fitting. At this time, when the insertion force of the component 6 is smaller than the air pressure inside the cylinder 22, the position of the piston 23 does not change, but when it becomes larger, the piston 23 contracts along the spline mechanism 24 according to Boyle's law, and the load cell 33 The signal becomes equal to the insertion force.

To summarize the above actions, the detection mechanism monitors the contact state between the part and the workpiece, presses the part against the workpiece surface with an appropriate force, and moves an arbitrary area on the workpiece surface that has a hole to be fitted along an appropriate path. When the signal of the detection mechanism becomes neutral, the edge of the hole on the front side in the direction of search is detected, and then the part is pushed into the hole with a constant pressing force or less.
The component is brought into contact with the edge of the hole on the back side in the direction of travel while reducing and correcting the eccentricity between the component and the hole in the direction perpendicular to the direction of travel by a signal that detects the contact state between the component and the edge of the hole; For constant pressing, adjust the insertion amount so that it is less than the force, and at the same time raise the inclination angle of the part to an upright position. To automatically insert parts to a predetermined depth with less than a certain insertion force while correcting to reduce misalignment of the parts. 7 In addition, by storing the relationship between the displacement of the two-dimensional light receiving element 30 and the insertion force of the component 6 in advance in the control means 39,
The piston 32 and load cell 33 may be omitted.

Further, each flexible component 26 may be provided parallel to the axis of the piston 23 instead of being provided so as to be inclined toward the center of rotation.

〔Effect of the invention〕

In this way, the fitting device of the present invention can fit the parts in a self-aligning manner without limiting the amount of eccentricity between the parts to be fitted and the hole. It is easy to mate, and it is possible to mate reliably with a small insertion force.In addition, it is possible to detect excess or deficiency of mating clearance, detect improperly mated parts, detect forgotten hole drilling, and Various detections such as hole position detection can be performed, and since parts are not forcibly inserted into the holes, damage to the parts, holes, and main body of the device can be prevented.

[Brief explanation of the drawing]

Figures 1 to 13. The figures up to figure b show one embodiment of the fitting device of the present invention, in which figure 1 is an overall perspective view, figure 2 is a perspective view of the gripping mechanism, figure 3 is a partially cutaway side view of the gripping mechanism, and figure 4 is a perspective view of the gripping mechanism.
The figure is a line diagram showing the judgment criteria by the detection mechanism, Figure 5 is an explanatory diagram showing the operating method by the device of the present invention, and Figures 6 to 11 are
The figures are side views showing the parts, holes, and conditions in each operating step by the apparatus of the present invention, FIG. 12 is a diagram showing the interference state, and FIGS. 13a and 13b are flowcharts showing the operating steps by the control means, respectively. , and FIGS. 14 to 16 are longitudinal sectional side views showing conventional devices. 6... Part, 7... Hole, 8... Workpiece, 20...
・Parts drive mechanism, three...control means. Applicant's agent Kiyoshi Inomata 10th 2nd eye 3rd eye 5th figure 6th eye 2nd eye 13 9th eye 10th eye 11th eye 12th figure 13a Figure 136th eye 11th eye How to write procedural amendments> November 2nd, 1982

Claims (1)

[Scope of Claims] A component drive mechanism that includes a gripping mechanism that grips a component to be fitted into the hole, moves the component in a three-dimensional direction, and supports the component so as to be tiltable with respect to the axis of the hole; a detection mechanism for detecting a contact state in the three-dimensional direction between the workpiece in which the part is drilled and the part, and a control means for instructing the part driving mechanism to move the part, the control means for instructing the part driving mechanism to move the part; The workpiece is pressed against the workpiece with an appropriate contact force in a tilted state with respect to the axis, and then, while the contact state between the workpiece and the part is detected by the detection mechanism, a part of the outer peripheral surface of the part in the direction of movement is inserted into the hole. A fitting device having a control means for sending an operation command to a component drive mechanism to cause the component to come into contact with the rear edge and then insert the component into the hole while standing up.