JPS5915779B2 - Fitting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fitting method in which a shaft component, such as a bearing and a bearing box, a piston and a cylinder, etc., is precisely fitted into a hole drilled in an object.

As a conventional technique for fitting ten shafts into holes (including fitting a hole to a shaft), a tactile fitting device described below is known.

That is, the shaft is gripped by a gripping section composed of a flexible object such as a spring and a tactile sensor, and the sensor detects the contact state 15 between the shaft and the hole. position·
A posture relationship is calculated, a predetermined search operation is performed according to this relationship, and the shaft portion is made to look into the hole. Next, the shaft is pressed against the hole, and the sensor determines whether or not the insertion is progressing. If it is not inserted, a predetermined shaft is inserted into the hole again. A searching motion is performed to insert the shaft into the hole. A spring like this
A shaft gripping portion constituted by a sensor, a sensor and an X-
By a method combining search control using a Y table etc., 25, that is, a tactile robot, to one hole of the axis.
Fittings with gaps on the order of microns were being performed. However, since this tactile fitting device performs a search operation and fits by controlling a sensor and an X-Y table, it requires a mechanism for 30 search operations such as an X-Y table, and also - It requires complicated control of the Y table, etc., and has the disadvantage of being unreliable and extremely expensive. In addition, in the conventional tactile fitting device described above, so-called multi-axis fitting is performed, in which two or more multi-axes, which are mutually fixed and have a mechanical restraint of about 35 degrees, are simultaneously fitted into corresponding holes. C. The problem is that sufficient positioning accuracy is not possible because each shaft is held movably by each grip made of a flexible object such as a spring. It was hot.

In this multi-axis fitting using tactile sensation, even if the fitting is performed sequentially, the first one axis will fit, but when it comes to the second and subsequent fits, the multiple axes will have some degree of mechanical restraint with each other as described above. Since the multi-axis gripping parts are connected to each other via flexible objects such as springs, it is impossible to perform a searching operation.The purpose of the present invention is to overcome the above-mentioned drawbacks of the conventional gripping parts. With a highly reliable and simplified mechanism, three holes are mounted on a platen and transported sequentially by a transport means. It is an object of the present invention to provide a fitting method that allows pistons to be fitted together.That is, the present invention provides a fitting method that allows pistons to fit together.That is, the present invention fits either a shaft component or an object having a hole into a regulating hole to fit within a preset tolerance range. a conveying means for sequentially conveying a platen on which the object or the other shaft component is positioned and placed thereon to a fitting position; Stop the platen conveyed by the platen at the fitting position, engage and place the positioning member on this platen, and install the table member at the fitting position so that it can move at least a small amount in the horizontal direction. When inserting the shaft part into the hole of the object, the insertion jig is simply moved vertically downward or upward so that they approach each other. A rod-shaped guide member with a chamfered tip and a constriction on the rear side of the shaft portion and a guided member having a hole with a relief with a larger diameter on the rear side are mutually engaged and guided. The table members are slightly moved in the horizontal direction to position them horizontally relatively within the range of each chamfer, and then the insertion jig is simply lowered or raised in the vertical direction to apply the insertion force. It is characterized by being able to provide multi-axis fitting by applying it from outside the area.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 is a schematic perspective view showing an embodiment of the uniaxial fitting device of the present invention, and FIG. 2 is a sectional view of the center of FIG. 1.

1 & ζ object, a hole 2 with a diameter D that is larger than the depth of about 9011 to 300 mm, for example about 30 to 100 mm, is drilled with high precision relative to the reference pin hole 4, and the entrance is A chamfer 3 is applied to the area.

Reference numeral 5 denotes an object gripping table member in which a pair of small-diameter dowel pins 8 are implanted in a central concave portion 1c to position the object 1 with high precision by making and fitting the dowel pin holes 4 drilled in the object 1. The holes 9 for guide pins opposite to each other at both ends (recesses with larger diameters are formed on the lower side).

) is integrally bored and supported on the base 6 within a predetermined range by a bearing 7 so as to be slidable in the horizontal direction. Reference numeral 11 denotes a shaft component of the target object having a diameter d that fits into the hole 2 of the object 1.

Reference numeral 12 denotes a chuck which is held movably in the horizontal direction by a spring 13, and holds the end of the shaft part 11 by vacuum suction or electromagnetic suction.

Reference numeral 14 designates an insertion jig supported on an upper base 15 so as to be movable under the ground along a guide rail 16, connected to a piston rod of a cylinder 16, and having both lower ends chamfered to have a sharp tip. , and a guide pin 18 having a constriction with a reduced diameter is implanted on the upper side of the shaft part of the shaft part 11, and the shaft part of the shaft part 11 is held with a predetermined clearance so as to restrict the movement, that is, the posture of the shaft part 11. A regulation hole 19 is provided for loose fit.

Therefore, first, the object 1 to be fitted is manually or automatically mounted in the recess 10 of the object gripping table member 5.
The object 1 is pressed downward to firmly fit the dowel pin 8 of the object gripping table member 5 into the dowel pin hole 4 of the object 1 to position it. Next, this object grasping table member 5
is moved in the direction of the arrow shown in FIG. 1 to the fitting station at the groove end 19 of the base 6 and stopped. In addition, the base 15 is a supply station (not shown) for the target object 11.
It is configured to horizontally reciprocate from to this fitting station. However, the upper end of the shaft component 11, which is a target object conveyed to the supply station by, for example, a parts feeder, is inserted through the regulation hole 19 by the downward drive of the cylinder 17, and is held by the chuck 12. Next, the base 15 moves from the supply station to the fitting station and stops, and the shaft part 11 is positioned on the side of the object 1. Next, cylinder 17
When the insertion jig 14 is lowered by driving the guide pin 1
At the same time when the pointed conical part 8 enters the entrance of the guide pin hole 9, the position of the object gripping table member 5 is moved and corrected in the horizontal direction by the conical part. When the insertion jig 14 is further lowered, the shaft portion of the guide pin 18 with the largest diameter is tightly fitted into the guide pin hole 9, and the object 1 and the insertion jig 14 are positioned in the horizontal direction. At this time, since the amount of movement of the shaft component 11 is regulated by the regulating hole 19, the chamfer at the tip of the shaft component 11 and the chamfer 3 at the entrance of the hole 2 become extremely close and face each other (third Diagram a
). Then, when the shaft component 11 descends considerably, the shaft portion of the guide pin 18 with the maximum diameter reaches the relief part (the part with a larger diameter) of the guide pin hole 9, and the constricted part of the guide pin 18 moves into the guide pin hole 9. The table member 5 is positioned at the minimum diameter portion of the entrance of the table member 5, and the table member 5 is in a state where it can be slightly moved in the Δx horizontal direction. Then, the object 1 is guided by the chamfer at the tip of the shaft part 11 and the chamfer 3 at the entrance of the hole 2, and the object 1 is slightly moved in the horizontal direction together with the table member 5, while the shaft part 11 is held in a vertical state by the regulating hole 19. 2 and insert it to complete the fit. In particular, if the shaft portion of the guide pin 18 with the largest diameter and the guide pin hole 9 are not tightly fitted with no gap, the chamfer at the tip of the shaft component 11 and the chamfer 3 at the entrance of the hole 2 will fall within the range This is because positioning becomes difficult. The constriction of the guide pin 18 and the relief part of the guide pin hole 9 allow the table member 5 to be moved slightly in the horizontal direction, thereby absorbing the error between the axis of the shaft component 11 and the axis of the hole 2. There is. The main problem here is the accuracy of the regulation hole 19 of the insertion jig.

In short, the shaft part 11 is XE3:L'X9'Max-(D
'-Dmin)/2=(L-2) Since it is a condition that the total positional error falls within the chamfered portion, the relative positioning of the shaft part 11 and the object 1 is determined as shown in Fig. 3a. The condition must satisfy the following equation (4): IEll+IE
2l+IE3l C1+C2・・・・・・・・・(4)
B Attitude determining condition The allowable inclination of the shaft component 11 by the regulating hole 19 must be such that the shaft portion at the tip of the shaft component 11 can be seen into the entrance of the hole 2.

That is, as shown in FIG. 3b, the following four conditions are necessary for fitting the tip of the shaft component 11 into the hole 2. By the way, the object of the condition is defined as follows. The maximum value of the outer diameter of the shaft of the a-axis component 11 is Dmax, the outer diameter of the shaft of the b-axis component 11, the minimum value is Dmin, the length of the shaft of the c-axis component 11 is L, and the tip of the shaft of the d-axis component 11 The chamfer amount is C1, e object 1
The maximum inner diameter of hole 2 is Dmax. f The minimum inner diameter of hole 2 of object 1 is Dmin, g The positional error between hole 2 of object 1 and the reference dowel pin hole is E1, h. The relative position error with respect to 19 is E2, i The amount of chamfering at the entrance of hole 2 of object 1 is C2, j The inner diameter of regulation hole 19 is D (k The length (width) of regulation hole 19 is w, l Friction angle is λ (=Tan-111.U is the coefficient of static friction).

A positioning condition The tip of the shaft part of the shaft component 11, which is the target object, is located in the hole 2 of the object 1.
be within the chamfer when contacting the entrance of each.

In other words, the length L' of the shaft excluding the chamfered portion at the tip of the shaft component 11
From the above definition, the following relationship (1) holds true. L′=
L-2C1・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・ 1) Also, the regulation hole 19
Based on the above definition, the following equation (2) holds true for the maximum value ψMax of the inclination angle of the shaft due to the gap between the shaft portion and the shaft portion of the shaft component 11.

ψ/Max=(D'-Dmin)/W ・・・・・・・・・
......(2) However, the positional error E3 of the shaft tip of the shaft component 11 due to the gap between the regulation holes is the above (1), (2)
), the relationship is as shown in equation (3).

)(D'-Dmin)/W-(D'-Dmin)/2
......{3) Maximum value φ of the inclination angle that can be inserted into the entrance of hole 2.

According to the above definition, Max has the relationship of the following equation (5). φ
0max=COs-1 (Dmax/Dmin)...
......《5) Therefore, from the relationship of equation (2) above, the inclination angle φ/ of the shaft part 11 given by the regulation hole 19 is
Max is defined by the above equation (5). It is necessary to determine the attitude by making it smaller than Max as shown in the following equation (6). ψ′Max≦φ0max゜゜゜゜゜゜゜゜゜”゜゜゜゜”゜゜゜゜゜゜゜゜゜0゜゜゜゜゛゜｜6)
C Insertion Condition When the shaft portion at the tip of the shaft component 11 looks into the entrance of the hole 2 and the line of action of +F does not pass through, there is no engagement and the fitting progresses.

Also, when passing, the lines of action of the three forces intersect at one point, and the resultant force of the three forces becomes zero, causing a bite. This is due to the property that the frictional force can vary within its friction angle in opposition to the external force. Therefore, as shown in FIG. 4c, L is the area where the external force F turns counterclockwise with respect to the instantaneous center point C, and R is the area where the external force F turns clockwise. By the way, shaft part 1
Since the maximum inclination of the shaft part 1 is determined by the gap between the shaft part 11 and the regulating hole 19, the shaft part 11 and the hole 2 are not connected until the shaft part 11 is inserted to the insertion depths e and h as shown in FIG. The situation is whether or not a bite will occur when contact occurs at points A and B.

In addition, until the insertion depth is reached, if the shaft part 11 is lowered, the shaft part 11 and the hole 2 will only make contact at point A or B, so it can be inserted smoothly into the hole 2 of object 1 without any jamming. can do. First, the insertion depths e and h are the maximum inclination ψ′Max of the shaft portion of the shaft component 11, and Dmin, dm
From the relationship with ax, it can be determined by equations (7) and (8) as follows. The line b has the relationship of the following equation (9), and the X coordinates Xa+, b+ of the intersection of the straight line Na+ and the straight line Nb+ have the relationship of the following (self) equation. ~54″″-11″
'Jv-, : (It is sufficient that the X coordinate Xf of the force acting on the shaft component 11 satisfies the relationship of the following AD formula.

j.

/2≦C1+C2lE,l-E2 condition is 0.2×0
．． 8, which is quite satisfying.

B Attitude determining condition: Formula (2) above? 5) From the formula (D'-Dmin)/Vl≦COs-1(DmaX./
Dm,n) is 0.0025rad<0.031
It is 7 rad, which is quite satisfactory.

The C insertion condition h is based on equations (7) and (8) above, so if -55.5mg<Xf<5.5U, C can be inserted without biting.

That is, if a force F in the vertical direction is applied to the object 11 at any point, the object 11 can be smoothly inserted into the hole without being bitten. Next, multi-axis fitting will be explained based on FIGS. 6 to 9. That is, the object 1a has three holes 2a, 2, each having a diameter D and formed at 120 degree intervals.
b and 2c, and two positioning pin holes 4 are bored at the bottom. Reference numeral 5a denotes a platen, in which a single dowel pin 8 of a small diameter is implanted, which positions the object 1a with high precision by fitting it into the dowel pin hole 4 drilled in the cylindrical object 1a. A cylinder member 21 in which a hole 20 that fits with the outer diameter is bored with a gap of about 0.2 mm is fixed in a fixed position, and a pair of holes 9 for guide pins are integrally bored at both ends, and the opposite positions are determined. A hole 22 for use is also bored.

23 is an X-Y
It is a table member supported movably in two axial directions and a rotational direction, and has a taper pin 25 implanted in its upper surface for relative positioning by fitting into a positioning hole 22 drilled in the platen 5a.

The maximum amount of movement of the table member 23 relative to the elevator table 24 is regulated by making a pin 26 formed at the upper end of the elevator table 24 look through a hole 27 formed in the table member 23. The lifting platform 24 has two guide shafts 30 that are slidably supported under the soil on bearings 29 installed on the lower frame 28 fixed to the lower side, and a cylinder 31 attached to the center of the lower base 28. The piston rod 32 is connected to the piston rod 32. Note that a flange portion 33 is formed at the lower end of the guide shaft 30, and abuts against the lower end of the bearing 29 to serve as a stopper. Reference numeral 34 designates a chain conveyor on which the platen 5a is mounted and conveyed, and is configured to move along a guide rail 35 as shown by the arrow in FIG.

36 is a stopper that comes into contact with and stops the platen 5a conveyed by the chain conveyor 34, and is L-shaped and rotatably supported around a pin 37, and one end is connected to the piston rod 39 of the cylinder 38. At that moment, I started to get excited. The ring 40 is suspended.

The base 15 includes a column 41 attached to the lower frame 28.
It is supported slidably in the direction of the arrow in FIG. 7 along a rail 42 provided at the upper end, and connects the tip of a piston rod 44 of a cylinder 43 attached to the upper end of the column 41. Reference numeral 45 is an insertion jig, and a guide rod 47 supported vertically movably by paired bearings 46 installed diagonally on the pace 15 is implanted at the upper end, and at the center of the base 15. a plate 50 connected to the piston rod 49 of the fixed cylinder 48;
A guide rod 52 is supported in a vertically movable manner by a pair of bearings 51 installed diagonally on the base 15, and a guide rod 52 extending above the base 15 is installed at the upper end, and a spring 53 serving as a buffer is installed between the guide rods 52. A pair of guide pins 18 are interposed and have a pointed tip, a conical shape, and a constricted shape.
The three pistons 11a, 11b-, 1 are installed on both ends of the lower side and assembled to the oblique disc 54 with a bearing 55 interposed therebetween.
1c.

By the way, the target object is a piston 11a, 1 with bearings 55 interposed on both sides of an oblique disk 54 fixed to a shaft 56.
Grooves 57a and 57 formed in the center of each of 1b and 11c
b, 57c are fitted into the form. Then, insert the shaft 56 into the hole 58 formed in the center of the main body 56 of the insertion jig 45.
is inserted, the end surface 59 of the flange portion is brought into contact with the lower end, and the shaft 56 is connected to the piston rod of the cylinder 60 by a chuck mechanism formed by connecting a piece 61 having an arcuate concave surface at the tip.
It is configured so that it can be held by holding it in place, or it can be moved back and removed. Further, holes 2a, 2b are provided at the lower end of the main body 56 of the insertion jig 45 so that the positions of the upper ends' of the pistons 11a, 11b, 11c can be regulated with a width W and a diameter D.
, 2c with the same pitch P as the regulating holes 62a, 62.
b, 62c are formed.

That is, each of the regulating holes 62a, 62b, 62c is formed by a v-shaped groove 65a, 65 formed at 120 degree intervals, as shown in FIG.
b, 65c, and from the outside the cylinders 64a, 64b,
It is formed by V-shaped grooves 66a, 66b, and 66c formed at the tips of pieces 63a, 63b, and 63c, which are connected to 64c and are formed to open and close by moving in the horizontal direction. In addition, chamfers 6 are provided at the tips of the V-shaped grooves 65a, 65b, and 65c so that the pistons 11A, Ilb, and llc can easily enter.
Ta, 6Tb, and 6Tc are applied. and piece 63a
, 63b, 63c grooves 68a, 68b formed at the tips of the grooves 68a, 68b.
, 68c, the diameter D of the regulation holes 62a, 62b, 62c formed from four directions by fitting and abutting the protruding shoulder portions at the tips of the υ-shaped grooves 66a, 66b, 66c.
' can be kept within an error range of 20 μm. TO is the oblique disk 5 at the supply station.
This is an assembling device for assembling the pistons Ila, Ilb, and Ilc to the main body 56 of the insertion jig 45 and holding the pistons Ila, Ilb, and Ilc. As shown in FIG. T, this assembly device TO has chucks (
A support member T4 supports an index table T3 (not shown) installed at 120 degree intervals so as to rotate intermittently at 120 degree intervals, and the support member T4 is rotated from a horizontal direction to a vertical direction by the power of a motor 75. axis T8 so that
The body frame 12 is supported by a main body frame 12 and configured to reciprocate a predetermined distance by a cylinder or the like along the rail T1, and a bearing 55 is assembled into the groove of the piston 11 in the previous process. A guide rail T1 which engages a feed pawl T6VC and sequentially feeds it to the ground point of the oblique disk 54 by sandwiching the feed pawl T6VC and moving along two paths. However, the piston 11 with the bearing 55 assembled in the groove is sandwiched between the guide rails TT and sequentially fed by the feed pawl T6, and the fed piston 11 is held by the chuck installed on the index table T3. , the pistons 11A, llb, -Ilc are assembled to the oblique disk 54 by rotational steps at 120 degree intervals, and the main body frame T2 is moved back to connect the outer periphery of the oblique disk 54 and the end of the twisted guide rail TT. Remove the engagement and remove the support member T4
is rotated 90 degrees from the horizontal direction to the vertical direction, and when the insertion jig 45 located above is lowered by the action of the cylinder 48, the shaft 56 is inserted into the hole 58 of the main body 56, and each piston is inserted into the hole 58 of the main body 56. Ila, llb, llc are grooves 65a
, 65b, 65c, and when the end surface 59 of the flange portion comes into contact with the lower end, the cylinder 60 is actuated and the piece 61
When the shaft 56 is pushed out and the chuck of the index table T3 is released at the same time, the object is held in the insertion jig 45 at the supply station. Next, cylinder 48
The insertion jig 45 is raised by operating the cylinder 43.
is operated to move the inserting jig 45 from the supply station to the fitting station, where it comes into contact with the stopper T9 formed at the end of the support column 41, positions it with high precision, and stops it. Each cylinder 64a of the insertion jig 45
, 64b, 64c to move the pieces 63a, 63b, 63
c is advanced to form regulation holes 62a, 62b, and 62c to regulate the movement of the upper ends of each piston 11A, Ilb, and Ilc. Next, operate the cylinder 48 to insert the insertion jig 4.
5 is lowered, each piston 11A, Ilb, Ilc is inserted into each hole 2a, 2b, 2c of object 1a while slightly moving via bearing 55 with respect to oblique disk 54, and fitting is completed. Incidentally, there is an error E4 in the pitch P between the holes 2a and 2b of the object 1, between the holes 2b and 2c, and between the holes 2c and 2a. However, the A' positioning condition needs to satisfy the following relationship of the Q (to) formula instead of the formula (4).

B' posture determining conditions and C' insertion conditions are the same as in the case of one axis.

D' However, multi-axis fitting conditions are required. That is, as shown in Fig. γ, it is necessary that the pistons Ila, Ilb, and Ilc enter sufficiently even with respect to the pitch position deviation error E4 of the holes 2a, 2b, and 2c. Therefore, the pitch error E1 of holes 2a, 2b, and 2c is set to 0. If it is kept below IU, both the Q and A° equations will be satisfied, and two or more axes can be fitted.

However, the reason why the guide pin 18 and the guide hole 9 are constricted is that after the hole of the object 1 and the shaft part of the object are fitted together, the object 1 and the shaft part 11 replace the guide hole and the guide pin. This is to guide you. In short, a shaft component 11 having a diameter d, which is a target object, is fitted into a regulating hole 19 having a width w and a diameter D, and the regulating hole 19 is provided so that it can move freely in the regulating hole 19. The shaft component 11 is held by an insertion guide jig 14 and configured to apply an insertion force including its own weight in the vertical direction, which is the axial direction of the regulation hole 19, to the shaft component 11, and the shaft component 11 is inserted. An object 1 having a hole 2 drilled therein is mounted on a table 5 that is positioned with high precision using, for example, a dowel pin hole 4 and a dowel pin 8 and that freely slides in a horizontal plane.
A guide hole 9 or a guide pin 18 formed in the soil,
The guide pin 18 or guide hole 9 formed on the insertion guide jig is inserted into the chamfer formed at the tip of the shaft component 11 and the entrance end of the hole 2 while being guided by the pointed part. The shaft part 11 held by the insertion guide jig 14 between the area with the chamfer 3 and the hole 2 of the object mounted on the table 5 is positioned relative to each other, and in this state it is bitten and protected from anyone other than the pirates. Due to the above-mentioned insertion force applied, the fitting between the shaft part 11 and the hole 2 proceeds smoothly without any biting, and the fitting force is satisfied.

In the above embodiment, the horizontal position, tilt, and other postures of the shaft component are regulated by fitting the shaft component into the regulation hole, but it is not necessary to fit the shaft component into the regulation hole. Even if they are fitted together, the same effects as described above can be achieved, and the invention is not limited to the above embodiments.

As explained above, according to the present invention, the shaft component is held,
In addition, by simply lowering an insertion guide jig equipped with a regulation hole that regulates the posture of the rod-shaped member and applying insertion force, mechanical restraint such as a swash plate type compression crosspiece, which is impossible with conventional tactile fitting methods, can be achieved. This has the effect of being able to continuously perform highly automatic assembly of multiple axes that receive the same amount of damage.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the shaft fitting device of the present invention, Fig. 2 is a central sectional view of Fig. 1, and Fig. 3a shows the positioning conditions of the shaft component and the hole. Figure 3b
is a diagram showing the conditions for determining the posture of the shaft part and the hole, Figure 4A,
b and c are diagrams shown to derive the conditions for engagement between the shaft component and the hole, Figure 5 is a diagram showing the conditions for engagement between the shaft component and the hole, and Figure 6 is an example of an implementation of the multi-axis fitting device. FIG. 7 is a side view of FIG. 6, FIG. 8 is a view taken along the line A-A in FIG. This is a diagram. Explanation of symbols, 1...object, 2...hole,
3... Chamfer, 4... Tsutsuk pin hole, 8
...Knock pin, 9 ... Guide pin hole, 11 ... Shaft part, 12 ... Chick, 14 ... Insertion jig , 18...Guide pin, 19...Regulation hole, 5a...
Platen, 23...Table member, 24...
... Lifting platform, 34... Chain conveyor.

Claims (1)

[Claims] 1. The three pistons are attached via ball bearings to a diagonal disk fixed to the shaft, and their positions are regulated so that each piston can move automatically within a minute tolerance range. The shaft is held in an insertion jig with the axis maintained almost vertically, and three holes into which each of the pistons fits are drilled at predetermined intervals, and a miller with a chamfered entrance is positioned. This platen is engaged with a positioning member and placed on a table member that can be moved in the horizontal direction, and at the fitting position, the insertion jig and the table member are moved relative to each other in a vertical direction. the guide member and the guided member are positioned in the horizontal direction within the range of the chamfers at the entrances of the three holes and the chamfers at the tips of the three shafts, and the guide member and the guided member are inserted while following the chamfers, A fitting method characterized in that the three pistons assembled on the oblique disk are fitted into a cylinder having three holes by applying this insertion force from outside the biting area.