JPH05501005A - Determining spatial relationships - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] l17, of (Field of invention) The present invention relates to a device for determining the spatial relationship between two relatively movable parts. , in detail, the coordinate measuring or coordinate manufacturing equipment and the coordinate measuring or coordinate manufacturing equipment. Regarding the relationship between the installation and the workpiece. This coordinate measuring or coordinate manufacturing device can be used for any number of Any coordinate system with axes can be used, and the coordinate system can be a rectangular coordinate system, a cylindrical polar coordinate system , spherical polar coordinate system, etc.

(Explanation of prior art) The manufacturing acid of the workpiece must be measured and evaluated for its quality or fitness for purpose. Place the crop in relation to the equipment or the equipment in relation to the workpiece in different linear or angular positions. It is often necessary to orient1 Usually measurements of the workpiece at different positions are created or all dimensions and shapes to be measured are globally related to a common coordinate system for the workpiece. should be related exactly as such.

For example, when measuring the characteristics of a workpiece in three dimensions, it is necessary to Access to a surface or to a machine tool axis at various angles is often required. Conventional This is achieved using a rotary table with a longitudinal axis to carry the workpiece. has been completed. For accuracy, to align the machine tool axis with the rotary table extremely precisely. or alternatively, calibrate the misalignment of the rotary table to be used at all angles of rotation. In order to do this, it is necessary to use an accurate and therefore expensive rotary table. usually Due to the presence of Corning errors in rotary tables, it is recommended to use a composite calibration method. It is preferable to This eliminates the need for excessive precision in the rotary table. However, the requirement for extremely good reproducibility remains, which is Tables are still expensive.

If the workpiece is very large, the required angular accuracy and/or repeatability of the rotary table may be degree is particularly difficult to achieve. Because the angle for a given linear accuracy This is because the above accuracy should become better in proportion to the increase in radius. very large For large workpieces, the cost of the rotary table is also very high indeed.

(Summary of the invention) According to the invention, determining the spatial relationship between two relatively movable first and second objects; An apparatus for making at least a first object a plurality of objects with respect to a second object. a moving means for moving to a selected one of the positions; The positioning includes means for effectively providing a six-point motion position to the first object. .

Preferably, the first object is provided with a plurality of positioning means for providing said plurality of positions. and said second object is positioned between said second objects for selectively engaging each one of said means. A spaced-apart (3 V-array configuration) that provides 6-point movement at selected positions. Provide location.

The means for positioning the first object may include a plurality of spherical members. arranged in a V-shape Each of the second bodies is connected at one end to the second body and at the other end to each said sphere. The legs may further include a pair of legs having bearing surfaces for engaging the shaped member. , each equipped with means to enable it to function as a single point in motion. Ru. Such means may include bi-directional hinges on the legs.

Each spherical member is formed of carbide and is connected to said first member by, for example, an expansion bolt. can be effectively fixed in a three-sided hole in the body, and the spherical member can be hydraulically pressed into the recess .

Alternatively, the first object is provided with a plurality of positioning means defining respective positions; Further, six positioning means may be provided at intervals on the second object. this position The six positioning means are selectively engageable with each one of the means. provides a six-point motion position at each position.

Each positioning means is coupled at one end to the second object and has a spherical portion at the other end. each positioning means of the first object includes a leg having a 3. Presenting two contact surfaces, each leg is designed to ensure that it functions as a single point of movement Means are provided. This means may be in the form of a bidirectional hinge. The above three The contact surface is provided with a flat surface that comes into contact with the three incorporated spheres or the spherical parts of the engaging legs. get.

According to the present invention, a pair of devices as described above are included, and a first object is attached to each device. A common assembly is also provided. As a result, the first object becomes more complex. The 6-point motion position with respect to the second object at each position of the number is also six-point motion positions of said second object with respect to the objects of are effectively provided, respectively.

(Brief explanation of the drawing) FIG. 1 is a schematic perspective view of a coordinate measuring machine equipped with a rotary table and a workpiece.

Figure 2 is an enlarged oblique view of one specific example of a rotary table for use in the coordinate measuring machine shown in Figure 1. This is a perspective view.

FIG. 3 is a schematic diagram of another embodiment of the rotary table.

FIG. 4 is a schematic diagram showing a part of another embodiment of the rotary table.

FIG. 5 is a schematic diagram showing a part of another embodiment of the rotary table.

FIG. 6 is an exemplary diagram of a differential rotary table.

Figure 7 shows the mechanism for raising the rotary table. FIG.

FIG. 8 is a longitudinal cross-sectional view of the mechanism shown in FIG. 7.

Figure 9a is a schematic representation of various movement positions.

Figure 9b is a schematic diagram of various movement positions.

Figure 9c is a schematic illustration of various movement positions.

Figure 9d is a schematic illustration of various movement positions.

(Explanation of Examples) Referring to the drawings, FIG. 1 shows a coordinate measuring machine having a pedestal 10. The seat is provided with a linear guideway 12 that supports a longitudinal support 14. longitudinal strut 14 has a support structure 16 mounted thereon for longitudinal movement; The structure 16 includes a horizontally movable tile 1 having a measuring probe 20 at one end thereof. A rotating table 22 is further attached to the 0 pedestal 10 on which the 8 is attached. A workpiece 24 to be measured can be supported on the table. This coordinate measuring machine is It has a street design shape.

To enable accurate determination of the spatial relationship between the workpiece 24 and the measuring probe 20 In this specific example, suitably, the workpiece 24 has a reproducible and accurate preset shape each time it is rotated. be moved to a position of knowledge. The principle of 6-point movement position at each position or station is the best used to obtain reproducibility.

In one embodiment, as shown in FIG. 2, the rotary table 22 is fixed relative to the base 10. a lower platen 26 arranged so as to be rotatable with respect to the lower platen 26; and an upper platen 28. A sphere 3o of the lower platen 26 is provided. It will be done. Each sphere 30 is preferably formed from carbide and extends from a circle on lower platen 26. Set in a conical recess. This conical recess is made by machining or hydraulic press. A hole consisting of a surface is effectively formed in the sphere 30, and a hole is formed in the sphere 30 for fixing the sphere 30. A hole is formed by electrical discharge corrosion to allow the expansion bolt to penetrate there. The body 30 is pressed into its seat by hydraulic means or otherwise, thereby creating a significant negative impact. A finite contact area is provided that can carry loads and reduce Hertzian distortion. next door Each mating pair of spheres effectively provides a V-shaped portion. On the lower surface of the upper platen 28 , three cylindrical members 32 whose axes extend in the radial direction are spaced apart by 120 degrees. It is formed by

When the upper platen 28 is placed on the lower platen 26, the cylindrical member 32 is inserted into the spherical body 3. 0 to engage each V-shaped portion defined by 0. In this way, the rotary table 22 of the angular position of the upper platen 28 at each V defined by the sphere 30. It can be accurately reproduced using the cylindrical member 32 seated on the character-shaped portion. This arrangement The required 6-point motion position at each angular position of the upper platen 28 is determined by provided.

The movement position should be removed and re-engaged at the new position or station.

The direction of movement is basically selected from two directions: horizontal and vertical. move When the mass to be moved is large, horizontal movement on an air support is possible because the required power is small. It is beneficial to let them do so. Certain problems associated with this design shape are that the mass is relatively This can be solved by a longitudinal movement which does not pose difficulties due to its small size.

Raising the upper platen is most easily done with compressed air. The aim is to ensure that the tensile strength is kept level even on extremely unbalanced workpieces.

This includes a central air cylinder 34 (see Figures 7 and 8) and a This can be achieved by using three pivot arms 36. Said pivot Arm 36 directs the movement of the piston upwardly through a hollow triangular plate 38. 28 to the lower peripheral area. Each pivot arm 36 is an over-center type lever. It has the form of a bar mechanism, and this over-center lever mechanism A lever arm 42 is pivotably mounted on the lower platen 26 and One end of the bar arm 42 operatively engages the rod 44 of the piston and the other end of the bar arm 42 operably engages the rod 44 of the piston. It is connected to one arm of the lever 46. The crank lever 46 is It is attached to the Latin 26 so that it can pivot freely, and the other arm is a hollow triangular shape. The lower shaped plates 38 each engage the lower surface of the upper platen 28 . This o The bar center type bar uniform structure is used in case of insufficient pressure during indexing operation. The upper platen 28 is also reliably maintained in the raised position. Ascend, index and descend The sequence of controlled.

A central air cylinder 34 reverses and lowers an over-center lever mechanism. It performs a double operation for this purpose.

A friction roll drive body for providing rotational driving force to the rotary table is attached to the upper platen 28. The surroundings are set up. This friction roll driver connects the motor 50 to a hollow triangular plate. With the hollow triangular plate 38 supported by the rotor at one side end, can be used as a driving roll.

The 6-point motion position has problems with pushing in with large forces and Hertzian distortion, and with large Based on the difficulty in ensuring 6-point engagement due to frictional forces (which can cause certain problems) Ru.

Furthermore, large stresses and frictional forces can cause wear and tear on the surface of the moving position, which can lead to long-term damage. Preventing reproducibility across tasks can be a problem. A special gathering as shown in Figure 3. The rotary table 22 of this type can prevent or alleviate such problems. .

In this embodiment, the tubular member shown in FIG. 2 is replaced by each pair of elongated members or legs 52. It has been replaced. Each leg is secured at one end to the upper platen 28 by a resilient hinge 54. determined. Each pair of legs 52 has longitudinal axes angled in relative directions and The other end of each leg 52 includes a spherically convex bearing surface 56 such that each pair of legs 52 Preferably, zero elastic hinges 54 engage a spherical convex bearing surface 56 of each one of the spheres 30. is a bidirectional hinge and can act as a V-shaped moving part by using a spherical convex bearing surface 56. This provides the required 6-point motion position at each angular position. two-way hint with orthogonally arranged unidirectional hinges or with orthogonally arranged unidirectional hinges or with orthogonally arranged unidirectional hinges or with orthogonally arranged unidirectional hinges. It should be appreciated that two cylindrical bearings could be substituted.

In yet another embodiment (FIG. 4), the angular position of each of the lower platens 26 is defined by three spheres 58 of the equation, while six independent legs 52 are spaced apart. and is connected to the upper platen 28. A sphere 60 is provided at the free end of each leg 52. It will be done. This sphere is located at the center of three spaced spheres 58 and The elastic hinge of each leg 52 maintains axial rigidity while the zero leg 52 makes three-point contact with the 54 can be moved slightly in the lateral direction, which allows simultaneous seating at all d-point movement positions. thus allowing three-point contact at each movement position to function as a single point. each The three spheres 58 in the moving position can be replaced by flat surfaces in contact with the surface of the spheres 60. I want to be recognized. Reverse this array configuration, incorporate the three spheres into the legs, and create a single A sphere is placed on the lower platen.

In yet another embodiment (FIG. 5), each leg 52 has a bore opening toward the free end of the leg 52. A hole 62 is formed to define an annular portion in which the sphere 30 can be positioned. It is. Perforation 62 may be connected to a conduit for delivering compressed air thereto.

An air pressure gauge or switch 66 is coupled to the compressed air line as a stop valve 68. be done.

When the leg 52 is seated on the sphere 30 while releasing compressed air into the perforation 62, the air pressure increases. It is displayed on the pressure gauge 66. The stop valve 68 is activated due to improper seating of the leg 52 on the sphere 30. After receiving the compressed air, check the source of the compressed air to monitor for air pressure drops due to leaks. be isolated. This determines whether any or all motion positions are correctly positioned. Provides array configuration to know. However, microswitches, proximity sensors – or recognized that other forms of monitoring such as capacitive transducers could be used. stomach.

0 cases where the 6-point motion position of the first object on the second object is available by other methods For example, a first object has multiple spheres, and a second object has a plurality of spheres positioned between each pair of spheres. The figure 7 member has a flattened side or a matching curved shape. Get the parts installed. A figure 7 recess is formed in the first object, and a plurality of spheres are formed in the second object. , thereby allowing each sphere to be positioned at different angular positions within the figure 7 recess.

Guarantees contact at all points, and also ensures that the initial contact points are not affected by friction. The legs 52 may be used to eliminate frictional forces, but alternatively the six point movement position are held at microscopic separation on a gas or hydraulic support, and the gas or flow A six-point motion position can be achieved by simultaneously reducing body pressure. . This method can be applied to a leg with several positioning points and using gas or hydraulic bearings; Positioning using the geoma can be combined with points.

Preferably, the point locations are spaced 5 degrees apart on the rotary table; alternatively, Two rotary tables 70, 72, one above the other or between two annular rings. As shown in Figure 6, one can be placed inside the other. In the latter case, the outer ring has 1 Set and obtain point positions at 0 degree intervals. In that case, the distance between the points on the inner ring is 9 degrees. The relative rotation of a certain 0-rotary table 70.72 is useful in making the division more fine. For example, by moving 10 degrees forward and 9 degrees in the opposite direction. The net forward movement is 1 degree, and by repeating this 360 times, 1 degree of interpal is obtained. You can get it. Rotary table with irregular intervals tailored to specific applications It is possible to design

Surface cleanliness is important for positioning, and during the indexing cycle the upper platen 28 is A piston that causes air flow into and out of an enclosed central volume. It is difficult to seal connections where the incoming air introduces dust particles; The easiest way to do this is to move clean air into the central volume by raising the platen upwards. It is to inject.

Other features included in this device include clamping the upper platen in the motion position. spring load to hold until applied, or otherwise of the movable surface. may include use. This allows you to move the upper platen from one station to the other. This prevents damage to the surface of the moving position when moving it to the station. Furthermore, Exercise value! Means shall be provided for covering the surface with a movable cover. The movable cover is a matter of luck. It can be automatically removed or retracted to keep moving surfaces clean. Movement position table As an alternative to injecting clean air to keep surfaces clean, rotating acid can be Reese sprays or any combination thereof can be installed. As yet another aspect , provide a means to pressure wash the enclosed mechanism with clean compressed air at low pressure; It is possible to reliably generate an outward flow to prevent dust from entering. Also, each stage 1 e.g. pneumatic or hydraulic cylinder for clamping the upper platen at the or apply an actuator, spring, magnetic force, screw, gravity or actual force Other means may be provided.

The upper platen is configured to prevent rotation about its approximate center when disengaged from the motion position. This should be achieved without affecting re-engagement to the motion position. need to be completed. For example, if there is sufficient clearance so that the upper platen can It is possible to use an external roll that falls into the gap. Furthermore, from a certain station Correct indexing before lowering the upper platen during a change to another station. The angle should be roughly detected. This is fixed to the pedestal and attached to the upper platen protrusion. This can be achieved by a proximity switch engaged with the trigger. This proximity switch The rotation of the balance in the raised position should be detected while it is free to rotate and lower. be. In addition, to identify which stations are in use, Available with a series of proximity switch arrays to detect when a dynamic position is engaged It is. Such proximity switches are preferably fixed to a pedestal to simplify wiring. It will be done.

As a further improvement, the device is designed to and means for calibrating the position with respect to the station. Calibration is currently pending carried out by an apparatus as described in British Patent Application No. GB8923948.7. be done.

The invention is not limited to rotary tables (but any combination of linear and angular deviations). It should be understood that this can be applied to combinations of around the static coordinate measuring device or by moving the working volume of the device into the entire air frame. Station the transfer equipment around the air frame so that it can be brought closer to the surface area. can be moved from station to station.

With respect to the movement position, the position of the movement is as follows, as schematically illustrated in FIGS. Two layouts exist in principle for six-point contact. That is, 3-point array, 2-point array Arrangement and 1 and 2 points on each side (Figure 9a), 2 points each on 3 sides (Figure 9b), 3 V-shaped recess (Fig. 9c) and each arrangement of three-sided holes, slots and single points (Fig. 9d) It is.

Various other modifications may be made without departing from the invention.

international search report 1M1llIIIllllllTjl^6”””””PCT/W90/n1g+7 -ysas1Aem+a+m*NIL PCT/Gl’! 90/n 1G 1 7 International Search Report GB 9001617 SA　41128

Claims (15)

[Claims] 1. An apparatus for determining a spatial relationship between two relatively movable first and second objects. positioning the at least one first object at a plurality of selected positions with respect to the second object; means for moving said first position at each of a plurality of positions; and means for effectively providing a six-point motion position to the object. A device for determining the spatial relationship between two objects. 2. the first object is provided with a plurality of positioning means providing a plurality of positions; The body has a plurality of spaced apart portions for selectively engaging each one of said locating means. Both have three V-array configurations that provide six-point motion positioning at selected locations. for determining the spatial relationship between two relatively movable objects according to claim 1. equipment. 3. Claims wherein the means for positioning the first object is provided by a plurality of spherical members Apparatus for determining a spatial relationship between two relatively movable objects according to claim 2. 4. Each V-array configuration of the second object is coupled at one end to the second object and at the other end to each V-shaped arrangement. including a pair of legs having bearing surfaces for engaging the spherical member, each leg having a bearing surface for engaging the spherical member; Claims that provide means for functioning as a single point on the system To determine the spatial relationship between two relatively movable objects as described in Section 2 or 3 equipment. 5. The means to enable each leg to function as a single joint is to A spatial relationship between two relatively movable objects according to claim 4 including a directional hinge. A device for determining who is involved. 6. Each spherical member is formed from carbide and is operatively fixed to a trilateral surface of the first object. The spatial relationship between two relatively movable objects according to claim 4 or 5 A device for making judgments. 7. A relative according to claim 6, wherein each spherical member is fixed by an expansion bolt. device for determining the spatial relationship between two movable objects. 8. The relative according to claim 6, wherein the spherical member is pressed into the recess by hydraulic pressure. A device for determining the spatial relationship between two movable objects. 9. a first object providing a plurality of positioning means defining respective positions; has six spaced apart positions that can be selectively engaged with each one of the six positioning means. Claim no. Apparatus for determining the spatial relationship between two relatively movable objects according to claim 1. 10. The positioning means each have one end coupled to the second object and a spherical portion at the other end. each of the first object positioning means engages the spherical portion; Each leg presents three contact surfaces to ensure it functions as a single point of interlocking of two relatively movable objects according to claim 9, wherein means are provided for A device for determining spatial relationships. 11. The means to ensure that each leg functions as a single point of motion is The space of two relatively movable objects according to claim 10, which has the form of a wedge. device for determining physical relationships. 12. The three contact surfaces for engaging the spherical portion of the first object include three built-in Two relatively movable parts according to claim 10 or 11, provided by a sphere. device for determining the spatial relationships of objects. 13. The three contact surfaces for engaging the spherical portion of the first object are the spherical portions of the engaging legs. Claim 10 or 1 provided by a flat surface arranged in contact with the part. Apparatus for determining the spatial relationship between two relatively movable objects according to claim 1. 14. An assembly comprising a pair of devices according to any one of the preceding claims, comprising: , the first object is common to each device, so that at each of a plurality of positions of the first object effectively provides a six-point motion position with respect to the second object, and a second object at each of the plurality of positions said assembly in which a six-point motion position of a second object with respect to three objects is effectively provided; -. 15. A device for determining a spatial relationship between two relatively movable objects, the device comprising: Said apparatus as herein described with reference to the accompanying drawings.