JPH0370762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shape measuring machine that measures the shape of a surface whose shape changes three-dimensionally, such as the body of an automobile, that is, a free-form surface.

Conventionally, when measuring the external shape of the object to be measured or the strain etc. on the designed external shape of the object to be measured,
It is common to use a three-dimensional measuring machine or a contour measuring machine. At this time, when measuring using a three-dimensional measuring machine, a measuring stylus that is movable in the X, Y, and Z axis directions is brought into contact with the surface to be measured, and the X, Y,
The amount of movement in the Z-axis direction is detected and measured, and the scale for detecting the amount of movement of this probe is
Since it can only move in directions parallel to the Y and Z axes, if the surface to be measured is an inclined surface, a computer connected to the coordinate measuring machine is used to perform coordinate transformation. The external shape or distortion is measured based on the coordinates. For this reason, there is a drawback that the device must be large-scale. In addition, when measuring using a contour measuring machine, the stylus (measuring needle) provided at one end of the swingable arm is brought into contact with the surface to be measured, and the arm is moved in the axial direction of the arm. The stylus is moved up and down following the surface to be measured, and the swinging of the arm based on the up and down movement of the stylus is detected and measured. However, in this type of contour measuring machine, the frame that supports the arm is completely fixed. Generally, the measuring machine is provided with a computer or the like that can be tilted only within the swinging plane of the arm, and is not equipped with equipment such as a computer that can perform coordinate transformation like the three-dimensional measuring machine. Therefore, if the surface to be measured of the object to be measured is tilted in the direction of rotation about the axis of the arm with respect to the swinging surface of the arm, measurement cannot be performed as is, and therefore must be tilted and placed perpendicular to the swing plane of the arm. Therefore, if the object to be measured is large, it is impossible to measure the shape using a contour measuring machine.

Under these circumstances, there was a desire to develop a shape measuring machine that does not require large equipment such as a coordinate measuring machine equipped with a computer, and that can measure large objects without tilting them. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a shape measuring machine that has a simple configuration and can measure the shape of a surface to be measured without tilting the object.

The present invention includes a hanging frame rotatably supported by a support member about a first axis such as a vertical direction, and a second axis extending from the hanging frame in a direction different from the first axis such as a horizontal direction. A swinging frame is provided which is rotatable about the axis of the swing frame and supported substantially at the center thereof, and the slider is movable with respect to the swinging frame along the guide member of the swinging frame, and the slider is movable along the guide member of the swinging frame and the direction of movement is the center axis. a first displacement detector for detecting displacement of the slider in the moving direction; and a measuring element is supported on the slider so as to be movable in a direction orthogonal to the slider moving direction. A second displacement detector is provided to detect the displacement of the measuring head in the moving direction, and a fixing means for fixing the slider at an arbitrary position is provided, thereby aligning the axis of the measuring head in the moving direction to a free-form surface. The object of the present invention is to achieve the above object by making it possible to always direct the probe in the normal direction and detecting the displacement of the probe in the slider movement direction and in the probe probe movement direction perpendicular to the slider movement direction.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 and 2, a support member 3 is supported slidably in a direction perpendicular to the plane of the paper in FIG. The support member 3 is movable in the direction of arrow P as the feed screw shaft 4 rotates.

At the center of the support member 3, the support member 3
A support shaft 5 extending in a predetermined direction orthogonal to the moving direction of the first frame, that is, the vertical direction in FIG. It is rotatably supported in the γ direction about a vertical axis, which is the axis of the .
A disc-shaped rotating flange 8 in the γ direction is protruded from the upper part of the suspension frame 7, and above the rotating flange 8, a fixed flange 9 having approximately the same shape as the flange 8 is integrally connected to the support shaft 5. It is installed protrudingly. A lock screw 10 is screwed into this fixing flange 9, and this lock screw 10 is attached to the handle 1.
1, the locking screw 10 is moved forward and backward into contact with or away from the rotating flange 8, and by contacting and tightening the locking screw 10 with the rotating flange 8, the rotating flange 8 and the fixed flange 9, that is, the supporting member 3 are connected. The suspension frame 7 is fixed integrally. Further, the rotating flange 8, the fixed flange 9, the lock screw 10, and the handle 11 constitute a γ-direction fixing means 12.

The lower part of the hanging frame 7 is formed into a bifurcated shape, and at the lower end of the bifurcated shape, a rotating shaft 15 protruding through a bearing 13 to both sides of the substantially central portion of the swing frame 14 is connected to a second bifurcated lower end. It is supported rotatably in the β direction about a horizontal axis, which is an axis. Among the rotating shafts 15 on both sides, the outer end of the rotating shaft 15 on the right side in FIG.
A worm wheel 16 is integrally fixed to this protrusion (see FIG. 2). A worm 17 is meshed with this worm wheel 16, and these worm wheels 16
A cover 18 is provided to cover the worm 17. This cover 18 is fixed to a bearing box 19 fixed to the suspension frame 7, and a shaft portion extends through the cover 18 and projects from one end of the worm 17.
A round handle 20 for rotating the worm is fixed to. This round handle 20, the worm 17, and the worm wheel 16 constitute a β-direction rotation angle fine adjustment mechanism 21 of the swing frame 14.

The swing frame 14 is rotatably supported in the β direction by the action of the rotation shaft 15, and is formed in the shape of a rectangular frame that is open in the vertical direction in FIG. , the X-axis direction). This swing frame 1
A pair of arcuate guides 22 are disposed on one side in the longitudinal direction of 4, that is, on the front side in FIG. Fixed. These arcuate guides 22, as shown in FIG.
These arcuate guides 2 are formed into a hollow box shape in cross section.
One movable piece 23 is slidably arranged in each of the pieces 2 . In addition, these arcuate guides 2
The tips of β-direction fixing brackets 24 protruding from both sides of the suspension frame 7 are slidably contacted on the outer surface of the frame 2, and a handle having a locking screw 25 at one end is attached to the tips of these fixing brackets 24. 26 is rotatably attached. The lock screw 25 of this handle 26 is connected to the arcuate guide 22.
It is inserted into the arcuate guide 22 through a groove 27 provided in an arcuate shape in the center of the outer surface of the slider, and is screwed onto the movable piece 23 . As a result, by operating the handle 26 and loosening the threaded engagement between the lock screw 25 and the movable piece 23 in the direction in which the movable piece 23 separates from the inner wall of the arcuate guide 22, the fixed bracket 24 and the arcuate guide 22, that is, the swing frame 14 are loosened. On the other hand, by operating the handle 26 in the opposite direction and tightening the lock screw 25, the fixed bracket 24 and the arcuate guide 22, that is, the swing frame 14 can be fixed. Here, the arc-shaped guide 22, the movable piece 23, the β-direction fixing bracket 24, and the handle 26 having the lock screw 25 constitute a β-direction fixing means 28.

A guide shaft 29 as a guide member extending in the X-axis direction is disposed at the center of the swing frame 14, and both ends of the guide shaft 29 extend in the α direction about the X-axis via bearings 30, respectively. It is rotatably supported. Both ends of the guide shaft 29 protrude from the swing frame 14, respectively.
A side plate 31 is fixed to each of the protrusions at both ends with a nut 32 so as to rotate together with the guide shaft 29. The upper ends of these side plates 31 extend beyond the upper edge of the swing frame 14,
A chain cover 33 is provided between these upper end portions, and a chain 34 as an endless band is disposed within this chain cover 33. This chain 3
One side of the motor 4, the right end in FIG.
The other side, the left end in FIG. 1, is wound around a driven sprocket 38 fixed to the left side plate 31. Here, the chain 34, motor 35, reduction gear 36, sprocket 37, and driven sprocket 38 constitute a slider moving mechanism 39.

One end of the guide shaft 29, the right end in FIG. 1, protrudes from the right side plate 31, and a worm wheel 40 is integrally fixed to this protrusion. A worm 41 is engaged with the worm wheel 40, and a cover 42 is provided to cover the worm wheel 40 and the worm 41. This cover 42 is fixed to the right side plate 31 via a support bracket 43, and a shaft portion at one end of the worm 41 projects through this cover 42, and this projecting shaft portion (not shown)
A round handle 44 for rotating the worm is fixed to. This round handle 44, the worm 41, and the worm wheel 40 constitute a fine adjustment mechanism 45 for the α-direction rotation angle of the guide shaft 29.

A lock screw 46 as an α-direction fixing means is screwed into the right side plate 31 by passing through the side plate 31, and by tightening the lock screw 46, the tip of the lock screw 46 is fixed to the right side surface of the swing frame 14. The side plate 31, that is, the guide shaft 29 can be fixed to the swing frame 14 by strongly abutting the guide shaft 29 against the swing frame 14.

A slider 47 is attached to the guide shaft 29.
A clamp 48 is integrally provided at the upper end of the slider 47, and the clamp 48 is removably engaged with the chain 34. As a result, when the chain 34 is rotated by the forward/reverse motor 35 while the clamp 48 is engaged with the chain 34, the slider 47 can be moved in the X-axis direction along the guide shaft 29 via the clamp 48. has been done. At this time, the structure of the clamp 48 is as follows:
A device that holds the chain 34 at any position like a clothespin, or a large number of dogs (not shown) provided at relatively short predetermined intervals on the chain 34, with holes and pins, etc., for easy engagement and detachment. There are various possible configurations that can be used.

A scale 49 having an optical, magnetic, or electromagnetic scale is provided along the axial direction on one side of the guide shaft 29, and a reading mechanism 50 is provided to read the amount of movement of the slider 47 with respect to the scale 49. A first displacement detector 51 is provided within the slider 47, and the scale 49 and reading mechanism 50 constitute a first displacement detector 51.

A second displacement detector 5 having substantially the same configuration as the first displacement detector 51 is provided on the lower surface of the slider 47.
A measuring element 54 is supported at the center of the second displacement detector 52 via a Z measuring shaft 53 so as to be movable in the Z-axis direction perpendicular to the X-axis direction. The probe 54 has a hemispherical tip and is removably attached to the Z measurement shaft 53 by screwing or the like, and the movement of the probe 54 in the axial direction, that is, the Z measurement shaft 5
3 is detected by the second displacement detector 52. Furthermore, the Z measurement axis 53 is supported by the second displacement detector 52, for example.
This is achieved by using a plurality of sets of three radial bearings arranged at equal positions of 120 degrees, so that the Z measurement axis 53 can be moved with a very small force.

Note that reference numeral 55 in the figure represents a cover that covers the left and right side plates 31, respectively.

Next, how to use this embodiment will be explained with reference to FIGS. 4 to 6.

In FIG. 4, the round handle 44 of the α-direction rotation angle fine adjustment mechanism 45 is rotated with the lock screw 46 as the α-direction fixing means loosened, and the measurement point on the measurement surface 61 of the workpiece 60 is adjusted. The guide shaft is moved through the worm 41 and the worm wheel 40 so that the center line of the Z measuring shaft 53 is perpendicular to the tangent _T1 , that is, so that the tip of the measuring stylus 54 contacts the surface to be measured 61 from the normal direction. Rotate 29 by α ₁ degree. This allows the Z measurement axis 5 to be adjusted via the slider 47.
3 becomes perpendicular to the tangent line T ₁ , the lock screw 46 serving as the α direction fixing means is tightened to fix the center line position of the Z measuring shaft 53 with respect to the swing frame 14 .

Next, as shown in FIG. 5, with the lock screw 25 of the β-direction fixing means 28 loosened by the handle 26, the β-direction rotation angle fine adjustment mechanism 21 is rotated.
Rotate the round handle 20 to align the worm 17 so that the center line of the Z measurement axis 53 is perpendicular to the average tangential direction on the surface 61 of the object 60 to be measured.
Then, the swing frame 14 is rotated by β ₁ degree around the rotation axis 15 via the worm wheel 16, and Z
When the center line of the measurement axis 53 reaches a predetermined angle, β
The lock screw 25 serving as a direction fixing means is tightened to fix the position of the swing frame 14 with respect to the hanging frame 7, and thus the center line position of the Z measurement axis 53.

Furthermore, as shown in FIG. 6, with the lock screw 10 of the γ-direction fixing means 12 loosened, the hanging frame 7 is rotated in the γ-direction in the horizontal plane about the vertical line, and the swinging frame 14, that is, the guide The center axis of the shaft 29 is set in the measurement direction inclined by γ1 _degree with respect to the initial position, and in this state, the lock screw 10 of the γ direction fixing means 12 is tightened to fix the suspension frame 7 to the support shaft 5.

In this way, the tip of the probe 54 is set to be substantially normal to the surface 61 to be measured of the object to be measured 60, and the direction of movement thereof is set, and each of the fixing means 12, 28, When the position, that is, the attitude of the slider 47 is maintained by the slider 46, the forward/reverse motor 35 as a drive source is driven in a predetermined direction, and the action of the chain 34 and the clamp 48, which rotate accordingly, as well as the guide shaft. 29, the slider 47 is moved in a predetermined direction. Therefore, the measuring stylus 54 is supported by the slider 47 via the second displacement detector 52 so as to be movable in the Z-axis direction, and is always urged in the projecting direction by a spring (not shown). The second displacement detector 52 detects the amount of movement in the Z-axis direction.
is detected and input to a recording means (not shown) or the like. Further, the movement of the guide shaft 29 of the slider 47 in the axial direction (X-axis direction) is detected by the first displacement detector 51.
The data detected and input to the recording means from the first and second displacement detectors 51 and 52 is recorded, for example, on an X-Y plotter as a digital quantity, or as a digital The quantity is converted into an analog quantity and recorded as a shape on an X-Y recorder. This causes the slider 47
The shape of the surface to be measured 61 in the same direction as the moving direction can be measured, and the shape can be compared with the designed shape.

Note that the entire apparatus is moved a predetermined distance in the direction of arrow P by moving the support member 3 as necessary, and the measurement at that position is performed in the same manner as described above.

According to the present embodiment as described above, the measuring tip 54 having a hemispherical tip is used, and the direction of contact of the measuring tip 54 with the surface to be measured 61 can be made almost in the normal direction. It is not necessary to perform coordinate transformation using large-scale equipment such as
The shape of the object to be measured 60 can be easily measured without any movement on the zero side, and is particularly suitable for measuring surface distortion of automobile exterior parts and the like. In addition, the parts below the hanging frame 7 are centered around the support shaft 5 as a whole.
The swing frame 14 can be rotated in the β direction with respect to the hanging frame 7, and the guide shaft 29 can be rotated in the α direction with respect to the swing frame 14. The axial direction, that is, the measurement direction can be freely set.
Therefore, it is possible to continuously and easily measure the surface shape of a continuous surface to be measured 61 of an automobile exterior part or the like by simply setting the guide shaft 29 parallel to the surface to be measured 61 and moving the slider 47. I can do it. At this time, the slider 47 is moved by the first displacement detector 51.
The amount of movement in the direction along the guide shaft 29 can be detected,
Since the second displacement detector 52 can detect the amount of movement of the probe 54 in the axial direction, the surface shape of the surface to be measured 61 can be directly detected from the detected values of each detector 51 and 52, and the detected value can be There is no need to perform processing such as coordinate transformation, and the surface shape of the surface to be measured 61 can be easily measured. Furthermore, since the mechanism of each part including the fixing means 12, 28, 46 is simple, it can be provided at low cost. In addition, the measuring head 54
Since the Z measuring shaft 53 to which the measuring element 54 is attached is always urged in the protruding direction by the action of the second displacement detector 52, the measuring stylus 54 can be reliably brought into contact with the surface to be measured 61. Further, since fine adjustment means such as the β direction rotation angle fine adjustment mechanism 21 and the α direction rotation angle fine adjustment mechanism 45 are provided, the rotation angle of the swing frame 14 in the β direction and the guide shaft 2 can be adjusted.
9, the rotation angle of the slider 47 in the α direction can be adjusted minutely and easily. Further, since the slider 47 is engaged with the chain 34 of the slider moving means 39 via a removable clamp 48, the slider 47 can be quickly moved manually to any position when the clamp 48 is released. This allows for more efficient measurement work. Furthermore, since the swinging frame 14 is supported by the suspension frame 7 at its substantially central portion, and the weight of the swinging frame 14 is well balanced, the suspension frame 7 is not deflected without being subjected to uneven loads. etc., and the measurement accuracy can be improved.

In the above embodiment, the slider moving means 39 has a structure using the motor 35 and the chain 34, but is not limited to this, and may have a structure using a feed screw shaft and a feed nut, or a fluid pressure cylinder. The configuration used may also be used. Further, the α, β, and γ direction fixing means 12, 28, and 46 are not limited to the configurations of the embodiments described above, but may be other fixing means such as a disc brake type, a belt brake type, or an electromagnetic brake type. Furthermore, first and second displacement detectors 51 and 52
The structure is not limited to the structure using the scale 49 or the like, and other displacement detectors such as a laser length measuring device may be used. Further, in the embodiment described above, the first axis, which is the rotation center of the support shaft 5, that is, the rotation center of the suspension frame 7, was explained as being vertical, but the present invention is not limited to this, and the support shaft 5, that is, the first axis which is the rotation center of the hanging frame 7 may point in another direction such as diagonally. Further, in the above embodiment, the rotation angles of the hanging frame 7, the swinging frame 14, and the slider 47 in the γ, β, and α directions are set once in advance and fixed by the respective fixing means 12, 28, and 46 for measurement. However, the γ direction fixing means 12 and the β direction and α direction rotation angle fine adjustment mechanisms 21, 4
The round handles 20 and 44 of 5 are drive means using step motors, etc., and these drive means are driven according to a program based on the designed shape of the surface to be measured 61, so that the tip of the probe 54 is always aligned with the surface to be measured 61. It is also possible to make it contact from the normal direction.

As described above, the present invention has the effect of providing a shape measuring machine that can perform more accurate measurements with a simple configuration.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the shape measuring machine according to the present invention, Fig. 2 is a partially cutaway left side view of Fig. 1, and Fig. 3 is a partially cutaway left side view of Fig. 1. −
4 is a right side view showing the state of use, FIG. 5 is a front view, and FIG. 6 is a plan view. DESCRIPTION OF SYMBOLS 1... Foundation member, 3... Supporting member, 7... Suspension frame, 12... γ direction fixing means, 14... Swinging frame, 21... β direction rotation angle fine adjustment mechanism, 28... β direction Fixing means, 29...Guide shaft as a guide member, 34...Chain as an endless band, 39...Slider moving means, 45...α direction rotation angle fine adjustment mechanism, 46...Lock as α direction fixing means Screw, 47...Slider, 48...
Clamp, 51...First displacement detector, 52...
Second displacement detector, 54... Measuring head, 60... Measured object, 61... Measured surface.

Claims (1)

[Scope of Claims] 1. A hanging frame rotatably supported by a support member around a first axis, and a hanging frame rotatable around a second axis in a direction different from the first axis. A swinging frame is rotatably supported at approximately the center, and the swinging frame is movable in a predetermined direction along a guide member provided on the swinging frame, and the swinging frame is rotatably pivoted about this moving direction as a central axis. a slider supported by a moving frame; a first displacement detector for detecting displacement of the slider in the predetermined direction; 1. A shape measuring machine comprising: a measuring element; a second displacement detector for detecting displacement of the measuring element; and fixing means for holding the slider in an arbitrary position. 2. The shape measuring machine according to claim 1, wherein the measuring element is attached to a slider in a state where it is always biased in a protruding direction. 3. The shape measuring machine according to claim 1 or 2, wherein the support member is movable in a direction perpendicular to the rotation axis of the hanging frame. 4. A shape measuring machine according to any one of claims 1 to 3, characterized in that a fine adjustment means for finely adjusting the amount of rotation of the slider is provided. 5. In any one of claims 1 to 4, the slider is moved via an endless band driven by a motor, and the slider and the endless band are attached via a detachable clamp. A shape measuring machine characterized by: