JPH0339609B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coordinate measuring machine, and particularly to a coordinate measuring machine in which probes are replaced, and can be used to reduce the number of probes used and speed up measurement work. It is something.

[Background technology and its problems]

The object to be measured placed on the stage and the probe supported by the measuring machine body are moved relative to each other in a three-dimensional direction, and the amount of relative movement displacement between the measurement surface of the object to be measured and the contact point of the probe is detected, Three-dimensional measuring machines that process this detected displacement amount in a predetermined manner using a data processing device to measure the dimensions of the object to be measured are well-known, and are widely used because they can quickly and accurately measure the dimensions and shapes of objects with complex shapes. has been done.

By the way, this measuring machine has two types: a type in which the relative movement between the object to be measured and the probe is manually performed;
There is a type that does this automatically by driving a motor, etc. In the case of the automatic type, in order to speed up the measurement work and make it unmanned, it is necessary to automatically attach a probe with a measuring point that corresponds to the shape of the measuring point of the object to be measured. must be replaced. Conventional general coordinate measuring machines that can automatically exchange probes have multiple probes attached to the measuring machine body, or in the case of many coordinate measuring machines, to the tip of a spindle that moves the probes in the vertical direction. However, in this state, the probe was selected according to the measurement location.

Therefore, conventional three-dimensional measuring machines have the following problems, which have hindered the rapid spread and expansion of automatic three-dimensional measuring machines.

When multiple probes are attached to the measuring device,
Since the load is large, the structure of the entire measuring machine must be strong.

Changing the measuring point of another probe must be done during the measurement process, that is, after the object to be measured has been set, and this is especially necessary every time the measurement point changes, which lengthens the measurement work. , the advantages of automatic three-dimensional measuring machines are reduced.

Depending on the drive source for changing the orientation of the probe, there may be problems such as thermal deformation, rust, etc. in the measuring device.

In particular, when measuring holes of the same shape with different diameters, such as when measuring the roundness of a hole, the above problem arises because each time the diameter changes, a probe with a corresponding measuring point must be provided. However, since the number of probes that can be attached is limited, the objects that can be measured are also limited, and the usable range of the three-dimensional measuring machine is limited.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to enable adjustment of the position of the probe according to the diameter of the hole to be measured, thereby enabling measurement with one probe. A three-dimensional measuring machine that can expand the range of hole diameters, reduce the number of probes, and change the position of the probe during the measurement process to shorten measurement work time. It's there to provide.

[Means and actions for solving problems]

For this reason, the present invention provides a position change mechanism for changing the position of the measuring point on the probe side, and provides a drive means for operating this position change mechanism on the probe stocker, so that the measuring device can change the position for the next measurement process while the measuring device is in measurement operation. The measuring element is changed and adjusted to a position corresponding to the next measurement process.

Specifically, the object to be measured placed on the stage and the probe supported by the main body of the measuring machine are moved relative to each other in three dimensions, and the measurement surface of the object to be measured and the contact point of the probe are moved relative to each other in three dimensions. In a three-dimensional measuring machine that detects a relative displacement amount and processes the detected displacement amount in a predetermined manner with a data processing device to measure dimensions of the object to be measured, a probe is provided on the object table and supports the probe. a stocker; a rotating means provided on at least one of the measuring machine body and the stage to rotate the probe and the object to be measured relative to each other; and a rotating means for rotating the probe and the measuring object relative to each other; a position changing mechanism that changes the position of the probe by moving it in a direction to move the probe; and a driving means that is attached to the probe stocker and connected to the probe position changing mechanism supported by the stocker to operate the position changing mechanism. and a probe attachment/detachment device for attaching the probe supported by the probe stocker to the measuring instrument main body.

〔Example〕

FIG. 1 is an overall perspective view of the coordinate measuring machine according to this embodiment. At the top of the base 1, a workpiece stand 3 is arranged between the two left and right raised wall members 2, and the workpiece stand 3, on which the object to be measured 4 is placed, On the other hand, it is movable in the Y-axis direction.

A beam member 6 is installed across the upper portions of the two left and right columns 5 fixed to the base 1, and a slider 7 is attached to the beam member 6 so as to be slidable in the X-axis direction. A spindle case 8 integrated with the slider 7 is provided with a quadrangular columnar spindle 9 movable in the vertical direction, that is, in the Z-axis direction, and a probe 10 is connected and supported at the lower end of the spindle 9. The above pillars 5, beam members 6, sliders 7, spindles 9
A measuring machine main body 11 is constructed by the above, and a probe 10 is attached to this measuring machine main body 11.

Movement of the workpiece table 3 in the Y-axis direction with respect to the base 1 is automatically performed by a drive device such as a motor or a ball screw disposed inside the bellows cover 12, and movement of the slider 7 in the X-axis direction and Movement of the spindle 9 in the Z-axis direction is also performed by a drive device incorporated in the beam member 6 and the spindle case 8.
These driving devices and the like constitute a moving mechanism that causes a three-dimensional movement displacement of the measurement object 4 and the probe 10, and the stage 3 serves as a movable member of this moving mechanism in the Y-axis direction. The measuring instrument main body 11 is a stationary member. Further, the slider 7 and the spindle 9 are movable side members in the X-axis direction and the Z-axis direction, and the beam member 6 and the spindle case 8 are stationary side members.

A probe stocker 13 is attached to the rear end of the stage 3. FIG. 3 shows this probe stocker 13. The probe stocker 13 is the stage 3
It consists of a bottom part 13A fixed to the top surface, a leg part 13B standing vertically from the bottom part 13A, and a top part 13C provided horizontally on the leg part 13B with an interval from the top surface of the stage 3. It is shaped like a letter.

A planar U-shaped groove 14 that opens forward is formed in the top portion 13C, and the probe 10 is inserted into this groove 14.
are inserted into the probe stocker 13 and supported by the probe stocker 13. A plurality of grooves 14 are formed in the probe stocker 13 so that a plurality of probes 10 can be supported.

The probe 10 includes a probe body 15, a probe position changing mechanism 16, a detection unit 17, and a probe 18. The probe 10 shown in FIG. Since this is a probe for measuring degree or cylindricity, the measuring stylus 18 that comes into contact with the measuring surface of the object to be measured 4 can change its posture by the reaction force from the measuring surface on the detection unit 17, specifically, can tilt and tilt. It is supported so that it can return to its original position when the reaction force is removed, and
The detection unit 17 includes a detection section that continuously outputs an analog signal corresponding to the amount of tilting of the probe 18 when the probe 18 tilts. In this way, the probe 10 serves as a measurement signal generator that has the function of capturing the amount of tilting of the probe 18, or the amount of tilting at the moment of contact with the object to be measured 4 and thereafter.

The probe body 15 includes a shank portion 15A for attaching the probe 10 to the spindle 9 constituting the measuring machine body 11, and this shank portion 15.
It has a tapered protrusion 15B and a flange part 15C provided at the lower part of A, and the flange part 15C is locked around the groove 14. Probe body 15
A supporting member 1 having a horizontal length is provided on the lower surface of the
9 is attached, and a screw shaft 21, which is a ball screw, is rotatably supported by bearing members 20 provided at both ends of this support member 19. A nut member 2 is screwed onto this screw shaft 21 whose axial direction is the horizontal direction.
2 is held inside a holding member 23, and the detection unit 17 is connected and supported by this holding member 23. The upper surface of the holding member 23 slidably contacts the lower surface of the supporting member 19 to prevent rotation of the holding member 23, and when the screw shaft 21 rotates, the holding member 23 moves in the horizontal direction due to the screw feeding action of the screw shaft 21. death,
The position of the probe 18 is changed. The above-mentioned support member 19, screw shaft 21, nut member 22, etc. constitute the measuring element position changing mechanism 16.

One end of the screw shaft 21 projects from one of the bearing members 20, and the first clutch member 2 is attached to this projecting end.
4 is installed. When the probe 10 is supported by the probe stocker 13, the first clutch member 24 passes through the hole 25 formed in the leg portion 13B and projects to the rear of the probe stocker 13.

A motor 27 is attached to the probe stocker 13 via a bracket 26, and a second clutch member 28, which is paired with the first clutch member 24, is attached to the output shaft of the motor 27, which is disposed on the probe stocker 13 side. provided. The first clutch member 24 and the second clutch member 28 constitute an electromagnetic clutch 29 which can be freely connected and disconnected. Further, the motor 27 constitutes a driving means 30 for operating the position changing mechanism 16, and the position changing mechanism 16 and the driving means 30 constitute a position adjustment device for the measuring stylus. A rotary encoder 31 is connected to the motor 27, and the rotary encoder 31 detects the amount of rotation of the motor 27, that is, the amount of rotation of the screw shaft 21 when the electromagnetic clutch 29 is connected.

FIG. 2 shows the internal structure of the spindle 9 shown in FIG. Inside the spindle 9, a hollow central shaft 32 is housed and supported by two upper and lower bearing bushes 33 so as to be rotatable around a vertical axis.
A tapered hole 34 having a shape corresponding to the tapered protrusion 15B of the probe 10 is formed at the lower end of the central shaft 32, and a ball holder 36 as a probe holding member is inserted into the upper part of the tapered hole 34 through a large diameter hole 35. A storage hole 37 for storing the
is provided. The ball holder 36 is coupled to the lower end of a drive rod 38, which is connected to the spring 3
9, it is always biased upward.

An air cylinder 40 is housed inside the spindle 9, attached to a bracket 41, and a piston rod 40B of a piston 40A of the air cylinder 40 extends downward and is connected to the drive rod 38. This connection is made through a ball 42 so that drive rod 38 and piston rod 40B move together axially, but drive rod 38 is rotatable relative to piston rod 40B. A plurality of balls 4 are placed inside the ball holder 36.
3 are arranged, and these balls 43 are movable in the radial direction of the shaft. More than 3 ball holders
6, drive rod 38, spring 39, air cylinder 4
0, a ball 43, and the like constitute a probe attachment/detachment device 44.

The probe 10 is held by the ball holder 36 with the shank portion 15A pressed by the ball 43, but when the piston rod 40B and the drive rod 38 are pushed down by the air cylinder 40 against the spring 39, the ball holder 36 is lowered. ball 4
3 is moved in the outer diameter direction by the weight of the probe 10 and the action of the shank portion 15A and enters the large diameter hole 35, so the shank portion 15A is released from the ball holder 36 and the probe 10 is removed from the spindle 9. Ru. Further, with the ball holder 36 lowered, the shank portion 15A is inserted into the inside of the ball holder 36, the air pressure of the air cylinder 40 is released, and the ball holder 36 is
When ball 4 is raised by the biasing force of spring 39, ball 4
Since the ball 3 is pushed by the inner peripheral wall of the storage hole 37 and moves in the radial direction, the ball 4
3, the shank portion 15A is pressed, and the tapered protrusion 15B is positioned and tightly contacted with the tapered hole 34, so that the probe 10 is held by the ball holder 36. At this time, the protrusion 46 of the bottom member 45 coupled to the lower end of the central shaft 32 engages with the hole formed in the flange portion 15C of the probe 10, and the probe 10 is positioned in the rotational direction.

A motor 48 is mounted inside the spindle 9 with a bracket 47 facing downward, and an output shaft 48A of the motor 48 is provided with a small diameter gear 49. A large diameter gear 50 that meshes with the small diameter gear 49 is provided at the upper end of the central shaft 32,
The rotational driving force of the motor 48 is transmitted to the central shaft 32 via a small diameter gear 49 and a large diameter gear 50 while being decelerated. These motors 48, small diameter gears 4
9. The large-diameter gear 50 and the like constitute a rotating device 51 as a rotating means for rotating the probe 10 in the case of roundness measurement, etc.

In FIG. 1, the object to be measured 4 attached to the object table 3 and the probe 10 attached to the spindle 9 of the measuring machine main body 11 are moved and displaced three-dimensionally by the moving mechanism controlled by a computer. It will be done. When the next measurement process according to a computer program is performed using the probe 10 for measuring roundness, etc. shown in FIG. The position of the probe 18 is changed and adjusted to a predetermined position.

That is, in FIG. 3, when a signal indicating that the next measurement step is to measure roundness, etc. is output from the control device of the coordinate measuring machine, the electromagnetic clutch 29 is connected and the motor 27 as the drive means 30 is connected. drives the rotation. As a result, the position changing mechanism 16 is actuated, and the detection unit 17 and the probe 18 are linearly moved in the radial direction of the probe body 15 by the screw feeding action of the rotating screw shaft 21. This amount of movement is determined by the rotary encoder 31
When the amount of linear movement of the contact point 18 etc. matches the diameter of the hole in the object 4 to be measured for roundness etc., the rotational drive of the motor 27 is stopped by a signal from the control device. The motor stops and the electromagnetic clutch 29 is disconnected.

In this way, the position of the probe 18 is changed to match the diameter of the hole in the object to be measured 4, so the number of probes attached to the spindle 9 is multiple and the probe is selected according to the diameter of the hole. It becomes unnecessary to do so. Further, the position of the measuring head 18 is changed while the probe 10 is waiting in the probe stocker 13, and the position changing process of the measuring head 18 is carried out while the previous measurement process is being performed, so that these processes are performed in parallel. and can be performed simultaneously, reducing measurement work time.

When the previous measurement step is completed, the document table 3 is moved in the Y-axis direction, and the probe stocker 13 is moved to a position below the spindle 9. Furthermore, the slider 7 moves in the X-axis direction and the spindle 9 also descends, causing the air cylinder 4 shown in FIG.
The probe 10 is removed from the spindle 9 by actuation of the probe attachment/detachment device 44 by supplying air pressure to the probe stocker 13, and is housed and supported at a predetermined position at the probe stocker 13. After this, the spindle 9 rises, and the slider 7 moves in the X-axis direction, and the position of the spindle 9 reaches directly above the probe 10 for measuring roundness, etc., where the change in the position of the measuring stylus 18 has been completed. Then, the spindle 9 is lowered and the probe 10 is mounted and supported on the spindle 9 by the probe mounting/detaching device 44.

Next, by operating the moving mechanism, the probe 10 is moved until the center axis of the hole, etc. of the object 4 to be measured, whose roundness etc. are to be measured, coincides with the center axis of the spindle 9.
is moved and displaced, and after the measuring stylus 18 comes into contact with the measuring surface of the measuring object 4, the rotating device 51 is driven. As a result, the probe 10 rotates around the axis of the vertical spindle 9, and the roundness and the like are measured by the detection unit 17 which outputs an analog signal in accordance with the amount of tilt of the probe 18.

Note that the measurement of roundness and the like may be performed by not providing the rotating device 51 inside the spindle 9 but by providing a turntable on which the object to be measured 4 is placed on the stage 3.

When the measurement of roundness, etc. is completed, the probe 10 is stored and supported at a corresponding predetermined position of the probe stocker 13 by the operation of the moving mechanism.

In the above, if the probe 10 for measuring roundness, etc. can be attached to the spindle 9 of the coordinate measuring machine, the coordinate measuring machine has the same functions as the conventional measuring machine for roundness, etc., and can also handle multiple coordinates. Compared to a method that detects the position and processes it to measure roundness, etc., this method has the advantage of significantly shortening the measurement time and obtaining a continuous analog signal.

In addition, the long screw shaft 21 can be attached to the probe 10 for measuring roundness, etc., and a large linear movement amount can be given to the probe 18. The circularity etc. of even large holes can be measured with one probe 10, and the scope of application of the probe 10 is expanded. Therefore, the range of the object 4 to be measured that can be measured by the coordinate measuring machine is expanded, and it is no longer necessary to attach a plurality of probes to the spindle 9 as described above, and the probes acting on the spindle 9 The reduction in weight eliminates the need to increase the strength of the structure of the coordinate measuring machine.

Further, since the driving means 30 for operating the position changing mechanism 16 of the probe 10 is attached to the probe stocker 13 and is not provided on the probe 10, the weight of the probe 10 acting on the spindle 9 is reduced accordingly. In addition, the size of the position changing mechanism 16 can be increased, and in this respect as well, the range in which the position of the probe 18 can be changed can be expanded, and the range of application of the probe 10 can be expanded. Furthermore, when the probe 10 is performing measurement work, the probe 10 and the driving means 30 are separated, so that adverse effects such as heat generation from the driving means 30 are prevented from reaching the probe 10 during the measurement work. can.

In addition to the above, since the probe stocker 13 is provided on the stage 3 and the probe attachment/detachment device 44 is provided on the spindle 9, which is a component of the measuring machine main body 11, the replacement work of the probe 10 can be performed as described above. This can be done by using the three-dimensional operation of the moving mechanism, and since the probe attachment/detachment device 44 is provided inside the spindle, the probe attachment/detachment device 44 can be placed effectively using dead space, saving space. can be realized.

The probe stored and supported in the probe stocker 13 may be one in which the position of the probe is not changed, or one in which the probe position is not changed. Further, the structure of the probe attaching/detaching device 44 is not limited to this embodiment, and may be any arbitrary structure.

Since the probe in this example was for measuring roundness, etc., the detection unit had a detection section that outputs a continuous analog signal. The sensor may include a detection unit that outputs a touch signal when a change in posture occurs due to contact with the object. That is, the probe may be a touch signal probe for measuring the coordinate position, length, etc. of the object to be measured using a displacement detector using an optical scale, for example, which is attached to a coordinate measuring machine, and if necessary, a measuring point. Any measurement signal generator may be used as long as the measurement signal generator includes a detection unit that includes a detection section that generates an output signal when a change in attitude occurs due to contact with the measurement target. In addition, the detection unit 17 is not fixedly attached to the holding member 23 constituting the position change mechanism 16, but is detachably attached, so that the detection unit for analog signal generation and the detection for touch signal generation can be combined. It may also be possible to make the unit interchangeable.

Furthermore, the present invention can be applied not only to a type of coordinate measuring machine in which the probe is automatically replaced, but also to a type in which the probe is replaced manually. It may also be a manual feed type.

Furthermore, the present invention can be applied to a three-dimensional measuring machine in which a probe moves relative to an object to be measured, a three-dimensional measuring machine in which an object to be measured moves relative to a probe, and a three-dimensional measuring machine in which both of these move. For example, it is sufficient that the object to be measured placed on the stage and the probe supported by the measuring machine body are moved relative to each other by a moving mechanism.

〔Effect of the invention〕

According to the present invention, since the position of the probe can be changed and adjusted, the range of hole diameters etc. that can be measured with one probe is expanded, and the number of probes required is reduced by expanding the applicable range of the probe. In addition, since the position of the probe can be changed during the measurement process, it is possible to shorten the measurement work time.

In particular, according to the present invention, since the probe stocker is provided on the stage and the probe attachment/detachment device is provided on the measuring machine main body, the probe can be replaced using the operation of the moving mechanism, and the structure is therefore simplified. Furthermore, it becomes possible to arrange the probe attachment/detachment device by making effective use of space.

[Brief explanation of the drawing]

Figure 1 is an overall perspective view of the coordinate measuring machine, Figure 2 is a sectional view showing the internal structure of the spindle shown in Figure 1, and Figure 3 is a partially sectional side view showing the structure around the probe stocker. It is. 3... Stage, 4... Measurement object, 9... Spindle, 10... Probe, 11... Measuring machine main body, 13...
Probe stocker, 15... Probe body, 16...
Position change mechanism, 18... Measuring head, 29... Electromagnetic clutch, 30... Driving means, 44... Probe attachment/detachment device,
51...Rotating device which is a rotating means.

Claims (1)

[Scope of Claims] 1. An object to be measured placed on a stage and a probe supported by a measuring machine body are moved relative to each other in three dimensions, so that the measurement surface of the object to be measured and the probe of the probe are moved relative to each other in three dimensions. In a three-dimensional measuring machine that detects the amount of displacement relative to the object and processes the detected amount of displacement in a predetermined manner with a data processing device to measure dimensions, etc. of the object to be measured, a probe is provided on the object table and supports the probe. a probe stocker that rotates the probe and the object to be measured relative to each other, which is provided on at least one of the measuring machine body and the stage; and a rotating means that rotates the probe and the object to be measured relatively; a position change mechanism that changes the position of the probe by moving it in a direction perpendicular to the probe position change mechanism; and a drive that is attached to the probe stocker and connected to the probe position change mechanism supported by the stocker and that operates the position change mechanism. A three-dimensional measuring machine, comprising: means; and a probe attaching/detaching device for attaching the probe supported by the probe stocker to a measuring machine main body.