JP5735337B2 - Surface texture measuring machine - Google Patents

Description

  The present invention relates to a surface texture measuring machine. More specifically, the present invention relates to a surface property measuring machine in which a measuring arm having a stylus to be brought into contact with the surface of a measurement object is replaceable.

  While the stylus is in contact with the surface of the object to be measured, the stylus is moved along the surface of the object to be measured. At this time, the displacement of the stylus caused by the surface shape and surface roughness of the object to be measured (stylus movement direction) There is known a surface property measuring machine that detects a surface property such as a surface shape and a surface roughness of an object to be measured from the displacement of the stylus.

In the surface texture measuring machine, a stylus (measurement arm) of various shapes is prepared in advance so that measurement sites of various shapes of the measurement object can be measured, and an optimum stylus according to the measurement site shape of the measurement object. It has been proposed to be able to measure by exchanging.
For example, in Patent Document 1, a column erected on a base, a holder provided on the column so as to be movable up and down via an adjusting device, a housing provided on the holder, and a linear motor in the housing. And a measurement arm connected to the seesaw via connecting means on the outside of the housing, and a stylus provided at the tip of the measurement arm, and the measurement is performed outside the housing. A contour measuring machine has been proposed in which the arms can be exchanged.

DE19617022C1 publication

In the surface texture measuring machine such as the above-described contour measuring machine, the pressure at which the stylus contacts the surface of the object to be measured, that is, the measuring force is set to the optimum measuring force according to the material or shape of the object to be measured. It needs to be adjusted.
Usually, when the measurement arm is replaced, the weight of the replaced measurement arm is often different from the weight of the original measurement arm, so that the balance of the measurement arm is lost and a measurement error occurs. Therefore, each time the measurement arm is replaced, it is necessary to adjust the balance of the measurement arm, that is, the balance so that the measurement arm is kept substantially horizontal before adjusting the measurement force.

  Conventionally, when the measuring arm is replaced, the stylus at the tip of the measuring arm is first placed on a measuring device that measures force, such as an electronic balance, and the measuring force adjustment mechanism is adjusted so that the value of the measuring device becomes 0 in this state. Because it had to be done, there was a problem of poor usability and poor work efficiency.

  An object of the present invention is to provide a surface texture measuring machine that can solve the above-described problems and can be expected to improve usability and work efficiency by automatically adjusting the balance of the measuring arm even if the measuring arm is replaced. There is.

The surface texture measuring machine of the present invention includes a measurement arm supported on the main body so as to be capable of arc motion with a support shaft as a fulcrum, a stylus provided at the tip of the measurement arm, a displacement detector for detecting the arc momentum of the measurement arm, And a detecting means having a measuring force applying means for applying a measuring force to the stylus by urging the measuring arm in the arc motion direction, a stage for placing the object to be measured, and the detecting means and the stage relative to each other. A relative movement mechanism that moves the stylus in contact with the surface of the object to be measured, while the relative movement mechanism moves the detection means and the stage relative to each other while the displacement detector detects the measurement arm. In the surface texture measuring machine that detects the arc momentum and measures the surface texture of the measured object from the arc momentum,
The measurement arm is provided on the main body so as to be capable of circular motion with the support shaft as a fulcrum, and is detachably provided at the tip of the first measurement arm via an attachment / detachment mechanism, and the stylus is provided at the tip. The measuring force applying means includes a voice coil that urges the measuring arm in the arc motion direction with the support shaft as a fulcrum. It is characterized by comprising a balance adjusting means for adjusting the balance of the measurement arm by adjusting the current applied to the voice coil after replacement.

According to such a configuration, the measurement arm is provided on the main body so as to be capable of circular motion with the support shaft as a fulcrum, and is detachably provided at the tip of the first measurement arm via the attachment / detachment mechanism. Since it comprises the 2nd measurement arm which has a stylus at the tip, the 2nd measurement arm which has a stylus can be exchanged. Therefore, measurement can be performed using a measurement arm having an optimum stylus according to the shape of the measurement site of the object to be measured.
At this time, when the second measuring arm is replaced, even if the weight of the new second measuring arm is different from the weight of the previous second measuring arm, the current applied to the voice coil is adjusted by the balance adjusting means. Since the balance of the measurement arm can be automatically adjusted, the measurement error associated with the replacement of the measurement arm can be reduced, and improvement in convenience and work efficiency can be expected.

In the surface texture measuring machine according to the present invention, the balance adjusting unit adjusts a current to be supplied to the voice coil while monitoring an arc momentum of the measuring arm detected by the displacement detector, so that the arc of the measuring arm is adjusted. at the stage of momentum becomes set value set in advance is intended to complete the balancing.

According to such a configuration, the balance adjustment means monitors the arc momentum of the measurement arm detected by the displacement detector, adjusts the current to be supplied to the voice coil, and sets the arc momentum of the measurement arm in advance. Since the balance adjustment is completed when the value is reached, the balance adjustment of the measurement arm can be performed accurately.

  In the surface texture measuring machine according to the present invention, the stylus has a pair of styluses protruding toward the arc movement direction at the tip of the measurement arm, and the voice coil has the measurement arm in the arc movement direction. It is preferable to configure a measurement arm posture switching mechanism that switches between a posture biased in one direction and a posture biased in the other direction.

  According to such a configuration, since the tip of the measurement arm has the pair of styluses protruding in the arc motion direction, the direction in which the measurement arm is urged can be switched by the measurement arm posture switching mechanism. In other words, if the measurement arm is switched to a posture biased in one direction of the arc motion direction and a posture biased in the other direction, for example, the surface properties of the upper and lower surfaces of the hole and the surface of the plate-like object to be measured The surface property of the back surface can be measured.

  The surface texture measuring instrument according to the present invention includes a speed control mechanism that controls a switching operation speed of the measurement arm to a preset speed when the posture of the measurement arm is switched by the measurement arm posture switching mechanism. Is preferable.

  According to such a configuration, when the measurement arm is switched from one direction (for example, upward) to the other direction (for example, downward) in the arc motion direction, the switching operation speed of the measurement arm is changed by the speed control mechanism. Since the speed is controlled to a preset speed, the switching operation speed of the measurement arm can be suppressed to a predetermined speed or less. Therefore, for example, in measuring the inner surface of the hole, the impact when the stylus collides with the inner surface of the hole can be suppressed, so that damage to the stylus and the object to be measured can be reduced.

The perspective view which shows the surface texture measuring machine which concerns on embodiment of this invention. The figure which shows the X-axis drive mechanism and stylus displacement detection means of embodiment same as the above. The top view which shows the relationship between the measurement arm and displacement detector of embodiment same as the above. The figure which shows the measurement arm and measurement arm attitude | position switching mechanism of embodiment same as the above. The figure which shows the measurement attitude | position and measurement force control circuit of embodiment same as the above. The disassembled perspective view which shows the attachment / detachment mechanism of embodiment same as the above. The figure which shows the contact detection circuit of embodiment same as the above. The block diagram which shows the control system of embodiment same as the above, The figure which shows the example which measures the upper and lower surfaces of the internal peripheral surface of a hole in embodiment same as the above, The figure which shows the example which measures thickness in embodiment same as the above. The flowchart which shows the procedure of balance adjustment of the measurement arm of embodiment same as the above. The flowchart which shows the other procedure of balance adjustment of the measurement arm of embodiment same as the above. The flowchart which shows the further another procedure of balance adjustment of the measurement arm of embodiment same as the above. The figure which shows the other example of the measurement attitude | position and measurement force control circuit of embodiment same as the above.

<Description of surface texture measuring instrument (see FIGS. 1 to 8)>
As shown in FIG. 1, the surface texture measuring instrument according to the present embodiment is in contact with a base 1, a stage 10 placed on the base 1 and placing an object to be measured on the upper surface, and the surface of the object to be measured. The stylus displacement detecting means 20 having the styluses 26A and 26B, and the relative movement mechanism 40 for relatively moving the stylus displacement detecting means 20 and the stage 10 are provided.

  The relative movement mechanism 40 is provided between the base 1 and the stage 10 and moves the stage 10 in one horizontal direction (Y-axis direction), and a column erected on the upper surface of the base 1. 42, a Z slider 43 provided on the column 42 so as to be movable in the vertical direction (Z-axis direction), a Z-axis drive mechanism 44 for raising and lowering the Z slider 43 in the vertical direction, and a stylus provided on the Z slider 43. An X-axis drive mechanism 45 that moves the displacement detection means 20 in a direction (X-axis direction) orthogonal to the movement direction (Y-axis direction) of the stage 10 and the movement direction (Z-axis direction) of the Z slider 43; Accordingly, the relative movement mechanism 40 includes the Y-axis drive mechanism 41 that moves the stage 10 in the Y-axis direction, the Z-axis drive mechanism 44 that moves the stylus displacement detection means 20 in the Z-axis direction, and the stylus displacement detection means 20 as X. The three-dimensional moving mechanism includes an X-axis driving mechanism 45 that moves in the axial direction.

The Y-axis drive mechanism 41 and the Z-axis drive mechanism 44 are not shown in the figure, but are constituted by, for example, a feed screw mechanism having a ball screw shaft and a nut member screwed to the ball screw shaft.
As shown in FIG. 2, the X-axis drive mechanism 45 includes a drive mechanism main body 46 fixed to the Z slider 43, a guide rail 47 provided on the drive mechanism main body 46 in parallel with the X-axis direction, and the guide rail. 47, an X slider 48 provided so as to be movable in the X axis direction, an X axis position detector 49 for detecting the position of the X slider 48 in the X axis direction, and the X slider 48 is moved along the guide rail 47. And a feeding mechanism 50 to be operated.
The feed mechanism 50 is provided on the drive mechanism main body 46 in parallel with the guide rail 47 and screwed to the X slider 48, a motor 52 as a drive source, and the rotation of the motor 52 that feeds the feed screw shaft 51. And a rotation transmission mechanism 53 for transmitting to the motor. The rotation transmission mechanism 53 is configured by mechanisms such as a gear train, a belt, and a pulley, for example.

  As shown in FIG. 2, the stylus displacement detecting means 20 includes a bracket 22 as a main body that is detachably supported by a X slider 48 via bolts 21, and a rotating shaft 23 as a support shaft attached to the bracket 22. A measurement arm 24 supported as a fulcrum so as to be swingable in the vertical direction (arc motion is possible), a pair of styluses 26A and 26B provided at the tip of the measurement arm 24, and an arc motion amount (Z-axis direction) of the measurement arm 24 The displacement detector 27 for detecting the displacement amount), the balance weight 29 provided on the measurement arm 24 so that the position can be adjusted, and the measurement arm 24 are biased in one direction (for example, upward) in the arc motion direction. A measurement arm posture switching mechanism 60 for switching between a posture and a posture biased in another direction (downward), a bracket 22, a measurement arm 24, a displacement detector 27, Lance weight 29, covering the measuring arm posture switching mechanism 60 is configured to include a casing 28.

The measurement arm 24 is mounted on the bracket 22 so as to be exchangeable via a detachable mechanism 25 at the front end of the first measurement arm 24A supported by the bracket 22 so as to be movable in a circular arc in the vertical direction about the rotation shaft 23. And the second measurement arm 24B. The attachment / detachment mechanism 25 connects the first measurement arm 24A and the second measurement arm 24B so that they are arranged in a straight line.
The styluss 26A and 26B are provided so as to protrude in the arc motion direction with respect to the second measurement arm 24B. In other words, an upward stylus 26A and a downward stylus 26B are provided to protrude perpendicularly to the vertical direction with respect to the second measurement arm 24B.

As shown in FIG. 3, the displacement detector 27 is provided along the arc motion range of the measurement arm 24, and is configured by a position detector that outputs a number of pulse signals corresponding to the amount of arc motion of the measurement arm 24. . Specifically, a scale 27A provided on the measurement arm 24 and curved in the arc movement direction of the measurement arm 24, and a detection head 27B attached to a bracket 22 as a main body facing the scale 27A are provided. The detection surface of the scale 27 </ b> A is arranged on the axis line of the measurement arm 24 and on the arc motion surface of the measurement arm 24. Accordingly, the detection surface of the scale 27A, the measurement arm 24, and the tips of the styluses 26A and 26B are arranged on the same axis.
The balance weight 29 is provided so that its position in the axial direction of the measurement arm 24 can be adjusted so that the weight on the first measurement arm 24A side and the weight on the second measurement arm 24B side are balanced with the rotation shaft 23 as a fulcrum. Yes. Specifically, the balance weight 29 is fixed to a desired position of the measurement arm 24 by a set screw. Alternatively, a male screw may be formed on the measurement arm 24, and the balance weight 29 may be screwed onto the male screw so that the position can be adjusted.

As shown in FIG. 4, the measurement arm posture switching mechanism 60 is fixed to the cylindrical magnet 61 provided in the middle of the first measurement arm 24A and the bracket 22 as the main body through the magnet 61. 24 is composed of a voice coil 62 that urges the rotating shaft 23 as a fulcrum in one direction (upward) and the other direction (downward) in the arc motion direction, and is controlled by a command from the measurement posture / measurement force control circuit 70. The When a current is passed through the voice coil 62 according to a command from the measurement posture / measurement force control circuit 70, the magnet 61 of the measurement arm 24 is attracted to the voice coil 62 by the electromagnetic force generated from the voice coil 62 and the magnetic force of the magnet 61. Then, the posture of the measurement arm 24 is switched to a posture in which the tip of the measurement arm 24 is urged upward or downward.
Here, the measurement arm posture switching mechanism 60 includes a voice coil 62 that urges the measurement arm 24 in the arc motion direction with the rotating shaft 23 as a fulcrum, and urges the measurement arm 24 in the arc motion direction to the stylus 26A, 26B. It also serves as a measuring force applying means for applying a measuring force.

As shown in FIG. 5, the measurement posture / measurement force control circuit 70 is preset according to a balance command, a switching operation command (upward or downward switching operation command), and a measurement force command output from the control device 101 described later. A command signal generating means 72 comprising a CPU for generating a voltage A (command speed signal) corresponding to the speed, and a digital / analog converter 73 for converting the voltage A (digital signal) from the command signal generating means 72 into an analog signal; A frequency voltage converter 74 as a measurement arm speed detection means for outputting a voltage B (operation speed signal) corresponding to the operation speed of the measurement arm 24 based on a pulse signal (frequency) from the displacement detector 27, and a command speed signal A subtractor 75 as a differential output means for outputting a differential voltage C between (voltage A) and the operation speed signal (voltage B); It is configured to include a constant current circuit 76 to be supplied to the voice coil 62 and converts the differential voltage C current measurement arm position switching mechanism 60. As a result, the measurement arm 24 can be moved in a circular arc while the operating speed of the measurement arm 24 is kept below a predetermined constant speed.
Here, the voltage A (command speed signal) generated from the command signal generating means 72 is a speed at which the stylus 26A, 26B and the measured object are not damaged when the stylus 26A, 26B contacts the measured object. Is set to

  The attaching / detaching mechanism 25 is disposed in the casing 28 as shown in FIG. Further, as shown in FIG. 6, the attachment / detachment mechanism 25 includes a rectangular plate-like first plate 81 provided at the distal end of the first measurement arm 24A and a rectangular plate-like shape provided at the base end of the second measurement arm 24B. A second plate 82, a positioning mechanism 83 that positions the second plate 82 at a predetermined position with respect to the first plate 81 when the second plate 82 is opposed to the first plate 81, and a first plate 81 includes a magnet 95 provided on 81 and a magnetic body 96 provided on the second plate 82 and attracted to the magnet 95.

  The positioning mechanism 83 includes a first seating portion 85 in which a pair of columnar positioning members 84A and 84B are arranged in parallel along the axial direction of the measurement arm 24 at a predetermined interval, and a pair of columnar positioning members 84A and 84B. And a pair of second seating portions 86 arranged in parallel and spaced apart from each other along the axial direction of the measurement arm 24 and spaced apart from the first seating portion 85 in the axial direction of the measurement arm 24. A third seating portion 87 in which cylindrical positioning members 84A and 84B are arranged at right angles to the axial direction of the measurement arm 24 and at a predetermined interval, and the first seating portion 85, the second seating portion 86, and the third seating. Engaging ball portions 88, 89, 90 that are provided corresponding to the portions 87 and can be engaged with and disengaged from each other, at least two engaging holes 91, 92, and engage with the engaging holes 91, 92, respectively. At least 2 or more And a coupling pin 93 and 94.

The first seat portion 85, the second seat portion 86, the third seat portion 87, and the engagement pins 93 and 94 are disposed on the first plate 81. Specifically, in the first plate 81, the first seating portion 85 and the second seating portion 86 are disposed at both ends of the measurement arm 24 that are separated from each other in the axial direction. A third seating portion 87 is disposed below and between 86 and 86. In addition, engagement pins 93 and 94 are disposed immediately below the first seating portion 85 and the second seating portion 86, and between the first seating portion 85, the second seating portion 86, and the third seating portion 87. A magnet 95 is arranged.
The engaging ball portions 88, 89, 90 and the engaging holes 91, 92 are arranged in the second plate 82. That is, when the second plate 82 is positioned at a predetermined position with respect to the first plate 81, the first seating portion 85, the second seating portion 86, and the third seating portion 87 of the first plate 81 in the second plate 82. Engagement balls 88, 89, 90 are arranged at positions corresponding to the engagement pins 93, 94, engagement holes 91, 92 are arranged at positions corresponding to the magnets 95, and magnetic bodies 96 are arranged at positions corresponding to the magnets 95, respectively. Yes.

Further, when the second plate 82 is positioned at a predetermined position with respect to the first plate 81, the engaging ball portions 88, 89, 90 fit between the corresponding cylindrical positioning members 84A, 84B of the corresponding seating portions, It arrange | positions so that cylindrical positioning member 84A, 84B may be contacted. The pair of columnar positioning members 84A and 84B and the engaging ball portions 88, 89, and 90 constituting the seating portions 85, 86, and 87 are formed of a conductive material. Then, as shown in FIG. 7, the contact between the pair of columnar positioning members 84A, 84B constituting the respective seating portions 85, 86, 87 and the engaging ball portions 88, 89, 90 engaged and disengaged thereto, Seating sensors 97, 98, and 99 that are opened and closed by separation are formed, and these seating sensors 97, 98, and 99 are connected in series and connected to the contact detection circuit 100.
The contact detection circuit 100 detects the contact and separation of the seating sensors 97, 98, and 99, and notifies the state by turning on / off the lamp, displaying on the display unit, or sound of a buzzer.
Further, the protruding amounts of the engaging pins 93 and 94 are set so that the magnetic body 96 is attracted to the magnet 95 after the engaging pins 93 and 94 start to engage with the engaging holes 91 and 92. .

FIG. 8 shows a control system of the surface texture measuring machine. The control device 101 includes a Y-axis drive mechanism 41, a Z-axis drive mechanism 44, an X-axis drive mechanism 45, a displacement detector 27 included in the stylus displacement detection means 20, a contact detection circuit 100, and a measurement arm posture switching mechanism 60 (this). Are connected via a measurement posture / measuring force control circuit 70), and an input means 102, an output means 103, a storage device 104, and the like are connected.
Here, the control device 101 includes any one of the sitting sensors 97,
When it is detected that 98 and 99 are separated from each other, drive stop means is configured to stop driving of the relative movement mechanism 40 (Y-axis drive mechanism 41, Z-axis drive mechanism 44, X-axis drive mechanism 45). . Further, the control device 101 constitutes balance adjustment means for adjusting the balance of the measurement arm 24 by adjusting the current supplied to the voice coil 62 of the measurement arm posture switching mechanism 60 after the replacement of the second measurement arm 24B. . Specifically, while monitoring the arc momentum of the measurement arm 24 detected by the displacement detector 27, the current supplied to the voice coil 62 was adjusted, and the arc momentum of the measurement arm 24 became a preset value. A balance adjusting means for completing the balance adjustment in stages is configured.

<Description of measurement method>
(When measuring the upper and lower surfaces of the inner peripheral surface of the hole)
For example, as shown in FIG. 9, when measuring the lower surface and the upper surface of the inner peripheral surface of the hole H of the workpiece W <b> 1, the relative movement mechanism 40 is driven and the styluses 26 </ b> A and 26 </ b> B of the measurement arm 24 are moved. After being positioned in the hole H of the workpiece W1, the controller 101 outputs a downward switching operation command and a measurement force command. Then, the measurement posture / measurement force control circuit 70 urges the tip of the measurement arm 24 downward, and a current corresponding to the command measurement force is applied to the voice coil 62 of the measurement arm posture switching mechanism 60.
Thus, the measurement arm posture switching mechanism 60 operates the measurement arm 24 at a speed set in advance in a direction in which the tip of the measurement arm 24 is urged downward, for example, and the downward stylus 26B moves to the hole H with the command measurement force. It is in contact with the lower surface. In this state, when the relative movement mechanism 40 relatively moves the stylus displacement detection means 20 and the stage 10 in the axial direction (X-axis direction) of the hole H, the displacement detector 27 detects the arc momentum of the measurement arm 24, The surface property of the lower surface of the hole H is measured from the arc momentum.

Next, an upward switching operation command and a measurement force command are output from the control device 101. Then, the measurement arm posture switching mechanism 60 operates the measurement arm 24 at a speed set in advance in a direction in which the tip of the measurement arm 24 is urged upward, and the upward stylus 26A performs command measurement on the upper surface of the hole H. Touched by force.
In this state, when the relative movement mechanism 40 relatively moves the stylus displacement detection means 20 and the stage 10 in the axial direction (X-axis direction) of the hole, the displacement detector 27 detects the arc momentum of the measurement arm 24, and this The surface property of the upper surface of the hole H is measured from the arc momentum.

(When measuring the thickness of a plate-like object to be measured)
As shown in FIG. 10, when measuring the thickness of the plate-like object W3, the stylus 26A, 26B of the measurement arm 24 is driven in the same manner by driving the relative movement mechanism 40 according to a command from the control device 101. Is positioned on the lower surface side of the object to be measured W3, and then the measurement arm attitude switching mechanism 60 switches the attitude of the measurement arm 24 to an attitude in which the tip of the measurement arm 24 is urged upward in the arc motion direction, thereby moving the upward stylus 26A to the object to be measured. Contact the lower surface of. In this state, when the stylus displacement detecting means 20 and the stage 10 are relatively moved in the X-axis direction by the relative movement mechanism 40, the displacement detector 27 detects the arc momentum of the measurement arm 24, and the object to be measured is detected from the arc momentum. The surface property of the lower surface of W3 is measured.

Next, the relative movement mechanism 40 is driven in accordance with a command from the control device 101 so that the stylus 26A, 26B of the measurement arm 24 is positioned on the upper surface side of the workpiece W3, and then measured by the measurement arm posture switching mechanism 60. The posture is switched to a posture in which the tip of the arm 24 is urged downward in the arc motion direction, and the downward stylus 26B is brought into contact with the upper surface of the workpiece W3. In this state, when the stylus displacement detecting means 20 and the stage 10 are relatively moved in the X-axis direction by the relative movement mechanism 40, the displacement detector 27 detects the arc momentum of the measurement arm 24, and the object to be measured is detected from the arc momentum. The surface texture of the upper surface of W3 is measured.
From the bottom surface property of the measured object W3 and the top surface property of the measured object W3 thus obtained, the thickness t, the step d, etc. of the measured object W3 can be accurately obtained.

  Therefore, since the pair of styluss 26A and 26B projecting in the arc movement direction are provided at the tip of the measurement arm 24, the direction in which the measurement arm 24 is urged can be switched by the measurement arm posture switching mechanism 60. In other words, if the measurement arm 24 is switched between a posture in which the measuring arm 24 is biased in one direction (upward) in the arc motion direction and a posture in which the measurement arm 24 is biased in the other direction (downward), for example, the surfaces of the upper and lower surfaces of the hole H The properties and the surface properties of the front and back surfaces of the plate-like workpiece W3 can be measured.

In the measurement operation described above, when the measurement arm 24 is operated, for example, when the tip of the measurement arm 24 is switched from the lower direction to the upper direction, the measurement posture / measurement force control circuit 70 causes the measurement arm 24 to move. The operation speed is controlled to a preset speed.
That is, when the distal end of the measurement arm 24 is switched from, for example, the lower direction to the upper direction by the measurement arm posture switching mechanism 60, a number of pulse signals corresponding to the arc momentum of the measurement arm 24 are output from the displacement detector 27. Is done. Then, the voltage B corresponding to the operating speed of the measurement arm 24 is detected by the frequency voltage converter 74 based on the pulse signal from the displacement detector 27. Then, a difference voltage C between the voltage B corresponding to the operating speed of the measuring arm 24 and the voltage A corresponding to the command speed signal output from the command signal generating means 72 is obtained, and the voice coil is determined based on the difference voltage C. Since the current flowing through 62 is controlled, the switching operation speed of the measurement arm 24 can be maintained at the command speed signal output from the command signal generating means 72.

Therefore, since the operation speed of the measurement arm 24 can be suppressed to a certain speed or less, the impact when the stylus 26A, 26B collides with the inner surface of the hole H can be suppressed. Therefore, damage to the stylus 26A, 26B and the object to be measured W1 can be reduced.
Further, since the operation speed of the measurement arm 24 can be maintained at an arbitrary command speed, the operation speed of the measurement arm 24 can be set to a speed suitable for the material of the object to be measured.
In addition, the measurement posture / measurement force control circuit 70 uses the arc motion amount of the measurement arm 24, that is, the pulse signal from the displacement detector 27 that detects the displacement of the stylus 26A, 26B. There is no need to provide special speed detection means for detecting the operation speed, and the apparatus can be configured inexpensively and compactly.

(Operation during measurement operation)
At the time of these measurements, the displacement detector 27 of the stylus displacement detection means 20 includes a scale 27A and a detection head 27B, and the detection surface of the scale 27A is on the axis of the measurement arm 24 and is an arc motion surface. Since it is arranged, an error due to an offset or the like can be reduced and high-precision measurement can be expected.

Further, during these measurements, if an external force larger than the attractive force of the magnet 95 acts on the stylus 26A, 26B or the measurement arm 24, the first plate 81 and the second plate 82 are disconnected. Then, since the external force beyond it does not act on the internal mechanisms of the stylus 26A, 26B, the measurement arm 24, and the stylus displacement detecting means 20, these damages can be prevented beforehand.
At this time, even if the connection between the first plate 81 and the second plate 82 is about to be released, the engagement pins 93 and 94 are caught in the engagement holes 91 and 92, so that the second measurement arm 24B may fall. In addition, since the attachment / detachment mechanism 25 is arranged in the casing 28, even if the external force acts on the measurement arm 24 and the stylus 26A, 26B and the second measurement arm 24B is detached from the attachment / detachment mechanism 25, the second measurement arm The possibility that 24B falls can be reduced. Therefore, the measurement arm 24 and the stylus 26A, 26B can be prevented from being damaged. Furthermore, since the attachment / detachment mechanism 25 is inside the casing 28, there is no possibility that the attachment / detachment mechanism 25 will collide with the object to be measured, so damage to the attachment / detachment mechanism 25 due to the collision with the object to be measured and contamination due to the external environment can be reduced. .

  At this time, when the contact detection circuit 100 detects that any of the seating sensors 97, 98, 99 is separated, the control device 101 constituting the drive stop means stops the driving of the relative movement mechanism 40. For example, even when the second measurement arm 24B is detached from the attachment / detachment mechanism 25, the driving of the relative movement mechanism 40 is stopped, so that the measurement work can be performed safely.

(Second measuring arm replacement work)
When exchanging with the second measurement arm 24B having a different stylus according to the measurement site of the object to be measured, first, the second plate 82 of the second measurement arm 24B is moved to the first with a force larger than the attractive force of the magnet 95. After being separated from the first plate 81 of the measurement arm 24A, the second plate 82 of the second measurement arm 24B having a stylus to be newly used is opposed to the first plate 81.
Then, the first plate 81 and the second plate 82 are attracted by the magnet 95 and the magnetic body 96 attracted thereto. At this time, the engaging ball portions 88, 89, 90 are fitted into the correct positions between them while being guided by the pair of columnar positioning members 84A, 84B constituting the seating portions 85, 86, 87. Even if it cannot be confirmed, a new second measurement arm 24 </ b> B can be mounted by a one-touch operation only by causing the second plate 82 to face the first plate 81 at a position that approximately matches the first plate 81.
Therefore, the measurement can be performed by exchanging with the second measurement arm 24B having an optimum stylus according to the shape of the measurement site of the object to be measured.

At this time, the engagement holes 91 and 92 formed in the second plate 82 are arranged on the first plate 81 and the engagement pins 93 and 94 are also engaged, but the engagement pins 93 and 94 are engaged with the engagement holes 91. The engagement pins 93 and 94 are set so that the magnetic body 96 is attracted to the magnet 95 after the engagement with the first plate 81. On the other hand, the fact that the second plate 82 is coupled at the correct position can be grasped as a touch using the attractive force of the magnet 95.
Further, since the contact detection circuit 100 can detect contact and separation of the seating sensors 97, 98, and 99, whether or not the second measurement arm 24B can be properly replaced when the second measurement arm 24B is replaced. Can be confirmed.

  Further, since the attachment / detachment mechanism 25 is disposed in the casing 28, that is, the attachment / detachment mechanism 25 is attached to the rotary shaft 23 that is a fulcrum of the measurement arm 24, compared to the case where the attachment / detachment mechanism 25 is disposed outside the casing 28. Therefore, when the second measuring arm 24B is attached / detached, the moment applied to the fulcrum can be reduced, and the bearing load on the fulcrum can be reduced and the damage can be prevented.

  In this state, that is, in a state where the first plate 81 and the second plate 82 are adsorbed, the position of the measuring arm 24 in the axial direction is restricted by the third seating portion 87, and the first seating portion 85 and the second seating are also seated. Since the rotation direction around the engaging ball portion 88 engaged with the first seating portion 85 is regulated by the portion 86, the first plate 81 and the second plate 82 can be accurately positioned in a predetermined relationship. In addition, in this state, the first seat 85 and the second seat 86 are provided apart from each other in the axial direction of the measurement arm 24, so that the measurement arm 24 has a relatively compact configuration and a small force. Can be held. The distance between the first seating portion 85 and the second seating portion 86 should be long, and the first seating portion 85 and the second seating portion 86 are measured on the first plate 81 as in this embodiment. The arm 24 is preferably disposed at both ends of the arm 24 that are separated in the axial direction.

Further, after the second measurement arm 24B is replaced, when the control device 101 outputs a balance command, processing is performed according to the flowchart shown in FIG. 11, and the balance of the measurement arm 24 is automatically adjusted.
That is, in step (hereinafter abbreviated as ST) 1, a setting command for measuring force 0 is output from the control device 101, and then the value monitoring of the displacement detector 27 is started in ST 2.
In ST3, when a command for setting a certain measuring force is output from the control device 101, in ST4, the control device 101 checks whether or not the value change amount of the displacement detector 27 within a certain time is within a certain range.
In ST4, when the amount of change in the value of the displacement detector 27 within a certain time is not within a certain range, that is, when the balance of the measurement arm 24 including the replaced second measurement arm 24B has been greatly lost. Then, the process proceeds to ST5, where a measurement force setting command is output in a direction opposite to the direction in which the value of the displacement detector 27 changes. In ST4, the value change amount of the displacement detector 27 within a certain time is within a certain range. The process of ST5 is repeated until.
When the value change amount of the displacement detector 27 within a certain time is within a certain range in ST4, it is determined in ST6 that the measurement arm 24 is balanced, and the process is terminated.
In order to set the measurement force at the time of measurement, the measurement force in a balanced state is set to 0, and then the measurement force added at the time of measurement is added to set the measurement force.

Therefore, even if the weight of the new second measurement arm 24B replaced is different from the weight of the previous second measurement arm 24B, the current supplied to the voice coil 62 is adjusted by the control device 101 constituting the balance adjusting means. Since the balance of the measurement arm 24 can be automatically adjusted, it is possible to reduce the measurement error associated with the replacement of the second measurement arm 24B and to improve the usability and work efficiency.
In particular, the balance adjusting means adjusts the current applied to the voice coil 62 while monitoring the arc momentum of the measurement arm 24 detected by the displacement detector 27, so that the arc momentum of the measurement arm 24 is set to a preset value. Since the balance adjustment is completed at this stage, the balance adjustment of the measurement arm 24 can be performed accurately.

<Modification>
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  In the above embodiment, the first seating portion 85, the second seating portion 86 and the third seating portion 87 constituting the attaching / detaching mechanism 25 are provided on the first plate 81, and the engaging ball portions 88, 89, 90 for engaging / disengaging with the first plate 81 are provided. Although provided on the second plate 82, these may be reversed. Further, although the magnet 95 is provided on the first plate 81 and the magnetic body 96 is provided on the second plate 82, these may be reversed. Furthermore, although the engaging pins 93 and 94 are provided in the first plate 81 and the engaging holes 91 and 92 are provided in the second plate 82, these may be reversed.

In the above-described embodiment, the measurement arm posture switching mechanism 60 is configured to include the voice coil 62 that urges the measurement arm 24 in one direction and the other direction in the arc motion direction with the measurement arm 24 as the rotation shaft 23 and the fulcrum. Absent. For example, a mechanism using a linear motor mechanism may be used.
Further, although the arc movement direction is the vertical direction in the above-described embodiment, it may be a horizontal direction, or may be a structure that swings in an oblique direction other than the vertical direction or the horizontal direction.

  In the above-described embodiment, the second measurement arm 24B having the pair of styluses 26A and 26B at the distal end of the measurement arm 24 has been described, but the structure need not necessarily have a pair of styluses. Any structure can be used as long as it can be replaced with a measurement arm having a stylus suitable for the measurement site.

  In the above embodiment, the method of adjusting the balance of the measurement arm 24 according to the procedure of the flowchart shown in FIG. 11 using the measurement command / measurement force control circuit 70 is shown. The adjustment may be made according to the procedure, or may be made according to the procedure of the flowchart shown in FIG.

In the procedure of the flowchart shown in FIG. 12, after a setting command for setting the downward maximum measuring force is output from the control device 101 in ST11, the value monitoring of the displacement detector 27 is started in ST12.
In ST13, the control device 101 checks whether the value of the displacement detector 27 is equal to or smaller than a certain value, that is, checks whether the counter value has been shaken.
In ST13, if the value of the displacement detector 27 is not less than a certain value, the process proceeds to ST14, and the direction in which the center measuring force from the maximum value to the minimum value or the center measuring force of the past two measuring forces has been shaken out. Gives a setting command in the opposite direction, and repeats the process of ST14 until the value of the displacement detector 27 becomes a certain value or less in ST13.
In ST13, when the value of the displacement detector 27 is equal to or smaller than a certain value, the process proceeds to ST15, and it is checked whether the value change amount of the displacement detector 27 within a certain time is within a certain range.
In ST15, if the amount of change in the value of the displacement detector 27 within a certain time is not within a certain range, the process proceeds to ST16, and the central measuring force from the maximum value to the minimum value or the past two measuring forces are changed. A setting command is issued in the direction opposite to the direction in which the value of the detector 27 changes, and the process of returning to ST13 is repeated.
In ST15, when the amount of change in the value of the displacement detector 27 within a certain time is within a certain range, it is determined in ST17 that the measurement arm 24 is balanced, and the process is terminated.

In the procedure of the flowchart shown in FIG. 13, after a setting command for setting the downward maximum measuring force is output from the control device 101 in ST21, the intermediate position is held in ST22.
In ST23, after a setting command for measuring force 0 is output, in ST24, the downward direction is set free, and in ST25, the value monitoring of the displacement detector 27 is started.
In ST26, the control device 101 checks whether the value of the displacement detector 27 is equal to or less than a certain value, that is, checks whether the counter value has been shaken.
In ST26, when the value of the displacement detector 27 is not less than a certain value, the process proceeds to ST27, and a setting command is given for a measurement force in a direction opposite to the direction in which the displacement is completely lost. In ST26, the value of the displacement detector 27 is set. The process of ST27 is repeated until the value becomes a certain value or less. In ST26, when the value of the displacement detector 27 becomes a certain value or less, the process proceeds to ST28, and the value change amount of the displacement detector 27 within a certain time is within a certain range. Check if it exists.
In ST28, when the amount of change in the value of the displacement detector 27 within a certain time is not within a certain range, the process proceeds to ST29, and the measurement force at the center of the past two measurement forces or the measurement force half of the previously set measurement force is obtained. Then, a setting command is issued in the direction opposite to the direction in which the value of the displacement detector 27 changes, and the process of returning to ST26 is repeated.
When the value change amount of the displacement detector 27 within a certain time is within a certain range in ST28, it is determined in ST30 that the measurement arm 24 is balanced, and the process is terminated.

In the embodiment, the measurement posture / measurement force control circuit 70 has the configuration shown in FIG. 5, but is not limited to this configuration. For example, the circuit configuration shown in FIG.
The measurement posture / measurement force control circuit 70 shown in FIG. 14 calculates the switching operation speed of the measurement arm 24 based on the pulse signal (position information) from the displacement detector 27, and the calculated switching operation speed is calculated in advance. Arithmetic control means 77 for generating a voltage (control signal) so as to achieve a set command speed, a digital / analog converter 73 for converting the voltage (control signal) from the arithmetic control means 77 into an analog signal, and this digital analog This is a configuration including a constant current circuit 76 that generates a current to be passed through the voice coil 62 based on an output from the converter 73.

  According to such a configuration, when the measurement arm 24 is switched from one direction to the other by the measurement arm posture switching mechanism 60, the number of pulse signals (corresponding to the amount of arc motion of the measurement arm 24) Position information) is output. Then, the calculation control means 77 measures the time from the start of movement, calculates the current operating speed of the measurement arm 24 from the measurement time and the pulse signal (position information) from the displacement detector 27, and calculates this calculation. The operation speed is compared with a command speed corresponding to the operation command given from the control device 101, and a voltage (control signal) is generated so that the operation speed becomes the command speed. As a result, a current that flows from the constant current circuit 76 to the voice coil 62 is generated based on the control signal from the arithmetic control means 77, so that the operation speed of the measurement arm 24 can be maintained at the command speed. Therefore, the same effect as the above example can be expected.

  In addition, the relative movement mechanism 40 is configured to be able to move the stage 10 in the Y-axis direction and the stylus displacement detection means 20 in the X-axis direction and the Z-axis direction, but is not limited thereto. In short, as long as the stage 10 and the stylus displacement detection means 20 can move in the three-dimensional direction, either of them may move.

  The present invention can be used, for example, when the inner surface of a hole or the thickness of a plate-like object to be measured is automatically measured.

10 ... stage,
20 ... Stylus displacement detection means,
22 ... Bracket (main body)
23 ... Rotating shaft (support shaft),
24 ... Measurement arm,
24A ... first measurement arm,
24B ... second measuring arm,
25. Detachable mechanism,
26A, 26B ... Stylus,
27: Displacement detector,
27A ... scale,
27B: Detection head,
28 ... casing, 40 ... relative movement mechanism,
60: Measuring arm posture switching mechanism (measuring force applying means),
61 ... Magnet,
62 ... voice coil,
70 ... Measuring posture / measuring force control circuit (speed control mechanism),
81 ... 1st plate,
82 ... second plate,
83 ... positioning mechanism,
84A, 84B ... Cylindrical positioning member,
85 ... first seating section,
86 ... Second seating section,
87 ... the third seating section,
88, 89, 90 ... engaging ball part,
91, 92 ... engagement holes,
93, 94 ... engaging pins,
95: Magnet,
96 ... magnetic material,
97, 98, 99 ... seating sensor,
100: Contact detection circuit,
101. Control device (drive stop means, balance adjustment means).

Claims (3)

A measurement arm that is supported on the main body so as to be capable of arc motion with a support shaft as a fulcrum, a stylus provided at the tip of the measurement arm, a displacement detector that detects the amount of arc motion of the measurement arm, and a direction of arc motion of the measurement arm A detecting means having a measuring force applying means for applying a measuring force to the stylus, a stage for placing an object to be measured, and a relative movement mechanism for relatively moving the detecting means and the stage, In a state where the stylus is in contact with the surface of the object to be measured, the arc movement of the measuring arm is detected by the displacement detector while the detection means and the stage are relatively moved by the relative movement mechanism, and the arc movement is detected. In the surface texture measuring machine that measures the surface texture of the object to be measured from
The measurement arm is provided on the main body so as to be capable of circular motion with the support shaft as a fulcrum, and is detachably provided at the tip of the first measurement arm via an attachment / detachment mechanism, and the stylus is provided at the tip. A second measuring arm having
The measurement force applying means includes a voice coil that urges the measurement arm in the arc motion direction with the support shaft as a fulcrum,
After replacement of the second measuring arm, Bei give a balance adjusting means for adjusting the balance of the measuring arm by adjusting the current supplied to the voice coil,
The balance adjusting means adjusts the current applied to the voice coil while monitoring the arc momentum of the measurement arm detected by the displacement detector, and the arc momentum of the measurement arm becomes a preset set value. Complete the balance adjustment at the stage
A surface texture measuring machine characterized by that. In the surface texture measuring machine according to claim 1 ,
The stylus has a pair of styluses respectively protruding toward the arc movement direction at the tip of the measurement arm;
The voice coil constitutes a measurement arm posture switching mechanism that switches between a posture in which the measurement arm is biased in one direction of the arc motion direction and a posture biased in the other direction.
A surface texture measuring machine characterized by that. In the surface texture measuring machine according to claim 2 ,
A speed control mechanism that controls the switching operation speed of the measurement arm to a preset speed when the posture of the measurement arm is switched by the measurement arm posture switching mechanism;
A surface texture measuring machine characterized by that.

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