JP4091851B2 - Collision detection device for contact type measuring machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a collision detection device for a contact-type measuring machine.
[0002]
[Background]
Conventionally, as a measuring instrument having a function of minimizing damage to a probe supporting the measuring element when an external force of a certain level or more is applied to the measuring element, the roundness measuring instrument 1 as shown in FIG. It has been known.
The roundness measuring machine 1 includes a main body 10, a measured object rotating mechanism 20 that is disposed near one side of the upper surface of the main body 10 and that rotates the measured object W, and is perpendicular to the other side of the upper surface of the main body 10. A column 30 erected, a slider 31 provided so as to be movable up and down in the longitudinal direction of the column 30, a horizontal arm 32 provided so as to be movable in a direction in which the slider 31 is separated from and to be measured, A probe 50 is provided at the tip of the horizontal arm 32 so as to be replaceable.
In the roundness measuring instrument 1, relative movement means for moving the probe 50 and the object W to be measured relative to each other includes the object rotation mechanism 20, a slider 31, and a horizontal arm 32.
[0003]
As the probe 50, for example, a configuration as shown in Non-Patent Document 1 is known. That is, as shown in FIG. 7 , the probe 50 includes a probe main body 51 provided at the tip of the horizontal arm 32 and a holder supported so as to be displaceable and returnable by a fulcrum (not shown) of the probe main body 51. The main body 521, the stylus 53, and the stylus holder 52 configured to include the leaf spring 522 that holds the stylus 53 interchangeably and elastically as shown in FIG. 8.
The holder main body 521 includes a support body 521A supported so as to be displaceable and returnable at a fulcrum of the probe main body 51, and a side surface support body 521B that supports the side surface of the stylus 53.
The leaf spring 522 is bent to have a substantially cross-sectional shape, and a convex portion 522A is provided in the vicinity of the bent vertex.
The side support body 521B and the leaf spring 522 are screwed to the support body 521A in the vicinity of their base ends so as to be substantially opposed to each other.
[0004]
The stylus 53 is engaged with a measuring element 531 that abuts the workpiece W on the side surface of the stylus 53 at a position where the convex portion 522A abuts when the stylus 53 is held by the stylus holder 52. When the external force acting on the stylus 53 is less than a certain value, the stylus 53 is positioned at a fixed position of the holder main body 521 by the engagement of the convex portion 522A and the concave portion 532.
[0005]
The roundness measuring device 1 is used, for example, when the stylus 53 collides with a foreign object during the movement of the probe 50, or when the probe 531 cannot move smoothly on the surface of the workpiece W during measurement, that is, the stylus. When an external force of a certain level or more is applied to 53, the stylus 53 is shifted from the fixed position, the leaf spring 522 is elastically deformed in a direction away from the stylus 53, and the stylus 53 is detached from the stylus holder 52, thereby further probes. 50 damages were avoided.
[0006]
On the other hand, there is known a measuring machine configured to include command means for detecting an abnormal state and instructing movement control of the measuring element when an external force of a certain level or more is applied to the measuring element (for example, a patent) References 1 and 2).
[0007]
[Non-Patent Document 1]
Mitutoyo Precision Measuring Instruments / General Catalog Catalog No. 13 Issued April 2001 Issued: Mitutoyo Corporation Page 409 Standard Detector Code No. 12AAB802
[Patent Document 1]
JP 2000-146666 A [Patent Document 2]
Japanese Patent Laid-Open No. 2001-147115
The measuring machine of Patent Literature 1 includes a movable lever body, a measuring element holder having a measuring element, and a three-point support mechanism that positions the measuring element holder in a fixed position with respect to the movable lever body and supports the moving element. A detector configured to measure the dimension of the object to be measured from the amount of movement of the probe; and a command unit that detects the movement of the probe holder when the probe holder is displaced from a fixed position and controls the movement of the detector. Yes.
[0009]
The three-point support mechanism includes three positioning means provided at an interval of 120 ° between the distal end side surface of the movable lever main body and the proximal end side surface of the measuring element holder, and a pull having both ends fixed to the movable lever main body and the holder main body. And a spring.
The positioning means includes a pair of conductive spheres provided on the distal end side surface of the movable lever, and a conductive cylindrical body that is engaged between the spheres and provided on the proximal end side surface of the holder body. It is configured.
The command means has a collision detection circuit in which two spheres and one cylindrical body of the positioning means are used as contacts, and each contact is electrically arranged in series via a conductor.
Usually, since the spherical body and the cylindrical body of each contact are in contact with each other by the action of the tension spring, the collision detection circuit is closed and the probe holder is positioned at a fixed position.
[0010]
In this measuring machine, when an external force of a certain level or more is applied to the measuring element, the measuring element holder is displaced from the fixed position due to the elastic deformation of the tension spring. When the collision detection circuit is opened, the command means detects an abnormal state and controls the movement of the detector.
[0011]
The collision detection device (hereinafter abbreviated as “Z-direction collision detection device”) in the measuring machine of Patent Document 2 includes a holder attached to a non-contact type probe, a ring-shaped collision detection unit, and this collision detection unit as a holder. On the other hand, there are provided holding means for holding the non-contact type probe so as to be displaceable and returnable in the axial direction, and command means for detecting the movement of the collision detector relative to the holder and controlling the movement of the non-contact type probe.
When an object collides with the collision detection unit, the collision detection unit moves in the axial direction (Z direction) of the probe with respect to the holder, and this is detected by the command means to control the movement direction of the non-contact type probe.
For collisions in the direction perpendicular to the axial direction of the non-contact type probe, an XY direction collision detection device having the same functions as the three-point support mechanism and command means of Patent Document 1 is provided at the tip of the Z direction collision detection device. The collision was detected by installing.
[0012]
[Problems to be solved by the invention]
However, for example, in the measuring instrument of Patent Document 1, a tension spring that supports a probe holder on a movable lever body, and a sphere and a cylinder having a switch function of command means are provided as separate members.
In the collision detection circuit, since each contact is electrically arranged in series via a conductor, for example, an abnormal state is detected even if one of the conductors is disconnected, and an external force acts on the probe. Even if not, the command means may malfunction and the movement of the detector may be controlled.
The Z-direction collision detection device of Patent Document 2 is configured so that the tip of the collision detection unit is located between the tip of the non-contact type probe and the object to be measured, and is therefore used for a measuring machine having a contact type probe. I could not.
[0013]
An object of the present invention is to provide a collision detection device for a contact-type measuring machine that can reliably detect a collision with a simple configuration.
[0014]
[Means for Solving the Problems]
A collision detection apparatus for a contact-type measuring machine according to the present invention includes a probe main body, a stylus holder supported on the probe main body so as to be displaceable and returnable, a probe having a stylus held by the stylus holder, and the probe. A relative movement means for relatively moving the object to be measured, wherein the stylus holder is supported by the probe body so as to be displaceable and returnable, and the stylus can be exchanged with the holder body in a resilient manner. A contact that measures the size and surface properties of the object to be measured based on the displacement of the stylus holder while the probe and the object to be measured are relatively moved by the relative movement means. In the collision detection device of the type measuring machine, the one contact having conductivity formed on at least a part of the spring; Provided between the stylus and the spring, positioning the stylus at a fixed position with respect to the holder body, and shifting the stylus from the fixed position when an external force of a certain level or more is applied to the stylus; and Positioning means for elastically deforming the spring, the other contact having conductivity that contacts or separates the one contact when the spring is elastically deformed, and the one contact and the other contact when contact or spaced, to the relative movement unit, stopping the relative movement of the probe relative to the object to be measured, or, the probe is commanded relative movement in the direction of retraction with respect to the object to be measured And command means.
[0015]
According to the present invention, when an external force of a certain level or more is applied to the stylus, the positioning means shifts the stylus from the fixed position and elastically deforms the spring holding the stylus. When the spring is elastically deformed, the one contact and the other contact are brought into contact with or separated from each other, and at this time, the command means stops the relative movement of the probe relative to the object to be measured or the foreign object, or the object to be measured or Commands relative movement in the direction in which the foreign object and the probe retract. One contact and the other contact have a switch function of command means.
Therefore, the spring has a function of holding the stylus and a switch function of the command means, and it is not necessary to use a separate member for holding the stylus and the switch of the command means as in the prior art. The number can be reduced and the configuration can be simplified.
Since the stylus is held by a stylus holder including a spring and is easily displaced from a fixed position by an external force exceeding a certain level acting on the stylus, an abnormal state can be reliably detected.
Since it is the structure which detects the external force more than the fixed which acts directly on a stylus, it can be used for a contact-type measuring machine.
[0016]
In the collision detection device for a contact-type measuring machine according to the present invention, the stylus holder includes the holder body supported by the probe body so as to be displaceable and returnable in a direction substantially orthogonal to the axis of the stylus, and the spring. The one contact and the other contact are arranged to face each other in a displacement direction of the stylus holder, and a measuring element provided on a side surface of the stylus in the displacement direction of the stylus holder is provided. When an external force that is less than a certain amount in the direction opposite to the measurement direction, which is the direction in which the stylus is displaced, is applied to the stylus when measuring the dimensions and surface properties of the measurement object while contacting the measurement object to, the stylus that is displaced together with the spring remains positioned in the position in the opposite direction by the positioning means, wherein the contacts are contact Or it is desirable that the instruction apart from is arranged to be outputted.
According to the present invention, when an external force in the measurement direction is applied to the stylus, the stylus holder holding the stylus is displaced in a direction in which the command means is not operated, so the command is not output, but the stylus is opposite to the measurement direction. When an external force in the direction is applied, the stylus holder is displaced in the direction in which the command means is operated, so that a command is output.
Therefore, an abnormal state can be detected even if the external force in the direction opposite to the measurement direction acting on the stylus is less than a certain level .
[0017]
In the collision detection device for a contact-type measuring machine according to the present invention, the positioning means is provided in a concave portion provided in one of the stylus and the spring, and provided in the other of the stylus and the spring, It is desirable to have a convex portion that engages with the concave portion.
According to the present invention, since the positioning means is provided with the concave portion and the convex portion that can be easily disengaged, the engagement between the concave portion and the convex portion is released when a certain external force acts on the stylus. By doing so, this abnormal state can be detected.
Therefore, the positioning means can be constituted by a concave portion and a convex portion having a simple structure.
[0018]
In the collision detection device for a contact-type measuring machine according to the present invention, it is desirable that at least one of the concave portion and the convex portion is formed in a substantially cone shape.
According to the present invention, since the concave portion and / or the convex portion are formed in a substantially cone shape having a slope, the concave portion and the convex portion are smoothly shifted along the slope of the substantially cone shape, and the spring is also continuously formed. Elastically deforms. Therefore, contact or separation between one contact and the other contact can be detected more instantaneously.
With a set of concave and convex portions, it is possible to detect an external force of a certain level or more from all directions acting on the stylus.
[0019]
In the collision detection device of the contact-type measuring machine according to the present invention, it is preferable that the spring and the one contact are formed by a single leaf spring, and the concave portion or the convex portion is provided in the leaf spring. .
According to the present invention, since one leaf spring is provided with one contact having the switch function of the command means and the concave portion or the convex portion as the positioning means, the number of parts can be reduced and the configuration can be simplified. Can do.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a probe 40 having a collision detection device for a contact-type measuring machine according to an embodiment of the present invention.
In the description of FIGS. 1 to 4, the same constituent elements as those in FIGS. 6 to 8 described above are denoted by the same reference numerals, and the description thereof is omitted or simplified.
The probe 40 is attached to the roundness measuring device 1 described above.
As shown in FIG. 1, the probe 40 is held by a probe main body 41, a stylus holder 42 supported by a fulcrum (not shown) of the probe main body 41 so as to be displaceable and returnable, and the stylus holder 42. The stylus 43 is provided.
[0021]
The stylus holder 42 includes a holder main body 521 that is swingably supported by a fulcrum of the probe main body 41, and a collision detection leaf spring 422 that can exchange and elastically hold the stylus 43 on the holder main body 521. .
The holder main body 521 includes a support body 521A and a side surface support body 521B.
The side support body 521B and the collision detection leaf spring 422 are screwed to the support body 521A in the vicinity of their base ends so as to face each other.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
The contact surface of the side support body 521B with the stylus 43 is formed as a curved surface along the side surface shape of the stylus 43 as shown in FIG.
The collision detection leaf spring 422 includes a convex portion 422A as a positioning means formed in a conical shape on a surface substantially opposite to the stylus 43, and a contact 422B at the tip of the back surface of the surface on which the convex portion 422A is provided. I have.
The collision detection leaf spring 422 is provided so as to be elastically deformable only in the direction of separating from and contacting the side surface support 521B.
[0022]
The probe main body 41 has an electrical contact leaf spring 411 as the other contact with which the contact 422B is brought into contact when the collision detection leaf spring 422 is elastically deformed. The measuring object rotating mechanism 20, the slider 31, and the horizontal arm 32) are instructed to stop the relative movement of the probe 40 with respect to the object to be measured W or to move in a direction in which the object to be measured W and the probe 40 are retracted. And command means (not shown) for issuing an abnormality alarm and notifying the operator of the abnormal state.
The contact 422B and the electrical contact leaf spring 411 are disposed to face each other in the displacement direction of the stylus holder 42, and both of them have a switch function of command means.
[0023]
The stylus 43 includes a measuring element 531 on the side surface of the tip, and a concave portion 432 serving as a positioning unit with which the convex portion 422A is engaged when the stylus 43 is held between the stylus holder 42. The concave portion 432 is formed in a conical shape corresponding to the vicinity of the tip of the convex portion 422A.
When the external force acting on the stylus 43 is less than a certain value, the stylus 43 is positioned at a fixed position of the holder main body 521 by the engagement between the convex portion 422A and the concave portion 432.
[0024]
The operation of this embodiment will be described.
For the sake of explanation, as shown in FIG. 3, the external force in the measurement direction (the displacement direction of the stylus holder 42) is Fx1, the external force in the direction opposite to the measurement direction is Fx2, and the external force in the direction orthogonal to the measurement direction is Fy1, Fy2. The external force from the tip direction of the stylus 43 is Fz2.
When a force in the measuring direction, that is, an external force in the Fx1 direction is applied to the stylus 43, the stylus holder 42 is displaced by this external force, and the contact 422B and the electric contact leaf spring 411 are separated from each other.
[0025]
Conversely, a force in the direction opposite to the measurement direction is applied to the stylus 43, for example, as shown in FIG. 4, when the stylus 43 collides with the workpiece W or the object M, an external force in the Fx2 direction is applied to the stylus 43. When acting, the stylus holder 42 is displaced by this external force, and the contact 422B and the electric contact leaf spring 411 come into contact with each other. By this contact, the command means causes the relative movement means to stop the relative movement of the probe 40 with respect to the object W or the object M or to move relative to the object W or the object M and the probe 40 in the retracting direction. In addition to commanding, an abnormal alarm is issued to notify the operator of the abnormal state.
That is, the command means operates even if the external force acting on the stylus 43 is less than a certain value.
[0026]
When an external force in the Fy1, Fy2 or Fz2 direction as shown in FIG. 1 acts on the stylus 43, the external force from these directions is different from the displacement direction of the stylus holder 42. The stylus holder 42 is not displaced and the command means does not operate.
However, when the external force exceeds a certain level, the engagement between the convex portion 422A and the concave portion 432 is released, and the convex portion 422A is relatively shifted along the slope of the concave portion 432. Then, the collision detection leaf spring 422 is elastically deformed and the contact 422B and the electrical contact leaf spring 411 are in contact with each other, so that a command such as a relative movement stop is issued from the command means.
[0027]
According to the above-described embodiment, there are the following effects.
Since the collision detection leaf spring 422 has a function of sandwiching the stylus 43 and a switch function of the command means, and it is not necessary to separately provide a stylus holder and a switch of the command means, the number of parts Therefore, a simple configuration can be obtained.
The stylus 43 is sandwiched by a stylus holder 42 including a collision detection leaf spring 422, and is easily displaced from a fixed position by a certain external force acting on the stylus 43, so that an abnormal state can be reliably detected. Can do.
In particular, in the present embodiment, the contact 422B and the electrical contact leaf spring 411 are arranged opposite to each other in the displacement direction of the stylus holder 42, so that the external force in the direction opposite to the measurement direction acting on the stylus 43 (Fx2 direction) is less than a certain value. Even so, this abnormal state can be detected.
[0028]
Since it is the structure which detects the external force more than the fixed which acts directly on the stylus 43, it can be used for a contact-type measuring machine.
In addition, by changing the elastic force of the collision detection leaf spring 422 or the distance between the contact 422B and the electric contact leaf spring 411 when no external force is applied to the stylus 43, the abnormal state detection sensitivity can be easily changed. Can do.
[0029]
Since the positioning means is provided with the convex portion 422A and the concave portion 432 that can be easily disengaged, the engagement between the convex portion 422A and the concave portion 432 is released when a certain external force is applied to the stylus 43. Thus, this abnormal state can be detected.
Therefore, the positioning means can be constituted by the convex portion 422A and the concave portion 432 having a simple structure.
[0030]
Since the convex portion 422A and the concave portion 432 are formed in a conical shape having a slope, the convex portion 422A and the concave portion 432 are smoothly shifted along the slope of the cone, and the collision detection leaf spring 422 is also continuously elastically deformed. . Therefore, the contact between the contact 422B and the electrical contact leaf spring 411 can be detected more instantaneously.
A set of convex portions 422A and concave portions 432 can detect an external force of a certain level or more from all directions acting on the stylus 43.
Further, if the apex angle of the cone is changed, the elastic deformation amount of the collision detection leaf spring 422 with respect to the relative displacement amount of the convex portion 422A and the concave portion 432 can be easily changed. Can be changed.
[0031]
Since the contact point 422B having the switch function of the command unit and the convex portion 422A as the positioning unit are provided in one collision detection leaf spring 422, the number of parts can be reduced and the configuration can be simplified.
[0032]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.
Although the convex portion 422A and the concave portion 432 have a conical shape, they may have a pyramidal shape, and any shape is acceptable as long as one is engaged with the other.
Although the stylus 43 is provided with the concave portion 432 and the collision detection leaf spring 422 is provided with the convex portion 422A, the stylus 43 may be provided with the convex portion and the collision detection plate spring 422 may be provided with the concave portion.
Although the positioning means is composed of a concave portion and a convex portion, another positioning means such as a magnet may be used.
[0033]
The switch of the command means is configured such that the command means operates when the contact 422B and the leaf spring 411 for electrical contact (hereinafter abbreviated as contacts) contact each other, but when the contacts are separated from each other. Alternatively, the command means may be configured to operate (break contact).
For example, the collision detection leaf spring 422 may be formed as shown in FIG. In this configuration, when an external force exceeding a certain level is not applied to the stylus 43, the command means does not operate because the contacts are in contact with each other. However, when an external force exceeding a certain level is applied, the collision detection leaf spring 422 is deformed and contacts Since they are separated from each other, the command means is activated.
Further, as shown in FIG. 5B, the stylus 43 is formed of a conductive material, the convex portion 422A has the role of a contact 422B, and the electric contact leaf spring 411 is formed with the stylus 43 and the side support 521B. It is good also as a structure provided in the part which contacts. In this configuration, when a certain external force is not applied to the stylus 43, the contact means are in electrical contact with each other via the stylus 43, so that the command means does not operate, but a certain external force is applied to the stylus 43. Is removed from the stylus holder 42, the contacts are separated from each other, so that the command means is activated.
[0034]
As described above, the reliability of the collision detection device can be improved by configuring the switch of the command means with a break contact.
That is, when the make contact is used, even if the contacts are in contact with each other in an abnormal state, the command means may not operate without being electrically contacted due to the influence of rust and dust on the contacts.
On the other hand, when using break contacts, the contacts are always in contact with each other, so they are not easily affected by rust and dust, and the command means can be reliably operated when the contacts are separated in an abnormal state. it can. Also, in the normal state, even if the contacts are not in electrical contact under the influence of rust or dust and the command means is activated, there is no actual collision and there is little actual damage. It can be set as the structure which considered the safety.
[0035]
Although the electric contact leaf spring 411 is fixed to the probe main body 41, the electric contact leaf spring 411 may be fixed to the base end portion of the collision detection leaf spring 422 or the holder main body 521 through an insulating material. .
[0036]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the collision detection apparatus of a contact-type measuring machine which can detect a collision reliably with a simple structure can be provided.
[Brief description of the drawings]
FIG. 1 is a front view of a probe having a collision detection apparatus according to an embodiment of the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is an explanatory schematic diagram of an action direction of an external force acting on a probe in the embodiment.
FIG. 4 is an explanatory diagram of a collision detection method in the embodiment.
FIG. 5 is a front view of a main part of a collision detection device according to another embodiment of the present invention.
FIG. 6 is a front view of a conventional roundness measuring machine.
FIG. 7 is a front view of a probe of a conventional roundness measuring machine.
FIG. 8 is a front view of a probe of a conventional roundness measuring machine.
[Explanation of symbols]
1 Roundness measuring machine (contact type measuring machine)
20 Measured object rotation mechanism (relative movement means)
31 Slider (relative movement means)
32 Horizontal arm (relative movement means)
40 Probe 41 Probe body 42 Stylus holder 43 Stylus 411 Electrical contact leaf spring (the other contact)
422 Collision detection leaf spring (spring)
422A Convex part (positioning means)
422B contact (one contact)
432 recess (positioning means)
521 Holder body

Claims (5)

A probe main body, a stylus holder supported on the probe main body so as to be displaceable and returnable, a probe having a stylus held by the stylus holder, and a relative moving means for relatively moving the probe and the object to be measured. Prepared,
The stylus holder includes a holder main body that is displaceably and reversibly supported by the probe main body, and a spring that exchanges and elastically holds the stylus on the holder main body, and the relative movement means In the collision detection device of a contact-type measuring machine that measures the dimensions and surface properties of the object to be measured based on the displacement of the stylus holder while relatively moving the probe and the object to be measured,
One conductive contact formed on at least a portion of the spring;
Provided between the stylus and the spring, positioning the stylus in a fixed position with respect to the holder body, and shifting the stylus from the fixed position when an external force of a certain level or more is applied to the stylus; and Positioning means for elastically deforming the spring;
The other contact having electrical conductivity with which the one contact is contacted or separated when the spring is elastically deformed;
When the the one contact and the other contact is in contact with or spaced, to the relative movement means, the stop of the relative movement of the probe relative to the object to be measured, or, the probe relative to the object to be measured Command means for commanding relative movement in the direction of retreating,
A collision detection device for a contact-type measuring machine. In the collision detector of the contact type measuring machine according to claim 1,
The stylus holder is configured to include the holder body supported by the probe body so as to be displaceable and returnable in a direction substantially orthogonal to the axis of the stylus, and the spring.
The one contact and the other contact are arranged opposite to each other in the displacement direction of the stylus holder, and a measuring element provided on a side surface of the stylus in the displacement direction of the stylus holder is attached to the object to be measured. When an external force less than a certain amount in the direction opposite to the measuring direction, which is the direction in which the stylus is displaced when measuring the dimensions of the object to be measured and the surface properties, is applied to the stylus, By being displaced in the reverse direction together with the spring while being positioned at the fixed position by the positioning means, the two contacts are arranged to contact or separate from each other and the command is output.
A collision detection device for a contact-type measuring machine. In the collision detection apparatus of the contact-type measuring machine according to claim 1 or 2,
The positioning means includes a recess provided on one of the stylus and the spring, and a protrusion provided on the other of the stylus and the spring and engaged with the recess.
A collision detection device for a contact-type measuring machine. In the collision detection device of the contact type measuring machine according to claim 3,
At least one of the concave portion and the convex portion is formed in a substantially conical shape,
A collision detection device for a contact-type measuring machine. In the collision detection device for a contact-type measuring machine according to claim 3 or 4,
The spring and the one contact point are formed by a single leaf spring, and the leaf spring is provided with the concave portion or the convex portion.
A collision detection device for a contact-type measuring machine.

Images