JPH09264705A - Touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch sensor in which the number of electric contact sections is markedly reduced. SOLUTION: A contact probe 2 of which tip side is protruding from a housing 1 is supported so as to be swingable and movable in a direction of an axis by a bearing means 3 bearing the probe 2 on an axis G1 which is identical to an axis of the housing 1. A switch means 4 is provided in opposition to the contact probe 2 on the identical axis center such that it is normally pressed toward a side of the contact probe 2 by a spring and is displaced in the direction of the axis to be operated by being pressed by the contact probe 2.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch sensor mounted on a spindle of a numerically controlled machine tool with an automatic tool changer (ATC) known as a machining center and used for detecting a machining position of a work.

[0002]

2. Description of the Related Art A conventional touch sensor of this type is disclosed in JP-A-49-94370, which has movable contact pins projecting in three directions along a plane perpendicular to a contact probe. , Each of which is configured to be supported at three points by V-shaped fixed contacts.

[0003]

In the above-mentioned conventional touch sensor, since the positioning of the contact probe and the electric contact are also used, if the number of times of use increases, the slippage of the positioning portion becomes worse due to electric corrosion, and the position is restored. There is a problem in that the contact property of the contact portion is deteriorated and the contact is poor.
In addition, because of the three-point support, uniform measurement pressure is not applied in the entire circumferential direction, and even if a perfect circle is measured, a triangular value is output.
There is so-called directionality. Further, the spring pressure required for positioning is stronger than the optimum pressure for the electric contacts, so that the life of the contacts is shortened. Furthermore, since there are 6 places that become electrical contacts, the risk rate is higher.

The present invention is intended to solve the above problems by minimizing the number of electrical contact points.

[0005]

The invention according to claim 1 is
The contact probe 2 whose tip side projects from the housing 1 is
It is swingably and axially movably supported by a bearing means 3 which is mounted on the same axis G1 as the axis of the housing 1, and faces the contact probe 2 by a spring which is always on the same axis. The switch means 4 is provided which is urged toward the contact probe 2 and pressed by the contact probe 2 to be displaced in the axial direction to operate.

In the present invention, the axis G1 of the contact probe 2 and the axis G2 of the switch means 4 are aligned with each other in a neutral state where the contact probe 2 is not in contact with the object to be measured. Then, when the contact probe 2 in contact with the object to be measured is displaced from the neutral state in the X direction, the Y direction, or a combination thereof, the contact probe 2 swings through the bearing means 3, and the contact probe 2 2 The displacement of the rear end in the Z direction, that is, the displacement in the direction of the axis G1 causes the switch means 4 to be pressed and displaced in the direction of the axis G2, and the switch means 4 operates. Further, when the contact probe 2 is displaced in the Z direction, the switch means 4 is pressed and displaced in the direction of the axis G2 as it is by the displacement of the rear end of the contact probe 2 in the Z direction (direction of the axis G1), and operates.

As described above, according to the present invention, the electrical contact may be provided at one place of the switch means 4 which is opened and closed by the pressing action of the contact probe 2 and the action of the spring, and the switch means 4 presses the contact probe 2. By the action, the Z direction,
That is, since it operates by being displaced in the direction of the axis G2, it is possible to always perform accurate and stable detection.
In addition, the service life can be extended without causing contact failure or the like.

According to a second aspect of the present invention, in the touch sensor according to the first aspect, the cylindrical hole portion 11 coaxially provided on the housing 1 side and the contact probe 2 side are integrally formed. The spherical shaft 12 is slidable in line contact with the inner peripheral surface of the cylindrical hole 11. Therefore, according to the present invention, the spherical shaft portion 12 has the cylindrical hole portion 1.
Since it slides in line contact with the inner peripheral surface of 1 in the circumferential direction,
The sliding resistance when the contact probe 2 swings or is displaced in the axial direction is very small, and the detection accuracy of the contact probe 2 can be improved.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the touch sensor according to item 1, the disc-shaped contact body 6 is concentrically provided at the rear end of the contact probe 2, and the disc-shaped contact body 6 has a support surface 9 on the outer peripheral front surface on the housing 1 side at all times by a spring 10. Is supported in contact with. In this way, since the disk-shaped contact body 6 is contacted and supported by the support surface 9 on the housing 1 side by the spring 10, the contact probe 2 is accurately positioned in the same axial direction as the housing 1.

According to a fourth aspect of the present invention, in the touch sensor according to any of the first to third aspects, the switch means 4 is a through hole portion provided on the rear end side of the housing 1 along the axis thereof. 13, a hollow spool 14 that is slidably fitted in the axial direction, a spring 15 that biases the hollow spool 14 toward the contact probe 2, and a spring 21 that is built in the hollow spool 14 and is normally When the movable contact 19 is in the closed position where it contacts the fixed contacts 20 and 20, the movable pin 22 that is integral with the movable contact 19 and projects from the tip of the hollow spool 14 is pressed by the contact probe 2. It is composed of a switch with a built-in contact 16 which is in an open position.

According to the present invention, since the switch 16 composed of the movable contact 19 and the fixed contact 20 is built in the hollow spool 14, dust or the like does not adhere to the switch 16, and an accurate and good detection action is always obtained. It can be performed, and the operation is reliable because the switch 16 is a normally closed contact. Further, even if the rear end of the contact probe 2 is largely displaced in the Z direction, the hollow spool 14 moves backward in accordance with this, so that damage to the contact probe 2 can be prevented.

According to a fifth aspect of the present invention, in the touch sensor according to the fourth aspect, a linear bearing 23 is interposed between the hollow spool 14 and the through hole portion 13. Therefore, according to the present invention, the sliding resistance can be minimized, the accuracy stability of the hollow spool 14 can be ensured, and the service life thereof can be extended.

According to a sixth aspect of the present invention, in the touch sensor according to any one of the first to fifth aspects, the switch means 4 is a through hole provided on the rear end side of the housing 1 along the axis thereof. 13, a solid spool 28 fitted axially slidably, a spherical contact body 29 fixed to the tip of the solid spool 28, and the solid spool 28 is urged to project toward the contact probe 2 side. A spring 30, and a movable contact 31 in the form of a shaft and a fixed contact 32 in the form of a shaft by the spring 30 at all times.
And a contact exposure type switch 33 which is in an open position when the solid spool 28 is pressed by the contact probe 2 via the spherical contact body 29 in a closed position in contact with the contact point of the movable contact of the switch 33. Reference numeral 31 is fixed by penetrating through the solid spool 28 so that their axes are orthogonal to each other, and the fixed contact 32 is fixed on the housing 1 side, and at the same time, is extended to the solid spool 28 in the axial direction. It penetrates through the hole 34 and comes in contact with and separates from the movable contact on the axial center of the spool 28.

In the present invention, the solid spool 28
When is touched by the contact probe 2 via the spherical contact body 29, the movable contact 31 of the contact exposure type switch 33 moves to the open position because the movable contact 31 is separated from the fixed contact 32. In this invention, since the switch 33 is exposed, the movable contact 3
1. It becomes easy to inspect and repair the fixed contacts 32 and the like. Also,
Since the switch 33 is also a normally closed contact, the switch operation is reliable.

According to a seventh aspect of the present invention, in the touch sensor according to the sixth aspect, a linear bearing 23 is interposed between the solid spool 28 and the through hole portion 13. Therefore, according to the present invention, the sliding resistance can be minimized, the accuracy stability of the solid spool 28 can be ensured, and the service life thereof can be extended.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1 showing a touch sensor according to the present invention, 1 is a cylindrical housing, 2 is a contact probe whose tip end side projects from the housing 1, and the rear end of this contact probe 2 is It is swingably and axially movably supported by bearing means 3 which bears on the same axis as the axis of the housing 1. Reference numeral 4 denotes a switch means provided on the same axis as the contact probe 2 so as to face each other. The switch means 4 is normally urged toward the contact probe 2 side and pressed by the contact probe 2. By doing so, it operates by being displaced in the axial direction, that is, ON
The signal is sent to a control circuit (not shown).

The contact probe 2 has a contactor 5 at the tip and a disk-shaped contactor 6 integrally formed concentrically at the rear end. The disk-shaped contact body 6 accurately positions the contact probe 2 in the same axial direction as the housing 1. The ring-shaped contact body 6 is concentrically arranged on the tip end side in the housing 1 and is bolted 7 to the ring member 8. The coil spring 10 is disposed so as to face the rear end support surface 9 and is normally supported by the coil spring 10 interposed between the contact body 6 and the ring member 8 in line contact with the support surface 9. . Three coil springs 10 are arranged at intervals of 120 degrees in the circumferential direction.

As can be seen from the enlarged view of FIG. 2, the bearing means 3 has a cylindrical hole portion 11 formed concentrically at the center of the ring member 8 and a concentric hole at the rear end of the contact probe 2. And a spherical shaft portion 12 that is slidable in line contact with the inner peripheral surface of the cylindrical hole portion 11.

The switch means 4 has a hollow spool 14 which is axially slidably fitted in a through hole 13 formed along the axis of the rear end of the housing 1 and has a hollow spool. The coil spring 15 interposed between the head 14a of the spool 14 and the housing 1 so as to urge the spool 14 toward the contact probe 2 side, and the hollow spool 1
4 and a switch 16 with a built-in contact. As shown in FIG. 3, this switch 16 with a built-in contact has a rod-shaped fixed contact 20 to which a spherical movable contact 19 can abut at the tip end side in an insulating casing 18 coaxially housed in a hollow spool 14. , 20 are provided, and the movable contact 19 is normally urged by the coil spring 21 so as to abut the fixed contacts 20, 20, and the movable pin 22 integrally connected to the movable contact 19 is connected to the casing 18 and the spool 14. The head 14a is slidably pierced to protrude from the tip end surface of the spool 14 by a required length.
4 The movable pin 22 protruding from the tip end surface is pressed by the contact probe 2, so that the movable contact 19 is separated from the fixed contacts 20 and 20 against the urging force of the coil spring 21 and is brought to the open position, whereby control is performed. ON to the circuit (not shown)
The signal is sent out. In FIGS. 1 and 3, reference numerals 24a and 24b denote a movable contact 19 and a fixed contact 20.
Are the lead wires respectively connected to.

A linear bearing 23 is interposed between the hollow spool 14 and the through hole portion 13 of the housing 1. Further, a stopper nut member 25 is screwed into the rear end portion of the hollow spool 14, and the nut member 25 is brought into contact with the rear end surface 1a of the housing 1 to allow the hollow spool 14 to be wound by the coil spring 15. The amount of protrusion of the hollow spool 14 can be adjusted by appropriately rotating the nut member 25. The spring force of the coil spring 15 is larger than the spring force of the coil spring 21 of the contact type switch 16. In addition, the tip of the movable pin 22 provided in the switch 16 with a built-in contact has a slight gap with respect to the rear end surface 2a of the contact probe 2 that faces the switch.

In FIG. 1, reference numeral 26 is a dustproof cover provided between the contact probe 2 and the tip of the housing 1, and 27 is a cover body attached to the rear end of the housing 1.

The operation of the touch sensor having the above-described structure will be described. FIG. 1 shows a neutral state in which the contact probe 2 is not in contact with the object to be measured. The axis G1 is on the same axis as the axis of the housing 1, the axis G1 of the contact probe 2 and the axis G2 of the switch means 4 are aligned, and the disk at the rear end of the contact probe 2 is present. The contact member 6 is in line contact with the rear end support surface 9 of the ring member 8, and there is a slight gap between the rear end surface of the disc contact member 6 and the tip of the movable pin 22 of the switch means 4.

Thus, from the neutral state of FIG. 1, the contact 5 of the contact probe 2 contacting the object to be measured (not shown) becomes
When the contact probe 2 is displaced in the front-back direction (X direction), the up-down direction (Y direction) or a combination thereof on the paper surface.
Oscillates via the bearing means 3, and the disk-shaped contact body 6 at the rear end portion of the contact probe 2 is partially separated from the support surface 9 of the ring member 8, whereby the rear end surface of the disk-shaped contact body 6 ( The rear end surface of the contact probe 2 is tilted and displaced, and the movable pin 22 of the switch means 4 is pushed by the displacement of the rear end surface of the disk-shaped contact body 6 in the Z direction (displacement of the axis G1). 16 movable contacts 19 are fixed contacts 20 and 2
The open position is set apart from 0. As a result, an ON signal is sent to the control circuit (not shown). When the contact probe 2 is displaced in the X direction, the Y direction, or the combined direction thereof, the disk-shaped contact body 6
Partially comes into contact with the support surface 9 in the circumferential direction, and the contact portion and the portion diametrically opposed to each other are separated from each other.

The switch means 4 operates when only the movable pin 22 of the switch 16 with a built-in contact is pressed by the displacement of the rear end face of the disk-shaped contact body 6 in the Z direction (displacement in the axial center G1 direction). However, when the disc-shaped contact body 6 is further displaced and a pressing load is applied to the hollow spool 14,
The hollow spool 14 slides in the through hole 13 along the axis G2 against the coil spring 15, and the load is absorbed. Since the linear bearing 23 is interposed between the hollow spool 14 and the through hole portion 13, the sliding resistance can be minimized, the stability of the accuracy of the hollow spool 14 can be ensured, and the use thereof can be improved. The life can be extended.

The bearing means 3 comprises a cylindrical hole portion 11 provided in the ring member 8 and a spherical shaft portion 12 formed integrally with the contact probe 2, and the spherical shaft portion. Since 12 slides in the circumferential direction in line contact with the inner peripheral surface of the cylindrical hole 11, the sliding resistance when the contact probe 2 swings or is displaced in the axial direction is increased. It is very small, and the detection accuracy of the contact probe 2 can be improved. The inner peripheral surface of the cylindrical hole portion 11 and the spherical shaft portion 12
There is actually a very small gap between the contact probe 2 and
At the time of swinging, the spherical shaft portion 12 has a cylindrical hole portion 1 in the swinging direction.
Since it comes into contact with the inner peripheral surface of No. 1, the opening and closing precision of the contacts of the switch means 4 is suppressed to the micron unit, and there is no inconvenience.

When the contact 5 of the contact probe 2 is separated from the object to be measured, the contact probe 2 is returned to the original neutral state by the spring force of the coil spring 10, and the switch means 4 is provided with the contact built-in switch 16. The movable contact 19 comes into contact with the fixed contact 20 by the spring force of the coil spring 21 to return to the closed position, and is brought into a non-operating state.

Further, when the contact 5 of the contact probe 2 comes into contact with the object to be measured and is displaced leftward (Z direction) from the neutral state of FIG. 1, the movable pin 22 of the switch means 4 makes a disc-shaped contact. Z at the rear end surface of the body 6 (rear end surface of the contact probe 2)
Direction, that is, the axial center G2 direction, the movable contact 19 is separated from the fixed contacts 20 and 20 to the open position, whereby an ON signal is sent to the control circuit (not shown). When the contact 5 of the contact probe 2 separates from the object to be measured, the switch means 4 returns to their original neutral states.

FIG. 4 shows another touch sensor according to the present invention. This touch sensor is the same as the touch sensor shown in FIG. 1 except for the switch means 4, and the same members as the touch sensor shown in FIG. The same reference numerals are given and the description is omitted. The switch means 4 of the touch sensor shown in FIG. 4 includes a solid spool 28 which is axially slidably fitted in a through hole portion 13 provided on the rear end side of the housing 1 along the axis G2 thereof. The spherical contact member 29 fixed to the tip of the solid spool 28, the coil spring 30 for biasing the solid spool 28 to project from the through hole 13 toward the contact probe 2, and the coil spring 30 at all times The shaft-shaped movable contact 31 is in the closed position where the shaft-shaped fixed contact 32 is in contact with the shaft-shaped fixed contact 32, and the spherical contact body 29 has the contact probe 2
The contact exposure type switch 33 is brought into an open position by being pressed by.

As shown in FIGS. 4 to 6, the movable contact 31 of the contact exposure type switch 33 is provided at the rear end of the solid spool 28 so as to pass therethrough such that their axes are orthogonal to each other. . The fixed contact 32 penetrates an elongated hole 34 formed in the solid spool 28 in the axial direction, and both ends of the fixed contact 32 are fixed to a donut-shaped insulator 35 attached to the rear end of the housing 1. It is configured to come into contact with and separate from the movable contact 31 on the axis G2 of the spool 28. In addition, the movable contact 31 has the solid spool 2 on the rear end surface of the insulator 35.
A pair of guide pins 36, 36 provided so as to project in parallel with 8 are guided. In FIGS. 5 and 6, 37a is a housing side electrode, 38a is a lead wire thereof, 37b is a contact side electrode, and 38b is a lead wire thereof.

The operation of the touch sensor of FIG. 4 described above will be described.
Is in a neutral state where it is not in contact with the object to be measured, the axis G1 of the contact probe 2 and the axis G2 of the switch means 4 are aligned, and the spherical contact body 29 of the switch means 4 is present.
Does not contact the rear end face of the disk-shaped contact body 6, and there is a slight gap between them.

Then, from the neutral state of FIG. 4, the contact 5 of the contact probe 2 contacting the object to be measured (not shown) becomes
When it is displaced in the front-back direction (X direction), the vertical direction (Y direction), or a combination thereof on the paper surface, the contact probe 2 swings around the bearing means 3 to form a disk-shaped rear end portion of the contact probe 2. By partially separating the contact body 6 from the support surface 9 of the ring member 8, the rear end surface of the disk-shaped contact body 6 (the rear end surface of the contact probe 2) is tilted and displaced, whereby the solid shape of the switch means 4 is formed. The spool 28 is the spherical contact body 2
The movable contact 31 is separated from the fixed contact 32 to the open position by being pushed in the direction of the axis G2 (Z direction) via the shaft 9. As a result, an ON signal is sent to the control circuit (not shown). Also, the contact probe 2
When the contact 5 is displaced in the Z direction, the displacement of the contact probe 2 in the Z direction pushes the solid spool 28 in the Z direction through the spherical contact body 29 as it is, and the movable contact 31 moves the fixed contact 32. To the open position.

In this case, in the switch means 4, the solid spool 28 is pressed by the displacement of the rear end surface of the disk-shaped contact body 6 (rear end surface of the contact probe 2) through the spherical contact body 29 in the Z direction, that is, the axis. It is displaced in the direction of the heart G2 and operates. Then, when the rear end of the disk-shaped contact body 6 is further displaced and a pressing load is applied to the solid spool 28, the solid spool 28 resists the coil spring 30 and moves in the through hole 13 along the axis G2. Sliding displacement. In addition, the solid spool 28
Since the linear bearing 23 is interposed between the through hole portion 13 and the through hole portion 13, the sliding resistance can be minimized and the spool 2
It is possible to secure the stability of accuracy of No. 8 and extend the service life thereof. Incidentally, in FIG. 1 and FIG.
Is a detent pin fixed in the housing 1, and is loosely fitted in the through hole portion 6 a of the disk-shaped contact body 6.

[0033]

According to the invention of claim 1, when the contact probe is displaced in the X direction, the Y direction, or a combination thereof, the contact probe swings through the bearing means, and the rear end of the contact probe moves. The switch means is displaced in the Z direction, whereby the switch means is pressed to operate, and the Z direction displacement of the contact probe causes the switch means to be pressed and operated as it is at the rear end of the contact probe. It is sufficient that the switch means is opened and closed by the pressing action of the contact probe and the action of the spring at one place, and the switch means is displaced by the pressing action of the contact probe in the Z direction, that is, the axial direction thereof. Therefore, accurate and stable detection can be always performed, and the service life can be extended without causing contact failure or the like.

According to the second aspect of the present invention, since the spherical shaft portion slides in line contact with the inner peripheral surface of the cylindrical hole portion in the circumferential direction, the contact probe swings or moves in the axial direction. The sliding resistance when displaced is very small, and the detection accuracy of the contact probe can be improved.

According to the third aspect of the present invention, since the disk-shaped contact body is supported by the spring in contact with the supporting surface on the housing side, the contact probe can be accurately positioned in the same axial direction as the housing. .

According to the fourth aspect of the invention, since the switch composed of the movable contact and the fixed contact is built in the hollow spool, dust or the like does not adhere to the switch, and an accurate and good detection operation is always performed. Can be made. Further, even if the rear end of the contact probe is largely displaced in the Z direction, the hollow spool moves backward in accordance with this, so that damage to the contact probe can be prevented. Further, since the switch is a normally closed contact, the operation is reliable.

According to the invention of claim 5, the sliding resistance can be minimized, the stability of accuracy of the hollow spool can be ensured, and the service life thereof can be extended.

According to the invention of claim 6, since the switch is exposed, inspection and repair of the movable contact, the fixed contact and the like are facilitated. Further, since this switch is a normally closed contact, the switch operation can be performed reliably.

According to the invention of claim 7, the sliding resistance can be minimized, the accuracy stability of the solid spool can be ensured, and the service life thereof can be extended.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a touch sensor according to the present invention.

FIG. 2 is an enlarged sectional view of a bearing means portion of the touch sensor of FIG.

FIG. 3 is an enlarged vertical sectional view showing a switch with a built-in contact.

FIG. 4 is a vertical cross-sectional view showing another example of the touch sensor according to the present invention.

5 is an end view of a rear end side of the touch sensor of FIG.

FIG. 6 is a perspective view of a contact exposure type switch of the touch sensor of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Contact probe 3 Bearing means 4 Switch means 5 Contact element 6 Disc-shaped contact body 8 Ring member 9 Support surface 10 Coil spring 11 Cylindrical hole part 12 Spherical shaft part 13 Through hole part 14 Hollow spool 15 Coil spring 16 Contact point Built-in switch 18 Casing 19 Movable contact 20 Fixed contact 21 Coil spring 22 Movable pin 23 Linear bearing 28 Solid spool 29 Spherical contact body 30 Coil spring 31 Movable contact 32 Fixed contact 33 Contact exposed switch

Claims (7)

[Claims] 1. A contact probe, the tip side of which protrudes from the housing, is oscillatably and axially movably supported by bearing means that bears on the same axis as the axis of the housing, and opposes the contact probe. The touch sensor is provided with a switch means which is normally biased by a spring toward the contact probe and is displaced in the axial direction by being pressed by the contact probe on the same axis. 2. The bearing means is formed integrally with a cylindrical hole portion provided coaxially on the housing side and on the contact probe side, and is in line contact with the inner peripheral surface of the cylindrical hole portion. The touch sensor according to claim 1, comprising a slidable spherical shaft portion. 3. A disk-shaped contact body is provided concentrically at the rear end of the contact probe, and the disk-shaped contact body is always supported by a spring with its outer peripheral front surface abuttingly supported by a supporting surface on the housing side. The touch sensor according to claim 1. 4. The switch means contacts a hollow spool, which is axially slidably fitted in a through hole provided on the rear end side of the housing along the axis of the switch. A spring that biases the probe toward the probe side, and a spring built into this hollow spool, which is normally in the closed position where the movable contact contacts the fixed contact by the spring, and is integrally formed with the movable contact to protrude from the end of the hollow spool. The touch sensor according to any one of claims 1 to 3, further comprising a switch with a built-in contact, which is brought into an open position when the movable pin is pressed by the contact probe. 5. The touch sensor according to claim 4, wherein a linear bearing is interposed between the hollow spool and the through hole. 6. The switch means comprises a solid spool fitted axially slidably in a through hole provided along the axis of the rear end of the housing, and a tip of the solid spool. A spherical contact body fixed to the portion, a spring for biasing the solid spool to project toward the contact probe, and a closed position where the shaft-shaped movable contact is normally in contact with the shaft-shaped fixed contact by the spring. , A contact-exposed switch in which the solid spool is brought into an open position by being pressed by a contact probe via a spherical contact body, and the movable contact of this switch is such that the axes of the switches are orthogonal to the solid spool. The fixed contact is fixed to the housing side and penetrates through a long hole opened in the axial direction of the solid spool so as to separate from and contact the movable contact on the axial center of the spool. Has become The touch sensor according to claim 1. 7. The touch sensor according to claim 6, wherein a linear bearing is interposed between the solid spool and the through hole portion.