JPH0131924Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a touch signal probe, particularly a touch signal probe that electrically detects contact with an object to be measured.

Three-dimensional measuring machines that measure the size and shape of a workpiece placed on a measurement base or devices that measure the position of a machine tool's tool rest and workpiece are well-known. In this method, a touch signal probe is attached to a movable stage that can be moved in any direction relative to the object to be measured. The touch signal probe outputs an electrical signal upon contact with the object to be measured, allowing the measuring device to perform accurate measuring operations.

In this type of touch signal probe, high accuracy was required for the return-to-origin property of the contact, so the configuration was complex and each member required high accuracy, and the vertical and lateral positioning was restricted. There was a problem that they interfered with each other.

Furthermore, in conventional touch signal probes, the contact is mainly biased in a predetermined direction by a biasing means such as a spring, and positioning is performed in a stationary state. There was a problem that a complicated structure was required to hold it, and that this stationary state became unstable, which adversely affected measurement accuracy.

Furthermore, conventional touch signal probes have had problems in that the probes have become large and heavy. For this reason, the movable table on which the probe is mounted must be made strong, which increases the cost of the measuring device and causes problems such as poor operability.

The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to obtain a good return-to-origin action of the contact and a stable stationary state of the contact with an extremely simple structure. An object of the present invention is to provide an improved touch signal probe that can be miniaturized.

In order to achieve the above object, the present invention includes a contact whose tip can come into contact with an object to be measured, a probe case which holds this contact so that it can tilt and move up and down with respect to its axis, and A stationary plate fixed to the proximal end, having a pair of adjacent side surfaces at a predetermined angle, and housed in the probe case; a lower peripheral edge protruding from below the stationary plate fixed to this stationary plate; 1 from each of the pair of sides of the board
three contact balls whose lower peripheral edges contact the lower seat of the probe case at three points to restrict the vertical movement of the stationary plate; A lateral member is fixed to the case and arranged to face each of the pair of side surfaces of the stationary plate, and contacts the lateral periphery of each of the three contact balls at three points to restrict lateral movement of the stationary plate. a receiving seat, a first biasing means for urging the lower peripheral edges of the three contact balls provided on the stationary plate toward the lower receiving seat of the probe case, and one end of which is engaged with the top portion connecting the pair of side surfaces. a second biasing means comprising a tension spring that tensions and biases the lateral peripheral edges of the three contact balls that are combined and provided on the stationary plate toward the side catch; and the stationary plate and the lower seat. Detecting means for detecting that any one of the three contact points or any one of the three contact points between the stationary plate and the horizontal receiving seat is released, and the three contact points It is characterized in that the rest position of the contact is fixed by the lower circumferential edge and the lateral circumferential edge of the ball.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

1 and 2 show a preferred embodiment of the touch signal probe according to the present invention.

In the figure, an approximately disk-shaped upper holder 12 is fixed to the open upper end of a cylindrical probe case 10 with an open upper end. A shank 14 for attaching and detaching is provided to protrude upward.

An opening 16 is formed on the opposite side of the probe case 10 from the shank 14, and a contact shaft 18 passes through the opening 16 and is held so as to be tiltable with respect to the probe case 10. A stationary plate 20 is housed in the probe case 10, and the contact shaft 18 is fixed to the stationary plate 20. Further, a contactor 22 is detachably fixed to the tip of the contactor shaft 18, and a ball 24 that contacts the object to be measured is closely fixed to the protruding end of the contactor 22.

Next, the tilting and vertically movable holding of the contactor shaft 18 mentioned above will be explained.

A substantially triangular prism-shaped stationary plate 20 is provided at the upper end of the contactor shaft 18, and on one side of the stationary plate 20,
A contact ball 28a whose circumferential edges protrude downward and in the lateral direction of the stationary plate 20 is fixed, and a contact ball 28b whose circumferential edges protrude downward and in the lateral direction of the stationary plate 20 is fixed on the other side of the stationary plate 20. , 28c are fixed.

In order to restrict the vertical movement of the stationary plate 20, the probe case 10 is formed with a lower seat surface 10a with which the lower peripheral edges of the contact balls 28a, 28b, and 28c come into contact. In addition, the stationary plate 20
In order to restrict the lateral movement of the contact ball 28a, the probe case 10 is provided with a lateral catch 30. In the embodiment, the lateral catch 30 includes a lateral catch piece 30a that contacts the lateral periphery of the contact ball 28a and a contact ball 28a. It consists of a lateral seat piece 30b that contacts the lateral peripheral edges of the balls 28b and 28c. Note that the contact balls 28a, 28b, and 28c are spherical, and the lower catch surface 10a, the side catch 30 (the side catch piece 30)
Since the contact surfaces of a and 30b) are flat, the contact balls 28a, 28b, 28c, the lower seat surface 10a, and the side seat 30 are easy to process and inexpensive, and
The contact balls 28a, 28b, 28c are on the lower seat surface 10
a. Since it slides on the contact surface of the side catch 30, the contact surface is cleaned and no conduction failure occurs.

Furthermore, a first biasing means is provided to press and bias the lower peripheral edges of the contact balls 28a, 28b, and 28c against the lower seat surface 10a of the probe case 10. In the embodiment, the first biasing means is , a spring 32 inserted between the upper pedestal 12 and the stationary plate 20. Further, a second biasing means is provided to press and bias the lateral peripheral edges of the contact balls 28a, 28b, 28c against the side seat pieces 30a, 30b, respectively, and in the embodiment, the second biasing means is It consists of a spring 34 whose one end is fixed to the stationary plate 20 and the other end is fixed to the probe case 10.

Further, a stopper piece 36 protrudes from the side opposite to the spring 34 of the stationary plate 20, and the probe case 10 is provided with a stopper receiver piece 38 that engages with the stopper piece 36. By engaging with 38, excessive tilting of the stationary plate 20 can be prevented.

As described above, it is possible to hold the contactor shaft 18 in a tiltable and vertically movable manner, and the contact balls 28a, 28
The rest position of the contactor shaft 18 can be fixed by the lower and lateral edges of b and 28c. In the present invention, the contactor 22 (contactor shaft 1
8) Separately separates the vertical position regulation and lateral position regulation of the stationary plate 20 that fixes the stationary plate 20, and on the stationary plate 20 side, there is a lower peripheral edge for engaging in the vertical direction and the lateral direction, respectively. Since contact balls 28a, 28b, and 28c having horizontal peripheral edges are provided, there is an advantage that a good return-to-origin action and stable positioning can be performed with a simple structure.

Further, according to the present invention, the stationary plate has a pair of side surfaces adjacent to each other at a predetermined angle, and the lateral peripheral edges of the three contact balls protrude from each of the pair of side surfaces of the stationary plate. Lateral supports that contact this contact ball at one point and two points are arranged to face each other and restrict the lateral movement of the stationary plate. Therefore, the stationary plate can be positioned at a predetermined position (a position where the contact can be positioned at the origin), and rotation of the stationary plate can be prevented. That is, the rotation of the stationary plate creates a force that presses one side of the side supports facing a pair of adjacent side surfaces at a predetermined angle, and the rotation is prevented by the drag of the side supports.

Further, the pair of side surfaces of the stationary plate are held in contact with the side seat at one point and two points by three contact balls protruding therefrom. Therefore, displacement due to rotation causes non-uniformity in the pressing force on the spherical body at two points.
Since this stationary plate is urged toward the side receiving seat by the second urging means, a force in the direction of eliminating the non-uniformity acts on the stationary plate. Therefore, even if a deviation occurs due to rotation, effective return to the origin can be performed.

Furthermore, the second biasing means is constituted by a tension spring whose one end is engaged with the top connecting the pair of side surfaces forming a predetermined angle. Therefore, rotation of the stationary plate always results in an increase in the tensile force of the tension spring, and a reliable return-to-origin force can be applied to the stationary plate.

By preventing this rotational shift, it is possible to prevent the tip of the contact from moving due to the rotation of the stationary plate, and it is possible to improve measurement accuracy.

Next, a detection means for detecting contact between the contactor 22 fixed to the tip of the contactor shaft 18 and the object to be measured will be described.

In the embodiment, each contact ball 28a, 28b,
28c and the lower seat surface 10a form a contact set. That is, the lower seating surface 1 of the probe case 10
0a includes lower fixed contacts 40a, 4 that abut the lower peripheral edges of the contact balls 28a, 28b, 28c, respectively.
0b, 40c are embedded and fixed, contact ball 28
a, 28b, 28c and lower fixed contacts 40a, 40
b and 40c form each contact set of the touch signal probe. And each contact ball 28a, 28
b, 28c and each lower fixed contact 40a, 40b, 40
For example, contact detector (not shown) → contact ball 28a → lower fixed contact 40a
→ Lower fixed contact 40b → Contact ball 28b → Contact ball 28
By forming a loop of c→lower fixed contact 40c→contact detector, it becomes possible to detect contact between the contactor 22 fixed to the tip of the contactor shaft 18 and the object to be measured.

That is, when the contactor 22 is in a non-contact state with the object to be measured, (the contact ball 28a, the lower fixed contact 40
a), (contact ball 28b, lower fixed contact 40b), (contact ball 28c, lower fixed contact 40c) are all in contact, so the contact detector is in a conductive state and the contact 22 comes into contact with the object to be measured, the contact shaft 18 tilts or moves up and down, and one of the three contact sets opens and separates, so the contact detector becomes non-conducting. This makes it possible to accurately detect contact between the contactor 22 and the object to be measured.

The embodiment of the present invention has the above configuration, and its operation will be explained below.

In FIGS. 1 and 2, the contactor 22 is held by springs 32 and 34 so as to be tiltable and vertically movable, and the springs 32 and 34 also cause the lateral peripheral edges of the contact balls 28a, 28b, and 28c to
a, 30b, contact balls 28a, 28b, 2
The lower peripheral edge of 8c is the lower seat surface 1 of the probe case 10.
Since it contacts 0a, the rest position of the contactor 22 can be fixed. Furthermore, (contact ball 28a,
Since the three contact groups of lower fixed contact 40a), (contact ball 28b, lower fixed contact 40b), and (contact ball 28c, lower fixed contact 40c) are all in contact with each other, the contact detector is in a conductive state.

When the contactor 22 fixed to the tip of the contactor shaft 18 comes into contact with the object to be measured, the contactor shaft 18 tilts or moves up and down, and one of the three contact groups is moved as described above. Since the contact set of is opened, the contact can be detected by the contact detector. At this time, the contactor shaft 18 can be tilted relative to the probe case 10 even if the movable table overruns, so that the contactor shaft 18 and the contactor 22 can be prevented from being damaged. Furthermore, the stopper piece 36 and the stopper receiver piece 3
8 restricts the contact shaft 18 from tilting beyond a predetermined angle, thereby preventing the springs 32 and 34 from being strained or damaged.

Then, when the contactor 22 is separated from the object to be measured, the contactor shaft 18 is restored to the neutral position by the urging force of the springs 32 and 34, and the contactor ball 18 is returned to the neutral position.
The horizontal edges of 8a, 28b, and 28c are the horizontal catch pieces 30
a, 30b, contact balls 28a, 28b, 2
The lower peripheral edge of 8c is the lower seat surface 1 of the probe case 10.
Contact 0a. As a result, the contactor shaft 18 is fixed at the rest position, and the contact detector returns to the contact state.

As described above, according to the present invention, it is possible to obtain a good return-to-origin action of the contact and a stable stationary state of the contact with a very simple structure. Also,
Since the first biasing means and the second biasing means are provided separately, the vertical and horizontal position restrictions do not interfere with each other, and even if the allowable tilting amount is increased, instantaneous return to the origin can be obtained. This has the advantage that the so-called overrun value in all directions can be increased, and furthermore, rotation of the stationary plate can be prevented.

Further, according to the present invention, it is possible to provide a small and lightweight touch signal probe. Therefore, there is no need to strengthen the movable stage on which the probe is mounted, so the cost of the measuring device is reduced and the operability is improved.

In the embodiment shown in FIGS. 1 and 2, the contact balls 28a, 28b, 28c and the probe case 1
The lower fixed contacts 40a, 40b, and 40c embedded and fixed in the lower seat surface 10a of 0 form three contact groups, and as shown in FIG. Contacting horizontal fixed contact 42a
is embedded and fixed in the horizontal catch piece 30a, and the contact ball 28
A horizontal fixed contact 42 that comes into contact with the horizontal peripheral edge of b and 28c
b, 42c are embedded and fixed in the horizontal catch piece 30b,
Contact balls 28a, 28b, 28c and horizontal fixed contact 4
Three contact sets can be formed by 2a, 42b, and 42c. In addition, the contact balls 28a, 28
b, 28c, lower fixed contact 40a, 40b, 40
It is also possible to form six contact sets by the lateral fixed contacts 42a, 42b, and 42c.

In addition, in the embodiment, the horizontal catch pieces 30a, 30
b can not only restrict the lateral movement of the stationary plate 20 (contact shaft 18) but also prevent rotation of the stationary plate 20 (contact shaft 18) about the probe axis.

Furthermore, in the present invention, three contact balls 28
The rest position of the contactor shaft 18 can be fixed by the lower and lateral edges of a, 28b, and 28c. In other words, since support is provided in two directions by one contact ball, a reliable stationary action can be performed with a minimum number of contact balls, and the touch signal probe can be miniaturized. .

As explained above, according to the touch signal probe according to the present invention, it is possible to obtain a good home return action of the contact and a stable stationary state of the contact with an extremely simple structure, and furthermore, it is small and lightweight. You can get a touch signal probe.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a preferred embodiment of a touch signal probe according to the present invention, FIG. 2 is a cross-sectional view along the line taken from FIG. 1, and FIG. 3 is an explanatory diagram showing another embodiment. Identical members in each figure are given the same reference numerals, and 10...
Probe case, 10a... Lower seat surface, 12...
Upper cradle, 14...Shank, 16...Opening, 18
... Contactor shaft, 20 ... Stationary plate, 22 ... Contactor, 24 ... Ball, 28a, 28b, 28c ...
...Contact ball, 30a, 30b...Side seat piece, 32...
... Spring, 34 ... Spring, 36 ... Stopper piece, 38 ... Stopper receiver piece, 40a, 40
b, 40c...lower fixed contact, 42a, 42b, 4
2c...Horizontal fixed contact.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A contact whose tip can come into contact with an object to be measured, a probe case that holds this contact so that it can tilt and move up and down with respect to its axis, and a base of the contact. A stationary plate fixed to an end, having a pair of adjacent side surfaces at a predetermined angle, and housed in a probe case; One lateral peripheral edge and two lateral peripheral edges protrude from each of the pair of side surfaces, and the lower periphery contacts the lower seat of the probe case at three points to restrict vertical movement of the stationary plate. three contact balls, which are fixed to the probe case and arranged to face each of the pair of side surfaces of the stationary plate;
A horizontal support that contacts at a point to restrict the lateral movement of the stationary plate, and a first support that urges the lower peripheral edge of the three contact balls provided on the stationary plate toward the lower support of the probe case.
and a tension spring whose one end is engaged with the top connecting the pair of side surfaces and which pulls and urges the horizontal edges of the three contact balls provided on the stationary plate toward the horizontal catch. and one of the three contact points between the stationary plate and the lower support seat or the three contact points between the stationary plate and the horizontal support seat is released. What is claimed is: 1. A touch signal probe comprising: a detection means for detecting a contact point; (2) In the touch signal probe described in claim (1) for utility model registration, a lower fixed contact that comes into contact with the lower peripheral edge of each contact ball is provided on the lower seat surface of the probe case, and each contact ball and each lower fixed contact are provided on the lower seat surface of the probe case. 1. A touch signal probe characterized in that contacts are arranged alternately in series, and a detection means electrically detects opening or opening of any of the contact sets when the probe is tilted. (3) In the touch signal probe described in claim (1) of the utility model registration, a horizontal fixed contact that comes into contact with the lateral peripheral edge of each contact ball is provided on the horizontal seat of the probe case, and each contact ball and each horizontal fixed contact are provided. A touch signal probe characterized in that the probes are arranged alternately in series, and a detection means electrically detects opening of any one of the contact sets when the probe is tilted. (4) In the touch signal probe described in claims (1), (2), or (3) for utility model registration, the contactor is detachably fixed to the contactor shaft provided on the stationary plate. Features of the Touch signal probe.