JPS59116502A - Contact detector - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of a simple structure and to obtain high accuracy, by arranging three or four balls on a concentric circle in an electrically insulated manner, and making the center of the curved surface of a sphere having a radius of R, which faces said balls, to agree with the center of a contact ball at the tip of a probe, which is protruded in the central part. CONSTITUTION:A convex curved surface body 2, which forms a part of a sphere having a radius R and a has a hole 3 at the center, is fixed at the central lower part of an outer part 1 so as to face upward. A cross shaped holding plate 4 is placed on said curved surface body 2. Balls 5-8 are provided on the concentric circle at the lower surfaces of the four protruded parts of the plate 4, so that the balls are electrically insulated. The balls 5-8 are pushed downward by a spring 11 so as to contact with the curved surface body 2. A probe 9 is lowered in the downward direction at the center of the cross shaped holding plate 4 so as to pass the central hole 3 of the curved surface body 2. A contact ball 10 is attached to the lower end of the probe 9. The distances beween the center of the contact ball 10 and the contact points of the balls 5-8 and the curved surface are made to be R.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact detector for detecting a measurement position and a reference position of an object to be measured and machined in devices such as coordinate measuring machines and machine tools.

In these devices, it is necessary to detect the position of a reference point and a predetermined point on the object, and for this purpose conventionally a contact ball at the tip of the probe is applied to the object.

A method was used to detect the position at the moment of impact. There are two methods for electrically detecting contact.

One is when the contact ball at the tip of the probe hits the target object,
The object is to be used as one end of a special tracing circuit to obtain a signal by making it a typical special tracing circuit. In this case, since a wide current flows between the contact sphere and the target object, the target object is ! , Must be a 1 character 'ia material, plastic.

Cannot be used on ceramics, etc. Furthermore, if the target object is soaked with cutting fluid or the like, conduction occurs between +)iJ that contacts the detection point, and a detection error occurs.

The second method is to incorporate a switch mechanism in the detector and operate the switch by the displacement when the contact ball hits, and the invention described in Japanese Patent Application Laid-Open No. 49-94370 is one example of this method. This has a switch mechanism within the detector.

The structure is complicated, and in order to fully ensure reliability, especially returnability of the probe and contact ball, which will be described later, there is a problem in that each part related to the switch mechanism must be manufactured with high precision. Regardless of which method is used, the other necessary conditions are that the escape mechanism of the probe should be supported after the contact is projected;
The contact ball may accurately return to a fixed position after it leaves the target object. Non-invention satisfies this condition.

In addition, the present invention provides a high-performance contact detector that can be manufactured at low cost using a simple mechanism.

In FIGS. 1 and 2, a convex-concave body 2, which forms part of a sphere with a radius of 1t and has a hole 3 in the center, is fixed upward at the lower center of the outer 11111 part 1.

A cross-shaped holding plate 4 is placed on the curved body 2, and balls 5, 6, 7, and 8 are provided on a concentric circle between the four protruding portions of the holding plate 4 so as to be electrically insulated from each other.

Hold the spring 11 from above and press it downward so that the ball 5, 6, 7, 8 and the curved surface body 2 are brought into full contact. A probe 9 is lowered toward the lower center of the cross-shaped holding plate 4 and passes through the center hole 3 of the bicurved body 2, and a contact ball 10 is attached to the lower end of the probe 9. The distance between the contact point of the ball 5,6,7.8 and the curved surface and the center of the contact ball 10 is set to be 1t. Each ball is connected to a power source through a circuit as shown in FIG. It is earthed through the outer part 1. Also, all the lines that enter each ball enter the AN1) circuit. Therefore, if you get +'i+U between songs even on one hole, 2. To1\・D timesj'i'J
Made by! Outputs 1-C01・1・゛ signal.

In such a 114 structure, the cross-shaped holding plate 5 plate 1 is
For ll+ 1 river [even if the yellow direction shift is 7,
Each ball and song [contact point and contact with the river! ■1', j! ball 10
The distance between the centers of is 1(, and the radius of the curve [11'' is the same <l(,), so the position of the 1 touch 10 is not changed to 'λ.And i ('i?i direction When the target object comes into contact with the contact ball 10, the contact whale 10 moves its position, and this (・Thus, the contact ball 10 contacts the curved surface M I,
The first hole I'm playing is the song [L from the river? iI[re OF 1. +1. (j: 'Tjk jjj force. Then, when the target object is t'a' from the contact ball 10, +I
The wheel that was spinning from the lr river is sphere 11
Returns to the curved surface due to the action of At this time, even if the position i4 where J is apart is different from the position of +i' + J, the tip contact tan,
Since the center of 10 is at the center of the curved surface, the contact sphere 10 (
Standing is no different from +iiJ's standing. Namely.

Even if contact detection is repeated, the contact ball 10 will always return to the predetermined contact state.

In addition, in the above example, four balls were installed under one cross-shaped holding plate, but three balls were placed on concentric circles under the holding plate with 30,000 radial protrusions. Even if the ball is placed, the effect is the same.

FIG. 1 shows another embodiment in which the relative positions of the two curved surfaces and the ball are reversed and the center of the half surface 1 of the curved surface of the plate 12 is aligned with the center of the contact ball 10.

The holding plate 12 is lifted out by the spring 13.
1 of 'l 11is l ((Pick the ball of 31 hardness or 11 hardness downward to l.) The curved surface of the holding plate 12 is configured so that it is always in contact with the ball. The same effect as described above can be achieved by wearing a f-hat or police.

Although the above description has been made of a convex curved surface, a concave curved surface can also be used. Figures 5 and 6
An example is shown in the figure. In FIG. 5, the concave 11'' body 15 of radius t is placed downward.

On the other hand, the holding plate with all the balls arranged on the top surface -L:
) Jj: Tsu\ra Subrinda 11 (Kyototo hoist (
Zutebo shij・Kokuma (Ko 1 ``j・i; Let's do it. At this time (Komo ball and Kokuma (ri 1・Mizuni: ``J
) and 4faHIQ', ij center point 1 of the sphere, 1''II
Both IEs are set to 11. Figure 6 shows 11 outside the ball building.
ii Part 1: Concave piece [``U'fJ:
Hold ζ 5 plate below (1 dip in fU is also C if you turn the hold 1 plate around the ball by bring and make it +1'M'.

The operation is the same in the case of 3':i, and it is simple. et fL;,).

1 Figure 111 totsu ii + j 11t 1 situation Ming 11th also I
Figure 100, No. 21 I (-i
：1st III OIf -II ++RThe figure 3 of the drawing is 'Ichiki Kai'8'+'r i) Light intensity 11, No. 51≦1
．． Figure 6 shows another implementation 1Tari.

1: Outside 11111 parts 2.12: Curved body 1: Cross '+' +: Samurai board 5.6.7.8: Hikari ball 10: Takeshi 1'l', +! Pig 11.13.11 Nispring 15: 4 Medical School: 1. ) l measurement, ·) 11 people Public Corporation, Higashitomi Kozufu +-1!

Claims (1)

[Scope of Claims] (1) Three or four balls are arranged concentrically in an electrically insulated state, and the center of the curved surface of the ball with a radius of 1, which faces the balls, protrudes into the medium heat part. did? A contact detector configured to align with the center of a contact ball at the tip of a J++ j child and biased so that the ball and the curved surface come into contact with each other. (2. In the statement of claim 1, a convex curved surface is provided upward, a holding plate for holding the ball is provided on the bottom surface thereof, and a central hole of the curved surface is penetrated from the center of this holding plate. A contact detector comprising a probe having a contact ball at its tip. (3) In claim 1, a ball is fixed to the outer part facing downward, and a convex curved surface is formed upward relative to the ball. A contact detector is provided with a retaining plate having a curved surface, and a probe having a contact ball at the tip is attached below the center of the curved surface of the retaining plate. A contact detector comprising a holding plate facing upward for holding a ball, and a contact probe having a contact ball at its tip attached to the lower center of the holding plate. (5) Scope of Claims No. In item 1, the ball is placed at the bottom of the outer part facing upward, a holding plate with a concave curved surface facing downward is provided on top of the holding plate, and a probe is attached to the tip of the holding plate below the center of the curved surface to prepare the contact ball. Contact detector.