JPH0641121Y2 - Measuring probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a measuring probe provided in a coordinate measuring machine or the like.

[Conventional technology]

Generally, in a measuring probe provided in a three-dimensional coordinate measuring machine or the like, a stylus is arranged so as to be displaceable in a predetermined direction, and the position is read when a certain amount of displacement is made after the stylus comes into contact with an object to be measured. Such control is performed.

With such a probe, coordinate measurement is performed when the stylus is displaced relatively minutely. Therefore, the stylus needs to be accurately returned to the neutral position in a free state, and therefore, it is necessary to hold the stylus in the neutral position with an elastic material having a relatively high spring constant. On the other hand, if the spring constant of the member that holds the stylus is unconditionally increased, a very large pressure (measurement pressure) will be generated from the time the stylus is placed on the object to be measured until the stylus is displaced by a predetermined amount. And other components are burdened with strength.

Therefore, in recent years, in order to hold the stylus in the neutral position, a number of elastic holding means having a two-step characteristic having a plurality of spring constants have been proposed. For example,
In Japanese Patent Laid-Open No. 56-35784, a stylus is supported by a bending bar and two coil springs, and a small displacement of the stylus is contracted by a bending deformation of a bending bar having a high spring constant. It is shown that a coil spring having a constant number is contracted by expansion / contraction deformation. With such a structure, the elastic force of the bending bar ensures a sufficient return force to the neutral position of the stylus, and after the stylus is displaced by a certain amount or more, the measured pressure rapidly increases even if the displacement increases. It does not rise and this protects the measuring probe.

[Problems to be solved by the device]

In the above structure, the stylus elastic holding means is required to have two types of members in order to have the two-stage characteristic, and moreover, these members are required to be assembled with high precision, and the manufacturing process However, the structure is complicated and the cost is high. Further, since the large displacement of the stylus is borne by the deformation of the coil spring, there is a limit in reducing the spring constant in this range, and an increase in the measured pressure due to the displacement of the stylus cannot be avoided.

In consideration of such circumstances, the present invention has a low-cost structure,
You can accurately return the stylus to the neutral position,
In addition, it is an object of the present invention to provide a measuring probe that can suppress an extremely small increase in measuring pressure with respect to an increase in the displacement in a range where the stylus is largely displaced.

[Means for Solving the Problems]

The present invention provides a fixing member fixed to a measuring machine body, a moving member movably connected to the fixing member in a preset relative movement direction, and attached to the moving member.
In a measuring probe provided with a stylus that moves together with the moving member, a fixed portion provided on the fixed member and protruding toward the moving member, and a moving portion provided on the moving member and protruding toward the fixed member. A protrusion,
A pair of closely-wound spiral springs fixed to the fixed member side or the movable member side and having the same spring constant are provided, and one of the fixed member portion and the moving protrusion is orthogonal to the relative movement direction of the other. The gaps are provided on both sides in the direction so that the dimensions of the respective protrusions in the relative movement direction are set to be equal, and the peripheral surfaces of the closely wound spiral springs are fixed to the both end faces of the fixed protrusion in the relative movement direction and the neutral position. These closely wound spiral springs are arranged so as to be simultaneously pressed against both end faces in the relative movement direction of the moving protrusion at both sides in the relative movement direction. By simultaneously sandwiching the fixed protrusion and the movable protrusion from both sides in the relative movement direction, the movable member is returned to the neutral position and held (claim 3). ).

Further, the present invention relates to a fixing member fixed to the measuring machine main body, a first moving member connected to the fixing member so as to be movable in a first direction, and the above-mentioned first moving member with respect to the above. A measurement probe provided with a second moving member movably connected to a second direction different from the first direction, and a stylus attached to the second moving member and moving together with the second moving member. A first fixed protrusion provided on the fixed member and protruding toward the first moving member; and a first movement protruding on the first moving member and protruding toward the fixed member. A protrusion, a second fixed protrusion provided on the first moving member and protruding toward the second moving member, and provided on the second moving member,
A second moving protrusion protruding toward the first moving member, and a pair of first closely wound spiral springs fixed to the fixed member or the first moving member and having spring constants equal to each other. A pair of second closely wound spiral springs fixed to the first moving member side or the second moving member side and having spring constants equal to each other, the first fixed protrusion, the first movement One of the protrusions is provided on both sides of the other in a direction orthogonal to the first direction, and the first fixed protrusion and the first movable protrusion are provided with the first protrusion.
And the circumferential surface of each of the first close contact spiral springs is the same in both end faces of the first fixed protrusion in the first direction and the first moving protrusion in the neutral position. These first close contact spiral springs are arranged so as to be pressed against both end faces in the first direction at the same time from both sides in the first direction, and the second fixed protrusion portion and the second movable protrusion are provided. One of the two parts is provided on both sides in the direction orthogonal to the second direction of the other part with a gap, and
The fixed protrusion and the second movable protrusion are set to have the same dimension in the second direction, and the peripheral surface of each second closely wound spiral spring is the second fixed protrusion in the second fixed protrusion.
In the second direction, and both end faces in the second direction of the second moving protrusion at the neutral position are simultaneously pressed from both sides in the second direction. The first contact spiral spring is elastically moved by the first fixed protrusion and the first moving protrusion from the both sides in the first direction at the same time to move the first movement. The member is returned to the neutral position and held, and the second
Of the closely wound spiral spring causes the elastic force of the second fixed protrusion and the second movable protrusion to simultaneously sandwich the second movable protrusion from both sides in the second direction to return the second movable member to the neutral position. , And is held (claim 2).

Further, the present invention relates to a fixing member fixed to the measuring machine main body, a first moving member connected to the fixing member so as to be movable in a first direction, and the above-mentioned first moving member with respect to the above. A second moving member movably connected in a second direction different from the first direction, and the first moving member with respect to the second moving member.
And a stylus attached to the third moving member and moving together with the third moving member, the third moving member being movably connected in a third direction different from the second moving direction. In the measurement probe, the first probe provided on the fixed member and protruding toward the first moving member.
Fixed protrusion, the first moving member provided on the first moving member and protruding toward the fixed member, and the first moving member provided on the first moving member facing the second moving member. Provided on the second moving member, and a second moving protrusion protruding toward the first moving member, and provided on the second moving member, A third fixed protrusion protruding toward the third moving member, a third movable protrusion provided on the third moving member and protruding toward the third moving member, and the fixed A pair of first close contact spiral springs fixed to the member side or the first moving member side and having equal spring constants, and fixed to the first moving member side or the second moving member side and equal to each other A pair of second closely wound spiral springs having a spring constant; A pair of third closely-wound spiral springs fixed to the second moving member side or the third moving member side and having the same spring constant, and the first fixed protruding portion and the first moving protruding portion. One of them is provided on both sides of the other in a direction orthogonal to the first direction of the other with a gap, and the first fixed protrusion and the first movable protrusion of the first
And the circumferential surface of each of the first close contact spiral springs is the same in both end faces of the first fixed protrusion in the first direction and the first moving protrusion in the neutral position. These first close contact spiral springs are arranged so as to be pressed against both end faces in the first direction at the same time from both sides in the first direction, and the second fixed protrusion portion and the second movable protrusion are provided. One of the two parts is provided on both sides in the direction orthogonal to the second direction of the other part with a gap, and
Of the fixed protrusion and the second movable protrusion are set equal to each other in the second direction, and the peripheral surface of each second closely wound spiral spring has the second direction in the second fixed protrusion. Of the second closely-wound spiral springs so that they are pressed against both end faces of the second moving protrusion at the neutral position and both end faces of the second direction in the second direction at the same time. However, one of the third fixed protrusion and the third movable protrusion is provided with a gap on both sides in the direction orthogonal to the other third direction, and the third fixed protrusion and the third movable protrusion are provided. The dimension of the moving protrusions of No. 3 in the third direction is set to be equal, and the peripheral surface of each third closely wound spiral spring is provided on both end faces of the third fixed protrusion in the third direction and at the neutral position. In the third direction in the third moving protrusion in The third close contact spiral springs are arranged so as to be pressed against the surface from both sides in the third direction at the same time, and the first close contact spiral springs are elastically exerted by the elastic force of the first fixed protruding portion. And the first moving protrusion are the first
In the same direction, the first moving member is returned to and held in the neutral position at the same time, and the second closely wound spiral spring is elastically moved by the second fixed protruding portion and the second moving member. The second moving member is returned to and held at the neutral position by simultaneously sandwiching the protrusion and the both sides in the second direction, and the third closely-wound spiral spring is elastically moved by the third fixing coil to cause the third fixing. The third moving member is returned to the neutral position and held by simultaneously sandwiching the protruding portion and the third moving protruding portion from both sides in the third direction (claim 3).

(Operation) First, in the measuring probe according to claim 1, in a state where an external force is not applied to the stylus, the pair of closely wound spiral springs elastically move the fixed protrusion and the movable protrusion on both sides in the relative movement direction. From the both sides in the relative movement direction with respect to both end faces in the relative movement direction of the fixed protrusion and both end faces in the relative movement direction of the movable protrusion by simultaneously sandwiching from each other. The moving member is held at a position (that is, a neutral position) where they are pressed together at the same time. From this state, when the stylus is pressed against the object to be measured, the stylus and the moving member are displaced with respect to the fixed member. As a result, the measurement pressure rises sharply, and the force for returning the stylus to the neutral position is sufficiently maintained. Furthermore, if the stylus is largely displaced, the spring constant becomes extremely small due to the characteristics of the close contact spiral spring,
Therefore, even if the stylus is displaced, the measurement pressure hardly rises.

Further, in the measurement probe according to claim 2, the first and second moving members and the stylus are displaced in the first direction with respect to the fixed member, and these are moved to the neutral position by the first contact spiral spring. And the second moving member and the stylus are displaced in the second direction with respect to the first moving member, and these are held in the neutral position by the second contact spiral spring.

Further, in the measurement probe according to claim 3, the third moving member and the stylus are displaced in the third direction with respect to the second moving member, and these are neutralized by the third close-wound spiral spring. Held in position.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. The measurement probe shown here is provided with a rectangular fixed plate (fixed member) 10 and a rectangular movable plate (movable member) 12 that are fixed to the main body of the measuring machine (not shown). They are connected by a leaf spring 14. The leaf springs 14 have the same vertical dimension, the reinforcing plates 16 are fixed to both front and back surfaces thereof, and the upper and lower ends thereof are fixed to the edges of the fixed plate 10 and the movable plate 12 by bolts or the like. As a result, the fixed plate 10 and the movable plate 12 are held in parallel with each other, and the movable plate 12 is moved relative to the fixed plate 10 in the X-axis direction (first
It is movable in the left-right direction of FIGS.

A stylus 17 is fixed to the lower surface of the moving plate 12 and moves together with the moving plate 12. At the lower end of the stylus 17, a contact ball 171 that contacts the object to be measured is formed.

On the surface of the fixed plate 10 facing the moving plate 12, a rectangular parallelepiped fixed block (fixed protruding portion) 18 is fixed by bolts or the like so as to project to the moving plate 12 side (lower side). Similarly, on the surface of the moving plate 12 facing the fixed plate 10, a rectangular parallelepiped moving block (moving protruding portion) 20 is fixed so as to project to the fixed plate 10 side (upper side).

As shown in FIG. 5, a convex portion 181 is formed in the center of the lower surface of the fixed block 18, and a concave portion 201 larger than the convex portion is formed in the center of the upper surface of the moving block 20,
Both blocks 18 and 20 do not interfere with each other. The width dimensions (dimensions in the X-axis direction) of both blocks 18 and 20 are set to be equal.

In addition, this measurement probe has a pair of closely wound spiral springs (Coiled Flat Springs) 22 as shown in FIGS.
Is equipped with. These closely-wound spiral springs 22 are formed by winding both ends of a thin plate 24 made of metal or the like, which is cut in a tape shape, around a core material.
It is formed by being plastically deformed, and has the same spring characteristics (details will be described later). And
The central portion of the thin plate 24 is the fixed plate 10 and the fixed block 18.
It is sandwiched between and fixed by this, so that the peripheral surfaces of both the closely wound spiral springs 22 are in pressure contact with the peripheral surfaces of both the fixed block 18 and the movable block 20 from both sides in the X-axis direction. ing.

These closely-wound spiral springs 22 sandwich the fixed block 18 and the movable block 20 from both sides by the elastic force thereof, which allows the stylus 17 and the movable plate 12 to have a side surface of the fixed block 18 without receiving an external force. And the side surface of the moving block 20 are held at a position where they are flush with each other (neutral position).

Although not shown, this measuring probe is provided with a sensor that detects that the movable plate 12 is displaced by a predetermined amount L with respect to the fixed plate 10.

Next, the operation of this measuring probe will be described.

As described above, the movable plate 12 and the stylus 17 are held at the neutral position by the close-wound spiral spring 22, but from this state, the entire measuring probe is driven in the X-axis direction and the stylus 17 contacts the object to be measured. The stylus 17 and the moving plate 12 are
Is displaced in the direction opposite to the advancing direction of the measuring probe with respect to the fixed plate 10 against the elastic force of the closely wound spiral spring 22.

Due to this displacement, the close contact spiral spring 22 is deformed as shown in FIG. 3 to generate a measurement pressure. As is well known, since the close contact spiral spring 22 has a two-step spring characteristic, The measurement pressure changes with the displacement of the stylus 17, as shown in FIG.

That is, in a range where the displacement of the stylus 17 and the moving plate 12 is extremely small, the measured pressure rapidly increases with the displacement, but when the measured pressure becomes P ₁ and the displacement of the stylus 17 becomes L _1. Therefore, even if the displacement of the stylus 17 increases, the measured pressure hardly rises. That is, the closely wound spiral spring 22 has a large spring constant k ₁ in a range where the displacement of the stylus 17 is a minute displacement L ₁ or less, and an extremely small spring in a range where the displacement of the stylus 17 exceeds L _1. It has a constant k ₂ .

Therefore, after the displacement of the stylus 17 exceeds L ₁ , the displacement of the stylus 17 proceeds with almost no increase in the measurement pressure. When the displacement of the stylus 17 reaches L, a probe drive stop signal is output and the coordinates at that time are read. After the measurement, by separating the stylus 17 from the object to be measured, the stylus 17 and the movable plate 12 are surely returned to the neutral position by the elastic force of the contact spiral spring 22.

As described above, with this measurement probe, it is possible to secure the returning force to the neutral position of the stylus 17 in the range where the close-wound spiral spring 22 has a high spring constant k ₁ , and an extremely low spring constant k ₂ . Within the range, the increase of the measured pressure due to the displacement of the stylus 17 can be suppressed to a small extent. Moreover, since the neutral position of the stylus 17 is held only by the pair of closely-wound spiral springs 22, the structure is very simple, and the stylus 17 can be used as compared with the conventional structure using two kinds of springs. It is possible to make the spring constant k ₂ extremely small in the range in which is greatly displaced.

It should be noted that the present invention is not limited to such an embodiment, and the following aspects can be taken as an example.

(1) In the present invention, the specific shapes of the fixed member and the moving member, and the connection structure thereof are not particularly limited, and the above effect can be obtained if the moving member is movable in one direction with respect to the fixed member. it can. Further, the shape of the fixed protruding portion and the moving protruding portion may be any shape as long as the closely wound spiral spring can be pressed against the side surfaces of both protruding portions while the moving protruding portion is in the neutral position.
For example, in the probe of the above embodiment, the fixed block 18
The concave portion may be provided on the side and the convex portion may be provided on the moving block 20 side, or both may be formed in a cylindrical shape or the like.

(2) In the above embodiment, the pair of close contact spiral springs 22 are formed by a single thin plate 24, but each close contact spiral spring 22 may be formed by a separate thin plate or the like. Also, the close contact spiral spring may be attached to the moving member side, for example, one close contact spiral spring may be fixed to the fixed member side and the other close contact spiral spring may be fixed to the moving member side. The effect can be obtained.

(3) Although the stylus 17 is displaced in the X-axis direction in the above embodiment, the stylus 17 may be displaced in the Y-axis and Z-axis directions in the same manner as in the above-described embodiment.

FIG. 7 shows a measuring probe in which the stylus 17 is displaced in three directions by combining the above structures in three steps.

In the figure, a plate (fixing member) 40 extending vertically is shown.
Is fixed to the main body of the measuring machine, and a plate (first moving member) 42 is movably connected to the plate 40 in the Z-axis direction (vertical direction; first direction). A plate (first moving member) 44 extending horizontally is fixed to the lower end of the plate. A plate (second moving member) 46 is connected to the plate 44 so as to be movable in the Y-axis direction (second direction) with respect to the plate 44, and with respect to the plate 46, in the X-axis direction (third direction). A plate (third moving member) 48 is connected so as to be movable in the direction), and a stylus 17 is fixed to the lower surface of the plate 48. Also,
A spring 50 is provided between the plate 40 and the plate 44, and the spring 50 pulls up members below the plate 42 to prevent the weight of the probe from affecting the displacement of the plate 42. There is.

Blocks similar to the fixed block 18 and the movable block 20 (first block) are provided on the surfaces of the plate 40 and the plate 42 facing each other.
Fixed protrusions 401) and blocks (first moving protrusions) 421 are fixed respectively, and similarly, the blocks (second fixed protrusions) 441 and the blocks are provided on the surfaces where the plate 44 and the plate 46 face each other. (Second moving protrusion) 461
However, on the surfaces where the plate 46 and the plate 48 face each other, a block (third fixed protrusion) 462 and a block (third fixed protrusion) are formed.
(Moving protrusions) 481 are fixed.

Further, the first close contact spiral spring 51 is attached to the blocks 401 and 421 so as to come into pressure contact with them from both sides in the Z-axis direction, and similarly, comes into contact with the blocks 441 and 461 from both sides in the Y-axis direction. Second closely wound spiral spring 52
However, the third closely wound spiral spring 53 is attached to the blocks 462 and 481 so as to come into pressure contact with the blocks from both sides in the X-axis direction. The preteau 42, 46, 48 is held in the neutral position by these closely wound spiral springs 51-53.

In such a structure, the plate 40 is the fixed side (fixing member in claim 1) in the Z-axis direction,
The members of 42 and below are the moving side (moving member in claim 1). Similarly, in the Y-axis direction, the members from the plate 40 to the plate 44 are the fixed side, and the members below the plate 46 are the moving part side, and in the X-axis direction, the plate is
Members from 40 to plate 46 are fixed side, plate
48 is the moving side. In such a measurement probe having a three-stage structure, the present invention may be applied only to a structure related to displacement in one direction, and the other parts may have a conventional structure. Further, in this measuring probe, by omitting any one of the connecting structure of the plates 40 and 42, the connecting structure of the plates 44 and 46, and the connecting structure of the plates 46 and 48, the probe becomes a two-dimensional coordinate measuring probe. Needless to say (Claim 2
Corresponding to the measurement probe described).

[Effect of device]

As described above, according to the present invention, the following effects can be obtained.

First, in the probe according to claim 1, the fixed projecting portion and the moving projecting portion are fixed to the surfaces of the fixed member and the moving member that face each other, and the closely wound spiral spring is arranged so as to be pressed against both the projecting portions. Since the close contact spiral spring holds the moving member and the stylus in the neutral position, the simple structure using the close contact spiral spring makes it possible to move the stylus to the neutral position. The measurement pressure for returning is secured, thereby maintaining high measurement accuracy, and in the range where the displacement of the stylus exceeds a certain value, the increase of the measurement pressure due to the displacement is suppressed to an extremely small level. There is an effect that can be protected.

Furthermore, since the probe according to claims 2 and 3 applies the above structure to displacement in a second direction different from the first direction, and further in a third direction, a two-dimensional coordinate measuring machine or a three-dimensional coordinate measuring machine is used. As the measuring probe for the dimensional coordinate measuring machine, it is possible to provide a measuring probe having the above-mentioned excellent effects.

[Brief description of drawings]

1 is a front sectional view showing a state in which a movable plate and a stylus are in a neutral position in a measuring probe according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. Is a front sectional view showing a state in which the movable plate and the stylus are displaced by a predetermined amount in the measurement probe, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, and FIG. FIG. 6 is a broken perspective view showing a main part, FIG. 6 is a graph showing spring characteristics of a close-wound spiral spring provided in the measurement probe, and FIG.
The figure is a perspective view showing a measuring probe whose stylus can be displaced in three directions. 10 ... Fixed plate (fixed member), 12 ... Moveable plate (movable member), 17 ... Stylus, 18 ... Fixed block (fixed protrusion), 20 ... Movable block (movable protrusion),
22 ... Closely wound spiral spring, 40 ... Plate (fixed member), 42 ... Plate (first moving member), 44 ... Plate (first moving member), 46 ... Plate (second moving member) Member), 48 ... Plate (third moving member), 401 ...
Block (first fixed protrusion), 421 ... Block (first movable protrusion), 441 ... Block (second fixed protrusion), 461 ... Block (second movable protrusion), 462 ......
Block (third fixed protrusion), 481 ... Block (third movable protrusion), 51 ... First closely wound spiral spring, 52
...... Second close contact spiral spring, 53 …… Third close contact spiral spring.

Claims (3)

[Scope of utility model registration request] 1. A fixed member fixed to a main body of a measuring machine, a moving member movably connected to the fixed member in a preset relative movement direction, and a moving member attached to the moving member. In a measurement probe provided with a stylus that moves together with the stylus, a fixed protrusion provided on the fixed member and protruding toward the movable member, and a movable protrusion provided on the movable member and protruded toward the fixed member. And fixed to the fixed member side or the moving member side,
A pair of closely-wound spiral springs having equal spring constants are provided, and one of the fixed protrusion and the movable protrusion is provided on both sides in a direction orthogonal to the relative movement direction of the other, and each protrusion is provided. The same relative dimension in the relative movement direction, and the peripheral surfaces of the closely wound spiral springs are both end surfaces in the relative movement direction in the fixed protrusion and both ends in the relative movement direction in the movement protrusion at the neutral position. The closely wound spiral springs are arranged so as to be pressed against the surface simultaneously from both sides in the relative movement direction, and the tightly wound spiral springs relatively move the fixed protrusion and the movable protrusion by their elastic force. A measuring probe, wherein the moving member is returned to a neutral position and held by being clamped from both sides in the direction at the same time. 2. A fixing member fixed to the main body of the measuring machine, a first moving member connected to the fixing member so as to be movable in a first direction, and the first moving member described above. First
Second movably connected in a second direction different from the direction
A moving member and a stylus attached to the second moving member and moving together with the second moving member, the measuring probe being provided on the fixed member and projecting toward the first moving member. A first fixed protrusion that
A first moving protrusion provided on the first moving member and protruding toward the fixed member; and a second moving protrusion provided on the first moving member and protruding toward the second moving member.
A fixed protruding portion, a second moving protruding portion provided on the second moving member and protruding toward the first moving member, and fixed to the fixed member side or the first moving member side, A pair of first close contact spiral springs having equal spring constants, and a pair of second close contact spiral springs fixed to the first moving member side or the second move member side and having equal spring constants. And one of the first fixed protrusion and the first movable protrusion is provided with a gap on both sides in the direction orthogonal to the first direction of the other, and these first fixed protrusions are provided. And the first of the first moving protrusions
Are set to be equal to each other, and the peripheral surface of each of the closely wound spiral springs has the first fixed protrusion portion at the first surface.
In the first direction and both end faces in the first direction of the first moving protrusion at the neutral position are simultaneously pressed from both sides in the first direction. One of the second fixed protrusion and the second movable protrusion is provided with a gap on both sides in the direction orthogonal to the second direction of the other, and the second fixed protrusion is provided. And the dimension of the second moving protrusion in the second direction is set to be equal, and the peripheral surface of each of the second close contact spiral springs has both end faces in the second direction of the second fixed protrusion. The second closely wound spiral springs are arranged so as to be pressed against both end faces of the second moving protrusion in the neutral position in the second direction at the same time. The closely wound spiral spring of No. 1 is fixed to the above-mentioned first by its elastic force. The first moving member is returned to the neutral position and held by simultaneously sandwiching the projecting portion and the first moving protruding portion from both sides in the first direction, and the elasticity of the second closely wound spiral spring is maintained. By force, the second fixed protrusion and the second
And the moving protrusion of the second moving member are simultaneously sandwiched from both sides in the second direction to return and hold the second moving member to the neutral position. 3. A fixing member fixed to the main body of the measuring machine, a first moving member connected to the fixing member so as to be movable in a first direction, and the first moving member described above. First
Second movably connected in a second direction different from the direction
Moving member, a third moving member movably connected to the second moving member in a third direction different from the first direction and the second direction, and the third moving member. And a stylus that moves with the third moving member, the measuring probe having a first fixed protrusion provided on the fixed member and protruding toward the first moving member; A first moving protrusion provided on the first moving member and protruding toward the fixed member; and a second fixed protrusion provided on the first moving member and protruding toward the second moving member. And a second portion provided on the second moving member and projecting toward the first moving member.
Moving protrusion, a third fixed protrusion provided on the second moving member and protruding toward the third moving member, and a second moving member provided on the third moving member. A third moving protrusion protruding toward the member, a pair of first closely wound spiral springs fixed to the fixed member side or the first moving member side, and having spring constants equal to each other; A pair of second closely wound spiral springs fixed to the moving member side or the second moving member side and having the same spring constant, and a pair of the second moving member side or the third moving member side, which are fixed to each other. A pair of third closely-wound spiral springs having equal spring constants, and one of the first fixed protrusion and the first moving protrusion is opposite to the other in the direction orthogonal to the first direction. These first fixed protrusions are provided with a gap between them. Beauty above first moving protrusion first
And the circumferential surface of each of the first close contact spiral springs is the same in both end faces of the first fixed protrusion in the first direction and the first moving protrusion in the neutral position. These first close contact spiral springs are arranged so as to be pressed against both end faces in the first direction at the same time from both sides in the first direction, and the second fixed protrusion portion and the second movable protrusion are provided. One of the two parts is provided on both sides in the direction orthogonal to the second direction of the other part with a gap, and
Of the fixed protrusion and the second movable protrusion are set equal to each other in the second direction, and the peripheral surface of each second closely wound spiral spring has the second direction in the second fixed protrusion. Of the second closely-wound spiral springs so that they are pressed against both end faces of the second moving protrusion at the neutral position and both end faces of the second direction in the second direction at the same time. However, one of the third fixed protrusion and the third movable protrusion is provided with a gap on both sides in the direction orthogonal to the other third direction, and the third fixed protrusion and the third movable protrusion are provided. The dimension of the moving protrusions of No. 3 in the third direction is set to be equal, and the peripheral surface of each third closely wound spiral spring is provided on both end faces of the third fixed protrusion in the third direction and at the neutral position. In the third direction in the third moving protrusion in The third close contact spiral springs are arranged so as to be pressed against the surface from both sides in the third direction at the same time, and the first close contact spiral springs are elastically exerted by the elastic force of the first fixed protruding portion. And the first moving protrusion are the first
In the same direction, the first moving member is returned to and held in the neutral position at the same time, and the second closely wound spiral spring is elastically moved by the second fixed protruding portion and the second moving member. The second moving member is returned to and held at the neutral position by simultaneously sandwiching the protrusion and the both sides in the second direction, and the third closely-wound spiral spring is elastically moved by the third fixing coil to cause the third fixing. A measuring probe, wherein the third moving member is returned to the neutral position and held by simultaneously sandwiching the protruding portion and the third moving protruding portion from both sides in the third direction.