JPS582029B2 - trace head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tracer head that enables highly accurate and highly efficient tracing.

A conventional tracer head is shown in FIG.

In this figure, the stylus 1 moves like a model 8.

This movement of the stylus 1 uses the ball 2 and the bearing 3 as supporting points.
It is transmitted to displacement detectors 6 and 7.

In this case, between the ball 2 and the bearing 3, and between the bearing 3 and the base 4
Since there is resistance and wobble due to sliding and friction between the stylus 1 and the stylus 1, the precision and sharpness with which the displacement detectors 6 and 7 detect the movement of the stylus 1 is poor. , 7 becomes nonlinear.

Generally, if the weight or rotational inertia of a movable part is large, its natural frequency will be small and the tracing ability will be poor.

If an attempt is made to increase the natural frequency while leaving the weight and rotational inertia of the movable part high, the contact pressure exerted by the stylus on the model will increase, which is undesirable.

The present invention eliminates the drawbacks of the conventional example described above, and has high precision and
The purpose of this invention is to enable highly efficient tracing and to provide an inexpensive tracer head.

That is, the present invention provides a base frame, a tracer shaft extending within the base frame and having a free end protruding outside, a stylus mounted on the free end of the tracer shaft and moving along the surface of a model; a bar spring extending from the other end of the tracer shaft into the base frame on the same axis as the other end; and a bar spring provided in the base frame at intervals in the length direction of the tracer shaft and the bar spring, respectively. at least two supports supporting the tracer shaft and the bar spring with springiness in the thrust direction and substantial rigidity in the radial direction; and at least two supports provided adjacent to the bar spring to detect movement of the stylus in the thrust direction. and a pair of displacement detectors provided adjacent to an extension of the tracer shaft to detect movement of the stylus in the radial direction. It's in the head.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to preferred embodiments illustrated in FIG.

As shown in FIG. 2, in a preferred embodiment of the present invention, a tracer shaft 5 projects from the inside of the base frame 17 to the outside through the center of the tip, and the stylus 1 is attached to the free end of the tracer shaft 5.

This tracer shaft 5 is supported within the base frame at the center of the leaf spring material 10 of the support portion A, and is biased in the thrust direction by coil springs 18 and 19.

A bar spring 9 disposed on the same axis as the tracer shaft 5 is connected to the other end of the tracer shaft 5, and the bar spring 9 is supported at the center of the leaf spring material 11 of the support portion B.

A rigid transmission piece 16 is also attached to the other end of the tracer shaft 5, and a pair of radial displacement detectors 6a. 6c is in contact.

Further, a displacement detector 6 in the thrust direction is provided at the rear end of the bar spring 9.
b is in contact.

Above A. Part B has moderate springiness in the Z direction or thrust direction (direction of tracer axis 5), and has a certain degree of strong springiness or rigidity in the radial direction (X-Y plane perpendicular to tracer axis 5). If it has, it may be made of leaf spring material or other material.

However, to show an example of part 8, B, 1 in Figures 3a to 3n
Four examples are shown in Figures 4a, b and 5a, b.

The frames 12 and 13 may be circular or various polygonal shapes.

Among the above, Nos. 3a, 3b, 3h. This is shown in Figure 3i, and uses a wire such as piano wire, and the way the wire is stretched can be considered as shown in the various figures.

Also, what is shown in Fig. 3c is a leaf spring material (face material), and the third
d, 3e, 3f, 3g, 3j, 3k. 3l,
3m. What is shown in Figure 3n is a plate spring material in which a cutout S section is formed, and various ways of cutting out can be considered depending on the purpose.

FIGS. 4a and 4b show examples using bellows materials, and welded bellows are preferable to conventional molded bellows from the viewpoint of rigidity in the radial direction.

The one shown in FIGS. 5a and 5b utilizes a combination of a linear motion ball bearing 14 and a spring 15, and the ball bega ring 14 has rolling resistance and some wobbling, but Use this when you want to increase the displacement and a small amount of resistance or rattling is not a problem.

The tracer head of the present invention can be used both horizontally and vertically.

Also, if necessary, it can be used as a diagonal shape between vertical and horizontal directions.

The rod spring 9 is non-directional and has a uniform and appropriate springiness in all directions with respect to the radial movement of the stylus 1.
It has sufficient strength against buckling in the Z direction.

Next, the configuration will be explained in more detail.

In FIGS. 2 and 6, the stylus 1 moves around a model (not shown).

The movement in the Z direction is transmitted to the displacement detector 6b via the tracer shaft 5 and the bar spring 9.

Movement in the X and Y directions passes through the tracer shaft 5 and the transmission piece 16,
It is transmitted to the displacement detector 6a (Y direction) or 6c (X direction).

This will be explained in detail as follows.

That is, when no external force is applied to the stylus 1, that is, when the stylus 1 is in a free state, the output signals of all the displacement detectors 6a, 6b, and 6c are adjusted to be zero.

This state is shown in FIG.

Next, when an external force 50 in the radial direction is applied to the center 1a of the squirt 1 as shown in FIG. Since it is supported by a fulcrum and the tracer shaft 5 is rigid, only the bar spring 9 bends upward into a convex shape.

Since the transmission piece 16 is an extension of the rigid tracer shaft 5, it is displaced upward using the center of the leaf spring material 10 as a pivot point.

Therefore, the protruding piece 6a-1 of the displacement detector 6a moves upward by Δ1, and the displacement detector 6a emits a negative output signal.

However, displacement detectors 6b and 6c remain at zero output.

Conversely, in FIG. 8, if an external force acts on the tracer head 1 from below to above, the bar spring 9 is deflected downward, the rear end of the transmission piece 16 moves downward, and the displacement detector 6a becomes positive. Emit an output signal.

In this case as well, the outputs of the displacement detectors 6b and 6c are zero.

Further, when an external force in the radial direction is applied in a direction perpendicular to the plane of FIG. 8 (or FIG. 7), the bar spring 9 is deflected in a plane perpendicular to the plane of the figure.

At this time, a positive or negative output signal is generated in the displacement detector 6c.

The outputs of the displacement detectors 6a, 6b are zero.

Furthermore, as shown in FIG. 9, if the applied external force is a force directed in the thrust direction, that is, from the left to the right in the figure, as indicated by reference numeral 51, the center of the leaf spring materials 10 and 11, that is, the tracer shaft 5, the bar spring The support point 9 moves to the right by a distance Δ2.

At this time, the bar spring 9 remains straight.

Therefore, a positive output is generated in the displacement detector 6b.

The outputs of the displacement detectors 6a, 6c remain at zero.

In this way, all three-dimensional movements of the squirrel 1 following the model are detected by the displacement detectors 6a, 6b, and 6c.

The displacement detectors 6a, 6b, and 6c may be installed at locations other than those shown.

For example, the displacement detector 6b may be attached to the bar spring 9 near the leaf spring material 10.

The purpose of the transmission piece 16 is not to transmit force but to transmit displacement, so it can be used for light and heavy objects (aluminum light alloy, etc.). use.

The leaf spring members 10 and 11 of the N and B sections have springiness in the Z direction and rigidity in the radial direction, and their frames 12 and 13 are attached to the base frame 17.

The coil springs 18 and 19 are used to adjust the spring constant in the Z direction or to balance the weight of the stylus 1 when the tracer head is used vertically.

Of course, the coil springs 18 and 19 may be attached to locations other than those shown.

For example, it may be attached to the opposite side of the bar spring 9 from the stylus 1.

When using this tracer head horizontally, the weight balance of the stylus 1 is
．． 13, the leaf spring materials 10 and 11, and the zero points of the displacement detectors 6a, 6b, and 6c.

In the case of this embodiment, the one shown in Fig. 3h can be used for the N section in Fig. 2, and the one shown in Fig. 3k can be used for the B section, or a combination such as the reverse can be used. You may.

When using a method other than those shown in Figures 5a and 5b, there is no sliding resistance or backlash, and high precision and high efficiency tracing becomes possible.

The tracer shaft 5 is the only movable part that requires sufficient rigidity to transmit the force from the stylus 1.
Since the leaf spring materials 10, 11 and the bar spring 9 are light in weight, the weight rotational habit of the movable parts of this tracer head is minimized to the limit for a system that utilizes spring properties in this way.

Therefore, the ideal that the contact pressure is small and the natural frequency of the moving part is constant is realized, extending the life of the model, reducing the influence of friction between stylus 1 and model 8, and improving tracing performance. It can be made good.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional tracer head, Fig. 2 is a sectional view showing the configuration of the tracer head of the present invention, and Figs. 3a and 3b.
, 3c. 3d, 3e, 3f, 3g, 3h, 3i, 3j.
Figures 3k, 3A', 3m, and 3n are plan views showing the forms of various spring materials of the support section in the direction of the arrows CC and D-D in Figure 2. A sectional view showing an example using bellows material, Figure 4b is C/C of Figure 4a.
Figure 5a is a cross-sectional view of an example of using a linear motion ball bearing in place of a spring in combination with another coil spring, and Figure 5b is a cross-sectional view taken from line C''/C'' in Figure 5r. FIG. 6 is a schematic view showing the principle of the tracer head of the present invention, and FIGS. 7 to 9 are cross-sectional views explaining the operating conditions of the tracer head of the present invention. 1... Stylus, 2... Ball, 3...
... Bearing, 4 ... Base, 5 ... Tracer shaft, 6, 7.6a, 6b, 6c ... Displacement detector, 8 ...・Model, 9... Bar spring, 10, 11... Leaf spring material, 12.13...
...Frame, 16...Transmission piece, 17...
... Base frame, 18.19 ... Coil spring.

Claims (1)

[Claims] 1 A base frame, a tracer shaft extending within the base frame and having a free end protruding outside, a stylus that moves along the surface of a model mounted on the free end of the tracer shaft, and a stylus that moves along the surface of a model mounted on the free end of the tracer shaft; a rod spring extending from the other end into the base frame on the same axis as the rod spring; and a rod spring provided within the base frame at intervals in the length direction of the tracer shaft and the rod spring, respectively. at least two supporting parts that support the bar spring with springiness in the thrust direction and substantial rigidity in the radial direction; and a displacement detector provided adjacent to the bar spring to detect movement of the stylus in the thrust direction. A tracer head for three-dimensionally tracing a model surface, the tracer head comprising: a stylus; and a pair of displacement detectors provided adjacent to an extension of the tracer shaft to detect movement of the stylus in the radial direction.