JPS601962Y2 - trace head - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tracer head that enables high-precision tracing without radial displacement of the tracer shaft affecting axial displacement during tracing movement.

A conventional tracer head is shown in FIGS. 1 and 2, and includes a tracer shaft 4 having a stylus 2 at its tip that contacts the copying model 1 and a rod spring 3 fixed to its rear end.
is attached to the tracer head main body 7 so as to be movable in the axial direction by a spring material 5 attached to the tracer shaft 4 and a spring material 6 attached to the bar spring 3.

When the tracer shaft 4 moves in the axial direction due to the tracing movement of the tracer head main body 7, in order to detect the amount of movement, the bar spring 3 is connected to the Z-axis direction displacement detector 8 attached to the tracer head main body 7 by the joint 9. connected.

A Z-axis damper mechanism 10 is disposed between the joint 9 and the biaxial displacement detector 8.

A cylindrical transmission piece 11 is coupled to the tracer shaft 4, and an X-axis displacement detector 12 for detecting radial displacement of the transmission piece 11 is attached to the tracer head body 7.

Further, a displacement detector 13 in the Y-axis direction is attached to the tracer head body 7 for detecting displacement in a direction perpendicular to the displacement detector 12 in the X-axis direction.

Weight balance springs 14 and 15 are attached to opposing positions of these two displacement detectors 12 and 13, respectively, as shown in Figure 2, and the force of these springs can be adjusted using adjustment screws 16 and 17. .

The transmission piece 11 has a displacement detector 12.1 in the X-axis and Y-axis directions.
3, an X-axis damper mechanism 18 and a Y-axis damper mechanism 19 are respectively disposed via elastic rod universal joints 20.

In addition, 21 is a compression spring, which applies a spring force to the tracer shaft 4 in the direction in which the tracer shaft 4 protrudes.
This is to quickly return to the origin in response to displacement in the Z-axis direction.

When model 1 is copied using the conventional tracer head described above, the movement of the stylus 2 in the Z-axis direction is caused by the tracer axis 4. This also causes the movement of the transmission piece 11 and the bar spring 3, and further causes the spring material 5. The movement is against the compression spring 21 and the like.

Therefore, the moving mass is large relative to the movement in the Z-axis direction, and the response speed when detecting displacement becomes slow.

In addition, the damper mechanisms 18 and 19 arranged in the Y-axis direction and the Therefore, the spring force of the bar universal joint 20 resists the movement of the transmission piece 11, etc., which slows down the response speed during detection in the Z-axis direction and adversely affects detection accuracy.

Since the rod spring 3 in the Z-axis direction and the damper mechanism are connected by a fixed joint, displacement of the rod spring 3 in the X-axis or Y-axis direction has a slight effect on the displacement detector in the two-axis directions.
There are drawbacks such as a decrease in detection accuracy.

Furthermore, since the weight balance is adjusted by the spring force of the spring, it lacks reliability, is unstable, and is inefficient due to the inefficient adjustment.

When the stylus returns to its origin, the vibrations of the springs 14 and 15 may counteract the damper effect and have an adverse effect.

In addition, the core of the displacement detector fits into the bearing of the displacement detector and is movable, and since the bearing and the core are designed to slide, there is a sliding resistance between the bearing and the core. There is a risk that distortion may occur and the displacement detection function may deteriorate.

A spring force is used to make the fur follow the displacement of the transmission piece 11 when detecting displacement, and it is difficult to adjust this spring force and lacks reliability, which may slow down the response speed when detecting displacement. .

As described above, in the prior art shown in FIGS. 1 and 2, the contact pressure increases when the stylus traces the model, resulting in poor tracing.

The present invention is arranged in the radial direction with respect to the tracer axis, that is, the X axis and the Y axis.
Displacement in the axial direction does not affect the displacement detector in the axial direction of the tracer axis, that is, in the Z-axis direction, and displacement in the Z-axis direction does not affect the displacement detectors in the X- and Y-axis directions. The main body of the tracer head moves a tracer shaft, the tip of which is provided with a stylus that comes into contact with the copying model, with respect to the copying model. The tracer shaft is supported by a rolling bearing within a cylindrical support attached via a spring material so as to be independently movable in the axial direction with respect to the support. Two X-axis displacement detectors and a Y-axis displacement detector that are perpendicular to each other are attached to the tracer head body, and the shaft of the Z-axis displacement detector that detects the axial displacement of the tracer shaft is attached to the tracer head body. The tracer head is connected to a shaft by a spherical universal joint, and the Z-axis direction displacement detector is attached to a housing that is attached to the tracer head body so as to be adjustable and movable in the radial direction.

Next, an explanation will be given with reference to an embodiment of the present invention shown in FIGS. 3 to 10. A tracer shaft 32 having a stylus 31 at its tip that contacts a copying model 30 is inserted into a cylindrical support 33 in the axial direction (Z-axis direction). ) is movably supported by a rolling bearing (ball bearing) 34, and the support 33 is attached via a spring member 35 within a tracer head main body 36 that moves along the copying model 30.

Therefore, the tracer shaft 32 is connected to the support 33 and the spring material 3.
5, it independently moves in the axial direction, that is, in the Z-axis direction.

The support 33 is provided with a displacement transmission piece 37, and in order to detect the displacement in the radial direction accompanying the tracing movement of the tracer head body 36, as shown in FIG.
A displacement detector 39 in the X-axis direction is housed in a case 38 attached to the case 38, and a core 40 of this displacement detector 39 in the Y-axis direction is connected to the displacement transmitting piece 37 at its tip.

Furthermore, in order to detect the radial displacement in the direction perpendicular to the displacement detector 39 in the X-axis direction, a displacement detector 4 in the Y-axis direction is installed in the case 41 attached to the tracer head body 36.
2 is accommodated, and the shaft 4 of this displacement detector 42 in the Y-axis direction
3 is connected to the displacement transmitting piece 37 at its tip.

Each mandrel (core) 40.43 and displacement transmission piece 37
As shown in FIG. 8, the connection is made by bringing the tips of the shafts 40 and 43 into contact with a roller 46 attached by a pin 45 to a cylindrical body 44 fitted to the tip of the displacement transmitting piece 37, and by using a spring material. 47 brings the mandrels 40 and 43 into pressure contact with the roller 45.

Displacement detector 39 in the X-axis direction and displacement detector 4 in the Y-axis direction
2 in the X-axis and Y-axis directions, respectively.
As shown in the figure, a threaded eccentric pin 50, in which the center of the pin part 48 at the tip is offset from the center of the threaded part 49, is screwed into the tracer head main body 36, and is inserted into the groove provided on the outer periphery of the case 38. A pin portion 48 is fitted into 51.

In order to buffer and support the radial movement of the displacement transmission piece 37,
The damper mechanism 52 in the axial direction and the damper mechanism 53 in the Y-axis direction are arranged at positions corresponding to the displacement detector 39 in the X-axis direction and the displacement detector 42 in the Y-axis direction, respectively. 53 is movably connected to the displacement transmission piece 37 by a rotation bearing 54.

Attachment of the shaft 40°43 to the displacement detector 39.42 is as follows:
As shown in FIG. 7, the mandrel 40° 43 is supported by a plurality of (three in the illustrated embodiment) rolling bearings 56 that are rotatably supported by pins 55 in the case 38, 41, resulting in less resistance. It is movably supported by.

Although FIG. 7 is a sectional view of the case 41 of the displacement detector 42 in the Y-axis direction, the same applies to the case 38 of the displacement detector 39 in the X-axis direction.

In order to detect the displacement of the tracer shaft 32 in the axial direction, that is, the displacement in the Z-axis direction, a biaxial displacement detector 58 is attached to the housing 57. , and a bar spring 60 connected to the tracer shaft 32 are connected by a spherical universal joint 61.

As shown in FIG. 8, the spherical universal joint 61 includes a steel ball 62 integrally formed at the tip of the mandrel 59, connecting fittings 63 and 64 for connecting this to the bar spring 60, and a steel ball seat 65. Consists of.

A biaxial damper mechanism 66 for damping movement of the tracer shaft 32 is attached to the housing 57, and the biaxial damper mechanism 66 is connected to the shaft 59 of the displacement detector 58 in the Z-axis direction.

Note that 67 is a bolt for attaching the housing 57 to the tracer head main body 36.

The housing 57 has a main body part 68 and a flange part 69. In order to adjust and move the center of the main body part 68, the main body part 68 is disposed between the main body parts as shown in FIGS. A slit groove 70 for swinging movement in the X-axis direction is formed except for the upper and lower connecting parts 71, and the main body part 68
A slit groove 72 for swinging movement in the Y-axis direction is formed leaving left and right connecting portions 73, and as shown in FIG. Two threaded pins 74 and 75 are attached to the tracer head body 36 in the X-axis direction, and the two threaded pins 74 and 75 are in contact with the housing 57. Pin 7 of
6.77 is slidably attached to the tracer head body 36 in the Y-axis direction, and steel balls 80 and 81 housed in recesses 78 and 79 formed in the tracer head body 36 are attached to the pin 76.
．． It is in contact with the rear end of 77.

As shown in FIG. 6, these steel balls 80, 81 are in contact with grooves eccentrically formed on the inner peripheral surface of an eccentric ring 82 rotatably fitted on the outer periphery of the tracer head main body 36. By rotating the eccentric ring 82, the two pins 76 and 77 slide, and the housing 57 is adjusted and moved in the Y-axis direction.

The tracer head body 36 further includes, as shown in FIG.
A steel ball 84 is housed in a recess 83 formed in the tracer head body 36, and a spring 85 holds the steel ball 84.
A spring force is applied toward the eccentric ring 82, thereby preventing the eccentric ring 82 from rotating and positioning it.

Note that 85 is a spring member, and connects the end of the bar spring 60 to the housing 57.

By moving the tracer head body 36 to follow the model 30, the stylus 31 moves to follow the model 30.

The movement in the Z-axis direction is caused by the tracer shaft 32 supported by a rolling bearing (ball bearing) 34 and the bar spring 6.
0 and is transmitted to the Z-axis direction displacement detector 58 via the spherical universal joint 61, where the amount of displacement is detected.

At this time, since the tracer shaft 32 is independently movably supported by the support 33, the movement of the tracer shaft 32 is not transmitted to the support 33, and the moving mass in the Z-axis direction becomes small.

The states of the tracer shaft 32 and the bar spring 60 at this time are shown in FIG. 10B, and as shown in FIG. 10A, in the conventional case, the displacement of the bar spring 3 is detected by the displacement detector 8. Although the influence is slight, in the tracer head of the present invention, the displacement in the X-axis direction and the Y-axis direction does not directly influence the displacement detector 58 in the Z-axis direction.

Movement in the X-axis direction and Y-axis direction is caused by the tracer shaft 32. X via the rolling bearing 34, support 33 and displacement transmission piece 37
The displacement in the axial direction is transmitted to the displacement detector 39, and the displacement in the Y-axis direction is transmitted to the displacement detector 42.

At this time, since the shaft 40.43 is pressed against the roller 46 by the spring material 47, the displacement can be reliably transmitted.

When the stylus 31 traces the model 30, subtle vibrations generated by the frictional resistance etc. are transmitted to the rod spring 60 or the displacement transmission piece 37, and the vibrations in the Z-axis direction are transmitted to the damper mechanism 66, and then to the X- and Y-axes. The vibrations in the directions are quickly absorbed by the damper mechanisms 52, 53 and disappear, so that the vibrations do not affect the detectors 39, 42, 58.

When adjusting the weight balance of the stylus 31, the balance in the Y-axis direction is adjusted by rotating the eccentric ring 82 and relatively moving the steel balls 8G and 81 housed in the recesses 78 and 79 in and out. 77 and swing the main body 68 on the distal end side of the slit groove 71 up and down for adjustment.

Further, the weight balance of the stylus in the X-axis direction is adjusted by moving the main body on the distal end side of the slit groove 70 horizontally by moving the threaded pins 74 and 75 in and out.

After adjusting the weight balance in the X-axis direction and Y-axis direction in this way, each displacement detector 39, 42.58
Each damper mechanism 52.53.6 is arranged correspondingly to
6 allows the axial center position to be maintained accurately and the tracer shaft 32, rod spring 60, and displacement transmitting piece 37 to be returned to the origin extremely quickly and accurately.

According to the present invention, the axial movement of the tracer shaft is performed independently with respect to the support and the spring material used to support it, so the axial movement mass of the tracer shaft is reduced, the response speed is fast, and the detection sensitivity is extremely high. It became good.

The X-axis displacement detector and the Y-axis displacement detector are not affected at all by the movement of the tracer shaft in the two-axis directions, and since the Z-axis displacement detector and the tracer axis are connected via a spherical universal joint, the X-axis Also, since the displacement in the Y-axis direction does not affect the displacement detection accuracy in the Z-axis direction at all, highly accurate detection is possible.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional tracer head, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, Fig. 3 is a sectional view showing an embodiment of the present invention, and Fig. 4 is a perspective view of the housing. Figure 5 is a sectional view taken along the line ■-V in Figure 3, Figure 6 is a sectional view taken along the line VI-VI in Figure 3, Figure 7 is a sectional view taken along the line ■-■ in Figure 5, and Figure 8 is a sectional view taken along the line ■--■ in Figure 5. is an enlarged cross-sectional view of part ■ in FIG. 3, FIG. 9A is a cross-sectional view showing the adjusting movement state of the housing in the Y-axis direction, FIG. 9B is a cross-sectional view showing the adjusting movement state of the housing in the X-axis direction, 1st
FIG. 10A is a schematic view showing the curved state of the bar spring in the prior art shown in FIGS. 1 and 2, and FIG. 10B is a schematic diagram showing the curved state of the bar spring in the present invention. In the drawing, 30 is a copying model, 31 is a stylus, 32 is a tracer shaft, 33 is a support, 34 is a rolling bearing, 3
5 is a spring member, 36 is a tracer head main body, 37 is a displacement transmitting piece, 39 is a displacement detector in the X-axis direction, 42 is a displacement detector in the Y-axis direction, 57 is a housing, and 58 is a displacement detector in the Z-axis direction. , 61 is a spherical universal joint.

Claims (1)

[Scope of utility model registration request] The tracer shaft, which has a stylus at its tip that contacts the copying model, is moved by a rolling bearing in a cylindrical support that is attached via a spring material to the tracer head body that moves to copy the copying model. independently supports the support so as to be freely movable in the axial direction,
Two X-axis displacement detectors and a Y-axis displacement detector, which are perpendicular to each other and which detect the radial displacement of the support, are attached to the tracer head body to detect the axial displacement of the tracer shaft. The shaft of the Z-axis displacement detector is connected to the tracer shaft by a spherical universal joint, and the Z-axis displacement detector is attached to a housing that is attached to the tracer head body so as to be adjustable and movable in the radial direction. tracer head.