JPS5942641Y2 - Sizing device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a sizing device used to control the finished dimensions of a cylindrical workpiece in a grinding machine that grinds the outer periphery of a cylindrical workpiece having narrow grooves in the circumferential direction. It is an object of the present invention to make it possible to measure the outer diameter of a workpiece with a required accuracy even when a contactor of a sizing device engages with a narrow groove of the workpiece.

Generally, on the outer periphery of a valve spool, etc., a plurality of thin grooves with a width of about 0.4 arm to 0.6 rrrm are carved in the circumferential direction, spaced apart in the axial direction, in order to smooth the sliding movement. .

When grinding the outer circumference of such a part as a workpiece,
The centers of the main shaft chorus and the Shinshindai are fitted into center holes drilled along the axis at both ends of the workpiece, and the workpiece is rotated around its axis, while the rotating grinding wheel cuts into the outer periphery of the workpiece.

At this time, the cut end of the grinding wheel, that is, the finished dimension of the workpiece, is determined by a sizing device that engages the outer circumference of the workpiece.
There are variations in the machining depth of the center hole of the workpiece, and the position of the workpiece in the axial direction may shift, causing the contact of the sizing device to fit into the narrow groove of the workpiece.

If the contact fits into a narrow groove, a measurement error will occur due to the depth of the groove.In the past, it was necessary to change the position of the contact in the workpiece axis direction for each workpiece, which was extremely troublesome. .

In order to solve this problem, it is possible to make the contact shape flat in the direction of the workpiece axis, but in this case, if the contactor is installed at an angle, only the edge of the contactor will come into contact with the workpiece. This has the disadvantage of causing measurement errors and damaging the ground surface of the workpiece in the housing.

In view of such conventional problems, the present invention has been developed to increase the radius of curvature of the contact by 1.
0012 (where t is the width knee m of the narrow groove).

That is, in FIG. 1, the measurement error Δr in the radial direction of the workpiece that occurs when the contact 10 with the radius R fits into the narrow groove 12 with the width t carved on the outer periphery of the workpiece W is Δr due to the geometric relationship. =R(1-r) and can be expressed as 1 6r, 8R by making the radius of curvature R of the contact 10 sufficiently larger than the groove width l.

Therefore, if the radius of curvature R is R≧10012, Δr≦0.
00125 mm, and even if the contactor 10 is practically positioned corresponding to the groove 11, the influence on the grinding accuracy can be ignored.

Embodiments of the present invention will be described below with reference to the drawings.

In Fig. 2, 20 is a table, and W is a workpiece rotatably supported around its axis at the center of the headstock and tailstock of an enclosure fixed on the table 20, as shown in Fig. 3. Narrow grooves 1 in the circumferential direction are spaced apart in the axial direction on the outer periphery of the grinding part.
It is represented as a pulp spool with a number 2 engraved on it,
Rotated by the enclosure motor.

Reference numeral 22 denotes a grinding wheel that rotates at high speed, and is fed toward the workpiece W by a well-known feeding mechanism to grind the outer periphery of the workpiece W.

In such a grinding apparatus, a base 25 of a sizing device 24 is fixed onto the table 20 by bolts in an enclosure.

A cylinder 26 is formed in the base 25 in a direction perpendicular to the axis of the workpiece W, and a piston rod 28 of a piston 27 that is slidably fitted into the cylinder 26 is fixed to a support member 29. The guide rod 30 is slidably fitted into the base 25 and prevents the support member 29 from rotating.

A sizing head 33 is rotatably supported by a pivot 34 on a bracket 32 which is fixed to the support member 29 so as to be vertically adjustable.

An upper contact holder 36 is fixed to the sizing head 33 so that its position can be adjusted in the vertical direction, and an upper contact 37 that engages with the grinding outer peripheral surface of the workpiece W is fixed to the front end of the upper contact holder 36.

The lower contact 38, which is engaged with the grinding outer circumferential surface of the workpiece W in a diametrical manner, is fixed to the tip of a lower contact holder 40 that is pivotally supported on the sizing head 33 by a cross spring 39. The rear end of 40 is a displacement detector 41 built into the sizing head 33. Specifically, it is engaged with the core 42 of the differential transformer.

The output of the displacement detector 41 is input to a well-known signal processing circuit 43, and the signal processing circuit 43 issues a sizing signal when the workpiece W is ground to an appropriate size depending on the magnitude of the output of the displacement detector 41, and outputs a sizing signal to the grinding wheel 22. Control the retreat of.

The surfaces of the upper and lower contacts 37 and 38 that engage with the outer periphery of the workpiece W are part of a cylindrical surface having a radius of curvature R in the axial direction of the workpiece W, as shown in FIGS. 3 and 4. It is formed as.

This radius R is compared to the groove width t carved on the outer periphery of the workpiece W, and R≧10012 (1:mm). Even if it faces the groove 12 of the object W or not, it hardly affects the measurement accuracy.

In FIG. 2, the stop member 46 screwed onto the cap 45 of the cylinder 26 is for regulating the forward end of the sizing head 33, and the forward end of the sizing head 33 can be adjusted by loosening the lock nut 47. .

Therefore, it is possible to change the engagement position of the contacts 37 and 38 with the workpiece W and to cope with wear of the contacts 37 and 38.

To explain the second embodiment of the contact shape shown in FIG. °53 is held.

Each of these contacts 52.53 has a shaft portion 60.61,
It is composed of a contact head 64.65 having a spherical surface 62.63 whose center is a point on the axes 52a, 53a of the shaft-shaped portion 60.61 and a radius of curvature R of R≧10012 (unit: rran). , this shaft-like portion 60, 61 is inserted into and supported by the contact holders 52, 53 so that its axes 52a, 53a are inclined with respect to the diameter line Wa of the workpiece W, and is rotatable about the axes 52a, 53a, Furthermore, it is tightened and fixed by nuts 54 and 55 screwed onto the tip thereof.

In this embodiment, the contacts 52,53 have their axes 52, 53
a.

Since it comes into contact with the workpiece W at a point C outside 53a, and its radius of curvature R is set to R≧100/:2 (7: mm), regardless of the correspondence with the groove 12 as in the first embodiment Measurement accuracy can be guaranteed, and when the contact point with the workpiece W wears out, contact can be made at a new point on the tip spherical surface by rotating the contacts 52 and 53 around the inclined axes 52a and 53a. Maintain measurement accuracy.

Note that in the first and second embodiments, the contact holder 36
, 50 are fixed to the sizing head 33, but they may be movable, and the displacement of the upper and lower contacts may be detected by separate displacement detectors, and the outputs may be calculated to generate the sizing signal. .

As described above, the sizing device of the present invention has a center point on the axis of the shaft-like part at the tip of the contact head, and a radius of curvature R of the shaft-like part.
Since it is configured to form a spherical surface with ≧100z (unit: ), it is possible to prevent the contact from falling into the groove, and the diameter of the workpiece can be measured with high precision.

In the sizing device of the present invention, a shaft-like part of a contact is inserted and supported in a contact holder such that its axis is inclined with respect to the diameter line of the workpiece and is rotatable around the axis, and its tip Since the contactor is fastened and fixed to the contactor holder by a nut screwed into the contactor, by rotating the contactor around the shaft, the spherical surface of the contact head is rotated against the workpiece. The contact point can be sequentially moved on a circular arc centered on the axis of the shaft-shaped part, and if necessary, the contact can be positioned at an advanced position in the axial direction using the shaft-shaped part as a guide, so that the spherical surface can be The workpiece can be brought into contact with the workpiece in sequence on arcs with a larger radius than the above-mentioned arc, and therefore, new points on the spherical surface can be brought into contact with the workpiece by the above operation, and measurement errors due to wear can be reduced. It can be prevented.

Moreover, since the spherical surface of the contact head contacts the workpiece at points with the regularity of circular arcs, it is possible to rotate the contact at regular angles or move the housing contact forward and backward at regular intervals. It has the advantage that it does not come into contact with the same place again, wears out the limited spherical surface uniformly, and makes effective use of its entire area.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an enlarged view of the state in which the contact of a general sizing device is engaged with a workpiece, Figs. 2 to 4 show a first embodiment of the present invention, and Figs. The figure is a side view partially cut away, FIG. 3 is a view taken from arrow 3 in FIG. 2, FIG. 4 is a perspective view of the lower contactor 38, and FIG. 5 is a second embodiment of the present invention. FIG. 12... Thin groove, 25... Base, 33... Sizing head, 36.50... Upper contact holder, 37.52
...Top contact, 38.53...Bottom contact, 40
．． 51... Lower contact holder, 41... Displacement detector, 43... Signal processing circuit.

Claims (1)

[Scope of utility model registration request] The outer diameter of the workpiece is measured by engaging a contact with the outer periphery of a cylindrical workpiece that has a thin groove L in the circumferential direction, and the displacement of this contactor is detected by the output of a displacement detector. It is a sizing device that emits a sizing signal, and this contactor is a shaft-like part, and the center is a point on the axis of this shaft-like part, and the radius of curvature R is R≧100t2 (however, the degree is mm). The shaft-shaped part is inserted into a contact holder so that its axis is inclined with respect to the diameter line of the workpiece and is rotatable around the axis, A sizing device characterized in that a contact is tightened and fixed to a contact holder by a screwed nut.