JPS5842885Y2 - Sensor of hole pitch error measuring machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sensor for a hole pitch error measuring machine that measures the error of a hole pitch with respect to a specified value in a plurality of holes drilled at intervals.

Conventionally, as shown in FIG. 1, this type of sensor has been constructed by suspending and fixing a measuring rod such as a leaf spring to a main body aa, and fixing a spherical contact C to the measuring rod. Attach a strain gauge d to the hole 5 and press the contact C of this sensor into the hole 5 of the workpiece e so that the center of the hole f' and the center of the measuring rod b'
A system has been proposed in which the bending deformation of the measuring rod due to the positional error between the hole and the hole is electrically detected by a strain gauge d to measure the hole pitch error.

However, with this structure, when the pressing force (measurement pressure) of the contactor C becomes large, the measuring rod buckles, and the strain gauge d is distorted more than the normal hole pitch error, resulting in a measurement error. There is a problem that this occurs.

This becomes noticeable when the contact C is strongly pressed when there is a crack or the like in the circumference of the hole f.

The present invention was developed in view of the above circumstances, and its purpose is to prevent the plate spring to which the strain gauge is attached from buckling even when the contact is strongly pressed against the hole, and to accurately measure the hole pitch error. It is an object of the present invention to provide a sensor for a hole pitch error measuring machine.

Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent figures.

An air cylinder 2 is fixed to the base 1, and a main body 4 is fixed to the piston rod 3 of the air cylinder 2.

A plurality of sensors 5 are suspended from the main body 4 at intervals.

The sensor 5 is constructed as follows.

That is, the holder 6 is tightened and fixed to the main body 4 with its flange I and bolts 8, and the bottom step 9a of the through hole 9 of the holder 60 is fixed.
A proximal end of a rod 11 is swingably supported via a spherical joint 10, and a spherical contact 12 is fitted into the tip of the rod 11 and fixed to the collar 11a with a nut 13.

A spacer 14 is fitted into the through hole 9 so as to come into contact with the spherical joint 10, and has a through hole NL 9a and an upper threaded portion 9b.
A urethane rubber 16 is provided between the pressing body 15 screwed to the spacer 14 and the pressing body 15 is rotated with its corner 15a projecting upward from the main body 4.
is pressed against the spherical joint 10 via the urethane rubber 16.

! In addition, each side of the lower four corners 6a of the holder 6 has first to fourth
The bases of the leaf springs 171 to 174 are brought into contact with each other, and the pressing piece 18 is pressed by the screw 19 to support the leaf spring 17 under pressure, and the tip of each of the leaf springs 171 to 174 is brought into contact with the contactor 12. ing.

Further, strain gauges 20.20 are attached to the first and second leaf springs 171.1γ2.

The strain gauge 20.20 is connected to a Wheatstone bridge circuit 21 as shown in FIG. 7, and is configured to measure the hole pitch error by measuring its output.

The contactor 12 is always held near the center by the first, second, third, and fourth leaf springs 171 to 174.

Then, when the body 4 is lowered by the air cylinder 2 and the contact 12 is pressed against the hole B of the workpiece A, the center 12a of the contact 12 coincides with the center B' of the hole B.
is displaced by medium tQJ/C.

The amount of displacement of the spherical tangent angle 12 appears as a resistance value 'ML' of the strain gauge 20 of the leaf spring 17, and by electrically amplifying this and reading it with a meter, the hole pitch error can be measured.

When drilling many holes at the same time, each sensor 5 has a slightly different height for each hole due to variations in hole diameter, inclination of the workpiece, etc. In this case, the contact 12 is made of urethane. Since the rubber 16 is compressed and moved upward, this problem can be solved.

Also, even if the contact 12 is strongly pressed against the hole B, the leaf spring 17
Since the measurement pressure does not act on the plate spring 17, the plate spring 17 does not deform more than the hole pitch error regardless of the measurement pressure, and the resistance value change of the strain gauge 20 becomes correct, so that the hole pitch error can be accurately measured.

As a result, even if there is a burr or the like on the periphery of the hole, the contact 12 can be strongly pressed, so that the hole pitch error can be measured more accurately.

In addition, since the rod 11 with the tangential angle 12 is swingably supported on the holder 9 via the spherical joint 10, the reaction force acting on the main body 4 when the contact 12 is pressed against the hole B is The radial reaction force becomes extremely small.

Therefore, the error and rigidity of the guide section of the main body of the measuring device can be alleviated.

Further, the gap between the spherical joint 10 and the stepped portion 9a of the holder 6 does not need to be precise, and processing is easy.

That is, since the displacement of the contactor 12 is directly transmitted from the contactor 12 to the leaf spring 17, even if there is play between the spherical joint 10 and the stepped portion 9a of the holder 6, it does not affect the damping accuracy at all.

Since the present invention is configured as described above, the contact 12 is connected to the hole B.
The plate spring 17 to which the strain gauge 20 is attached will not buckle even if it is strongly pressed.

Therefore, the hole pitch error can be accurately measured even if there is a burr or the like on the periphery of the hole.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a front view showing an embodiment of the present invention, Fig. 3 is a side view, Fig. 4 is a sectional view of main parts, Fig. 5
The figure is a bottom view, FIG. 6 is a sectional view taken along the line Vl--Vl in FIG. 4, and FIG. 7 is an electric circuit diagram. 4 is the main body, 6 is the holder, 11 is the rod, 12 is the contact,
17 is a leaf spring, and 20 is a strain gauge.

Claims (1)

[Scope of utility model registration request] A holder 6 is fixed to the vertically movable main body 4, and a rod 11 provided with a spherical contact 12 is swingably supported on the holder 6, and the bases of a plurality of leaf springs 17 are attached to the tips of the holder 6. A sensor for a hole pitch error measuring machine characterized in that a strain gauge 20 is attached to each of the plate springs 17 fixedly fixed so as to be in contact with the tangent angle 12.