JPH0579933A - Automatic stopping device for three-dimensional measuring instrument - Google Patents

Abstract

PURPOSE:To surely detect the pressing force applied to a stanchion when a worker or the like is pinched by the stanchion. CONSTITUTION:A contact pressure detecting sensor 33 is stuck to the supporter main body (stanchion) 32 of a three-dimensional measuring instrument. A tubular cover 34 is fitted to the supporter main body 32 with brackets 36 and screws 37 via an elastic member 35, and the supporter main body 32 is covered by the cover 34. A contact pressure detecting sensor 33 is provided on the back face of the cover 34, and an air bag 38 filled with air of the preset pressure is fitted. When a worker or the like is pinched by the supporter 18 and the cover 34 is pressed, the elastic member 35 is warped, and the cover 34 is moved. The air bag 38 is brought into contact with the contact pressure detecting sensor 33 to press it. The contact pressure detecting sensor 33 detects the pressing force and operates a stopping device to stop the three-dimensional measuring instrument.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional measuring machine which automatically stops the measuring machine on the basis of the detection of a contact pressure sensor provided on a column standing on a table on which an object to be measured is placed. The present invention relates to an automatic stop device.

[0002]

2. Description of the Related Art A coordinate measuring machine, for example, as shown in FIG. (Only shown), a beam 3 extending in the X-axis direction on the upper ends of the pair of columns 2, a slider 4 movable in the X-axis direction along the beam 3, and a Z-axis direction attached to the slider 4. And a probe 6 attached to the spindle 5. Then, by moving the probe 6 along the surface of the object to be measured placed on the table 1, the size, shape, and position of the object to be measured are X,
It is measured as Y and Z coordinate values.

In the coordinate measuring machine, a contact pressure sensor 7 is attached to the column 2, and an automatic stop device for stopping the measuring machine based on the detection of the contact pressure sensor 7 is provided. If an operator or the like is caught between the column 2 and a movable part such as the slider 4, the contact pressure detection sensor 7 detects this, and the automatic stop device operates to stop the measuring machine.

Conventionally, the contact pressure detecting sensor 7 is attached to the surface of the column main body 2a as shown in FIG. 6, and is covered with a resin cover 8 via a gap. Resin cover 8
Is a tubular body with a rectangular cross section.
2a is inserted and is fixed to the column main body 2a with a screw 9. With this configuration, when an operator or the like is sandwiched between the column 2 and a movable portion such as the slider 4, the resin cover 8 bends to press the contact pressure detection sensor 7 and the automatic stop device operates.

[0005]

However, in the above-described conventional automatic stop device, since the resin cover 8 has a different relationship between the pressing force and the amount of deflection depending on the pressed portion, the resin cover 8 is pressed even if the pressing force is the same. The detected value of the contact pressure sensor 7 varies depending on the part to be touched. For example, the vicinity of the corners of the resin cover 9 has high flexural rigidity, and the mounting portion of the screw 9 to the column main body 2a is also difficult to flex, so that the pressing force is hard to be sensed at these parts.

The contact pressure sensor 7 is, for example, as shown in FIG.
As shown in FIG. 2, a pair of flat flexible members 12 and 13 having conductors 10 and 11 arranged on the surface thereof are arranged parallel to each other with the conductors 10 and 11 facing each other and an elastic member 14 made of an insulator on the periphery. They are arranged and further covered with a cover 15. And
When the cover 15 is pressed, the flexible member 12 or 13 bends and the conductive wires 10 and 11 come into contact with each other, so that the pressing force is sensed. However, when the vicinity of the peripheral edge of the contact pressure sensor 7 is pressed, the conductive wires 10 and 11 are separated by the elastic member 14, and therefore the conductive wires 10 and 11 do not come into contact with each other even if the flexible member 12 or 13 bends. No pressing force is detected. In addition, such a dead zone at the peripheral edge of the contact pressure sensor 7 is often located near the corner of the resin cover 8, which makes it difficult to detect the pressing force. The contact pressure sensor 7 is
When bent, the conductors 10 and 11 are always in contact with each other, so that they cannot be arranged at the corners of the resin cover 8.

FIG. 9 shows the result of actually measuring the pressing force that can be detected by the contact pressure sensor 7 at each of the measurement points shown in FIGS. 7 and 8 on the column 2. 7 shows one of the columns (supporters) shown in FIG. 5, and FIG. 8 shows the other column (column) not shown. From FIG. 9, the resin cover 8
It can be seen that the pressing force that can be detected is large near the corners and the attachment to the column. The pressing force that can be detected when the contact pressure sensor 7 is directly pressed is 7.8 N.
Above, it is desirable that the pressing force that can be detected at each part of the support column 2 is within about 49.0N.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an automatic stop device for a coordinate measuring machine capable of reliably detecting a pressing force applied to a column.

[0009]

In order to solve the above-mentioned problems, the present invention provides a contact pressure sensor on a column standing on a table on which an object to be measured is placed, and the contact pressure sensor is provided. In an automatic stop device for a coordinate measuring machine that stops a measuring machine based on detection, the contact pressure detection sensor is fixed to the support, and a cover covering the support is attached to the support via an elastic member. An air bag is attached to the back surface so as to face the contact pressure sensor.

[0010]

With this structure, when the cover is pressed, the elastic member bends and the cover moves, and the air bag is pressed against the contact pressure detecting sensor, so that the contact pressure detecting sensor detects the pressing force. To do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 3 shows an overall view of the coordinate measuring machine. As shown in FIG. 3, in the coordinate measuring machine 16, a table 17 on which an object to be measured is placed is provided with a supporter 18 and a column 19 which are provided upright to constitute a pair of columns movable in the Y-axis direction. A beam 20 in the X-axis direction is installed between the upper ends of the supporter 18 and the column 19, and the supporter 18, the column 19, and the beam 20 are integrally moved in the Y-axis direction by a drive device 21 provided on the column 19 side. It is movable. The beam 20 includes a slider 22 that is movable along the beam 20 in the X-axis direction.
Is provided. The slider 22 is provided with a spindle 23 movable in the Z-axis direction, and a probe adapter 24 for attaching a probe (not shown) is attached to a tip end portion of the spindle 23. In the figure, 26 is a control device, 27 and 28 are data processing devices, and 29 is a joystick control box.

Contact pressure sensing devices 30 and 31 are provided on the surfaces of the supporter 18 and the column 19 facing the probe adapter 24. Since the contact pressure sensing devices 30 and 31 are similarly provided on the supporter 18 and the column 19, only the contact pressure sensing device 30 on the supporter 18 side will be described below.

As shown in FIGS. 1 and 2, the surface of the supporter body 32 in the shape of a prism is opposed to the probe adapter 24.
A contact pressure sensor 33 similar to the conventional one shown in FIG. 4 is bonded. The contact pressure sensor 33 is connected to a stop device (not shown) that stops the coordinate measuring machine upon detection of the contact pressure sensor 33. A cylindrical cover 34 having a rectangular cross section is provided to allow the supporter main body 32 to be inserted therethrough and to cover the supporter main body 32 with a predetermined gap. The cover 34 is
Brackets 36 and screws 37 are attached to the supporter main body 32 via elastic members 35 near the upper end and lower end thereof, and are supported by the supporter main body 32 in a floating state by the elastic members 35. Therefore, the cover 34
Can be freely moved vertically and horizontally depending on the bending of the elastic member 35.

A flat air bag 38 is attached to the back surface of the cover 34 so as to face the contact pressure sensor 33 with a predetermined gap. The air bag 38 has a hose with a valve 39.
40 is connected, and the amount of air filled in the air bag 38 can be adjusted by an external air supply / discharge device (not shown) via the hose 40.

The operation of this embodiment having the above-mentioned structure will be described below. When a worker or the like is sandwiched between the supporter 18 and a movable portion such as the slider 22 and the cover 34 is pressed, the elastic member 35 bends and the cover 34 moves. And
When this pressing force exceeds a predetermined value, the air bladder 38 contacts the contact pressure detection sensor 33 and applies a contact pressure thereto. When the contact pressure detection sensor 33 detects this contact pressure, the coordinate measuring machine 16 is stopped by the stop device.

At this time, since the cover 34 is supported in a floating state by the elastic member 35 and can freely move vertically and horizontally, even if any portion is pressed, it is possible to move with a slight pressing force. Become. Therefore, even if an operator or the like is caught in any part of the cover 34, the contact pressure sensor 33 can reliably detect the movement of the cover 34 and stop the coordinate measuring machine 16.

Since the entire cover 34 moves regardless of which part is pressed, the movement can be reliably detected by one contact pressure sensor 33. Therefore, the number of contact pressure detection sensors 33 is smaller than that of the conventional one, and the cost is low.

When the hose 40 is connected to an air supply / exhaust device to supply / exhaust air to / from the air bag 38 and increase the air pressure in the air bag 38, the gap between the air bag 38 and the contact pressure sensor 33 becomes small. As the air bag 38 increases in elasticity, the cover
The sensitivity of the contact pressure detection sensor 33 with respect to the pressing force acting on the 34 is increased. If the air pressure inside the air bladder 38 is reduced, the air bladder will
Since the gap between the 38 and the contact pressure sensor 33 becomes large and the elasticity of the air bag 38 becomes small, the sensitivity of the contact pressure sensor 33 to the pressing force acting on the cover 34 becomes low.
In this way, by adjusting the air pressure in the air bag 38, the sensitivity of the contact pressure detection sensor 33 with respect to the pressing force acting on the cover 34 can be easily adjusted.

[0019]

As described above in detail, in the automatic stop device for the coordinate measuring machine according to the present invention, the contact pressure detecting sensor is fixed to the supporting column, and the cover for covering the supporting column is attached via the elastic member. Since the air bag is attached so as to face the contact pressure detection sensor, when the cover is pressed, the elastic member bends and the cover moves, and the air bag is pressed against the contact pressure detection sensor. Detects the pressing force and stops the coordinate measuring machine. As a result, even if an operator or the like is caught in any part of the cover, the contact pressure sensor can reliably detect the movement of the cover and stop the coordinate measuring machine. Further, by adjusting the air pressure in the air bag, the sensitivity of the contact pressure detecting sensor with respect to the pressing force acting on the cover can be easily adjusted. Further, since the movement of the cover can be reliably detected by one contact pressure detection sensor, the number of the contact pressure detection sensors is smaller and the cost is lower than that of the conventional one, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an embodiment of the present invention.

2 is a cross-sectional view of the device of FIG. 1 taken along the line AA.

FIG. 3 is a perspective view showing the entire coordinate measuring machine according to the present invention.

FIG. 4 is a vertical sectional view of a contact pressure sensor.

FIG. 5 is a perspective view showing a main part of a conventional coordinate measuring machine.

FIG. 6 is a vertical cross-sectional view showing a part of a column of a conventional coordinate measuring machine.

FIG. 7 is a diagram showing an arrangement of measurement points of sensitivity of a contact pressure detection sensor on a supporter side strut of a conventional coordinate measuring machine.

FIG. 8 is a diagram showing an arrangement of measurement points for sensitivity of a contact pressure detection sensor on a column-side strut of a conventional coordinate measuring machine.

9 is a diagram showing the sensitivity of the contact pressure detection sensor for each measurement point in FIG.

[Explanation of symbols]

 16 Coordinate measuring machine 17 Table 18 Supporter (support) 19 Column (support) 33 Contact pressure sensor 34 Cover 35 Elastic member 38 Air bag

Claims (1)

[Claims] 1. An automatic stop device for a coordinate measuring machine, which comprises a contact pressure detecting sensor provided on a column standing on a table on which an object to be measured is placed, and which stops the measuring machine based on the detection of the contact pressure detecting sensor. In the above, the contact pressure detecting sensor is fixed to the support, a cover covering the support is attached to the support via an elastic member, and an air bag is attached to the back surface of the cover so as to face the contact pressure detecting sensor. Automatic stop device for coordinate measuring machine characterized by.