JPH0527607U - CMM - Google Patents

Abstract

(57) [Summary] [Purpose] The squareness posture of the bridge structure 3 is kept constant regardless of the position of the X-axis carriage 4 in the X-axis direction. [Arrangement] Coordinate measuring devices 7a and 7b for measuring coordinates of an X-axis carriage 4 provided on an X-axis beam 3B of a bridge structure 3, a controller 8 for outputting a signal according to the coordinate values, and a controller. The proportional solenoid valve 9 for outputting the gas pressure corresponding to the signal of 8 to the air pad c and the air source 10 are installed so that the surface plate 1 can be moved even if the X-axis carriage 4 moves.
The air gap between the air guide c and the air guide c is always constant.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for correcting a squareness of a bridge structure of a coordinate measuring machine.

[0002]

[Prior Art]

 A conventional coordinate measuring machine is configured as shown in FIG. In FIG. 2, a Y-axis direction guide 2 is fixedly installed on a surface plate 1, and a bridge structure 3 that moves along the Y-axis direction guide 2 in the Y-axis direction (direction perpendicular to the paper surface) is guided. The bridge structure 3 includes a guide side leg 3A having air guides a, b, and d (two sets are arranged in front of and behind the Y-axis direction guide 2 (not shown)), and a support having an air guide c. It is composed of a side leg 3C, and an X-axis beam 3B that connects the guide side leg 3A and the support side leg 3C above. The X-axis beam 3B of the bridge structure 3 guides the X-axis carriage 4 that moves in the X direction (left and right direction of the paper) with the X-axis beam 3B as a guide surface. The X-axis carriage 4 has a Z-axis spindle 5 that moves in the Z-axis direction (vertical direction on the paper surface), and a probe probe 6 is provided at the lower tip of the Z-axis spindle 5.

[0003]

[Problems to be solved by the device]

 Problems of the conventional coordinate measuring machine will be described with reference to FIGS. 3 and 4. The conventional bridge movement type three-dimensional measuring machine has a structure in which an X-axis carriage 4 equipped with a Z-axis spindle 5 having a tracing stylus probe 6 is guided by an X-axis beam 3B of a bridge structure 3. Considering when the X-axis carriage 4 is at the center of the X-axis beam 3B as a reference, when the X-axis carriage 4 is near the support side leg 3C as shown in FIG. 3, the load applied to the air guide c by the weight of the X-axis carriage 4 Will increase.

On the other hand, when the X-axis carriage 4 is near the guide side leg 3A as shown in FIG. 4, the load applied to the air guide c is reduced. The floating amount (clearance) of the air guide is inversely proportional to the amount of change in the load load in the region where the rigidity of the air guide can be considered to be constant. Therefore, as shown in FIGS. 3 and 4, the bridge structure 3 has the X-axis carriage. The rolling phenomenon around the Y-axis occurred depending on the position of the No. 4 in the X-axis direction.

As a result, there is a problem in that the perpendicularity posture of the bridge structure 3 changes according to the position of the X-axis carriage 4 in the X-axis direction. Even if the rolling phenomenon occurs, a steel ball is engaged between the air pad of the air guide b and the air pad of the air guide d and the guide side leg 3A to guide the air pads of both air guides b and d. By allowing the side legs 3A to rotate, the air gap distance between the air guides b and d and the Y-axis direction guide does not change.

The present invention has been made in view of the above problems, and in a bridge movement type three-dimensional measuring machine, the right angle posture of the bridge structure caused by an eccentric load accompanying the movement of the X axis carriage 4 is changed to the X axis. This is a squareness correction device whose purpose is to always maintain a constant squareness posture regardless of the position of the carriage 4.

[0007]

[Means for Solving the Problems]

 In the present invention according to claim 1, coordinate measuring devices 7a and 7b for measuring the X coordinate of the X-axis carriage 4 are provided between the X-axis carriage 4 and the X-axis beam 3B, and from the coordinate measuring devices 7a and 7b. A signal output means 8 for outputting a signal according to the position of the X-axis carriage 4 in the X direction is provided, and a gas pressure adjusting means 9 for outputting a gas pressure according to the signal of the signal output means 8 is provided. Further, the gas pressure adjusted by the gas pressure adjusting means 9 is supplied to the air guide c.

The present invention according to claim 2 provides a coordinate measuring device 7a provided between the X-axis carriage 4 and the X-axis beam 3B for measuring the X coordinate of the probe probe 6 provided on the Z-axis spindle 5. Is also used. According to the present invention in claim 3, one of the two legs of the bridge structure 3 is guided by the Y-axis direction guide provided on the surface plate 1, and the gas pressure adjusting means 9 is provided on the lower surface of the other of the two legs and the surface plate 1. The gas pressure between and is adjusted.

The present invention according to claim 4 uses a proportional solenoid valve as the gas pressure adjusting means.

[0010]

[Action]

 According to the above configuration, when the X-axis carriage 4 is at the center of the X-axis beam 3B as a reference, when the X-axis carriage 4 is moved from the center to the guide side leg 3A, the weight of the X-axis carriage 4 gradually increases. Since it is hooked on the air guide a provided on the guide side leg 3A, the flying height of the air guide c tends to increase and the flying height of the air guide a tends to decrease. At this time, the pressure of the gas supplied to the air guide c is gradually reduced by the gas pressure adjusting means 9 to reduce the floating amount of the air guide c, and to maintain the squareness posture of the bridge structure 3 constant at all times. It can be moved axially. On the contrary, when the X-axis carriage 4 is moved to the support side leg 3C, the gas pressure adjusting means 9 may gradually increase the pressure of the gas supplied to the air guide c.

With the above-described configuration, the squareness posture of the bridge structure 3 can be kept constant by keeping the air gap between the surface plate 1 and the air guide c constant.

[0012]

【Example】

 FIG. 1 shows an embodiment of the present invention. A Y-axis direction guide 2 is fixedly mounted on the surface plate 1, and a bridge structure 3 movable along the Y-axis direction guide 2 is installed. The bridge structure 3 has a guide side leg 3A having air guides a, b and d (two sets are arranged with respect to the Y-axis direction guide 2 (not shown)), and a support side leg having an air guide c. 3c, and an X-axis beam 3B that connects the guide-side leg 3A and the support-side leg 3C above, and moves in the Y-axis direction (perpendicular to the plane of the drawing) with the Y-axis direction guide 2 and the surface plate 1 as guide surfaces. It is possible. The bridge structure 3 is provided with an X-axis carriage 4 which is movable in the X-axis direction (left and right direction on the paper) using the X-axis beam 3B as a guide. The X-axis carriage 4 has a Z-axis spindle 5 movable in the Z-axis direction (vertical direction on the paper surface), and a probe probe 6 is provided at the lower end of the Z-axis spindle 5.

An X-axis scale 7a is installed on the X-axis beam 3B of the bridge structure 3, and a scale detector 7b for scanning the X-axis scale 7a is attached to the X-axis carriage 4. The scale of the X-axis scale 7a is read and converted into a signal by the scale detector 7b of the X-axis carriage 4, and the detected signal is input to the controller 8 through the signal line 11. The origin is when the X-axis carriage 4 is at the center of the X-axis beam 3B. A gas proportional to the current value of the controller 8, which is connected to the controller 8 that generates a current corresponding to the X-axis coordinates, the controller 8 and the air source 10. A proportional solenoid valve 9 that outputs pressure is installed. The gas pressure controlled by the proportional solenoid valve 9 is supplied to the air guide c provided on the support side leg 3C.

In the above structure, when the X-axis carriage 4 is located at the center of the X-axis beam 3B as a reference, the X-axis carriage 4 is guided from the center to the guide side leg 3A (hereinafter, this direction is referred to as a positive direction). .), The weight of the X-axis carriage 4 gradually hangs on the air guide a provided on the guide side leg 3A, so that the flying height of the air guide c tries to increase, and the flying height of the air guide a increases. Tries to decrease. At this time, the controller 8 sends a control signal to the comparative solenoid valve 9 in response to a signal from the scale detector 7b of the X-axis carriage 4, and the proportional solenoid valve 9 shifts from the center of the X-axis carriage 4 in the positive direction. Accordingly, the pressure of the gas supplied to the air guide c is gradually reduced. As a result, the flying height of the air guide c is gradually reduced, and the perpendicularity posture of the bridge structure 3 is always kept constant. On the contrary, when the X-axis carriage 4 moves from the center of the X-axis beam 3B toward the support side leg 3C (hereinafter, this direction is referred to as a negative direction), the scale detector 7b of the X-axis carriage 4 moves Signal from the controller 8, the controller 8 sends a control signal to the comparative solenoid valve 9, and the proportional solenoid valve 9 gradually increases the pressure of the gas supplied to the air guide c according to the deviation from the center of the X-axis carriage 4 in the negative direction. Increase.

As described above, the controller 8 sends a control signal to the proportional solenoid valve 9 according to the position of the X-axis carriage 4 in the X direction, so that the air gap between the surface plate 1 and the air guide c is always constant. Therefore, the right angle posture of the bridge structure 3 can be kept constant. Although the gas pressure adjusted by the proportional solenoid valve 9 is supplied to the air guide c in the above-described embodiment, the adjusted gas pressure may be supplied to the air guide a instead of the air guide c. That is, when the gas pressure of the air guide a is adjusted, a proportional solenoid valve for adjusting the gas pressure of the air guide a is provided so that the gas pressure of the air guide a can be adjusted, and the controller 8 is used instead of the air guide a. Should control this proportional solenoid valve. Further, it is also possible to supply the regulated gas pressure to both the air guide a and the air guide c to make the square structure of the bridge structure 3 constant. That is, when supplying the adjusted gas pressure to both the air guide a and the air guide c, a dedicated proportional solenoid valve is provided for each of the air guide a and the air guide c, and one controller 8 is used to control the air guide a and the air guide c. Adjust the proportional solenoid valve of each guide c, or install a new controller on the guide side leg 3A separately from the controller 8 and adjust the proportional solenoid valves of the air guide a and air guide c separately. Can also

In the above description of the embodiment, the origin is when the X-axis carriage 4 is in the center of the X-axis beam 3B, but the origin is when the X-axis carriage 4 is in the vicinity of the support-side leg 3C, and the highest in the air guide c. The gas pressure of the air guide c may be decreased in proportion to the position of the X-axis carriage 4 by applying the gas pressure. Further, although the gate moving type three-dimensional measuring machine has been described in the present embodiment, it is needless to say that the present invention can be applied to other three-dimensional measuring machines such as the bridge / bed type and the gantry type.

[0017]

[Effect of the device]

 As described above, according to the present invention, the perpendicularity posture of the bridge structure can be always kept constant, and the change in the perpendicularity of the Z-axis spindle with respect to the surface plate can be prevented. This can be expected to improve measurement accuracy.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the device according to the present invention.

FIG. 2 is a front view showing a configuration of a device according to a conventional technique.

FIG. 3 is a front view illustrating one of the behaviors of the device according to the related art.

FIG. 4 is a front view illustrating one of the behaviors of the device according to the related art.

[Explanation of symbols]

 1 surface plate 2 Y-axis direction guide 3 bridge structure 3A guide side leg 3B X-axis beam 3C support side leg a, b, c, d air guide 4 X-axis carriage 5 Z-axis spindle 6 probe probe 7a X-axis scale 7b Scale detector 8 Controller 9 Proportional solenoid valve 10 Air source 11 Signal line

Claims (4)

[Scope of utility model registration request] 1. An X connecting two legs and the two legs at an upper end.
A bridge structure configured to move in the Y-axis direction on a surface plate, an air guide formed between the lower ends of the two legs and the surface plate, and a Z-axis spindle. A coordinate measuring machine having an X-axis carriage guided by an X-axis beam, wherein the signal output means for outputting a signal according to the position of the X-axis carriage in the X direction and the position of the X-axis carriage A gas pressure adjusting means for adjusting the pressure of the gas forming the air gap in accordance with a signal from the signal outputting means so that the air gap of the air guide is always constant. Original measuring machine. 2. The signal output means also serves as a coordinate measuring device provided between the X-axis carriage and the X-axis beam for measuring the X-coordinate of a probe provided on the Z-axis spindle. The coordinate measuring machine according to claim 1, wherein: 3. One of the two legs of the bridge structure is guided by a Y-axis direction guide provided on the surface plate, and the gas pressure adjusting means includes the lower surface of the other of the two legs and the surface plate. The coordinate measuring machine according to claim 1, wherein the gas pressure between the two is adjusted. 4. The coordinate measuring machine according to claim 1, wherein the gas pressure adjusting means is a proportional solenoid valve.