JP2729700B2 - Flow measuring device for porous hydrostatic gas bearing - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a flow rate measuring means for a porous hydrostatic gas bearing, in particular, a cylindrical radial bearing.

[Prior art] In order to obtain a bearing performance such as a predetermined rotational accuracy, a load capacity, and a bearing rigidity in a porous gas bearing, it is necessary to supply a gas at a predetermined pressure to a porous body per unit area of a bearing surface. It is required that the flow rate of the gas to be ejected, that is, the gas flow rate, is uniform at a predetermined value over the entire bearing surface. Conventionally, as such a flow rate adjustment method, after the bearing surface is impregnated with a resin so that the flow rate is equal to or less than a predetermined flow rate, the pores of the porous material are closed, and the resin is appropriately removed with a solvent while measuring the gas flow rate. And the flow rate was adjusted to be uniform. As shown in FIG. 10, the conventional method of measuring the gas passage flow rate is to manually press a measurement pad 130 having the ring-shaped elastic body 2 attached to the tip against the radial bearing surface 1a.

[Problems to be Solved by the Invention] In the conventional method of measuring the flow rate of the radial bearing surface, the measurement pad is pressed by hand against the inner surface of the cylindrical porous body, so that the workability is poor. Due to the poor sitting of the elastic body, measured values became unstable and it took time. Furthermore, since the pressing force is applied by hand, the pressing force is not constant, and the amount of deformation of the elastic body is different for each measurement, so that there is a problem that the measured values are not reproducible.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described drawbacks of the related art, and has as its object to provide a radial bearing flow rate measuring unit capable of automatically and accurately measuring a flow rate of a radial bearing surface.

[Means and Actions for Solving the Problems] To achieve the above object, according to the present invention, a flow meter,
The gas passing flow rate of the porous hydrostatic gas bearing is achieved by pressing the ring elastic body at a constant pressure against the radial bearing surface of the porous hydrostatic bearing having a predetermined curvature by the ring elastic body, spherical bearing and compression spring. Can be measured accurately and efficiently.

[Embodiment] FIG. 1 is an overall plan view of the apparatus, and FIG. 2 is a side view thereof. This apparatus is an NC robot section (A section) having two orthogonal axes (X, Z).
, A flow rate detecting section (B section), a flow rate adjusting section (C section), a work indexing and pattern indexing section, and (D section).
70 is an operation unit. The NC robot (part A) positions each of the flow detecting part (part B) and the flow regulating part (part C) with respect to the radial bearing surface 1a of the porous hydrostatic bearing 1 for which the flow is to be regulated by a preset program. Let it.

FIG. 3 (A) shows the appearance of the porous hydrostatic gas bearing, and FIG. 3 (B) shows its cross section. 1a is the radial bearing surface, 1b
Is the thrust bearing surface, 1c is the compressed air supply path, 1d is the air supply D
And the joint is attached. With the above configuration, the rotating body 1E (dashed line) is statically supported.

FIG. 4 shows the details of the flow rate detection section (B section). FIG. 4A is a plan view, and FIG. 4B is a longitudinal sectional view. 1a shows a radial bearing. Reference numeral 2 denotes a ring-shaped elastic body made of a soft material such as a silicon-based O-ring. The ring-shaped elastic body 2 is pressed against the bearing surface 1a and collects the gas flow rate therethrough. Reference numeral 3 denotes a spherical bearing, which makes the elastic body adhere to the bearing surface when the ring-shaped elastic body 2 is pressed against the bearing surface 1a. 3a is a movable side bearing, 3b is a fixed side bearing. Reference numeral 4 denotes a compression spring, which acts at a constant pressure on the bearing surface during measurement. Reference numeral 5 denotes a bracket for fixing the ring-shaped elastic body 2, and a mounting surface of the elastic body 2 is rounded in accordance with the curvature of the radial bearing surface 1 a.
The elastic body 2 is fixed to the bracket 5 with an adhesive. A plurality of brackets 5 to which the ring-shaped elastic body 2 is attached may be prepared according to the curvature of the radial bearing surface to be measured, and may be appropriately replaced. A pin 6 is fixed on the spherical bearing side to prevent rotation of the bracket 5 and guide the spherical bearing 3 during measurement. The bracket 5 is fixedly supported on the piston 7 by a hollow bolt 10. The piston 7 is inserted into the movable portion 3a of the spherical bearing, and can slide freely in the axial direction. By providing such a spherical bearing 3, the pressing direction of the piston can be freely adjusted, and pressing can be performed from a precise direction even on a cylindrical surface. Reference numeral 8 denotes a joint, and a flow sensor 10
9 and piping connection. 9 is a gas communication path for collecting and measuring the gas passing flow rate.

In the above configuration, the flow detecting section B is provided with the air cylinder 20.
(FIG. 2), it descends without contacting the inside of the radial bearing 1, and stops at a predetermined position. Next, NC robot 60
Moves in the X-axis (+) direction, with respect to the radial bearing surface 1a.
The ring-shaped elastic body 2 is brought into contact, and the robot moves at a slow speed and presses the elastic body 2 against the bearing surface. Next, when the pressing force becomes larger than the compression spring 4,
The compression spring 4 starts to bend, and the spherical bearing 3 moves to the (+) side with the piston 7 as a guide.
Stop at the teaching position. The elastic body 2 is pressed against the bearing surface 1a with a constant pressure by the compression spring 4. At this time, the pin 6 guides the movement of the bracket 5 and also stops rotation. Also, at this time, since the piston 7 is supported by the spherical bearing 3, the ring-shaped elastic body 2 attached to the bracket 5 is securely brought into close contact with the measurement section, and accurate flow measurement can be performed.

The flow rate adjusting section (C section) is provided with a spray for solvent application and a mask for limiting the range in which the flow rate is to be adjusted. FIG. 5 shows the details of the part C. A is a side view, B is a front view, and C is an EE 'arrow view. Reference numeral 11 denotes a spray body for spraying a predetermined amount of the solvent, 12 is an adjustment knob for adjusting the spray amount of the solvent, 13 is a spray nozzle, and a hole 13a for blowing off the solvent is provided on the tip side surface. . Reference numeral 14 denotes a mask for limiting the range in which the flow rate should be adjusted, and prevents the solvent from flowing to other portions. 14a is a window for passing the solvent through the area to be adjusted.

The indexing section (D section) includes a pattern indexing section for controlling the amount of solvent applied and a workpiece indexing section for dividing and positioning the work in the circumferential direction. FIG. 6 shows details of the pattern indexing unit. As shown in the figure, the clearance between the work 1 and the pattern 17 is 1 m with respect to the radial bearing 1a.
It is manufactured circumferentially so as to be about m, and is arranged coaxially with the bearing surface 1a. FIG. 7A shows a developed view of the pattern. The pattern 17 has a circular opening (17 g to 1
7k) are arranged in five types. As shown in FIG. 7 (B), each opening has a hole 17a and has a diameter of 0.5.
mm. Table 1 shows the aperture ratio of each opening.

The pattern 17 is connected to a stepping motor 18 with a speed reducer, and a required aperture ratio is determined according to the flow rate. Further, the pattern indexing portion is connected to the air cylinder 21 and is released downward when the flow rate is detected.

The 7-7 indexing portion is composed of a small gear 30 and a large gear 40,
The small gear 30 is fitted with the shaft of the speed reducer 31. The speed reducer 31 is connected to a DC servo motor 33 via a coupling 32. 34 is a motor fixing bracket. Also large gear
40 is supported by a cross roller bearing 41. Reference numeral 42 denotes a jig for supporting the work 1.

An embodiment of the present invention will be further described with reference to FIG.

FIG. 8 is a block diagram showing the configuration of the apparatus. In the figure, reference numeral 60 denotes an orthogonal two-axis NC robot that positions the detection pad 2, the mask 14, and the spray gun 13 with respect to the adjustment point on the radial bearing surface 1a. 104 is a motor driver of the NC robot 60, and 120 is an NC controller, which is connected to the CPU 114. The memory 115 is connected to the CPU 114. The memory 115 stores a flow rate adjustment control program, and the CPU 114 controls a flow rate adjustment operation described later based on the program. 22 is an air cylinder for moving the mask and spray up and down, 23 is an electromagnetic valve for switching the air cylinder 22 up and down, and 24 is a driver for an electromagnetic valve 23, which is connected to the CPU 114. Reference numeral 25 denotes an electromagnetic valve for intermittently supplying compressed air to the spray gun 13, and reference numeral 26 denotes a driver thereof, which is connected to the CPU 114. Reference numeral 109 denotes a flow rate sensor that converts a detected flow rate into an electric signal, and 110 denotes an A / D converter that converts an analog signal into a digital signal.
It is connected to the. 27 is an electromagnetic valve for switching the air cylinder 20, and 28 is a driver of the electromagnetic valve 27, which is connected to the CPU 114. Reference numeral 29 denotes a motor driver for operating the servo motor 33, which is connected to the CPU 114. Reference numeral 43 denotes an electromagnetic valve for switching ON / OFF of the compressed air supplied to the porous static pressure bearing 1, and reference numeral 44 denotes a driver of the electromagnetic valve 43, which is connected to the CPU 114. Reference numeral 45 denotes a driver of the motor 18 for driving the pattern 17, which is connected to the CPU 114. Reference numeral 21 denotes an air cylinder for raising and lowering the pattern indexing unit, 46 denotes a solenoid valve for switching the cylinder up and down, and 47 denotes a driver of the solenoid valve 46, which is connected to the CPU 114. 101 is a compressed air source compressor, which is connected to each of the above-mentioned solenoid valves.

 Next, the operation of the above constituent device will be described.

The work (bearing) 1 is set on the large gear 40 using a jig. The solenoid valve 43 is turned on, and compressed air is supplied to the work 1. Next, the flow rate detection unit (detection pad 2) is moved to a starting point (a position that can be inserted into the bearing 1), which has been preliminarily taught by an instruction from the CPU 114. At this position, the solenoid valve 27 is switched, the cylinder 20 is operated, and the flow detecting unit is lowered to the inside of the radial bearing 1. Further, the NC robot 60 moves in the X-axis direction according to a command from the CPU 114, the pad 2 is pressed against the radial bearing surface 1a, and the flow rate is detected. At this time, the pattern 17 is lowered and separated from the radial bearing surface in the downward direction in the drawing and is retracted. The detected flow rate is converted into an electric signal by the flow rate sensor 109, and
It is converted into a digital signal by the / D converter 110 and sent to the CPU 114. Next, the solenoid valve 27 is switched and the cylinder 20 operates,
The detector rises.

In the CPU 114, an appropriate pattern 17 (7th
Figure) is selected. Next, a command is issued from the CPU 114 to the driver 45, the motor 18 is operated, and the selected pattern 17 is determined. Furthermore, the solenoid valve 46 is switched and the cylinder
21 operates and the pattern 17 rises and is inserted into the radial bearing 1. Next, a command is issued to the NC robot 60, and the positions of the mask 14 and the flow rate detector 2 are switched to the positions where teaching has been performed in advance. In addition, a command is issued from the CPU 114 and the solenoid valve
23 is switched, cylinder 22 operates and mask 14, spray
13 falls. Further, the solenoid valve 25 is operated intermittently, compressed air is supplied to the spray gun body 11, and the solvent is atomized from the tip of the nozzle 13, and is sprayed on the radial bearing surface 1a via the mask 14 and the pattern 17. FIG. 9 shows the sprayed state of the solvent. The spray nozzle 13 and the mask 14 are inserted inside the pattern 17.

Next, the solenoid valves 23 and 46 are simultaneously switched, and the cylinders 22 and 21 are switched.
Operates, the mask 14 and the spray 13 rise, and the pattern indexing part falls. Further, a command is issued to the robot, and the positions of the detection unit, the mask and the spray unit are switched, and the flow rate after the spray is detected.

The above operation is repeated to terminate the flow rate detection in the preset flow rate range. Next, the detection pad 2 is moved to the escape position, and the NC robot 60 is moved downward to slide the detection portion downward, thereby positioning the bearing 1 at the next point (next measurement range) along the vertical direction of the bearing 1. Here, the same adjustment as described above is performed, and when the adjustment of all the division points in the vertical direction is completed, the detection unit is released upward, a command is issued from the CPU 114 to the motor driver of 21, the servo motor 33 is operated, The next point in the circumferential direction of the radial bearing surface 1a is indexed. The above operations are sequentially repeated, and when the flow rate adjustment is completed at all the divided points, the flow returns to the initial state, and all the operations are completed.

[Effects of the Invention] As described above, according to the present invention, the flow rate of the porous hydrostatic gas bearing can be measured accurately and accurately, and the flow rate can be automatically and continuously adjusted. Attained and uniform quality is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing the configuration of an embodiment of the present invention, FIG. 2 is a side view showing the configuration of the embodiment of FIG. 1, and FIGS. 4 (A) and 4 (B) are a plan view and a longitudinal sectional view, respectively, of a flow rate detecting unit, and FIGS. 5 (A), (B), (C) are side views of a spray and a mask, respectively. FIG. 6 is an external view of the pattern and the porous hydrostatic bearing. FIGS. 7A and 7B are a development view of the pattern and a detailed view of the small hole, respectively. FIG. 8 is the present invention. FIG. 9 is a block diagram showing the configuration of the embodiment, FIG. 9 is an external view of the embodiment of the present invention when a solvent is applied, and FIG. 10 is an explanatory diagram of the prior art. 1: porous static pressure gas bearing, 2: ring-shaped elastic body, 11: spray gun body, 13: spray nozzle, 14: mask, 17: pattern, 60: orthogonal Z-axis (X, Z) NC robot, 101: compressor.

Claims (2)

(57) [Claims] An apparatus for measuring a flow rate of gas ejected from a radial bearing surface of a cylindrical porous hydrostatic gas bearing, comprising: a ring-shaped elastic body that can be in close contact with the bearing surface; A piston for pressing against the bearing surface, a gas passage formed in the piston, and a flow sensor for measuring a flow rate of gas ejected from the bearing surface into the ring-shaped elastic body through the gas passage. And a spherical bearing in which the piston is slidably inserted. 2. The apparatus according to claim 1, further comprising a spring for applying a constant pressure to the pressing by the piston.