CN101469977A - Collimation test device of direction gauge - Google Patents

Abstract

The invention relates to a collimation testing device for a converter-type direction gauge, which belongs to the testing field. The device of the present invention includes a direction gauge, an industrial control computer, a stepper motor, a water-cooled and bakeable magnetic fluid seal driver, a truncated double-cone collimator, a thin tube, an air inlet valve, a bellows, a vacuum chamber, and a pump. Air port and other components. The direction gauge is installed on the upper bottom of the vacuum chamber, and the lower bottom is connected to a vacuum pump unit with a high pumping speed; the truncated biconical collimator is installed in the vacuum chamber; the gas is introduced through the intake valve, bellows and thin tube; the stepping motor passes through The magnetic fluid sealed drive drives the truncated double-cone collimator to rotate around the axis at low speed; the whole test work is completed by the collimation test software of the direction gauge. The invention improves the alignment test accuracy and automation degree of the direction gauge, has compact structure, simple and convenient operation, and can be used for the direction angle measurement of the converter direction gauge.

Description

A kind of collimation test device of direction gauge

technical field

The invention relates to a collimation testing device for a converter-type direction gauge, which belongs to the testing field.

Background technique

For space gas, due to the low degree of vacuum and the "molecular sinking" effect in space, most of the airflow appears as beams in different directions. However, in the experimental device on the ground, the gas molecules will collide with the wall, and The collided molecules are emitted according to the law of cosines, so that the equilibrium state is quickly reached in the container, and it is difficult to form a stable directional beam.

The directional flow that the initial research focuses on is the airflow at the inlet of the large-diameter pump in the vacuum system. Because the pumping speed is very high, it can be considered that the gas molecules entering the pump inlet will no longer return to the container, thus forming a certain directional flow. The converter type Directional gauges also originally appeared to study this airflow. As the research progressed, it was found that the directivity of the direction gauge needs to be measured and determined, and it is necessary to produce a directional beam with good directivity.

Research and experiments have shown that the airflow flowing out of the long tube has a certain directionality due to the clustering effect of the tube. If the long tube is properly designed, the directional angle can reach 30° (the gas molecules with a transmission probability greater than 50% of the maximum value are distributed in the same direction as the axis In the cone with an included angle of ±15°), it can be used to generate a directional beam.

Figure 1 is a schematic diagram of using this device to study the directionality of the regulation, the valve 1 is connected to the stabilized air source, the 2 is the magnetic fluid seal driver, the 3 is connected to the bent plate, the long pipe 4 is facing the direction gauge 5, and at its entrance axis. When working, open the valve 1, the air flow is introduced from the long pipe 4, and the actuator 2 is rotated to guide the long pipe to rotate at a certain angle through the curved plate 3. This angle can be read or calculated from the rotation angle of the actuator, and different angles are selected. The angular response of the direction gauge can be obtained.

This method can be used to study the directionality of the traditional hole-entry type direction gauge, but for the multi-capillary-type and spherical-cone converter direction gauges, since the directionality of the gauge itself is very good (directivity angle is less than 30°), When using this device to study directionality, the actual directionality of the gauge will be covered up due to the large airflow distribution angle generated by the device, and the purpose of the experiment cannot be achieved.

Contents of the invention

The object of the present invention is to provide a collimation testing device and method for a direction gauge in order to overcome the deficiencies of the prior art.

The object of the present invention is achieved through the following technical solutions: a device for testing the alignment of a direction gauge, including a direction gauge, an industrial control computer, a stepper motor, a water-cooled and bakeable magnetic fluid sealed drive, a truncated double Conical structure collimator, thin tube, air intake valve, bellows, vacuum chamber, and air extraction port. The structure collimator is installed in the vacuum chamber; the gas is introduced through the inlet valve, bellows and thin tube; the stepping motor drives the truncated double-cone structure collimator to rotate around the axis at low speed through the magnetic fluid sealed drive; the whole test works through the direction Standard collimation test software to complete.

A method for testing the collimation of a direction gauge is:

(1) Preparation before the test, install the direction gauge on the flange interface of the vacuum chamber; start the vacuum pumping unit to make the vacuum chamber reach the ultimate vacuum degree of 10 ^-7 Pa;

(2) Open the intake valve to inflate the vacuum chamber, adjust the gas flow, and stabilize the reading of the reference gauge at a certain value;

(3) Connect the serial communication interface between the industrial control computer and the stepper motor control unit, start the collimation test software, run the test software, set the motor speed, steering, position and collection time interval, and rotate the collimator inlet to At the position of θ=90° to the normal line of the direction gauge entrance, collect the reading P(90°) of the direction gauge at this time;

(4) Rotate the entrance of the collimator to the position where θ=0° is formed with the normal line of the entrance of the direction gauge, and collect the reading P(0°) of the direction gauge;

(5) Real-time acquisition of the turned angle θ and the reading P(θ) of the direction gauge through the test software, and automatically calculate the directional flow passing rate at the angle θ

(6) Δθ twice the angle θ when ω(θ) is 0.5 is the directional plane angle of the direction gauge.

The beneficial effect of the present invention compared with prior art is:

(1) Using industrial control computer to control the stepper motor through PLC, the problem of precise positioning and measurement of the rotation angle is solved;

(2) The water-cooled and bakeable magnetic fluid seal actuator is adopted, which has the characteristics of good sealing performance and almost no leakage, and solves the vacuum sealing problem of 10 ^-7 Pa;

(3) The collimator adopts a truncated biconical structure, which has high collimation and can produce a directional beam with good directionality.

(4) The vacuum chamber adopts a cylindrical container, the cylinder is short and the diameter is large, so that the gas in the vacuum chamber is quickly drawn out, and the influence of the molecules colliding with the wall on the direction gauge is reduced.

Description of drawings

Fig. 1 is a structural schematic diagram of a direction gauge collimation test device in which the collimator is a long tube.

Fig. 2 is a structural schematic diagram of a direction gauge collimation testing device with a truncated double-cone structure as the collimator.

In the figure: 1—Valve, 2—Magnetic Fluid Sealed Actuator, 3—Connecting Bending Plate, 4—Slender Tube, 5, 6—Direction Gauge, 7—Industrial Control Computer, 8—Stepping Motor, 9—Water Cooling Baked ferrofluid sealed actuator, 10—truncated biconical structure collimator, 11—thin tube, 12—intake valve, 13—bellows, 14—vacuum chamber, 15—air extraction port.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 2, a kind of collimation test device of direction gauge of the present invention is made up of direction gauge 6, industrial control computer 7, stepper motor 8, water-cooled ferrofluid seal driver 9 that can bake, truncated double cone structure A collimator 10, a thin tube 11, an air inlet valve 12, a bellows 13, a vacuum chamber 14, and an air extraction port 15 are composed.

0.50m×0.50m的柱形容器，选用真空熔炼的特殊SUS316L不锈钢制作。截头双圆锥结构准直器10安装在真空室14内，其孔半径为4mm、锥高(与锥间距相等)为60mm、锥倾角为120°，仍选用真空熔炼的特殊SUS316L不锈钢制作。通过进气阀、波纹管和细管引入气体，进气阀12采用面密封微调阀，波纹管和细管的直径为2.5mm。步进电机8通过磁流体密封传动器9驱动截头双圆锥结构准直器10低速绕轴旋转，磁流体密封传动器9的泄漏量小于10^-12Pa.m³/s；抽气口的直径为0.25m，真空室14的极限真空度为10^-7Pa。A direction gauge 6 is installed on the upper bottom surface of the vacuum chamber 14, and the lower bottom surface is connected with a vacuum pump unit with a large pumping speed. The vacuum chamber 14 adopts

The cylindrical container of 0.50m×0.50m is made of special SUS316L stainless steel melted by vacuum. The truncated double-cone collimator 10 is installed in the vacuum chamber 14. The hole radius is 4mm, the cone height (equal to the cone spacing) is 60mm, and the cone inclination angle is 120°. It is still made of special SUS316L stainless steel melted in vacuum. The gas is introduced through the intake valve, the bellows and the thin tube. The intake valve 12 adopts a face-seal fine-tuning valve, and the diameter of the bellows and the thin tube is 2.5 mm. The stepper motor 8 drives the truncated double-cone collimator 10 to rotate around the axis at low speed through the magnetic fluid seal driver 9, and the leakage of the magnetic fluid seal driver 9 is less than 10 ^-12 Pa.m ³ /s; the diameter of the air inlet is 0.25m, and the ultimate vacuum degree of the vacuum chamber 14 is 10 ^-7 Pa.

Example

(1) Install the direction gauge 6 on the flange interface of the vacuum chamber 14; start the vacuum pumping unit to make the ultimate vacuum degree of 10 ⁻⁷ Pa in the vacuum chamber 14 (2.4×10 ⁻⁷ Pa);

(2) Open the intake valve 12 to inflate the vacuum chamber 14, adjust the gas flow rate, and stabilize the reading of the reference gauge at a certain value (8.6×10 ^-6 Pa);

(3) connect the industrial control computer 7 and the control unit serial communication interface of the stepper motor 8, start the collimation test software, test software operation, set the rotating speed, turning, position and collection time interval of the motor 8, and align The entrance of the straightener 10 is rotated to a position of θ=90° with the entrance normal of the direction gauge 6, and the reading P(90°) (7.2×10 ^-6 Pa) of the direction gauge is collected at this time;

(4) Rotate the entrance of the collimator 10 to the position of θ=0° with the entrance normal of the direction gauge 6, and collect the reading P(0°) (3.8×10 ⁻⁵ Pa) of the direction gauge;

(5) Collect the turned angle θ (7°) and the reading P(θ) (2.3×10 ^-5 Pa) of the direction gauge in real time through the test software, and automatically calculate the directional flow passage at the angle θ

(6) Δθ twice the angle θ when ω(θ) is 0.5 is the directional plane angle (14°) of the direction gauge.

Claims (3)

1, a kind of collimation test device of direction gage is characterized in that: comprise direction gage (6), industrial control computer (7), stepper motor (8), the bakeable magnet fluid sealing driver of water-cooled (9), butt double cone structural alignment device (10), tubule (11), gas admittance valve (12), corrugated tube (13), vacuum chamber (14), bleeding point (15); On the upper bottom surface installation direction rule (6) of vacuum chamber (14), bottom surface connects the vacuum pump unit of big pumping speed by flange; Butt double cone structural alignment device (10) is installed in the vacuum chamber (14); Introduce gas by gas admittance valve (12), corrugated tube (13) and tubule (11); Stepper motor (8) drives butt double cone structural alignment device (10) by magnet fluid sealing driver (9) and pivots.

2, a kind of collimation method of testing of direction gage is:

(1) prepares before the test, direction gage is installed on the flange-interface of vacuum chamber; Start the vacuum suction unit, make to reach 10 in the vacuum chamber ^-7The final vacuum of Pa;

(2) open air intake valve and inflate in vacuum chamber, the adjustments of gas flow makes the reference gauge stable reading at a certain numerical value;

(3) connect industrial control computer and step motor control unit serial communication interface, start the collimation testing software, the testing software operation, set motor speed, turn to, position and acquisition time at interval, and collimating apparatus inlet rotated to the position that becomes θ=90 ° with direction gage inlet normal, gather the reading P (90 °) of direction gage this moment;

(4) collimating apparatus inlet is rotated to the position that becomes θ=0 ° with direction gage inlet normal, gather the reading P (0 °) of direction gage;

(5) gather in real time the angle θ that turns over and the reading P (θ) of direction gage by testing software, and the oriented flow percent of pass when calculating angle θ automatically

(6) ω (θ) is that the twice Δ θ of 0.5 o'clock angle θ is the directivity plane angle of direction gage.

3, the collimation test device of a kind of direction gage according to claim 1, the material of described vacuum chamber can adopt the special 316L stainless steel of vacuum melting.