CN213874911U - Adjustable pressure device for sliding expansion test - Google Patents

Abstract

The utility model discloses a landing leg inner wall is arranged in to experimental adjustable pressure device that expandes slides, a serial communication port, including friction mechanism, 1# loading frock, 2# loading frock and hydro-cylinder, friction mechanism comprises two semi-circular bosss, and its half-round produces frictional force with landing leg internal contact, installs 1# loading frock and 2# loading frock between the boss respectively, places the hydro-cylinder between 1# loading frock and the 2# loading frock. The utility model discloses adjustable pressure device successfully is applied to landing leg and expandes the experiment in, realizes different pressure loads through pressure regulating valve and manometer to can apply pressure between two friction mechanism, the size and the loading contact surface of fine simulation spring force, the pressure loading that can carry out 60kN at the utmost is applicable to the pressure loading in various narrow and small spaces.

Description

Adjustable pressure device for sliding expansion test

Technical Field

The utility model belongs to the technical field of the space flight test, concretely relates to slip expandes experimental adjustable pressure device.

Background

When a novel return rocket is developed, the design of landing legs needs to be overcome. Landing legs are generally divided into a plurality of sections, and when the rocket takes off, one section of leg with a small diameter is contracted inside one section of landing leg with a large diameter; when the rocket lands, the landing legs can be unfolded under the action of gravity, a sliding mechanism is arranged between the two landing legs, and the friction force generated by the mechanism ensures that the landing legs can be unfolded under the action of gravity and the speed when the landing legs are unfolded in place does not exceed the designed speed. Therefore, the frictional force generated by the sliding mechanism needs to be within a certain range, and the frictional force is related to the pressure and sliding speed between the sliding mechanisms, and the pressure is generated by the spring.

In a test for investigating the relationship between the friction force and the pressure and the deployment speed, since the friction coefficient is uncertain, it is necessary to perform the deployment test using different pressures. For this purpose, a sliding expansion test adjustable pressure device is designed, the device is installed in a space of 196 mm 130 mm 184mm, the height of the whole loading device can normally work within the range of 182mm and 194mm, and the maximum pressure of 40kN can be generated.

Disclosure of Invention

The utility model provides a landing leg inner wall is arranged in to experimental adjustable pressure device that expandes that slides, including friction mechanism, 1# loading frock, 2# loading frock and hydro-cylinder, friction mechanism comprises two semi-circular bosss, and its half-round produces frictional force with landing leg internal contact, installs 1# loading frock and 2# loading frock between the boss respectively, places the hydro-cylinder between 1# loading frock and the 2# loading frock.

The oil cylinder is provided with two oil pipes, wherein the pipe a is close to the lower end of the oil cylinder, and the pipe b is close to the upper end of the oil cylinder.

The adjustable pressure device is connected with a control system, and the control system comprises an oil outlet electromagnetic valve and an oil return electromagnetic valve; opening an oil outlet electromagnetic valve, discharging oil from the pipe a, generating pressure at the lower end of the oil cylinder to eject the ejector rod to generate set pressure, monitoring the pressure by the oil outlet electromagnetic valve in the stretching process, and automatically discharging and pressurizing when the pressure is reduced; after the landing leg is stretched for a certain length, the stretching is stopped, the oil return electromagnetic valve is opened, oil enters the upper end of the oil cylinder from the pipeline b at the moment, pressure is generated to push the ejector rod back to the original position, oil at the lower end flows out from the pipe a, and the pulled landing leg is pushed back to the original position after the pressure is unloaded.

The height range of the adjustable pressure device is 182mm-194 mm.

The utility model has the advantages as follows:

the utility model discloses adjustable pressure device successfully is applied to landing leg and expandes the experiment in, realizes different pressure loads through pressure regulating valve and manometer to can apply pressure between two friction mechanism, the size and the loading contact surface of fine simulation spring force, the pressure loading that can carry out 60kN at the utmost is applicable to the pressure loading in various narrow and small spaces.

Drawings

FIG. 1 is a schematic view of the adjustable pressure device of the present invention;

the device comprises a 1-oil cylinder 2-1# loading tool, a 3-2# loading tool, a 4-friction mechanism 5-landing leg inner wall, a lifting mechanism and a lifting mechanism, wherein the lifting mechanism is arranged on the inner wall of the landing leg;

FIG. 2 is a machining drawing of a No. 1 loading tool;

FIG. 3 is a machining drawing of # 2 loading tooling;

FIG. 4 is a control system schematic;

fig. 5 is a graph of weight versus drop distance.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and the detailed description. It is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the claimed invention.

As shown in fig. 1, the utility model provides a slip expandes experimental adjustable pressure device arranges landing leg inner wall in, including friction mechanism 4, 1# loading frock 2, 2# loading frock 3 and hydro-cylinder 1, friction mechanism comprises two semi-circular bosss, its semicircle face and landing leg internal contact production frictional force, install 1# loading frock and 2# loading frock between two bosss respectively, place the hydro-cylinder between 1# loading frock and the 2# loading frock, the hydro-cylinder is equipped with two oil pipes, it is a pipe to be close to the hydro-cylinder lower extreme, it is b pipe to be close to the hydro-cylinder upper end.

The utility model discloses adjustable pressure device is connected with control system, this control system can control the size of loading pressure, and realize pressurization and release, and guarantee pressure stability, can realize the pressurization automatically when pressure reduces, in addition when pressure is too big, can automatic disconnection motor, prevent danger, control system schematic diagram is shown in fig. 4, set for the pressure value as required, open control system mains, later start fan cooling system, the starter motor, open out oil solenoid valve, oil carries out hydro-cylinder lower extreme production pressure from a pipe and ejecting with the ejector pin, the hydro-cylinder ejector pin stretches out the stroke that is greater than 50%, produce the settlement pressure. The landing leg with the small diameter is slowly pulled out from the landing leg with the large diameter at a constant speed by using a weight, a pulley and a steel wire rope, the tension is recorded in real time, and the tension is equal to the friction force according to the Newton's second law. In the stretching process, the oil outlet electromagnetic valve monitors pressure, and when the pressure is reduced, oil outlet pressurization can be automatically carried out, so that the pressure is guaranteed to stably change within a small range. And after the landing leg is stretched for a certain length, stopping stretching, opening an oil return electromagnetic valve, pushing the upper end of the oil cylinder by oil from the pipeline b to generate pressure to push the ejector rod back to the original position, enabling the oil at the lower end to flow out of the pipe a, pushing the pulled landing leg back to the original position after the pressure is unloaded, replacing the set pressure value, and carrying out the test again.

Take a landing leg deployment test as an example:

the initial height of the oil cylinder ejector rod of the hydraulic press is 7mm, the initial height of the whole loading device is 174mm, the extending stroke of the oil cylinder ejector rod is 20mm, and the oil cylinder ejector rod needs to extend more than 8mm for ensuring the normal work of the oil cylinder, so that the height of the whole loading device can work normally within the range of 182 plus or minus 194mm, and the requirement of a test space is met. The pressure which can be generated by the oil cylinder ejector rod is calculated by a pressure gauge on the hydraulic press, the precision is 1% FS, and the pressure is adjusted by an adjusting knob on the hydraulic press.

Firstly, three legs (four legs) are fixed on a horizontal beam through a tool, the horizontal beam is fixed on a base on the ground, two legs (three legs) are contracted inside the three legs (four legs), a stretching tool is installed on the two legs (three legs), the horizontal stretching amount is converted into vertical downward through a steel wire rope, a lifting lug, a horseshoe ring and 2 fixed pulleys, and the balance weight falls to drive the two legs (three legs) to move outwards through a releasing hook. A tension sensor is connected in series between the two legs (three legs) and the fixed pulley, so that the tension is monitored in real time. An overload sensor is bonded on the counterweight to measure the acceleration change of the counterweight block. During testing, the pressure is adjusted by a hydraulic mechanism arranged between tenon mechanisms of two legs (three legs). And recording the acceleration change process in the stretching process through an overload sensor on the counterweight, and integrating the acceleration to obtain a speed-time curve. And acquiring the speeds of 1m/s, 2m/s and 3m/s, and acquiring the corresponding tension from the tension-time curve. After the primary test is finished, the hydraulic press is adjusted to reduce the pressure, so that the pressure between the tenon and the leg wall is reduced, the two-section leg (three-section leg) is pushed back into the three-section leg (four-section leg), the pressure is changed, and the test is carried out again.

Because the adopted weight is adopted for traction during sliding expansion, the maximum speed of the primary stretching process is calculated to reach 3m/s, the uniform acceleration process and the theoretical maximum friction force are considered, and the relation between the falling height and the weight is shown in figure 5. Comprehensively considering, 3 tons of counter weights are selected for releasing and stretching, and the falling height of more than 1.4m can reach the speed of 3 m/s.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. The utility model provides a landing leg inner wall is arranged in to slip expandes experimental adjustable pressure device, its characterized in that, includes friction mechanism, 1# loading frock, 2# loading frock and hydro-cylinder, friction mechanism comprises two semi-circular bosss, and its semicircle face and landing leg internal contact produce frictional force, install 1# loading frock and 2# loading frock between the boss respectively, place the hydro-cylinder between 1# loading frock and the 2# loading frock.

2. An adjustable pressure device according to claim 1, wherein the cylinder is provided with two oil pipes, an a-pipe being located near the lower end of the cylinder and a b-pipe being located near the upper end of the cylinder.

3. The adjustable pressure device of claim 2, in connection with a control system comprising an oil outlet solenoid valve and an oil return solenoid valve.

4. An adjustable pressure device as claimed in any one of claims 1 to 3, wherein the adjustable pressure device has a height in the range 182mm to 194 mm.

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