SU611037A1 - Pneumatic drive - Google Patents

Description

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The invention relates to testing mechanisms and can be used in testing. equipment for dynamic testing of products.

And there is a drive arrangement with constant piston working areas, which, when moving at high speed, decrease the force due to a decrease in pressure in the cylinder cavity as the volume increases.

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The known pneumatic actuator contains a cylinder with hollow plungers force movably placed inside it, a rod fixed on the bottom of the cylinder and entering inside the plunger from the side of the open end of the last

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However, this device is too soft in design and does not provide constant force along the plunger.

The purpose of the present invention is to simplify the design of the pneumatic actuator by creating and maintaining a predetermined amount of force over the entire course of the plunger,

It is achieved by the fact that the rod fixed on the bottom of the cylinder is made of empty heads with longitudinal windows on the cylindrical surface, and on the inner cylindrical surface of the plunger adjacent to its open end, annular grooves are installed in which elastic sealing rings are installed.

FIG. 1 depicts the proposed pneumatic actuator; in fig. 2 is a graph of the force variation on the plunger as it goes.

The pneumatic actuator contains a cylinder 1, in which the hollow plunger 3 is movably mounted on the sealing sleeve 2. Inside the plunger, an empty rod 4 is placed along its axis, fixed to the bottom of the cylinder 5 and having longitudinal windows 6 and ring dials that are fitted with reagent rings 7. On the inner shinsky surface of the plunger 3, which is adjacent to its open end 8, annular grooves are made in which the inserted sealing pins 9. The bottom of the compressed gas is drained and drained (air, nitrogen, etc.) al indr 1 is equipped with a Bentils l4J 11

In the initial position, the plunger 3 is held by the stand lock (in FIG.

the cavity of the plunger 3 is sealed with rubber rings 7 from the passage of the gaseous medium from the cavity of the cylinder 1,

Shilevmga described: rivo works after “the next way. When opening the castle walls and the plunger 3 moves out of the shchindra 1.

When the plunger 3 leaves the cylinder 1, the volume of free space in the cavity of cylinder 1 increases, the pressure in cavity 1 drops, but as the plate / cylinder 3 moves, the sealing elastic rings 9 slide along the rod 4, opening the slots of the longitudinal windows 6. Compressed gas from the cavity cylinder 1 passes through the slots of the long windows 6, into the cavity of the plunger 3, In the latter rises davlegshe. Elastic sealing rings 9 create a sufficient seal between the plunger 3 and the rod 4 so that the compressed gas from the cavity of the schnandra 1 flows into the cavity of the plunker 3 only along the longitudinal windows 6,

When creating pressure in cylinder 1, force P -P (6-5i) acts on it, where

Р - pressure in cylinders

S is the section area of the plunger 3, the cross-section of the cross section of the rod 4.

When Plunger 3 is moving, gas pressure in Cshnshdre 1 will be applied to it

force (5-6 t-t-Pa 1,.

where Pj is the pressure in cylinder 1 (it is less than the initial pressure and decreases as Piston 3 moves);

Pji - gas pressure in the plunger cavity. 3 (it increases with the movement of the plunger 3 and tends to the value of IP.). Depending on what a given amount of force on the entire course of the Hai plunger to hold, structurally select the cross-sectional area of the rod 4 and the total area of the longitudinal windows 6,

In order to obtain reliable data when testing on the stands of shock-absorbing devices and products for dynamic strength, it is necessary that the magnitude of the force on the plunger 3 be equal.

FIG. 2 graphically illustrates an example of maintaining a constant amount of force on the plunger 3 over the entire course of the plunger.

Curve 2 characterizes the decrease in the magnitude of the component (. (B in t) of the force on the plunches) of re 3 in its course N.

Curve 1 characterizes the increase in the second component of Pp i force on the plunger 3 /

Since the cross-sectional areas of the rod 4 and the slots of the LONG-SHAPED windows 6 are structurally selected so that the first compaction Sj decreases), the second also increases; component P 2 S J. I then the magnitude of the force P on the plunger 3 remains constant throughout its course N.

Thus, a top bar 4 core with longitudinal windows on the schishldrichesky surface and annular canals on the inner cylindrical surface of the plunger 3, in which the sealing rings are installed, ensures the creation and maintenance of a given amount of force on the entire plunger stroke and thereby greatly simplifies the design pneumatic actuators

Claims (1)

1. USSR author's certificate No. 465489, cl. Р 15 В 11 / О4, 1973. // Phi1.1 four