RU2783725C1 - Pressure indicator of a fire extinguisher - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to the field of instrument manufacture, in particular, to apparatus for indicating and measuring the pressure of gaseous or liquid media applied in fire extinguishers. Pressure indicator of a fire extinguisher comprises a body (1) with a supply channel for the measured medium, a transparent cover (2), a membrane (3), a sealing ring (4), a dial (6), a pointer (7), an axle (8), a board (11), a return elastic element (12) made in in the form of a flat spring shaped as two concentric rings connected primarily by spiral sections, and the dial is configured to rotate relative to the pointer (7) up to the die of the body. The axle (8) comprises a threaded section (9) in the form of a multiple thread, the tangent of the lead angle whereof is greater in pitch diameter than the friction factor of the materials of the axle (8) and the board (11) containing another section of the mating multiple thread. The thickened part (10) of the axle (8) protrudes beyond plane A by 0.8…1 of the strain value of the elastic membrane (3) due to the force created by the elastic strain of the return elastic element (12) when the pointer (7) comes in contact with the dial (6). The thread in the board (11) is made at a length of 0.5…0.7 of the thickness of the bottom thereof, and the pointer (7) is made with a protrusion fitting into the bottom hole of the board (11) wherein the inner radius is made.

EFFECT: possibility of reducing the labour intensity of manufacturing the indicator and raising the quality of indication due to the stability of the value of rotation of pointer (7).

6 cl, 1 dwg

Description

Technical field

The alleged invention relates to the field of instrumentation, in particular to devices for indicating and measuring the pressure of gaseous or liquid media used in fire extinguishers.

Prior Art

A pressure indicator is known (RU 82324, G01L 19/08, dated 04/20/2009), containing a housing with a pipe for supplying pressure of the working medium, a transparent cover, a board, an elastic membrane connected to the pointing element by means of a lever-gear mechanism, a return elastic element, in the form of a spiral spring, a sealing gasket and a spacer. The disadvantage is the presence of a complex converting mechanism in the form of a rack and pinion mechanism, as well as the presence of a board.

A pressure indicator for a fire extinguisher is known (RU 2042122, G01L 7/00/, dated 08.20.1995), containing a housing with a channel for supplying the measured medium, a transparent cover, a board, an elastic membrane connected to the pointing element by means of a converting mechanism, in the form of a rod with a screw a groove and a gearbox, a returnable elastic element in the form of a spring, as well as an annular partition. The disadvantage is the presence of a complex converting mechanism in the form of a rod with a screw groove, a gearbox, and an annular partition.

The closest to the proposed invention (prototype) is a utility model Fire extinguisher pressure indicator device (RU 160228, G01L 19/08, dated 10/23/2015), containing a cylindrical body with a channel for supplying the measured medium, a transparent cover, an elastic membrane, a pointing element, a converting mechanism , a returnable elastic element, the cylindrical body has an internal thread and a groove in which a transparent cover is installed, and the end part of the cylindrical body has an external thread, and the sealed gasket is concentrically located at the bottom of the cylindrical body, while the elastic membrane is tightly attached to the sealed gasket, which is held with the help of a board made in the form of a cylindrical plug, fixed inside a cylindrical body, by means of a threaded connection, moreover, a pressure measurement scale is applied on the end of the board, in addition, the board has a central screw channel and an internal cavity in which a return elastic element is installed nt, which is a flat spiral tape torsion spring connected to a converting mechanism consisting of a screw pin located in the central screw channel of the board, one of the ends of the screw pin is made integral with the pointing element, and the other end is in contact with the elastic membrane. The disadvantage is the relative complexity of the design, the lack of a dial as a separate part, does not allow its production in a typographical way, as well as adjusting the position of the arrow relative to the dial scale, in addition, the small amount of movement of the screw pin due to its large diameter, caused by the need to fix the helical return spring on the helical a finger with an index element, which does not allow a sufficient angle of helix of the thread for easy axial movement of the screw finger and turning it together with the arrow at a sufficient angle to provide clarity of pressure indication.

The technical task is to create a pressure indicator that does not have the above disadvantages.

The technical result of the invention is achieved due to the fact that the return elastic element is made, for example, in the form of a flat spring in the form of two concentrically arranged rings, connected mainly by spiral sections, which simplifies the design and reduces the diameter of the threaded section of the axis, which increases the angle of rotation of the arrow when the same axial movement, and the execution of the dial with the possibility of rotation relative to the arrow allows you to adjust the setting of the dial relative to the arrow, thereby increasing the accuracy of the arrow hitting the risk, showing the nominal pressure in the fire extinguisher after applying pressure to the submembrane cavity, i.e. the final assembly of the pressure indicator can be carried out without applying operating pressure to the submembrane cavity of the indicator when installing the pointer, which reduces the complexity of the assembly. The housing of the pressure indicator can be made in one piece with the housing of the shut-off and starting device (LPU) of the injection powder fire extinguisher, which also reduces the laboriousness of manufacturing the LPU.

The axis contains a section in the form of a multi-start thread, the tangent of the helix angle of which along the average diameter is greater than the coefficient of friction of the materials from which the axis with the threaded section and the board are made, also containing a section of the counter multi-start thread. This reliably converts the axial movement of the axis into its rotational movement together with the pointer and allows for a maximum pointer rotation angle to improve the visual indication of pressure.

The protrusion of the thickened part of the axis beyond plane A is 0.8 ... 1 of the value of the deformation of the elastic membrane under the action of the force created by the elastic deformation of the return elastic element when the pointer contacts the dial. This ensures the maximum possible turn of the pointer and its stability, which allows the pointer to be installed along the mounting risk without applying pressure to the submembrane cavity.

The pressing force of the pointer onto the axle is greater than the axial force generated by the elastic deformation of the return elastic element to the height of the thickened part of the axle ensures the integrity of the assembly unit of the indicator mechanism and keeps the installed dial from shifting when it is placed in the case, which also ensures the accuracy of the indication. After the final assembly, the connection of the pointer with the axis is practically unloaded by the force of the membrane.

The thread in the board is made at a length of 0.5 ... 0.7 of its bottom thickness, and the arrow is made with a protrusion entering the bottom hole, in which an inner radius is made, which increases the surface area of the arrow press-in, the direction of the arrow along the axis, and the radius simplifies its installation when pressing.

Simultaneously with the pressing of the arrow, the tip is deformed, for example, by melting it, which provides additional strength for fixing the arrow from axial movement relative to the axis.

Brief description of the drawings

In FIG. 1 shows a fire extinguisher pressure indicator in isometric view with a quarter cutout and an additional glass cutout.

Embodiments of the invention

The fire extinguisher pressure indicator contains a housing 1 with a channel for supplying the measured medium, a transparent cover 2, a membrane 3, a sealing ring 4 is located between the membrane 3 and the housing 1, forming a sealed sub-membrane cavity 5, a dial 6, an arrow 7, an axis 8 having a threaded section 9 multi-threaded threads and a thickened part 10, a board 11, a returnable elastic element 12, consisting of two concentrically arranged rings connected by spiral sections. The dial 6 contains mounting risk 13 and risk 14, showing the nominal pressure, located on the green section 15 of the scale, the yellow section 16 of the scale showing excess pressure and the red section 17 of the scale, showing the lack of pressure.

The pressure indicator of the fire extinguisher is assembled as follows on the plane of the fixture between three pins, one of which is able to move in the radial direction, the thickened part 10 of the axis 8 is installed and fixed with a movable pin. The return elastic element 12 is put on the axis 8, the board 11 is screwed on, the dial 6 is put on and the arrow 7 is pressed in, while at the end of the pressing the peripheral part of the punch rests through the dial 6 against the peripheral part of the board 11, deforming the return elastic element 12, and the boring is made in the central part of the punch has a depth that provides a gap between the arrow 7 and the dial 6 equal to 0.8 ... 1 of the value of the deformation of the membrane 3 under the action of the force created by the elastic deformation of the return elastic element 12. If it is necessary to increase the fixation strength of the arrow 7, the upper part of the axis 8 is melted. the elastic element 12 moves the axis 8 until the arrow 7 stops in the dial 6, while ensuring a stable protrusion of the lower end of the thickened part 10 of the axis 8 by the value of the previously provided gap equal to 0.8 ... The stop of the peripheral part of the punch and pressing the return elastic element 12 to the plane of the device with a large force eliminates the influence of tolerances on the manufacture of parts 6, 11 and 12 on the gap between the dial 6 and the arrow 7, i.e. the size of the gap between the arrow 7 and the dial 6 is affected only by the tolerance for the manufacture of the height of the boring made on the punch and the tolerance for the thickness of the arrow 7, which are performed with the highest possible accuracy. This assembly technology provides maximum and stable movement of the axis 8 and, accordingly, the rotation of the arrow when pressure is applied to the submembrane cavity 5 and allows you to press the arrow without applying pressure to the submembrane cavity 5, setting the arrow 7 by turning the dial 6 on the mounting risk 13. In the future, the resulting assembly unit is placed into the body 1 after placing the sealing ring 4 and the membrane 3 into it, then a transparent cover 2 is placed and the body 1 is crimped. and the coincidence of the arrow 7 with the risk 14 is visually fixed. If the arrow 7 does not reach the risk 14 or passes it, then the setting of the arrow 7 relative to the mounting risk 13 is adjusted accordingly, increasing the accuracy of the indicator. The process is repeated until an acceptable result is obtained. The adjustment is necessary because the metal from which the membrane 3 is made has a thickness tolerance and varying mechanical properties of the metal from batch to batch of metal. Since tens of millions of indicators are assembled, the exclusion of applying pressure to each indicator when setting arrow 7 gives a significant economic effect.

The device works as follows, when pressure is applied to the submembrane cavity 5, the membrane 3 straightens out and compensates for its deflection towards the submembrane cavity 5, overcoming the force created by the return elastic element 12, and with a further increase in pressure, it bends in the opposite direction, which increases the stroke of the axis 8, and therefore , and the angle of rotation of the arrow 7 and, accordingly, the quality of the indication, this is also facilitated by the small diameter of the threaded section 9 made on the axis 8. Smooth running is ensured by the fact that the tangent of the angle of helix along the average diameter of the multi-start thread of the threaded section 9 of the axis 8 is greater than the coefficient of friction of materials , of which the axis 8 and the board 11 are made, also containing a section of the reciprocal multi-start thread.

With a decrease in pressure in the submembrane cavity 5 due to the elasticity of the membrane 3 and the force of action of the return elastic element 12 on it through the thickened part 10 of the axis 8, the membrane 3 and, accordingly, the arrow 7 return to its original state, indicating that the fire extinguisher is discharged, while the force of the return elastic element 12, acting through the thickened part 10 of the axis 8 on the membrane 3, ensures its snapping through zero (the shortfall to zero is caused by the residual deformation of the membrane 3 and fixing its periphery) and additional deflection in the opposite direction, the value of which exceeds the loss of the deflection value of the membrane 3 under the action of the displacing gas, when the increase in the deformation of the membrane 3 is reduced by the force of the return elastic element 12 acting on it through the thickened part 10 of the axis 8. The maximum force of the return elastic element 12 is no more than 10% of the force acting on the membrane 3 by the pressure of the displacing gas in the cavity 5 is selected from the condition the greatest difference between the deflection from the force of the return elastic element 12 and the loss of upward deflection under the action of pressure in the submembrane cavity 5. From the above description, it can be seen that the fire extinguisher pressure indicator is novel and industrially feasible by known means, while the design allows you to automate the production of parts and assemblies and increases the stability of the amount of movement of the axis 8 and the rotation of the arrow 7 under the action of pressure in the submembrane cavity 5 and the quality of the indication, and also reduces the complexity of its manufacture.

Claims (6)

1. Fire extinguisher pressure indicator, containing a body (1) with a channel for supplying the measured medium, a transparent cover (2), a membrane (3), a sealing ring (4), a dial (6), an arrow (7), an axis (8), a board (11), a return elastic element (12), characterized in that the return elastic element (12) is made in the form of a flat spring in the form of two concentrically arranged rings connected by spiral sections, and the dial is rotatable relative to the arrow until the body (1) is crimped. ). 2. The fire extinguisher pressure indicator according to claim 1, characterized in that the axis (8) contains a thickened part (10) and a threaded section (9) in the form of a multi-start thread, the tangent of the helix angle of which along the average diameter is greater than the coefficient of friction of materials, from of which the axis (8) and the board (11) are made, also containing a section of the reciprocal multi-start thread. 3. The pressure indicator of the fire extinguisher according to claim 2, characterized in that the protrusion of the thickened part (10) of the axis (8) beyond the plane of the membrane A is 0.8 ... 1 of the deformation value of the elastic membrane (3) under the action of the force created by the elastic deformation of the return elastic element ( 12) when the pointer (7) contacts the dial (6). 4. Fire extinguisher pressure indicator according to claim 1, characterized in that the pressing force of the arrow (7) onto the axle (8) is greater than the axial force generated by the elastic deformation of the return elastic element (12) to the height of the thickened part (10) of the axle (8). 5. The fire extinguisher pressure indicator according to claim 1, characterized in that the thread in the board (11) is made at a length of 0.5 ... inner radius is done. 6. The pressure indicator of the fire extinguisher according to claim 4, characterized in that, simultaneously with the pressing of the arrow (7), the protruding tip of the axis (8) is deformed, for example, by melting it.

Images