RU87522U1 - OVER PRESSURE SENSOR - Google Patents

Abstract

1. An overpressure sensor including a support (1) of the membranes, a first membrane (2) receiving pressure, a pusher (3) connecting the first membrane (2) to the second membrane (4) on which the strain gauges (5) are located, and cavity (6) between the membranes, characterized in that the support (1) is made of two elements welded together: the first support ring (7) connected to the first membrane (2) and the second support ring (8) connected to the second membrane (4), and the cavity (6) is connected to the surrounding atmosphere through leaks of the welded joint (9) p the first- and second support rings (7, 8). ! 2. The sensor according to claim 1, characterized in that the first and second membranes (2, 4) are made in the form of disk membranes with a rigid center. ! 3. The sensor according to claim 1, characterized in that the first support ring (7) is made in the form of a disk with an opening for the passage of the pusher (3) and is equipped with an annular protrusion (10) for connection with the first membrane (2) at its periphery. ! 4. The sensor according to claim 3, characterized in that a gap (11) is made between the planes of the first membrane (2) and the first support ring (7). ! 5. The sensor according to claim 1, characterized in that the leaks of the welded joint of the first and second support rings are formed by performing intermittent weld. ! 6. The sensor according to claim 1, characterized in that the area of the first membrane (2) is larger than the area of the second membrane (4).

Description

The utility model relates to the technique of semiconductor devices, in particular, to the manufacture of strain gauges of mechanical quantities using strain-sensitive semiconductor resistors.

The closest in technical essence is a pressure sensor, including a first membrane connected to the support, receiving pressure, which is connected by a pusher to the second membrane, also connected to the support through a rigid compensation membrane. The deformation of the second membrane is transformed by strain-sensitive semiconductor resistors (strain gauges) located on the second membrane into an electrical signal recorded by measuring equipment. A closed cavity is made between the two membranes.

(DE 10131688, G01L 9/00, G01L 9/04, publ. 2002.07.04)

However, the known pressure sensor cannot be used as an overpressure sensor because it measures pressure against pressure in a closed cavity between two membranes. When making a hole connecting the cavity between the membranes with the surrounding atmosphere, aggressive substances (gases, vapors, oils, liquids) enter the specified cavity, which, as a result of corrosion of the sensitive elements of the membranes, can lead to significant changes in the parameters of the pressure sensor over time.

The objective and technical result of the utility model is the creation of an overpressure sensor with two membranes, which has an increased operating time in aggressive environments.

The technical result is achieved in that the overpressure sensor includes a support (1) of the membranes, a first membrane (2) receiving pressure, a pusher (3) connecting the first membrane (2) with a second membrane (4) on which the strain gauges (5) are located ), as well as the cavity (6) between the membranes, and the support (1) of the membranes is made of two elements welded together: the first support ring (7) connected to the first membrane (2) and the second support ring (8) connected to the second membrane (4), and the cavity (6) is connected to the surrounding atmosphere through otnostitsja welded joint (9) of the first and second support rings (7, 8).

In addition, the first and second membranes (2, 4) are made in the form of disk membranes with a rigid center; the first support ring (7) is made in the form of a disk with an opening for the passage of the pusher (3) and is equipped with an annular protrusion (10) for connection with the first membrane (2) at its periphery; between the planes of the first membrane (2) and the first support ring (7), a gap (11) is made; leaks of the welded joint of the first and second support rings (7, 8) are formed by performing an intermittent weld; the area of the first membrane (2) is larger than the area of the second membrane (4).

The utility model can be illustrated by a pattern of membranes on a support of two elements (Fig. 1, side view), as well as a pattern of an overpressure sensor including membranes on a support of two elements (Fig. 2, side view), where:

1 - membrane support;

2 - the first membrane;

3 - pusher;

4 - the second membrane;

5 - strain gauge (strain-sensitive semiconductor resistor);

6 - the cavity between the membranes;

7 - the first support ring;

8 - the second support ring;

9 - welded joint of support rings (7, 8);

10 - annular protrusion of the first support ring;

11 - the gap between the planes of the first membrane (2) and the first support ring (7).

If the pressure sensor according to the utility model has two membranes (2, 4) with a rigid center on the support (1), which have a different area and which are connected by a pusher (3), the effect of pressure amplification (multiplication) takes place, which allows using the sensor for low pressure measurements. The implementation of the support (1) of the membranes from two elements welded together: the first and second support rings (7, 8), the welded connection of which has leaks (through holes, lack of penetration, the absence of a part of the weld, etc.), allows you to create a channel ( channels), connecting the cavity (6) between the membranes, with the surrounding atmosphere. The presence of the connection of the cavity (6) with the surrounding atmosphere makes it possible to use the sensor according to the utility model as an overpressure sensor. The leakages of the welded joint (9) - the weld having a small size, act as a filter, preventing particles of aggressive substances from entering the cavity (6) from the surrounding atmosphere, which increases the time of reliable operation of the overpressure sensor according to the utility model.

According to the utility model, the membranes and support elements (1) are mainly made by turning from stainless steel 03X11H10M2T or titanium alloy VT 22 with a high modulus of elasticity.

Example 1. A sensor was manufactured according to a utility model, the membranes of which (2, 4), the pusher (3) and the support elements (7, 8) were made of 03X11H10M2T steel. The first disk membrane (2) with a diameter of 20 mm was made with a rigid center by grooving an annular groove 2.5 mm wide and an external diameter of 18 mm. The first membrane was peripherally connected by welding with an annular protrusion (10) of the first support ring (7), made in the form of a disk with a central hole for the passage of the pusher (3). Between the planes of the first membrane (2) and the first support ring (7), a gap (11) was made to limit the course of the membrane. The second disk membrane (4) with a diameter of 10 mm was made with a rigid center by grooving an annular groove with an outer diameter of 7 mm and an inner diameter of 3 mm. This membrane was connected by welding with a pusher (3) and along the periphery with a second support ring (8). The support rings were joined (7, 8) by laser welding. Leaks in the welded joint (9) were carried out by the formation of an intermittent (dashed) weld by interrupting the laser beam. At 5 mm of the weld, the lack of penetration was 1 mm (the gap size of 20 μm between the elements being welded is specified by the requirements for welding). After connecting the first membrane (2) with the pusher (3), strain gauges (5) were applied to the surface of the second membrane (4) by known methods and connected to the Wheatstone measuring bridge.

Tests of the overpressure sensor according to a utility model in highways operating in an aggressive atmosphere containing particles of oil and dust at temperatures up to 130 ° C showed stable operation of the sensor for 1,500 hours.

Claims (6)

1. An overpressure sensor including a support (1) of the membranes, a first membrane (2) receiving pressure, a pusher (3) connecting the first membrane (2) to the second membrane (4) on which the strain gauges (5) are located, and cavity (6) between the membranes, characterized in that the support (1) is made of two elements welded together: the first support ring (7) connected to the first membrane (2) and the second support ring (8) connected to the second membrane (4), and the cavity (6) is connected to the surrounding atmosphere through leaks of the welded joint (9) p the first- and second support rings (7, 8). 2. The sensor according to claim 1, characterized in that the first and second membranes (2, 4) are made in the form of disk membranes with a rigid center. 3. The sensor according to claim 1, characterized in that the first support ring (7) is made in the form of a disk with an opening for the passage of the pusher (3) and is equipped with an annular protrusion (10) for connection with the first membrane (2) at its periphery. 4. The sensor according to claim 3, characterized in that a gap (11) is made between the planes of the first membrane (2) and the first support ring (7). 5. The sensor according to claim 1, characterized in that the leaks of the welded joint of the first and second support rings are formed by performing intermittent weld. 6. The sensor according to claim 1, characterized in that the area of the first membrane (2) is larger than the area of the second membrane (4).