Sensor and measuring device with sensor

Abstract

For a sensor (1) for detecting pressure and temperature of a fluid medium (9), comprising a sensor housing (10) with a connecting tube (5) for insertion into a measuring opening (112), a pressure sensing element (2) arranged in the sensor housing (10), a channel (40) filled with a pressure transmission liquid (4) running in the connecting tube (5), which channel is closed on a side facing the fluid medium (9) with a diaphragm (16) and which channel is connected on a side facing away from the fluid medium (9) to the pressure sensing element (2), such that a pressure of the medium (9) acting on the diaphragm (16) can be transmitted by the pressure transmission liquid (4) onto the pressure sensing element (2), and a temperature probe (6) with a temperature probe (6) arranged on the sensor housing (10) for insertion into the measuring opening (112), it is proposed that the connecting tube (5) has a first section (13) connected to the sensor housing (10), a second section (14) connected to the first section (13) and a third section (15) connected to the second section (14), wherein an outer diameter of the second section (14) is configured to be smaller than an outer diameter of the first section (13) and an outer diameter of the third section (15), such that a free space (17) is formed between the first section and the third section, wherein the temperature probe (6) is guided through the first section (13) and protrudes into the free space (17).

Description

Technical Field

[0001] This invention relates to a sensor and a measuring device having the sensor. Background Technology

[0002] Various sensors are known in the prior art, representing combinations of pressure and temperature sensors and constructed as measuring probes. These probes are inserted via a connecting tube into a measuring opening in a channel component containing a flow path for the fluid medium to be measured. To achieve the most accurate and rapid measurement of the temperature of the flowing medium, it is advantageous to arrange the temperature measuring unit as close as possible to the end face of the measuring probe in the region introduced into the medium. Here, especially with regard to gaseous media, the thermal mass of the temperature probe should be as small as possible.

[0003] To measure pressure in corrosive media, pressure sensors exist with a so-called oil receiver (Ölvorlage), which uses an isolation diaphragm to ensure the isolation of the measured medium from the actual pressure measuring unit. The diaphragm size has a significant impact on the accuracy achievable by the sensor. The larger the diaphragm, the more accurate the pressure signal. Such sensors are known, for example, from DE102008054382A1.

[0004] A sensor with combined pressure and temperature measurement functions is known from DE 102012 204 950 A1, in which a temperature probe is guided through the center of an isolation diaphragm within a sleeve. Simultaneously, the isolation diaphragm moves in a direction toward the center of the sensor housing. Therefore, the medium must be guided into the interior of the connecting tube through a supply opening. This limits the sensor's advantages, such as freeze resistance. Summary of the Invention

[0005] This invention relates to a sensor for detecting the pressure and temperature of a fluid medium, comprising: a sensor housing having a connecting tube for insertion into a measuring opening; a pressure sensing element disposed within the sensor housing; a channel extending in the connecting tube and filled with a pressure-transmitting liquid, the channel being closed by a diaphragm on the side facing the fluid medium and connected to the pressure sensing element on the side facing away from the fluid medium, such that the pressure exerted by the medium on the diaphragm can be transmitted to the pressure sensing element via the pressure-transmitting liquid; and a temperature probe disposed on the sensor housing for insertion into the measuring opening. According to the invention, the connecting tube is provided with a first section connected to the sensor housing, a second section connected to the first section, and a third section connected to the second section in a longitudinal extension direction, wherein the outer diameter of the second section is constructed to be smaller than the outer diameters of the first and third sections, such that a free space is formed between the first and third sections, wherein the temperature probe is guided through the first section and extends into the free space.

[0006] Furthermore, the present invention relates to a measuring device having a sensor and a channel component having a flow channel for a flowing fluid medium, wherein a measuring opening is constructed in the channel component, wherein a connecting tube of the sensor is inserted into the measuring opening such that at least a third section of the connecting tube having an isolation diaphragm and an end section of the temperature probe having a temperature measuring unit are exposed to the flowing medium.

[0007] The sensor for detecting the pressure and temperature of a fluid medium according to the invention advantageously improves the installation space of combined temperature and pressure sensors with an oil receiver. Since the connecting tube to be inserted into the measuring opening can be extended into the flow channel of the medium, it is advantageous to create a region by extending the connecting tube, in which unnecessary material of the connecting tube can be omitted to form a free space in which a temperature probe with a temperature measuring unit can be embedded. Therefore, in the solution according to the invention, viewed from the end face of the connecting tube and along its longitudinal extension direction, the temperature measuring unit of the temperature probe can advantageously be moved back (zurückversetzt) ​​behind the oil receiver. Conversely, viewed along this longitudinal extension direction, the diaphragm with the oil receiver is arranged in front of the temperature measuring unit. Thus, it is unnecessary to guide the temperature probe through the diaphragm, or, however, unnecessary to guide the temperature probe around the diaphragm in a laborious manner within the same measuring opening, which would result in the unfavorable shrinkage of the diaphragm. The diaphragm on the third section of the connecting tube can therefore be constructed to be relatively large in diameter, wherein the maximum diameter is advantageously limited by the insertability of the connecting tube into the measuring opening, but not by the space requirements of the temperature probe.

[0008] The advantageous configurations and extensions of the present invention can achieve further features.

[0009] In a simple manner, the free space can be formed as an annular groove surrounding the second section, which is laterally bounded by the free space-facing (especially annular) surface of the first section and the free space-facing (especially annular) surface of the third section. Thus, the third section, which is fixed to the second section of the connecting pipe, can be held in the flow of the medium like a disc platform or a plunger.

[0010] The temperature probe can advantageously extend into the free space from the free space-facing (especially annular) side of the first section of the connecting tube, with its end section having a temperature measuring unit. Thus, the temperature measuring unit of the temperature probe is sufficiently flushed from all sides by the flowing medium, even though the isolation diaphragm is arranged in front of the temperature measuring unit in the longitudinal extension direction.

[0011] In an advantageous embodiment, the end section may be configured to at least partially coil around the second section of the connecting tube in free space. This significantly improves the thermal decoupling between the temperature measurement unit and the connecting tube.

[0012] The temperature probe may have a connection area facing away from the end section, which is arranged within the housing space of the sensor housing. The connection area can contact the circuit carrier or contact element within the housing space in a simple manner.

[0013] The isolation diaphragm is preferably arranged on the end of the third section of the connecting tube away from the sensor housing, and thus on the end face of the connecting tube that is inserted into the measuring opening.

[0014] The temperature probe may have a substrate extending in the longitudinal direction, the substrate being made of, for example, plastic, and a connecting conduit extending in the longitudinal direction. The connecting conduit may be, for example, injected into the plastic of the substrate. The end sections of the substrate with the temperature measuring unit may have different shapes. Advantageously, many degrees of freedom exist here, because the entire free space between the first and third sections can be used for the geometric configuration of the end sections. The substrate can be sealed relative to the receiving opening in the first section by a simple sealing element. Thus, the temperature probe can be easily, for example, pushed into the receiving opening located in the first section of the connecting conduit.

[0015] Furthermore, it is advantageous to have a measuring device with a sensor having the aforementioned features and a channel component having a flow channel for a flowing fluid medium, wherein a measuring opening is constructed in the channel component, into which a connecting tube of the sensor is inserted, such that at least a third section of the connecting tube equipped with an isolation diaphragm and an end section of the temperature probe equipped with a temperature measuring unit are exposed to the flowing medium. A first section of the connecting tube is inserted into the measuring opening and does not need to protrude from it. Therefore, advantageously, a sealing element for sealing the measuring opening can be arranged on the first section.

[0016] In an advantageous embodiment, the measuring opening may have an orifice opening toward the flow channel. The orifice may be, for example, tapered. The end section of the temperature probe with the temperature measuring unit may be at least partially arranged within the region of the measuring opening formed by the orifice. This advantageously achieves, on the one hand, that the third section of the connecting tube with the diaphragm does not need to be deeply inserted into the flow channel; however, on the other hand, effective circulation of the temperature probe with the temperature measuring unit can still be achieved. The connecting tube is preferably shaped such that the flowing medium flows into the region of the orifice in a reinforced manner. Attached Figure Description

[0017] Possible embodiments of the invention will now be explained with reference to the accompanying drawings. The drawings show: Figure 1 A cross-section of a measuring device having a sensor according to the invention, according to a first embodiment. Figure 2 A cross-section of a measuring device having a sensor according to the invention; Figure 3 A cross-section of a measuring device having a sensor according to the invention; Figure 4 An example of how a temperature probe can be implemented. Detailed Implementation

[0018] Figure 1A cross-section of a measuring device 100 having a sensor 1 according to the invention is shown. The sensor 1 includes a sensor housing 10, which is, in this case, constructed in two parts and has a lower housing part 12, for example, made of metal or plastic, and an upper housing part 11, for example, made of plastic. The upper housing part 11 can be arranged on the lower housing part 12 with the insertion of a sealing element 51, wherein a closed housing internal space 8 is formed between the lower housing part 12 and the upper housing part 11, in which a pressure sensing element 2, for example, configured as a pressure measuring unit, is arranged. The pressure sensing element 2 can, for example, be in electrical contact with a circuit board 3, which in turn can be electrically connected to a connecting pin 52 of the upper housing part 11 via a contact spring (not shown). However, the pressure sensing element 2 can also contact the connecting pin 52 in other ways. The lower housing part 12 has a connecting tube 5, which can be integrally constructed with the lower housing part 12 and is adapted to be inserted into a measuring opening 112 of a channel part 110, as will be further explained below. The connecting tube 5 may have a cylindrical outer wall, and may be pushed into a preferably cylindrical measuring opening 112. The outer wall of the connecting tube 5 may have a circumferential seal 50, such as an O-ring, on the first section 13 of the connecting tube, which seals the measuring opening 112.

[0019] In only Figure 3 The second section 14 and the third section 15 are connected to the first section 13 along the longitudinal extension direction L of the connecting tube 5 (which extends parallel to the insertion direction of the connecting tube 5 into the measuring opening 112). Figure 1 As can be identified, the outer diameter of the second segment 14 is constructed to be significantly smaller than the outer diameter of the first segment 13. The outer diameter of the third segment 15 corresponds to the outer diameter of the first segment 13 and is therefore significantly larger than the outer diameter of the second segment 14, resulting in a circumferential annular groove constructed on the connecting pipe 5, which is laterally bounded by the annular surface 13a of the first segment 13 and the annular surface 15a of the third segment 15. Thus, a free space 17 exists between the first segment 13 and the third segment 15.

[0020] like Figure 1As also shown, the connecting pipe 5 has a channel 40 filled with pressure transmission fluid 4, which is closed at the end face of the third section 15 by a flexible isolation diaphragm 16 (e.g., made of steel), and this channel is connected to the pressure sensing element 2 on the side facing away from the fluid medium, so that the pressure of the medium 9 acting on the isolation diaphragm 16 can be transmitted to the pressure sensing element 2 through the pressure transmission fluid 4. The channel 40 may have a first channel section 42 arranged in the first section 13 of the connecting pipe 5, a second channel section 43 arranged in the second section 14 of the connecting pipe 5, and a third channel section 44 arranged in the third section 15 of the connecting pipe 5. The diameter of the second channel section 43 may be constructed to be smaller than the diameters of the first channel section 42 and the third channel section 44. This is not mandatory, but may help to reduce the outer diameter of the second section 14 of the connecting pipe 5. Figure 1 As shown, channel 40 can be filled with pressure transfer liquid 4 through a side channel 41, for example, provided in the first section 13 and which can be closed by a plug or otherwise.

[0021] In addition, sensor 1 also has a temperature probe 6. The temperature probe 6 is guided longitudinally through the first section 13 and extends into the free space 17, originating from the internal space 8 of the housing. The temperature probe 6 extends into the free space 17 via an end section 66, originating from the surface 13a of the first section 13 of the connecting tube 5 facing the free space 17. Figure 1 Temperature measuring unit 63 (not shown). The connection area of ​​the back end section 66 of the temperature probe can be arranged in the housing interior space 8 of the sensor housing 10, and can be electrically contacted there, for example, with the circuit board 3.

[0022] exist Figure 2 An extended embodiment of the sensor 1 according to the present invention is shown in the figure. Figure 2 Sensor 1 in Figure 1 The difference in the implementation is only that the end section 66 with the temperature measuring unit 63 is at least partially coiled around the second section 14 within the free space 17 (coiling portion 67), more specifically preferably coiled in such a way that it does not contact the housing of the second section 14. The entire outline of the end section 66 is contained within the boundary of the projection of the third section 15 along its longitudinal extension direction onto the first section 13, such that no part of the end section 66 protrudes beyond the free space 17. This facilitates the smooth insertion of the connecting tube 5 into the measuring opening 112. Figure 2 The configuration shown, with the end section 66 featuring the coiled portion 67, advantageously allows the temperature measuring unit 63 to be held in flow by the arrangement of the temperature probe 6 in a very long, exposed section in free space. Therefore, compared to... Figure 1Compared to the previous embodiment, the actual temperature measurement unit 63 of the temperature probe 6 is better thermally decoupled from the first section 13 of the connecting tube 5.

[0023] also, Figure 1 and Figure 2 The diagram also shows a measuring device 100, which, in addition to the sensor 1 already described, includes a channel component 110. The channel component 110 may, for example, have a cylindrical wall surrounding a flow channel 111, in which a cylindrical measuring opening 112, for example, is arranged, opening into the flow channel. A fluid medium 9 (gas or liquid) whose pressure and temperature are to be detected flows in the flow channel 111 during operation. Figure 1 and Figure 2 In the sensor 1, the connecting tube 5 is inserted into the measuring opening 112, such that at least the third section 15 of the connecting tube 5, which has an isolation diaphragm 16, and the end section 66 of the temperature probe 6, which has a temperature measuring unit 63, are exposed to the flowing medium 9. The measuring opening 112 is sealed by an O-ring on the first section 13, which is configured as a seal 50. To secure the sensor 1, a ring-shaped retaining plate 30, formed as a deep-drawn piece, can be used, which is fastened to the housing of the channel component 110. This is achieved by means of a disc spring 31 (which is supported on the retaining plate 30 on one end and on a retaining ring 32 fitted onto the lower component 12 of the housing), allowing the connecting tube 5 to move in the measuring opening 112 in the longitudinal extension direction L against the spring force of the disc spring 31. This measure is for freeze protection.

[0024] An advantageous variation of the measuring device 100 and the sensor 1 is shown in Figure 3 In this embodiment, the measuring opening 112 has an enlarged aperture 113 that opens toward the flow channel 111. As shown, the enlarged aperture 113 may be constructed, for example, in a tapered shape. The end section 66 of the temperature probe 6, with its coiled portion 67 and housing the temperature measuring unit 63, is at least partially arranged within the region of the measuring opening 112 formed by the enlarged aperture 113. Nevertheless, the temperature measuring unit 63 still functions as... Figure 2 The flow is directly exposed to medium 9, just like in the middle. It can be seen that, compared to... Figure 1 and Figure 2 In contrast, this allows the first section 13 of the connecting tube 5 to be constructed shorter, and the third section 15 of the connecting tube 5 with the isolation diaphragm 16 does not need to be like... Figure 1 and Figure 2 It is inserted as deeply into the flow channel 111. This reduces the space requirement for arranging the sensor 1 in the longitudinal direction L.

[0025] An embodiment of temperature probe 6 is in Figure 4As shown in the diagram. The temperature probe 6 may, for example, have a base 64 extending in the longitudinal direction L, the base being made of, for example, plastic, and a connecting line 61 extending in the longitudinal direction L. The connecting line 61 may be injected into the base 64 and may have a connecting section 62 protruding therefrom at a first end section of the base 64. Using its end facing away from the connecting section 62, the connecting line 61 is connected to a temperature measuring unit 63, which is encapsulated in a second end section 66 of the base 64. The base 64 may be sealed relative to a receiving opening 69 in the first section 13 of the connecting tube 5 by a sealing element 53 (e.g., an O-ring) inserted into a groove 65. Such a temperature probe 6 may, for example, be used in... Figure 1 In sensor 1 shown.

Claims

1. A sensor (1) for detecting the pressure and temperature of a fluid medium (9), comprising: A sensor housing (10) having a connecting tube (5) for insertion into a measuring opening (112); a pressure sensing element (2) disposed in the sensor housing (10); a channel (40) extending in the connecting tube (5) and filled with a pressure transmission liquid (4), the channel being closed on the side facing the fluid medium (9) by a diaphragm (16), and the channel being connected to the pressure sensing element (2) on the side facing away from the fluid medium (9), such that the pressure of the medium (9) acting on the diaphragm (16) can be transmitted to the pressure sensing element (2) through the pressure transmission liquid (4); and a temperature probe (6) disposed on the sensor housing (10). The temperature probe is used to insert into the measurement opening (112), characterized in that the connecting tube (5) has a first section (13) connected to the sensor housing (10), a second section (14) connected to the first section (13), and a third section (15) connected to the second section (14) in the longitudinal extension direction (L), wherein the outer diameter of the second section (14) is constructed to be smaller than the outer diameter of the first section (13) and the outer diameter of the third section (15), such that a free space (17) is formed between the first section (13) and the third section (15), wherein the temperature probe (6) is guided through the first section (13) and extends into the free space (17).

2. The sensor (1) according to claim 1, characterized in that, The free space (17) is formed by an annular groove surrounding the second segment (14), the annular groove being laterally bounded by the face (13a) of the first segment (13) facing the free space (17) and the face (15a) of the third segment (15) facing the free space (17).

3. The sensor (1) according to claim 1 or 2, characterized in that, The temperature probe (6) extends into the free space (17) from the face (13a) of the first section (13) of the connecting tube (5) facing the free space (17) with the end section (66) having the temperature measuring unit (63).

4. The sensor (1) according to claim 3, characterized in that, The end section (66) is at least partially coiled around the second section (14) in the free space (17).

5. The sensor (1) according to claim 3, characterized in that, The temperature probe (6) has a connection area (62) facing away from the end section (66), the connection area being arranged in the housing interior space (8) of the sensor housing (10).

6. The sensor (1) according to claim 1 or 2, characterized in that, The isolation diaphragm (16) is arranged on the end of the third section (15) of the connecting tube (5) away from the sensor housing (10).

7. The sensor (1) according to claim 1 or 2, characterized in that, The temperature probe (6) has a base (64) extending in the longitudinal extension direction (L), the base having a connecting line (61) extending in the longitudinal extension direction (L), wherein the base (64) is sealed relative to the receiving opening (69) in the first section (13) by a sealing element (53).

8. A measuring device (100) having a sensor (1) according to any one of claims 1 to 7 and having a channel component (110) having a flow channel (111) for a flowing fluid medium (9), wherein, A measurement opening (112) is constructed in the channel component (110), wherein the connecting tube (5) of the sensor (1) is inserted into the measurement opening, such that at least the third section (15) of the connecting tube (5) provided with the isolation diaphragm (16) and the end section (66) of the temperature probe (6) provided with the temperature measuring unit (63) are exposed to the flowing medium (9).

9. The measuring device (100) according to claim 8, characterized in that, The measuring opening (112) has an enlarged aperture (113) opening toward the flow channel (111), and the end section (66) of the temperature probe (6) having the temperature measuring unit (63) is at least partially arranged in the area of ​​the measuring opening (112) formed by the enlarged aperture (113).

Images