JP2009047670A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the stress applied to a wire by oil flow generated by vibration in an oil sealing type pressure sensor. <P>SOLUTION: The case 1 includes oil 70 for receiving measuring pressure, a sensing section 20 for pressure detection, a terminal 10a for taking out a signal, and the wire 40 for electrically connecting the sensing section 20 to the terminal 10a. The sensing section 20 and the wire 40 are sealed in the oil 70, the upstream side of the wire 40 in the flow of the oil 70 caused by the oil 70 vibration out of the periphery of the wire 40 in the case 1 is provided with a lid member 2 as a wire protective member so that it is interposed between the flow of the oil 70 and the wire 40, and the flow of the oil 70 is prevented from abutting on the wire 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an oil-sealed pressure sensor that receives a measurement pressure with oil and detects the oil pressure at that time by a sensing unit sealed with the oil.

Conventionally, as this type of pressure sensor, a case, oil stored in the case and receiving a measurement pressure, a sensing unit for pressure detection provided in the case, and a signal from the sensing unit provided in the case are extracted. Terminal and a wire that electrically connects the sensing unit and the terminal, the sensing unit and the wire are sealed with oil, and the sensing unit detects the oil pressure when the measured pressure is received The thing is proposed (for example, refer patent document 1).
JP 2003-315193 A

  However, conventionally, the wire is also sealed with oil together with the sensing unit, and when vibration is applied to the pressure sensor, the oil in the pressure receiving unit also vibrates, and this vibration causes a flow in the oil. This oil flow applies stress to the wire. For this reason, the oil-sealed pressure sensor has a problem that it is difficult to ensure reliability in a high vibration environment.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce stress applied to a wire by an oil flow generated by vibration in an oil-sealed pressure sensor.

  In order to achieve the above object, according to the present invention, in an oil-sealed pressure sensor, the oil (70) generated when the oil (70) vibrates in the peripheral portion of the wire (40) in the case (1). A wire protection member (2, 3, 4) is provided on the upstream side of the wire (40) in the flow, and the wire protection member (2-4) prevents the flow of the oil (70) from hitting the wire (40). It is characterized by that.

  According to this, the flow generated in the oil (70) by the vibration of the oil (70) comes toward the wire (40), but this flow does not hit the wire (40) by the wire protection member (2-4). Therefore, the stress applied to the wire (40) by the flow can be reduced. As a result, it is possible to provide a pressure sensor having high reliability even in a high vibration environment.

Here, the wire protection member can be configured as a lid member (2) provided in the case (1) so as to be interposed between the flow of the oil (70) and the wire (40) ( (Refer to FIGS. 3 to 6 described later)
The lid member (2) may cover the entire wire (40) against the flow of the oil (70) (see FIG. 3 to be described later), or against the flow of the oil (70). A part of the wire (40) may be covered (see FIG. 4 described later).

  Moreover, as a wire protection member, what was comprised as a wall (3) arrange | positioned next to a wire (40) along the direction orthogonal to the longitudinal direction of a wire (40) may be comprised, and this wall ( 3) may prevent the flow of the oil (70) in the direction orthogonal to the longitudinal direction of the wire (40) from hitting the wire (40) (see FIGS. 7 and 8 described later).

  In particular, the wire (40) is easily bent when a stress in a direction orthogonal to the longitudinal direction of the wire (40) is applied, but such a wall (3) can suppress the stress in the direction. Therefore, it is preferable.

  Here, the wall (3) may be disposed on both sides of the wire (40) along a direction orthogonal to the longitudinal direction of the wire (40) (see FIG. 9 described later).

  According to this, since the wire (40) is sandwiched between the pair of walls (3) arranged on both sides of the wire (40), the wire (40) extends in a direction perpendicular to the longitudinal direction of the wire (40). When the wire is about to be displaced, the wire (40) hits the pair of walls (3), thereby preventing significant displacement.

  In this case, in addition to the wall (3), the cover member (2) as a wire protection member is provided in the case (1) so as to be interposed between the flow of the oil (70) and the wire (40). May be. Also in this case, the lid member (2) may cover the entire wire (40) against the flow of the oil (70), or cover a part of the wire (40). Also good.

  Moreover, as a wire protection member, it may be comprised as a gel member (4) which coat | covers a wire (40) (refer below-mentioned FIG. 10, FIG. 11). Also in this case, the flow generated in the oil (70) by the vibration of the oil (70) can be prevented from hitting the wire (40).

  In this case as well, in addition to the gel member (4), the lid member (2) as a wire protection member is interposed between the flow of the oil (70) and the wire (40). ). Further, the lid member (2) may cover the whole wire (40) against the flow of the oil (70), or may cover a part of the wire (40).

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
FIG. 1 is a diagram showing a schematic cross-sectional configuration of a pressure sensor S1 according to the first embodiment of the present invention, and FIG. 2 is a schematic plan view of the vicinity of the sensing unit 20 in the pressure sensor S1 shown in FIG. is there. In FIG. 2, a portion covered with a lid member 2 (shown by a broken line in FIG. 2) to be described later is shown through the lid member 2.

  This pressure sensor S1 is an oil-sealed differential pressure sensor attached to a vehicle as a member to be attached. Although not limited, this embodiment is attached to the exhaust pipe in order to detect a pressure loss of a DPF (diesel particulate filter) provided in an exhaust pipe of a diesel engine of a vehicle, for example. It can be applied as a differential pressure (relative pressure) detection type pressure sensor for detecting the differential pressure of the exhaust pipe.

[Sensor configuration, etc.]
In FIG. 1, the first case portion 10 is made by molding a resin material such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide).

  In the first case portion 10, a first pressure detection chamber 11 a is formed on the one surface side (upper surface side in FIG. 1) as a first recess that is recessed from the one surface, and is opposite to the one surface. On the other surface side (the lower surface side in FIG. 1), a second pressure detection chamber 11b is formed as a second recess that communicates with the first pressure detection chamber 11a and is recessed from the other surface.

  Here, as shown in FIG. 1, a hole 11c is formed at the bottom of the first pressure detection chamber 11a and the second pressure detection chamber 11b as a hole communicating the both pressure detection chambers 11a and 11b. ing.

  A sensing unit 20 for pressure detection is provided in the first pressure detection chamber 11 a of the first case unit 10. In the present embodiment, as shown in FIG. 2, the sensing unit 20 is configured by the sensor chip 21 and the circuit chip 22. The sensor chip 21 is provided so as to block the hole 11c (see FIG. 1).

  The sensor chip 21 generates an electric signal having a level corresponding to the pressure difference between the pressure in the first pressure detection chamber 11a and the pressure in the second pressure detection chamber 11b. Specifically, as such a sensor chip 21, a semiconductor diaphragm type sensor chip having a diaphragm as a thin portion on a semiconductor substrate such as a silicon substrate can be adopted.

  Such a semiconductor diaphragm type sensor chip is formed, for example, by forming a bridge circuit composed of a diaphragm, a diffusion resistance element and the like on a silicon semiconductor chip by a semiconductor process. Then, the diaphragm of the sensor chip is distorted by pressure, and a resistance value change caused by the distortion is converted into an electric signal and output.

  As shown in FIG. 1, a pedestal 30 made of glass or the like is bonded to the sensor chip 21, and the sensor chip 21 and the pedestal 30 are integrated. Here, the sensor chip 21 and the pedestal 30 are bonded by, for example, anodic bonding.

  The sensor chip 21 is bonded to the bottom surface of the first pressure detection chamber 11a in the first case portion 10 via the pedestal 30 with an adhesive such as a silicone adhesive (not shown). Thereby, the sensor chip 21 and the pedestal 30 are provided in a form fixed to the first case portion 10.

  Here, the pedestal 30 is formed with a through hole 31 that communicates with the second pressure detection chamber 11b through the hole 11c (see FIG. 1). That is, the second pressure detection chamber 11 b communicates with the through hole 31 of the base 30 through the hole 11 c, but the tip is blocked by the sensor chip 21. In other words, the first pressure detection chamber 11a and the second pressure detection chamber 11b are cut off from the sensor chip 21 as a boundary.

  Further, the circuit chip 22 is formed by forming an integrated circuit composed of transistors or the like on a silicon semiconductor chip by a semiconductor process, for example. The circuit chip 22 and the sensor chip 21 are electrically connected by a bonding wire 23 (see FIG. 2). The signal from the sensor chip 21 is output after being subjected to processing such as adjustment and amplification in the circuit chip 22.

  The first case portion 10 is provided with a terminal 10a, and this terminal 10a is a wiring member for taking out a signal from the sensing portion 20. In the present embodiment, as shown in FIG. 1, the terminal 10 a is a plurality of rod-shaped members made of a conductive metal such as brass, and for example, the first case 10 is insert-molded into the first case portion 10. It is fixed to the case part 10.

  As shown in FIGS. 1 and 2, one end of the terminal 10a is exposed in the first pressure detection chamber 11a in the vicinity of the sensing unit 20, and the sensing unit 20 and a wire made of aluminum or gold are used. 40 is connected and electrically connected. The wire 40 can be formed by, for example, a normal wire bonding method.

  Here, a sealing material 50 for sealing a gap between the terminal 10a and the first case portion 10 is provided around one end portion of the terminal 10a exposed in the first pressure detection chamber 11a. (See FIG. 1). The sealing material 50 is made of, for example, a resin such as a silicone resin or an epoxy resin.

  As shown in FIG. 1, the end of the terminal 10 a opposite to the connection portion with the wire 40 is exposed to the outside from the opening 10 b of the first case portion 10. The exposed end portion of the terminal 10a can be connected to an external wiring member (not shown) together with the opening 10b of the first case portion 10.

  That is, the opening portion 10b of the first case portion 10 is configured as a connector portion for connecting to the outside together with the terminal 10a exposed there. Accordingly, the sensing unit 20 can exchange signals with an external circuit (for example, an ECU of the vehicle) via the wire 40 and the terminal 10a.

  As shown in FIG. 1, the two pressure ports 12 and 13 as the second case portion are assembled to the first case portion 10 so as to sandwich the first case portion 10. The first pressure port 12 is provided to face the first pressure detection chamber 11 a on one surface side of the first case portion 10, and the second pressure port 13 is the other surface of the first case portion 10. It is provided on the side facing the second pressure detection chamber 11b.

  These pressure ports 12 and 13 are made by molding a resin material such as PBT or PPS, for example, in the same manner as the first case portion 10. The first pressure port 12 and the second pressure port 13 are respectively provided with introduction ports 12a and 13a for introducing pressure from the outside, as indicated by a two-dot chain line in FIG. Yes.

  Here, the first case portion 10 and the first pressure port 12, and the first case portion 10 and the second pressure port 13 are screwed together using a bolt 60 and a nut 61, It is assembled together. These bolts 60 and nuts 61 are not particularly limited in material, but are made of an iron-based metal or the like.

  And in the state which laminated | stacked the 1st case part 10 and the 1st and 2nd pressure ports 12 and 13, the volt | bolt 60 has penetrated these 3 members 10, 12, and 13, and this bolt 60 is mounted | worn with it. The three members 10, 12, and 13 are fastened by the tightening force between the nut 61 and the bolt 60. Thus, in the pressure sensor S1, the first case portion 10 and the second case portions 12 and 13 are assembled to constitute one case 1.

  Here, the first pressure detection chamber 11a and the second pressure detection chamber 11b in the first case portion 10 are filled with oil 70 as a pressure medium. The oil 70 is made of fluorine-based oil or the like.

  A first metal diaphragm 81 is interposed between the first case part 10 and the first pressure port 12, and between the first case part 10 and the second pressure port 13. A second metal diaphragm 82 is interposed.

  In the present embodiment, the first and second metal diaphragms 81 and 82 are made of a metal having excellent corrosion resistance and heat resistance, such as Cr and Ni. For example, pitting corrosion represented by (Cr + 3.3Mo + 20N) It can be made of a material having an index of 50 or more and Ni containing 30% by weight or more. The two metal diaphragms 81 and 82 have, for example, a planar circular sheet shape.

  As shown in FIG. 1, the first metal diaphragm 81 is arranged so as to cover the first pressure detection chamber 11a, and seals the oil 70 in the first pressure detection chamber 11a. On the other hand, the second metal diaphragm 82 is disposed so as to cover the second pressure detection chamber 11b, and seals the oil 70 in the second pressure detection chamber 11b.

  In the first case portion 10, O-rings 90 are provided on the outer peripheral portion of the first pressure detection chamber 11a and the outer peripheral portion of the second pressure detection chamber 11b. And the peripheral part of the 1st and 2nd diaphragms 81 and 82 is O by the assembly | attachment force of both the case parts 10, 12, and 13 which comprise the said case 1, and the fastening force by the said volt | bolt 60 and the nut 61 here. It is pressed against the ring 90.

  The O-ring 90 has a ring shape made of a normal O-ring material such as rubber. By providing the O-ring 90, the oil 70 in the pressure detection chambers 11a and 11b is more surely sealed by the first and second metal diaphragms 81 and 82.

  Thus, on one surface side of the first case portion 10, the measurement pressure introduced into the first pressure port 12 is applied to the first pressure detection chamber 11 a via the first metal diaphragm 81, On the other hand, on the other surface side of the first case portion 10, the pressure introduced into the second pressure port 13 is applied to the second pressure detection chamber 11 b via the second metal diaphragm 82. ing.

  Although detailed operation will be described later, in the pressure sensor S1 of the present embodiment, the measurement pressure applied to the first pressure detection chamber 11a and the measurement pressure applied to the second pressure detection chamber 11b are: The pressure is received by the oil 70 and applied to the sensor chip 21 via the oil 70, and the pressure is detected based on the difference between the two pressures. In other words, the sensing unit 20 detects the pressure of the oil 70 when the measured pressure is received.

  Here, in the pressure sensor S <b> 1 of the present embodiment, the sensing unit 20 and the wire 40 that electrically connects the sensing unit 20 and the terminal 10 a are sealed with oil 70. The wire 40 employs a unique configuration as described below.

  FIG. 3 is an enlarged cross-sectional view of a connection portion of the sensing portion 20 and the terminal 10a by a wire 40. The sensing unit 20 shown in FIG. 3 may be either the sensor chip 21 or the circuit chip 22, and in either case, the configuration is substantially as shown in FIG.

  In the present embodiment, when a vibration such as a vehicle vibration is applied to the oil 70, the oil 70 vibrates, and a flow Y is generated in the oil 70 as indicated by an arrow Y in FIG. Hereinafter, this oil flow Y is referred to as oil flow Y caused by vibration. Although the flow direction is not limited, in FIG. 3, the oil flow Y due to vibration flows from the sensing unit 20 side toward the wire 40 along the longitudinal direction of the wire 40.

  And the wire protection member 2 is provided in the upstream of the wire 40 in the oil flow Y by this vibration. Here, the wire protection member 2 is the lid member 2 provided in the case 1 so as to be interposed between the oil flow Y caused by vibration and the wire 40.

  The lid member 2 is a plate-like member made of resin, ceramic, metal, or the like, and is attached to the first case portion 10 so as to cover a part of the first pressure detection chamber 11a as the first recess. It is fixed. Here, as shown in FIG. 2, the planar shape of the lid member 2 is a rectangular shape, and a part of the first pressure detection chamber 11 a protrudes outside each side of the lid member 2. ing.

  For fixing the lid member 2 to the first case portion 10, various joining methods such as adhesion, welding, welding, caulking, and fitting can be adopted depending on the material of the lid member 2. Here, the lid member 2 is bonded to one surface of the first case portion 10 at the hatched portion shown in FIG. Specifically, a portion of the opening edge portion of the first pressure detection chamber 11 a serving as a recess that is covered with the lid member 2 is bonded to the lid member 2.

  Even if the lid member 2 is present, the transmission path of the measurement pressure to the sensing unit 20 via the oil 70 is sufficiently secured, and there is no problem. That is, as shown in FIGS. 2 and 3, there is a portion of the first pressure detection chamber 11 a that protrudes from the lid member 2, and the pressure is received by the oil 70 from the first metal diaphragm 81 through this portion. The measured pressure is transmitted to the sensor chip 21 which is the sensing unit 20.

  Moreover, although the sensing part 20 and the wire 40 are sealed with the oil 70, the wire 40 is interrupted | blocked by the cover member 2 as a wire protection member with respect to the oil flow Y by vibration.

  In other words, since the lid member 2 is positioned on the upstream side of the wire 40 in the oil flow Y due to vibration, the oil flow Y toward the wire 40 is inhibited by the lid member 2 in front of the wire 40. Is prevented from hitting the wire 40.

[Pressure sensor manufacturing method, etc.]
Next, an example of a manufacturing method of the pressure sensor S1 will be described. A first case portion 10 in which the terminal 10a is held by insert molding or the like is prepared. In the first case portion 10, one end portion of the terminal 10a exposed in the first pressure detection chamber 11a is sealed with a sealing material 50. Seal by.

  Next, the sensor chip 21 and the circuit chip 22 integrated with the pedestal 30 are fixed by being bonded to the first pressure detection chamber 11 a of the first case portion 10. Then, wire bonding is performed between the sensor chip 21 and the circuit chip 22, and between the sensor chip 21 and the terminal 10 a, and connection is performed using the wires 23 and 40.

  Next, the lid member 2 is fixed to the first case portion 10, and the oil 70 is injected into the first pressure detection chamber 11a. Then, the first case portion 10 and the first pressure port 12 are assembled via the first metal diaphragm 81 and the O-ring 90, and the bolt 60 and the nut 61 are integrated while being screw-coupled.

  Thereafter, similarly to the first pressure port 12, the second pressure port 13 is also connected to the first case portion 10 with the bolt 60 and the second diaphragm 82, the oil 70, and the O-ring 90. The nut 61 is used for screw connection. Thereafter, characteristic adjustment and inspection are performed as necessary, and the pressure sensor S1 shown in FIG. 1 is completed.

  The pressure sensor S1 is attached to an appropriate position of the vehicle as a member to be attached via a metal bracket or the like, and detects the differential pressure of the exhaust pipe before and after the DPF in the diesel engine of the vehicle.

[Operation etc.]
The pressure detection operation of the pressure sensor S1 will be specifically described. For example, in FIG. 1, the introduction port 12a of the first pressure port 12 is connected to the upstream side of the DPF in the exhaust pipe by a rubber hose or the like, and the introduction port 13a of the second pressure port 13 is connected to the exhaust pipe. A rubber hose or the like is connected to the downstream side of the DPF.

  As a result, the upstream pressure (ie, pre-pressure) of the DPF is introduced to the first pressure port 12, and the downstream pressure (ie, the post-pressure) of the DPF is introduced to the second pressure port 13. The measured pressure introduced into the pressure ports 12 and 13 is transmitted to the sensor chip 21 via the metal diaphragms 81 and 82.

  Specifically, the upstream pressure of the DPF introduced into the first pressure port 12 is applied to the first metal diaphragm 81, and the downstream pressure of the DPF introduced into the second pressure port 13 is the first pressure. The second metal diaphragm 82 is applied.

  The pressure applied to the first and second metal diaphragms 81 and 82 is received by the sensor chip 21 through the oil 70 in the pressure detection chambers 11a and 11b, respectively. The sensor chip 21 detects a differential pressure between the pressure received from the first metal diaphragm 81 side and the pressure received from the second metal diaphragm 82 side.

  For example, when the sensor chip 21 provided in the pressure detection chambers 11a and 11b is of a semiconductor diaphragm type, the sensor chip 21 has an inner surface of the first pressure detection chamber 11a on the surface of a diaphragm (not shown). The pressure is transmitted from the oil 70.

  The through hole 31 of the pedestal 30 that communicates with the second pressure detection chamber 11b is also filled with the oil 70 in the second pressure detection chamber 11b, and the sensor chip 21 has a diaphragm (not shown). The pressure is transmitted from the oil 70 in the second pressure detection chamber 11b to the back surface of the second pressure detection chamber 11b.

  Therefore, the pressure on the upstream side of the DPF is received from the first metal diaphragm 81 side through the oil 70 with respect to the surface of the diaphragm of the sensor chip 21 (not shown), while the second surface of the diaphragm of the sensor chip 21 is The pressure on the downstream side of the DPF is received from the metal diaphragm 82 side through the oil 70.

  The diaphragm of the sensor chip 21 is distorted due to the pressure difference between the front and back surfaces, and a signal based on the distortion is input from the sensor chip 21 to the circuit chip 22 via the bonding wire 23, where signal processing is performed. The signal is output from the terminal 10a to the outside through the wire 40. In this way, pressure detection is performed.

[Effects]
By the way, according to the present embodiment, the lid member 2 as a wire protection member is provided on the upstream side of the wire 40 in the oil flow Y due to vibration in the peripheral portion of the wire 40 in the case 1.

  According to this, the oil flow Y due to vibration comes toward the wire 40, but since this flow Y does not directly hit the wire 40 by the lid member 2, the stress applied to the wire 40 by the flow Y is reduced. Can do. As a result, it is possible to provide the pressure sensor S1 having high reliability even in a high vibration environment.

  Next, various embodiments after the second embodiment will be described as embodiments other than the first embodiment. Here, regarding the cross-sectional views of the drawings of the following embodiments, as in FIG. 3, a connection portion by the wire 40 between the sensing unit 20 and the terminal 10 a in the pressure sensor according to each embodiment is illustrated.

  In each of these cross-sectional views, as in the first embodiment, the sensing unit 20 shown in the figure may be either the sensor chip 21 or the circuit chip 22, and in either case. The configuration is substantially as shown in the figure. Moreover, the pressure sensor which concerns on each following embodiment can be set as the structure similar to what is shown by the said FIG. 1 in parts other than the site | part shown.

(Second Embodiment)
FIG. 4 is a schematic cross-sectional view showing the main part of the pressure sensor according to the second embodiment of the present invention. In the example shown in FIG. 3, the lid member 2 covers the entire wire 40 with respect to the oil flow Y caused by vibration. If the lid member 2 is provided on the upstream side, the lid member 2 may cover a part of the wire 40.

  In FIG. 4, the portion located on the upstream side of the wire 40 is covered with the lid member 2, but the end portion of the wire 40 located on the downstream side of the flow Y of the wire by vibration is the oil caused by the vibration. No flow Y is coated. The stress due to the oil flow Y due to vibration does not affect the downstream wire 40 part so much.

  Also according to the present embodiment, the lid member 2 is positioned on the upstream side of the wire 40 in the oil flow Y due to vibration, so that the oil flow Y toward the wire 40 is inhibited by the lid member 2 before the wire 40, Since it does not directly hit the wire 40, the stress applied to the wire 40 by the flow Y can be reduced.

(Third embodiment)
FIG. 5 is a schematic cross-sectional view showing a main part of a pressure sensor according to a third embodiment of the present invention. Also in the present embodiment, the lid member 2 covers a part of the wire 40 against the oil flow Y caused by vibration, but here, the lid member 2 is a mesh-like one having a large number of openings. It is said.

  Also in this case, since the oil flow Y due to vibration is blocked by the lid member 2 and does not directly hit the wire 40, the stress applied to the wire 40 by the flow Y can be reduced.

(Fourth embodiment)
FIG. 6 is a schematic cross-sectional view showing a main part of a pressure sensor according to a fourth embodiment of the present invention. Here, the lid member 2 covers the entire wire 40 against the oil flow Y caused by vibration, but unlike the above-described FIG. 3, the lid member 2 is not plate-shaped.

  In the lid member 2 of the present embodiment, as shown in FIG. 6, the inner surface of the lid member 2 facing the wire 40 is not a flat surface, but follows the unevenness formed by the sensing unit 20, the wire 40, and the terminal 10a. It has an uneven shape.

  Thereby, the gap between the inner surface of the lid member 2 and the sensing unit 20 and the wire 40 is made as small as possible, and the flow of the oil 70 entering the gap is decelerated. And the stress added to the wire 40 can be made small by decelerating this flow.

(Fifth embodiment)
FIG. 7 is a schematic plan view of the vicinity of the sensing unit 20 in the pressure sensor according to the fifth embodiment of the present invention, and FIG. 8 is a wire between the sensing unit 20 and the terminal 10a in the pressure sensor shown in FIG. FIG. In FIG. 7, the surface of the wall 3 is hatched for the sake of convenience for easy identification.

  In the present embodiment, as shown in FIG. 7, the oil flow Y caused by vibration is intended to flow in a direction orthogonal to the longitudinal direction of the wire 40. And in this embodiment, it replaces with the said cover member as a wire protection member, and the wall 3 is provided in the upstream of the wire 40 in the flow Y of this oil. That is, the wall 3 is disposed next to the wire 40 along the direction orthogonal to the longitudinal direction of the wire 40.

  The wall 3 is made of resin, ceramic, metal or the like, and is fixed to the first case portion 10 by various joining methods such as adhesion, welding, welding, caulking, and fitting. When the wall 3 is made of resin, the wall 3 may be formed integrally with the first case portion 10.

  And the wall 3 has the height which protrudes rather than the wire 40 with respect to the case 1, ie, the 1st case part 10, as FIG. 8 shows. Therefore, the oil flow Y caused by the vibration in the direction orthogonal to the longitudinal direction of the wire 40 does not hit the portion of the wire 40 that is blocked from the flow Y by the wall 3.

  Of the four wires 40 shown in FIG. 7, the wire 40 located on the most upstream side of the oil flow Y due to vibration (the wire 40 located on the bottom in FIG. 7) is the upstream side. The wall 3 is not provided. This is because, for the wire 40, the wall of the first pressure detection chamber 11 a as a recess plays a role of inhibiting the flow Y.

  7 and 8, the wall 3 blocks the top of the wire loop of the wire 40 and its vicinity from the flow Y, but the wall 3 extends over the entire length of the wire 40. It may be provided.

  In particular, the wire 40 is easily bent when stress in a direction perpendicular to the longitudinal direction is applied to the wire 40 rather than stress in the longitudinal direction of the wire 40. According to the present embodiment, the stress in the direction applied to the wire 40 can be reduced by the wall 3.

  FIG. 9 is a schematic plan view showing a preferred embodiment of the present embodiment. In this case, the wall 3 is disposed on both sides of the wire 40 along a direction orthogonal to the longitudinal direction of the wire 40. That is, the wall 3 is provided so that the pair of walls 3 sandwich the single wire 40. For example, in FIG. 7, there is a wire 40 in which the wall 3 is disposed only on one side, but in FIG. 9, the wall 3 is disposed on both sides for all the wires 40.

  According to the example shown in FIG. 9, since the wire 40 is sandwiched between the pair of walls 3 arranged on both sides of the wire 40, the direction perpendicular to the longitudinal direction of the wire 40 (the arrow in FIG. 9). When the wire 40 is about to be displaced along a direction parallel to Y), if the displacement is large, the wire 40 comes into contact with the pair of walls 3 and stops, so that significant displacement is prevented.

  The first to fourth embodiments may be combined with the present embodiment. That is, in addition to the wall 3, the lid member 2 as a wire protection member may be provided in the case 1 so as to be interposed between the oil flow Y caused by vibration and the wire 40.

  Also in this case, the lid member 2 may cover the entire wire 40 with respect to the oil flow Y, or may cover a part of the wire 40. The specific configuration of the lid member 2 in this case can be the same as that shown in each of the drawings shown in the first to fourth embodiments.

(Sixth embodiment)
FIG. 10 is a schematic plan view of the vicinity of the sensing unit 20 in the pressure sensor according to the sixth embodiment of the present invention, and FIG. 11 is a wire between the sensing unit 20 and the terminal 10a in the pressure sensor shown in FIG. FIG. In FIG. 10, a portion covered with the gel member 4 (illustrated by a broken line in FIG. 10) is shown through the gel member 4.

  In this embodiment, instead of the lid member or the wall, a gel member 4 that covers the wire 40 is employed as the wire protection member.

  In the case where the oil 70 is a fluorinated oil, the gel member 4 desirably avoids the same system, that is, a fluorinated gel material. Specifically, it is desirable that the gel member 4 employs a silicone gel. Such a gel member 4 is arranged by applying the wire 40 on the wire 40 and curing it after connecting the wire 40.

  Further, when the wire 40 is covered with a resin harder than the gel member 4 instead of the gel member 4, the resin may cover the pressure-sensitive portion of the sensor chip 21, which may make sensing impossible. . In that respect, if the gel member 4 is used, even if the pressure-sensitive portion of the sensor chip 21 is covered, the pressure can be transmitted through the soft gel member 4, so that sensing is possible.

  In addition, the first to fourth embodiments may be combined with this embodiment. That is, in addition to the gel member 4, the lid member 2 as a wire protection member may be provided in the case 1 so as to be interposed between the oil flow Y caused by vibration and the wire 40.

  Also in this case, the lid member 2 may cover the entire wire 40 with respect to the oil flow Y, as in the respective drawings shown in the first to fourth embodiments. A part of the wire 40 may be covered.

(Other embodiments)
2 and 9 described above, not only the wire 40 that connects the sensor chip 21 and the circuit chip 22 constituting the sensing unit 20 and the terminal 10a, but also the wire that connects the sensor chip 21 and the circuit chip 22. 23, the lid member 2 and the gel member 4 are provided to protect from the flow of the oil 70, but the lid member 2 and the gel member 4 may be provided only on the wire 40 connected to the terminal 10a.

  Further, the electrical take-out structure of the sensing unit 20 and the attachment structure to the case 1 in the pressure sensor S1 shown in FIG. 1 are only specific examples, and are not limited to the illustrated examples. .

  The sensor chip 21 may be any sensor chip that outputs a signal based on the difference in pressure (differential pressure) of the oil 70 in the first and second pressure detection chambers 11a and 11b. It is not limited to sensor elements.

  The sensor chip 21 may be a so-called integrated sensor chip in which a circuit portion for processing sensor signals is integrally formed by a semiconductor process or the like. And as a sensing part, only the sensor chip 21 may be sufficient and the circuit chip 22 may not exist. For example, a separate circuit board may be provided outside the sensor, and signal processing may be performed on this circuit board.

  Furthermore, the pressure sensor may not be the differential pressure type as described above. For example, in the pressure sensor S1 shown in FIG. 1, the configurations of the pressure ports 12, 13, the pressure detection chambers 11a, 11b, and the metal diaphragms 81, 82 are provided on the one surface side and the other surface side of the first case portion 10, respectively. However, in the pressure sensor S1 shown in FIG. 1, the second pressure port 13 and the second metal diaphragm 82 may be omitted.

  In this case, there is no second pressure detection chamber 11b, and there is one metal diaphragm and one pressure port. In this case, the back surface side (lower side in FIG. 1) of the sensor chip 21 serves as a reference pressure, and the front surface side (upper side in FIG. 1) of the sensor chip 21 receives pressure from one metal diaphragm 81. Thus, it is configured as a so-called absolute pressure type pressure sensor.

  In addition, the case can store oil, and if the sensing unit and the terminal, as well as the wire connecting them, can be installed, the first case unit and the second case unit are not assembled. It may be a case made of one component.

It is a schematic sectional drawing of the pressure sensor which concerns on 1st Embodiment of this invention. It is a schematic plan view of the vicinity part of the sensing part in the pressure sensor shown in FIG. It is an expanded sectional view of the connection part by the wire of a sensing part and a terminal in a 1st embodiment. It is a schematic sectional drawing which shows the principal part of the pressure sensor which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the pressure sensor which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the pressure sensor which concerns on 4th Embodiment of this invention. It is a schematic plan view of the vicinity part of the sensing part in the pressure sensor which concerns on 5th Embodiment of this invention. It is a schematic sectional drawing which shows the connection part by the wire of the sensing part and terminal in the pressure sensor shown by FIG. It is a schematic plan view which shows the preferable form of 5th Embodiment. It is a schematic plan view of the vicinity part of the sensing part in the pressure sensor which concerns on 6th Embodiment of this invention. It is a schematic sectional drawing which shows the connection part by the wire of the sensing part and terminal in the pressure sensor shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Lid member as wire protection member, 3 ... Wall as wire protection member,
4 ... Gel member as wire protection member, 10a ... Terminal, 20 ... Sensing part,
40 ... wire, 70 ... oil.

Claims (13)

Case (1),
Oil (70) received in the case (1) and receiving the measurement pressure;
A sensing unit (20) for pressure detection provided in the case (1);
A terminal (10a) provided in the case (1) for taking out a signal of the sensing unit (20);
A wire (40) for electrically connecting the sensing unit (20) and the terminal (10a);
The sensing unit (20) and the wire (40) are sealed with the oil (70), and the pressure of the oil (70) when the measured pressure is received is detected by the sensing unit (20). In the pressure sensor
On the upstream side of the wire (40) in the flow of the oil (70) generated when the oil (70) vibrates among the peripheral portions of the wire (40) in the case (1), a wire protection member (2, 3, 4) is provided, and the wire protective member (2-4) prevents the flow of the oil (70) from hitting the wire (40). . The wire protection member is configured as a lid member (2) provided in the case (1) so as to be interposed between the flow of the oil (70) and the wire (40). The pressure sensor according to claim 1. The pressure sensor according to claim 2, wherein the lid member (2) covers the entire wire (40) against the flow of the oil (70). The pressure sensor according to claim 2, wherein the lid member (2) covers a part of the wire (40) against the flow of the oil (70). The wire protection member is configured as a wall (3) disposed next to the wire (40) along a direction orthogonal to the longitudinal direction of the wire (40), and the wall (3) allows the The pressure sensor according to claim 1, wherein the flow of the oil (70) in a direction perpendicular to the longitudinal direction of the wire (40) is prevented from hitting the wire (40). The pressure sensor according to claim 5, wherein the wall (3) is arranged on both sides of the wire (40) along a direction orthogonal to the longitudinal direction of the wire (40). In addition to the wall (3) as the wire protection member, a lid member (2) as the wire protection member is interposed between the flow of the oil (70) and the wire (40). The pressure sensor according to claim 5 or 6, wherein the pressure sensor is provided in the case (1). The pressure sensor according to claim 7, wherein the lid member (2) covers the entire wire (40) against the flow of the oil (70). The pressure sensor according to claim 7, wherein the lid member (2) covers a part of the wire (40) against the flow of the oil (70). The pressure sensor according to claim 1, wherein the wire protection member is configured as a gel member (4) covering the wire (40). In addition to the gel member (4) as the wire protection member, a lid member (2) as the wire protection member is interposed between the flow of the oil (70) and the wire (40). The pressure sensor according to claim 10, wherein the pressure sensor is provided in the case (1). The pressure sensor according to claim 11, wherein the lid member (2) covers the entire wire (40) against the flow of the oil (70). The pressure sensor according to claim 11, wherein the lid member (2) covers a part of the wire (40) against the flow of the oil (70).

Images