JP2013064728A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety pressure sensor which prevents breakage due to high pressure, even if used for detecting the pressure of a flow channel and the like through which high pressure coolant such as COpasses.SOLUTION: A pressure sensor 1 includes: a pressure detection element 2; a base 4 in which the pressure detection element is fixed on an inner surface; a receiving member 5 disposed oppositely to the base; a diaphragm 6 clipped by the base and the receiving member; a clipping member 13 for clipping the base and the receiving member clipping the diaphragm so as to prevent both from separating from each other; and liquid sealed in a space between the base and the diaphragm. Pressure in a space between the receiving member and the diaphragm is transmitted to the pressure detection element through the diaphragm and the liquid. As the clipping member 13 is provided, even if high pressure is repeatedly applied between the base and the receiving member, both are prevented from separating from each other, and even if the base and the receiving member are welded, the cracking of a welding portion can be avoided, and the breakage of the pressure sensor can be prevented.

Description

  The present invention relates to a pressure sensor, and more particularly to a liquid-filled pressure sensor in which a liquid is sealed in a pressure-receiving space that houses a pressure detection element.

  Conventionally, liquid is sealed in a pressure receiving space in which a pressure detection element is accommodated, and pressure applied from the outside to the pressure detection chamber is transmitted to the pressure detection element via the liquid, so that the pressure detection element can respond to the external pressure. Various pressure sensors that output a voltage signal have been proposed.

  As an example of the liquid-filled pressure sensor, Patent Document 1 is connected to a pressure introduction pipe that introduces pressure from the outside by a through hole formed in the bottom, and connected to the pressure detection element by a weld along the outer periphery. And forming a welded portion when fluid pressure is applied to the inner surface of the lid member by forming at least a part of the longitudinal section extending from the outer periphery of the lid member to the through hole in an L shape. A pressure sensor that reduces the force in the rotation direction as a fulcrum and prevents breakage of the weld is described.

JP 2005-308397 A

However, in the pressure sensor described in the above-mentioned patent document, the pressure resistance is improved by preventing the welded portion of the lid member from being broken. However, the refrigerant of the refrigeration equipment and the air conditioning equipment using a high-pressure refrigerant such as CO ₂ is used. When used for detecting the pressure of a flow path or the like, since a high pressure is repeatedly applied to the welded portion or the like, a crack or the like may occur in the welded portion, leading to damage.

Therefore, the present invention has been made to solve the above-described problem, and even when used for detecting the pressure of a flow path or the like through which a high-pressure refrigerant such as CO ₂ passes, it prevents damage due to high pressure and is safe. An object is to provide a simple pressure sensor.

  In order to achieve the above object, the present invention provides a pressure sensor, a pressure detection element, a base having the pressure detection element fixed to the inner surface, and a receiving member disposed to face the base. A diaphragm sandwiched between the base and the receiving member, and sandwiching the base and the receiving member in a state of sandwiching the diaphragm so as to prevent them from separating from each other A member and a liquid sealed in a space between the base and the diaphragm, and the pressure in the space between the receiving member and the diaphragm is the pressure detecting element via the diaphragm and the liquid. It is transmitted to.

  According to the present invention, the clamping member holds the base and the receiving member in a state in which the diaphragm is clamped to prevent the two from separating from each other. Even when a high pressure is repeatedly applied to the base plate, they are not separated from each other, and even when the base and the receiving member are welded together, cracking of the welded portion can be avoided and damage to the pressure sensor can be prevented. .

  In the pressure sensor, the base and the receiving member each include a bulging part and a peripheral part, and the diaphragm is sandwiched between the peripheral parts of the base and the receiving member, and one end of the clamping member is connected to the base and the receiving part. One of the members can be engaged with the bulging portion or the peripheral portion, and the other end can be welded to the other peripheral portion of the base and the receiving member.

  In the pressure sensor, the clamping member includes a cylindrical portion and an inner flange portion provided at one end of the cylindrical portion, and the inner flange portion engages with a peripheral portion of one of the base and the receiving member. The other end can be welded to the other peripheral portion of the base and the receiving member.

  The clamping member includes a cylindrical portion and an inclined portion provided at one end of the cylindrical portion, and the inclined portion engages with a shoulder portion of one of the base and the bulging portion of the receiving member. The other end can be welded to the other peripheral portion of the base and the receiving member.

  Further, the sandwiching member includes a cylindrical portion and an inner flange portion provided at one end of the cylindrical portion, and the inner flange portion is formed around the upper surface portion of the bulging portion of one of the base and the receiving member. The other end can be welded and joined to the other peripheral portion of the base and the receiving member.

  In this case, an arc-shaped recess for escaping the hermetic hole formed in the expanding portion can be formed on the inner periphery of the inner flange portion.

  Furthermore, the clamping member includes a cylindrical portion and a ceiling portion provided at one end of the cylindrical portion, and the ceiling portion is in contact with the entire upper surface of the bulging portion of one of the base and the receiving member. In addition, the other end can be welded to the other peripheral portion of the base and the receiving member.

  In this case, a hole for escaping the hermetic hole formed in the expansion part may be formed in the ceiling part.

As described above, according to the present invention, even when used for detecting pressure in a flow path or the like through which high-pressure refrigerant such as CO ₂ passes, damage due to high pressure can be prevented and a safe pressure sensor can be provided. .

It is a figure which shows 1st Embodiment of the pressure sensor which concerns on this invention, Comprising: (a) is a top view, (b) is the sectional view on the AA line of (a). It is a figure which shows 2nd Embodiment of the pressure sensor which concerns on this invention, Comprising: (a) is a top view, (b) is the BB sectional drawing of (a). It is a figure which shows 3rd Embodiment of the pressure sensor which concerns on this invention, Comprising: (a) is a top view, (b) is CC sectional view taken on the line of (a). It is a figure which shows 4th Embodiment of the pressure sensor which concerns on this invention, Comprising: (a) is a top view, (b) is the DD sectional view taken on the line of (a).

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a first embodiment of a pressure sensor according to the present invention. This pressure sensor 1 includes a pressure detection element 2, a base 4, and a receiving member disposed to face the base 4. 5, a diaphragm 6 sandwiched between the base 4 and the receiving member 5, and a sandwiching member (holding member) 13 for further sandwiching (holding) the base 4 and the receiving member 5 in a state of sandwiching the diaphragm 6. Is provided. Liquid (oil) is sealed in the pressure receiving space 7 between the base 4 and the diaphragm 6.

  The pressure detection element 2 is fixed to the base 4 inside the pressure receiving space 7. A pressurizing space 8 as a pressure introducing space is formed between the receiving member 5 and the diaphragm 6, and the pressurizing space 8 communicates with the internal space of the inflow pipe 3 into which the refrigerant flows.

  The base 4 is formed, for example, by press work, and includes a bulging portion that bulges upward from the inside of the peripheral edge portion (ridge portion) 4c, and is formed in a lid shape in which a lower portion is opened. The bulging portion includes a side surface portion 4d that rises from the inside of the peripheral edge portion 4c and an upper surface portion 4e that is provided continuously to the side surface portion 4d. The pressure detection element 2 is fixed to the lower surface of the bulging portion of the base 4 (that is, the lower surface of the upper surface portion 4e) by adhesion or the like.

  The receiving member 5 is formed by, for example, press working, and has a bulging portion that bulges downward from the inside of the peripheral edge portion (saddle portion) 5a, and is formed in a dish shape with an upper portion opened. The bulging portion includes a side surface portion 5b that falls from the inner side of the peripheral edge portion 5a and a lower surface portion 5c that is provided continuously to the side surface portion 5b. The inflow pipe 3 is brazed and fixed to the opening at the center of the bulging portion of the receiving member 5 (that is, the center of the lower surface portion 5c).

  The outer peripheral edge of the diaphragm 6 is sandwiched between the peripheral edge 4 c of the base 4 and the peripheral edge 5 a of the receiving member 5, and these three members 4 to 6 are outer peripheral edges from which the outer peripheral edge of the diaphragm 6 is exposed. The portions are simultaneously welded by laser welding or the like (welded portion 14) and integrated. In the pressure receiving space 7, after liquid (oil) is injected from a filling hole (not shown) formed through the upper surface portion 4 e of the base 4, the filling hole is formed on the upper surface of the base 4 with the ball 9. Sealed by.

  The clamping member 13 includes a cylindrical portion 13b having an inner diameter slightly larger than the outer diameter of the base 4 and the receiving member 5 in a state where the diaphragm 6 is sandwiched, and an inner flange portion extending inward at the upper portion of the cylindrical portion 13b. 13a, and holds the base 4 and the receiving member 5 so as to prevent them from separating from each other. The cylindrical portion 13b of the clamping member 13 is mounted on the outer periphery of the base 4 and the peripheral portions 4c and 5a of the receiving member 5 from above, and the cylindrical portion 13b is engaged with the inner flange portion 13a on the upper surface of the peripheral portion 4c of the base 4. Is welded to the side surface of the peripheral edge 5a of the receiving member 5 by laser welding or the like (welded portion 15).

  The pressure detection element 2 is an IC chip including, for example, a piezo element and a signal processing circuit. A piezo element is a kind of ferroelectric substance and is also called a piezoelectric element. When a force such as vibration or pressure is applied, a voltage is generated. Conversely, when a voltage is applied, the piezo element expands and contracts.

  The pressure detection element 2 is electrically connected to the output lead pin 11 (11A to 11C) and the adjustment lead pin 12 (12A to 12E) through the through hole 4a formed in the upper surface portion 4e of the base 4 via the wire 10. Connected. The output lead pin 11 is for outputting a voltage signal corresponding to the pressure detected by the pressure detecting element 2 to the outside, and the adjustment lead pin 12 is used for voltage correction at the time of manufacture. In this example, the three output lead pins 11 </ b> A to 11 </ b> C, the adjustment lead pins 12 </ b> A to 12 </ b> E, and the above-described filling holes are arranged at equal angles on the same circumference from the center of the base 4.

  The through hole 4a of the base 4 is sealed so that there is no liquid (oil) leakage by the hermetic seal 4b after the output lead pin 11 and the adjustment lead pin 12 are inserted. The output lead pin 11 is connected to a substrate (not shown) at its upper end, and the substrate is further connected to an external output lead wire via a connector (not shown).

  The pressure sensor 1 having the above configuration changes the pressure of the pressurized space 8 due to the pressure change of the refrigerant flowing from the inflow pipe 3, and deforms the diaphragm 6. Due to the deformation of the diaphragm 6, the pressure of the liquid (oil) sealed in the pressure receiving space 7 changes, and the pressure change propagates to the pressure detecting element 2. The pressure detected by the pressure detection element 2 is converted into a voltage, and at that time, a predetermined voltage correction according to the characteristics of the pressure sensor 1 is performed. The corrected voltage signal is transmitted to the external output lead wire via the output lead pin 11, the substrate, and the connector.

When this pressure sensor 1 is used to detect the pressure of a refrigerant flow path or the like of an air conditioner using a high-pressure refrigerant such as CO _2, a high pressure of the refrigerant flowing in from the inflow pipe 3 is repeatedly applied to the pressurized space 8. A large force is repeatedly applied in a direction in which the base 4 and the receiving member 5 are separated from each other. In addition to the receiving member 5 and the diaphragm 6 being integrated in the welded portion 14, the diaphragm 6 is held by the holding member 13. Since the respective peripheral portions of the base 4 and the receiving member 5 are sandwiched, there is no possibility that the welded portion 14 will be cracked, and the pressure sensor 1 can be effectively prevented from being damaged.

  Next, a second embodiment of the pressure sensor according to the present invention will be described with reference to FIG.

  The pressure sensor 21 includes a clamping member (holding member) 22 different from the pressure sensor 1 shown in FIG. 1, and other components are the same as those of the pressure sensor 1. Therefore, in FIG. 2, the same or equivalent components as those of the pressure sensor 1 of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The clamping member 22 is formed continuously with a cylindrical portion 22b having an inner diameter slightly larger than the outer diameter of the base 4 and the receiving member 5 in a state where the diaphragm 6 is sandwiched, and an upper portion of the cylindrical portion 22b. 13b, and an inner flange portion 22c extending inward from the inclined portion 22a. The shoulder portion of the bulging portion of the base 4 and the receiving member 5 are provided. By sandwiching (holding) the peripheral edge portion 5a, the base 4 and the receiving member 5 are prevented from being separated from each other. The inclined portion 22a has a truncated cone shape.

  The cylindrical portion 22b of the clamping member 22 is mounted on the outer periphery of the peripheral portion 4c, 5a of the base 4 and the receiving member 5 from above, and the inner surface of the inclined surface 22a is the shoulder portion of the bulging portion of the base 4 (that is, the inclined surface portion 4d). The lower portion of the cylindrical portion 22b is joined to the side surface of the peripheral edge portion 5a of the receiving member 5 by laser welding or the like in a state of abutting and engaging with the portion).

  As a result, the pressure sensor 21 can hold the base 4 and the receiving member 5 more securely so that the base 4 and the receiving member 5 are not separated from each other in the same manner as the pressure sensor 1 shown in FIG. Since it can support inside the peripheral part 4c, compared with the pressure sensor 1 of FIG. 1, the deformation | transformation of the base 4 at the time of high voltage | pressure introduction can further be suppressed. As a result, excessive stress on the hermetic seal 4b portion is reduced, and the effect of preventing the seal portion from being broken can be enhanced.

  If it is desired to suppress deformation of the receiving member 5, the clamping member 22 may be attached by being reversed in the vertical direction. In this case, the inclined portion 22 a is shouldered on the bulging portion of the receiving member 5. The cylindrical portion 22b may be welded to the side surface of the peripheral edge portion 4C of the base 4 by engaging with the portion (the inclined portion of the side surface portion 5b).

  Next, a third embodiment of the pressure sensor according to the present invention will be described with reference to FIG.

  The pressure sensor 31 includes a clamping member (holding member) 32 different from the pressure sensors 1 and 21 shown in FIGS. 1 and 2, and other components are the same as those of the pressure sensors 1 and 21. is there. Therefore, in FIG. 3, the same or equivalent components as those of the pressure sensors 1 and 21 of FIGS.

  The clamping member 32 is formed continuously with a cylindrical portion 32b having an inner diameter slightly larger than the outer diameter of the base 4 and the receiving member 5 in a state where the diaphragm 6 is sandwiched, and an upper portion of the cylindrical portion 32b. 32b includes an inclined portion 32a provided so as to incline in the direction of the central axis of 32b, and an inner flange portion 32c extending inwardly from the inclined portion 32a. 4e) and the peripheral edge 5a of the receiving member 5 are held (held) to prevent the base 4 and the receiving member 5 from being separated from each other. The inclined portion 32a has a truncated cone shape.

  The inner peripheral end of the inner flange portion 32c is provided close to the circumference connecting the centers of the output lead pins 11A to 11C, the adjustment lead pins 12A to 12E, and the filling holes, and is used for hermetic use. Arc-shaped dents 32x and 32y are formed from the through hole 4a and the ball 9 so as to recede somewhat at equal distances.

  The sandwiching member 32 configured in this manner is mounted on the outer periphery of the peripheral portions 4c and 5a of the base 4 and the receiving member 5 from the cylindrical portion 32b, and the inner flange portion 32c abuts and engages with the upper surface portion 4e of the base 4. In the joined state, the lower portion of the cylindrical portion 32b is welded and joined to the side surface of the peripheral portion 5a of the receiving member 5 by laser welding or the like. Thereby, since the pressure sensor 31 can support the base 4 further inside as compared with the pressure sensor 21 shown in FIG. 2, the base 4 and the receiving member 5 are securely clamped and the hermetic seal portion is broken. Can be more effectively prevented.

  Next, a fourth embodiment of the pressure sensor according to the present invention will be described with reference to FIG.

  The pressure sensor 41 includes a clamping member (holding member) 42 different from the pressure sensors 1, 21 and 31 shown in FIGS. 31. Therefore, in FIG. 4, the same or equivalent components as in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The clamping member 42 is formed continuously with a cylindrical portion 42c having an inner diameter slightly larger than the outer diameter of the base 4 and the receiving member 5 in a state where the diaphragm 6 is sandwiched, and an upper portion of the cylindrical portion 42c. An inclined portion 42d provided so as to incline in the central axis direction of 42c and a plurality of holes (in this embodiment, eight holes 42a and one hole 42b) are provided continuously to the inclined portion 42d. The base 4 and the receiving member 5 are sandwiched (held) by holding (holding) the entire surface of the bulging portion of the base 4 (the entire surface of the upper surface portion 4e) and the peripheral portion 5a of the receiving member 5. Are prevented from being separated from each other. The inclined portion 42d has a truncated cone shape.

  When the cylindrical portion 42c of the clamping member 42 is mounted on the outer periphery of the peripheral portions 4c and 5a of the base member 4 and the receiving member 5, the plurality of holes 42a and 42b are formed so that the ceiling portion 42e is the ball 9, the lead pins 11 (11A to 11C), 12 (12A to 12E), which is set larger than the ball 9 and the hermetic through hole 4a so as to pass through them so as not to interfere with the hermetic sealing glass. The sandwiching member 42 has the cylindrical portion 42c attached to the outer periphery of the peripheral portions 4c and 5a of the base 4 and the receiving member 5, and the ceiling portion 42e is in contact with and engaged with the upper surface portion 4e of the base 4. Is welded and joined to the side surface of the peripheral edge 5a of the receiving member 5 by laser welding or the like.

  The pressure sensor 41 configured as described above can securely hold the base 4 and the receiving member 5, and the holding member 42 is supported over the entire upper surface 4 e of the base 4. Expansion of the base 4 at the time of introduction can be further effectively prevented, and as a result, the hermetic seal portion can be more reliably prevented from being damaged than the pressure sensors 1, 21, and 31 shown in FIGS. It becomes possible.

  Now, the welding (welded portion 15) between the cylindrical portions 13b, 22b, 32b, and 42c of the respective holding members and the peripheral portion 5a of the receiving member 5 described in the above-described embodiments extends over the entire circumference of each cylindrical portion. Or may be partially formed around it. Moreover, it is good to perform welding with each clamping member and the peripheral part 5a on the lower end side of this clamping member so that it may separate from the heat affected zone of the welding part 14 as much as possible.

  In the embodiment described with reference to FIG. 2, the inclined portion 22a of the clamping member 22 supports the shoulder portion of the expanding portion of the base 4, and therefore the inner flange portion 22c provided at the end of the inclined portion 22a is omitted. be able to.

  3 and 4, the inner flange portion 32c and the ceiling portion 42b of the holding members 32 and 42 support the bulging portion of the base 4, and the inclined portions 32a and 42d are in contact with the bulging portion. Although the structure does not contact or support, the present invention is not particularly limited to this, and has a function of supporting the bulging portions on the inclined portions 32a and 42d as well as the inner flange portion 32c and the ceiling portion 42b. You may have it. In this case, by holding the inner contour of the inner flange portion 32c and the inclined portion 32a, or the inner contour of the ceiling portion 42b and the inclined portion 42d, similar to the contours of the peripheral edge portion 4c, the side surface portion 4d and the upper surface portion 4e of the base 4, It becomes possible to support the base 4 on the entire surface.

DESCRIPTION OF SYMBOLS 1 Pressure sensor 2 Pressure detection element 3 Inflow pipe 4 Base 4a Through-hole 4b Hermetic seal 4c Peripheral part 4d Side surface part 4e Upper surface part 5 Receiving member 5a Peripheral part 5b Side surface part 5c Lower surface part 6 Diaphragm 7 Pressure receiving space 8 Pressurization space 9 Ball 11 (11A to 11C) Output lead pin 12 (12A to 12E) Adjustment lead pin 13 Holding member 13a Inner flange portion 13b Cylindrical portion 14, 15 Welding portion 21 Pressure sensor 22 Holding member 22a Inclined portion 22b Cylindrical portion 22c Inner flange Part 31 pressure sensor 32 clamping member 32a inclined part 32b cylindrical part 32c inner flange part 32x, 32y recess 41 pressure sensor 42 clamping member 42a, 42b hole 42c cylindrical part 42d inclined part 42e ceiling part

Claims (8)

A pressure sensing element;
A base on which the pressure detecting element is fixed to the inner surface;
A receiving member disposed opposite the base;
A diaphragm sandwiched between the base and the receiving member;
A clamping member for clamping the base and the receiving member in a state of clamping the diaphragm so as to prevent the two from separating from each other;
A liquid sealed in a space between the base and the diaphragm;
A pressure sensor, wherein pressure in a space between the receiving member and the diaphragm is transmitted to the pressure detection element via the diaphragm and the liquid. The base and the receiving member each include a bulging portion and a peripheral portion, and the diaphragm is sandwiched between the peripheral portions of the base and the receiving member,
The clamping member has one end engaged with one of the bulging portion or the peripheral portion of the base and the receiving member, and the other end weld-joined with the other peripheral portion of the base or the receiving member. The pressure sensor according to claim 1. The clamping member includes a cylindrical portion and an inner flange portion provided at one end of the cylindrical portion,
The inner flange portion is engaged with one of the peripheral portions of the base and the receiving member, and the other end is welded and joined to the other peripheral portion of the base and the receiving member. The pressure sensor according to claim 2. The clamping member is composed of a cylindrical portion and an inclined portion provided at one end of the cylindrical portion,
The inclined portion engages with a shoulder portion of one of the bulging portions of the base and the receiving member, and the other end is welded and joined to the other peripheral portion of the base and the receiving member. The pressure sensor according to claim 2. The clamping member includes a cylindrical portion and an inner flange portion provided at one end of the cylindrical portion,
The inner flange portion engages with the periphery of the upper surface portion of one of the base and the receiving member, and the other end is welded to the other peripheral portion of the base and the receiving member. The pressure sensor according to claim 2.   The pressure sensor according to claim 5, wherein an arc-shaped recess for escaping a hermetic hole formed in the expansion portion is formed on an inner periphery of the inner flange portion. The clamping member is composed of a cylindrical portion and a ceiling portion provided at one end of the cylindrical portion,
The ceiling portion engages with the entire upper surface of the bulging portion of one of the base and the receiving member, and the other end is welded to the other peripheral portion of the base or the receiving member. The pressure sensor according to claim 2.   The pressure sensor according to claim 7, wherein a hole for escaping a hermetic hole formed in the expansion portion is formed in the ceiling portion.

Images