JP6101596B2 - Pressure detection device - Google Patents

Description

  The present invention relates to a pressure detection device, and more particularly to a pressure detection device capable of detecting a pressure in a space partitioned by a diaphragm.

  2. Description of the Related Art Conventionally, there is known a pressure detection device that detects a pressure of a fluid by deforming a diaphragm according to a pressure change of a fluid that is a pressure detection target, and detecting the deformation amount by a magnetic sensor (see, for example, Patent Document 1). ). In this pressure detection device, a pressure chamber and an atmospheric pressure chamber are partitioned by a diaphragm, and a fluid that is a pressure detection target is introduced into the pressure chamber. Coil springs are respectively provided on both surfaces of the diaphragm. When the pressure chamber and the atmospheric pressure chamber are at the same pressure, the diaphragm is maintained at a predetermined position by the balance of the elastic force exerted by each coil spring. When the pressure in the pressure chamber changes from this state, the diaphragm is deformed, one coil spring is extended, and the other coil spring is contracted.

Japanese Patent No. 3470129

  However, since the pressure detecting device described above requires two coil springs, the first coil spring is used when the second coil spring is mounted after the first coil spring is mounted. Installation work is performed while receiving force. For this reason, there exists a problem that the operation | work which assembles two coil springs and a diaphragm becomes difficult. In addition, since the atmospheric pressure chamber is also provided with a coil spring, there is a problem that a place where a detecting means such as a magnet or a magnetic sensor for detecting pressure is arranged is restricted.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a pressure detection device that can alleviate layout restrictions and facilitate assembly work.

The pressure detection device of the present invention is a pressure detection device capable of detecting both positive pressure and negative pressure, and includes a housing having a communication portion through which fluid can enter and exit, and the first space and the first space separated from the housing. A diaphragm that can be deformed according to the pressure in the first space that forms two spaces and communicates with the communication portion, and a movable member that is disposed in the second space and is movable according to the deformation of the diaphragm, An urging member for deformably supporting the diaphragm; and a detecting unit disposed in the second space for detecting movement of the moving member. The urging member is fixed to the diaphragm side. The first space comprises a leaf spring including one portion, a second portion fixed to the housing side, and an elastically deformable deformable portion provided between the first portion and the second portion. disposed in said housing, first Ke including the communication unit And a second case that is attached to the first case and that accommodates the moving member, and the first case and the second case provide a peripheral portion of the diaphragm and a second portion of the biasing member. Doo is characterized Rukoto is sandwiched.

According to the pressure detection device, since the urging member is a leaf spring, the urging force of the two coil springs can be applied by a single leaf spring as in the conventional device. Therefore, the diaphragm can be supported by a single leaf spring without installing two coil springs, and the assembly work can be facilitated. In addition, since the biasing member is disposed in the first space, the degree of freedom in layout of the detection means and the like disposed in the second space can be increased.
Moreover, the peripheral part of a diaphragm and the 2nd part of a biasing member can be easily fixed to a housing | casing with the simple structure of clamping by the 1st case and the 2nd case.

In the pressure detection device, the moving member includes a moving body that is positioned via a gap on an inner peripheral surface of the casing that forms the second space, and the diaphragm includes a base attached to the moving body ; and a thin portion located between the front SL base and the peripheral edge portion, the thin portion is protruded into the second space side between the inner peripheral surface of the casing and the outer peripheral surface of the movable body It is preferable that the folded portion is folded so as to form a folded portion, and the position of the folded portion is displaced by a pressure change in the fluid in the first space so that the moving member can be moved. In this case, since the position of the folded portion of the diaphragm is displaced due to the pressure change, the reaction force of the diaphragm is hardly generated, and the pressure detection accuracy can be improved.

  In the pressure detecting device, the diaphragm has a protruding portion protruding from the base portion toward the first space, the first portion of the urging member is supported by the protruding portion, and the urging member It is preferable that the deforming portion is separated from the base portion. In this case, even if the first space becomes negative pressure and the diaphragm is deformed toward the first space, it is possible to prevent the deformed portion of the biasing member and the base portion of the diaphragm from coming into contact with each other. The influence on detection can be eliminated.

  In the pressure detection device, it is preferable that the moving member is fixed to a base portion of the diaphragm in a region located outside the first portion of the biasing member. In this case, the base portion of the diaphragm can be prevented from moving away from the moving member, and the thin wall portion can be prevented from being deformed into an undesired shape. Thereby, it is possible to avoid an unintended reaction force due to the deformation of the thin-walled portion, and it is possible to perform more stable pressure detection.

  In the pressure detection device, the detection means preferably includes a magnet that moves together with the moving member and a magnetic sensor that faces the magnet. As the detecting means for detecting the movement of the moving member, one that changes the oscillation frequency of the LC resonance circuit with the movement of the moving member is conceivable. However, in such a detection means, a situation may occur in which the detection accuracy is reduced due to the resistance of the coil itself constituting the resonance circuit. According to the above configuration, since the detection unit is configured by the magnet and the magnetic sensor, it is possible to prevent such a decrease in detection accuracy. Further, when the magnetic sensor is a GMR element, detection accuracy can be ensured even if the magnetic force of the magnet becomes weak by detecting the direction of the magnetic flux.

  The pressure detection device preferably includes a first adjustment mechanism that adjusts a relative position between the magnet and the magnetic sensor in a moving direction of the moving member. In this case, the output characteristics of the magnetic sensor with respect to the detected pressure can be adjusted by adjusting the relative position between the magnet and the magnetic sensor in the moving direction of the moving member by the first adjusting mechanism. The difference in output characteristics can be better eliminated.

  The pressure detection device preferably includes a second adjustment mechanism that adjusts a relative position between the magnet and the magnetic sensor in a direction intersecting a moving direction of the moving member. In this case, by adjusting the relative position between the magnet and the magnetic sensor by the second adjustment mechanism, the output characteristics of the magnetic sensor with respect to the detected pressure can be adjusted. It can be eliminated better.

  According to the present invention, since the leaf spring as the urging member is disposed in the first space, the layout restriction in the second space can be relaxed, and the assembling work can be facilitated. .

It is a disassembled perspective view of the pressure detection apparatus which concerns on embodiment. It is sectional drawing of the pressure detection apparatus which concerns on the said embodiment. It is a perspective view in the state where the pressure detection device concerning the above-mentioned embodiment was assembled. It is a perspective view of the lower case which the pressure detection apparatus concerning the above-mentioned embodiment has. 5A and 5B are explanatory diagrams of the positional relationship between the magnetic sensor and the magnet, and FIGS. 5C and 5D are graphs showing the relationship between the output of the magnetic sensor and the pressure in the first space.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The pressure detection device according to the present embodiment is used, for example, for pressure detection of an air trap accompanying a water level change in a washing machine or the like. In addition, about the use of the pressure detection apparatus which concerns on this Embodiment, it is not limited to these, It is applicable to the pressure detection of arbitrary apparatuses.

  FIG. 1 is an exploded perspective view of a pressure detection device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the pressure detection device 1 according to the present embodiment. FIG. 3 is a perspective view showing an appearance of the pressure detection device 1 according to the present embodiment. In the following, for convenience of explanation, the vertical direction and the horizontal direction shown in FIG. 1 will be referred to as “the vertical direction of the pressure detection device 1” and “the horizontal direction of the pressure detection device 1,” respectively. Further, the front side of the paper surface illustrated in FIG. 1 is referred to as “the front side of the pressure detection device 1”, and the back side of the paper surface illustrated in FIG. 1 is referred to as “the rear side of the pressure detection device 1”.

  As shown in FIG. 1 to FIG. 3, the pressure detection device 1 according to the present embodiment includes an upper case (first case) 3 and a lower case (second case) 4 that constitute a housing 2, and the housing 2 is partitioned by a diaphragm 5 to form a first space S1 and a second space S2 (see FIG. 2). The upper case 3 and the lower case 4 are integrated by sandwiching the outer peripheral sides of the diaphragm 5 and the urging member 6, and the engaging protrusion 41 of the lower case 4 is engaged with the engaging hole 31 of the upper case 3. Has been. A moving member 7 is attached to the lower surface side of the diaphragm 5, and a holding member 8 and a screw member 9 are attached to a columnar portion 71 of the moving member 7. The lower case 4 holds a substrate 10. The upper case 3, the lower case 4, the moving member 7, the holding member 8 and the screw member 9 are formed by molding an insulating resin material, for example.

  The upper case 3 has a lid shape opened to the lower side, and defines a first space S1 inside. The top wall portion 32 of the upper case 3 is formed in a circular shape when viewed from above, and a side wall portion 33 extending downward from the periphery thereof is formed. The side wall portion 33 is formed in a cylindrical shape, and a plurality of the engagement holes 31 described above are formed at predetermined intervals in the circumferential direction. A circumferential groove 33a that opens the lower side is formed at an upper position on the inner periphery of the side wall 33 (see FIG. 2). A protruding portion 33b that protrudes downward and contacts the upper surface of the biasing member 6 is formed at a position adjacent to the circumferential groove 33a. Further, a tubular communication portion 34 is provided on the outer peripheral surface of the side wall portion 33 so as to extend outward (right side), and the communication portion 34 communicates with the first space S1. A pipe (not shown) through which air (gas) to be measured from the outside passes is connected to the communication part 34. Accordingly, air whose pressure is detected flows into or out of the first space S1 through the communication portion 34.

  The lower case 4 has a container shape opened to the upper side, and defines a second space S2 inside. The peripheral wall portion 42 of the lower case 4 is generally formed in a cylindrical shape. At the upper end of the peripheral wall portion 42, an annular rib 42 a that protrudes upward is formed, and the rib 42 a is inserted into the peripheral groove 33 a of the upper case 3 (see FIG. 2). On the lower inner surface side of the rib 42a in the peripheral wall portion 42, a mounting portion 42b including a step portion on which the diaphragm 5 and the urging member 6 are mounted is formed. On the outer peripheral surface of the peripheral wall portion 42, a plurality of the engaging convex portions 41 described above are formed at positions corresponding to the engaging holes 31 of the upper case 3. The engaging convex portion 41 is engaged with the outer peripheral edge of the lower region thereof in contact with the lower inner peripheral edge of the engaging hole 31, whereby the upper case 3 rises with respect to the lower case 4. And their relative rotation in the circumferential direction are restricted.

  FIG. 4 is a schematic perspective view of the lower case 4 as viewed from above. As shown in FIG. 4, the inner peripheral surface of the peripheral wall portion 42 is formed in a shape along the cylinder. On the lower end side of the peripheral wall portion 42, a bottom wall portion 43 having various steps on the upper surface side is formed. The bottom wall 43 forms a rectangular first opening M1 between the bottom wall 43 and the peripheral wall 42 on the left side. In addition, on the right side of the bottom wall 43, a square-shaped second opening M <b> 2 is formed between the bottom wall 43 and the peripheral wall 42. The first opening M1 is formed so that the holding member 8 positioned in the second space S2 can be exposed to the outside when viewed from the lower side of the lower case 4 (see FIG. 2). Holding grooves 44 extending in the vertical direction are formed on both front and rear sides of the second opening M2. An end of the substrate 10 is inserted and held inside the holding groove 44. Note that the inner peripheral surface of the peripheral wall portion 42 may not be a perfect cylindrical surface, but may be formed in a shape in which a slight depression or the like is applied to the cylindrical surface.

  A cylindrical guide portion 45 extending in the vertical direction is formed at the center position of the bottom wall portion 43 in plan view. The screw member 9 is inserted into the guide portion 45 so that the vertical movement and rotation of the screw member 9 are smoothly guided. On both the front and rear sides of the guide portion 45, a rectangular column portion 46 extending in the vertical direction is connected, and a guide groove 46a is formed in each rectangular column portion 46. A guide convex portion 72d, which will be described later, of the moving member 7 is inserted into the guide groove 46a.

  The diaphragm 5 is formed of an elastic material such as rubber, for example. As shown in FIG. 2, the diaphragm 5 has a disk-like base 51 that is in surface contact with the upper surface of the moving member 7. At the center of the upper surface of the base portion 51, a protruding portion 51a protrudes upward, and the protruding portion 51a is provided in a shape having a flange portion 51b with a tapered surface at the upper end. Further, an annular rib 51c is projected from a position on the upper surface of the base 51 and surrounding the protruding portion 51a. The height of the annular rib 51c is formed slightly lower than the lower end of the flange portion 51b. Thus, the first portion 61 of the biasing member 6 can be sandwiched and held between the upper end of the annular rib 51c and the lower end of the flange portion 51b. A plurality of engagement protrusions 51d are formed on the lower surface of the base 51, and each engagement protrusion 51d is configured to fit into an engagement hole 72c described later of the moving member 7.

  The diaphragm 5 is provided with a peripheral edge portion 52 on the outer periphery thereof, and the peripheral edge portion 52 is sandwiched between the protruding portion 33 b of the upper case 3 and the mounting portion 42 b of the lower case 4 and is fixed to the housing 2. . A thin-walled portion 53 having a thickness smaller than that of the base portion 51 is formed between the peripheral edge portion 52 and the base portion 51. The thin-walled portion 53 protrudes in a convex shape toward the second space S2 in the cross-sectional view of FIG. 2, has a shape folded back to form a U shape, and forms a folded portion 53a in the lower region. The thin portion 53 is configured to be deformable so that the position of the folded portion 53 a is displaced in the vertical direction by the vertical movement of the base portion 51. The thickness and hardness of the thin portion 53 are set so that no reaction force is generated by such deformation.

  The biasing member 6 is a leaf spring having a circular outer shape in plan view, and is disposed in the first space S1. The biasing member 6 includes a first portion 61 that forms a central region thereof. A round hole 61 a through which the protruding portion 51 a of the diaphragm 5 passes is formed at the in-plane center position of the first portion 61. When the protruding portion 51a passes through the circular hole 61a, the first portion 61 is placed on the upper end of the annular rib 51c, and the first portion 61 is sandwiched between the upper end of the annular rib 51c and the lower end of the flange portion 51b. It is. In addition, although the protrusion part which mounts and supports the 1st part 61 is used as the annular rib 51c in this Embodiment, if it is a shape which can support the 1st part 61, it will not be limited to a ring shape. For example, a plurality of protruding portions having a circular shape or a polygonal shape may be disposed around the protruding portion 51a.

  The urging member 6 includes an annular second portion 62 that forms an outer peripheral side region thereof. The second portion 62 is fixed to the housing 2 by being sandwiched by the protruding portion 33 b of the upper case 3 and the mounting portion 42 b of the lower case 4 together with the peripheral edge portion 52 of the diaphragm 5. Between the second portion 62 and the first portion 61, a deformable portion 63 that can be elastically deformed is provided continuously. The deformable portions 63 are formed at four positions at intervals of 90 ° in the circumferential direction of the first portion 61, and are formed in the same planar shape only by changing the direction of each. The deformation portion 63 extends so as to meander from the outer edge of the first portion 61 toward the inner edge of the second portion 62 in plan view. The deforming portion 63 can be elastically deformed from the state shown in FIG. 2 regardless of whether the first portion 61 is displaced in the upward or downward direction, and is proportional to the amount of displacement, with a force in the direction opposite to the displacement direction. The first portion 61 is biased. Further, the deforming portion 63 is separated from the base portion 51 of the diaphragm 5 in a state where the first portion 61 is supported on the annular rib 51 c and fixed to the diaphragm 5, and the second portion 62 is fixed to the housing 2. It is arranged to do.

  The moving member 7 has a moving body 72 that comes into surface contact with the lower surface of the base portion 51 and the thin portion 53. The moving body 72 includes a main body plate 72a having a circular shape in plan view, and a drooping portion 72b that extends downward from the outer periphery of the main body plate 72a. A columnar portion 71 extending downward from the center position of the lower surface is connected to the main body plate 72 a, and a male screw 71 a is formed on the outer peripheral surface of the columnar portion 71. Engagement holes 72c are formed at four positions in the surface of the main body plate 72a. By engaging with the engagement holes 72c with the engagement protrusions 51d inserted, a movable body is formed on the lower surface of the base 51. 72 is fixed. The engagement hole 72c and the engagement protrusion 51d are located outside the first portion 61 in plan view. The hanging portion 72b is located on the inner peripheral surface of the peripheral wall portion 42 of the lower case 4 via a gap, and the thin portion 53 is disposed in this gap. A pair of guide projections 72d (only one of which is shown in FIG. 1) are provided in a row on the hanging portion 72b. 72 d of guide convex parts are inserted in the guide groove 46a (refer FIG. 4), the rotation of the circumferential direction in the mobile body 72 is controlled, and it is comprised so that it can slide to the up-down direction within the guide groove 46a.

  The holding member 8 includes a through portion 81 having a through hole 81a through which the columnar portion 71 is inserted. The through hole 81 a is set to an inner diameter dimension that is not in contact with the outer surface of the columnar portion 71, and the columnar portion 71 and the holding member 8 are provided so as to be relatively rotatable around the axis of the columnar portion 71. A holding recess 82 that opens downward is formed on the right side of the penetrating portion 81 (see FIG. 2). The holding recess 82 receives and holds a magnet 13 described later. On the left side of the penetrating portion 81, a pair of protruding portions 83 having an arm shape are formed in a row. The projecting direction of each projecting portion 83 is the left direction, and is directed in a direction that intersects the up and down direction, which is the moving direction of the moving member 7.

  The screw member 9 includes a cylindrical screw body 91 having an internal thread 91a formed on the inner peripheral surface (see FIG. 2). The female screw 91a is configured to mesh with the male screw 71a of the columnar portion 71 and rotate the screw main body 91 around the axis of the columnar portion 71 so that the screw main body 91 can be moved in the axial direction (vertical direction). The outer diameter dimension of the screw body 91 is set slightly smaller than the inner diameter dimension of the guide portion 45. Thereby, the rotation of the screw main body 91 is guided on the inner peripheral surface of the guide portion 45, and the vertical movement of the screw main body 91 is also guided. A hexagonal hole 91b is formed at the bottom of the screw body 91, and a tool such as a hexagon wrench is inserted into the hexagonal hole 91b so that the screw body 91 can be rotated. A support portion 92 that supports the holding member 8 is formed on the upper portion of the screw body 91. The support portion 92 is formed in a flange shape that protrudes outward from the upper portion of the screw body 91, and supports the holding member 8 from below with the lower surface of the through portion 81 being in contact therewith.

  A pair of locking pieces 93 are formed on the upper portion of the screw body 91 so as to protrude upward. Each locking piece 93 is inserted into the through hole 81 a of the holding member 8, and the insertion restricts the holding member 8 from moving in the front-rear and left-right directions with respect to the screw member 9. Each locking piece 93 is formed in a hook shape at the tip, and is provided on the upper surface of the penetrating portion 81 in a state of being inserted into the through hole 81 a of the holding member 8. In this locked state, the holding member 8 is sandwiched from the vertical direction by the support portion 92 and the locking piece 93, and the vertical movement of the holding member 8 with respect to the screw member 9 is restricted. Accordingly, the screw member 9 and the holding member 8 are in an integrated state, and in this state, the screw member 9 and the holding member 8 are configured to be relatively rotatable around the axis of the screw main body 91. Further, in the locked state by the locking piece 93, the opening side of the holding recess 82 is closed by the support portion 92, and the magnet 13 described later cannot be detached from the holding recess 82. In the state where the moving member 7 and the screw member 9 are coupled, the screw member 9 supports the holding member 8 to be rotatable with respect to the columnar portion 71. The holding member 8 and the screw member 9 constitute a second adjustment mechanism, which will be described later, capable of adjusting the relative position between the magnet 13 and the magnetic sensor 12.

  The substrate 10 is fixed in a state where both front and rear end sides of the upper half region are inserted into the holding grooves 44. The substrate 10 is electrically connected to an external device (not shown) via the harness 11. A magnetic sensor 12 is mounted on the substrate 10, and the magnetic sensor 12 is configured by a GMR (Giant Magneto-Resitive) element which is a kind of magnetoresistive effect element. A GMR element basically has an exchange bias layer (antiferromagnetic layer), a fixed layer (pinned magnetic layer), a nonmagnetic layer, and a free layer (free magnetic layer) stacked on a wafer (not shown). Is formed. The magnetic sensor 12 is provided so as to be able to detect the direction of magnetic flux in the magnet 13 held by the holding member 8. The magnet 13 is magnetized so that the right side, which is the magnetic sensor 12 side, is an N pole, and the left side, which is the opposite side to the magnetic sensor 12 side, is an S pole. Here, the magnetic sensor 12 and the magnet 13 constitute detection means for detecting the movement of the moving member 7.

  Next, a method for assembling the pressure detection device 1 will be described. First, after the magnet 13 is inserted (press-fitted) into the holding recess 82 of the holding member 8, each locking piece 93 is inserted into the through hole 81 a and locked to the through part 81. As a result, the holding member 8 and the screw member 9 are integrated, the holding recess 82 is closed by the support portion 92, and the magnet 13 is held so as not to fall off the holding member 8.

  Next, the moving member 7 is coupled to the integrated holding member 8 and screw member 9. In this connection, the tip of the columnar portion 71 is passed through the through hole 81a, and the male screw 71a is engaged with the female screw 91a of the screw body 91 to be screw-connected. By this screw connection, a tool is inserted into the hexagonal hole 91b and rotated around the axis of the columnar portion 71, whereby the holding member 8 and the screw member 9 are moved in the axial direction (vertical direction) that is the extending direction of the columnar portion 71. ) Can be moved.

  The diaphragm 5 is attached to the moving member 7 so as to cover the moving body 72 from above. In this attachment, the engaging protrusion 51d of the diaphragm 5 is inserted into and engaged with the engaging hole 72c of the moving body 72. Thereby, the moving member 7 and the diaphragm 5 are united so that the base 51 and the main body plate 72a of the moving body 72 may overlap vertically.

  A biasing member 6 is attached to the upper surface side of the diaphragm 5. In this attachment, the protruding portion 51a is inserted into the round hole 61a of the first portion 61, and the urging member 6 is sandwiched between the upper end of the annular rib 51c and the lower end of the flange portion 51b from the vertical direction. At this time, the lower surface of the outer periphery of the second portion 62 of the biasing member 6 is in surface contact with the upper surface of the peripheral portion 52, and the deformable portion 63 is separated from the upper surface of the base portion 51 and is not in contact.

  As described above, the holding member 8 (including the magnet 13 to be held), the screw member 9, the moving member 7, the diaphragm 5, and the urging member 6 are integrally assembled, and this unit is stored from above the lower case 4. To do. In this storage, the screw main body 91 is inserted into the guide portion 45, and the guide convex portion 72d of the moving member 7 is inserted into the guide groove 46a. Further, the protrusion 83 of the holding member 8 is positioned so as to be positioned just above the first opening M1, and the peripheral edge 52 of the diaphragm 5 is placed on the mounting portion 42b of the lower case 4. From this state, after disposing the upper case 3 so as to cover the upper region of the lower case 4, the engaging protrusion 41 is engaged with the engaging hole 31 of the upper case 3. Accordingly, the upper case 3 and the lower case 4 are integrated as the housing 2, and the peripheral portion 52 and the second portion 62 of the biasing member 6 are sandwiched between the mounting portion 42 b and the protruding portion 33 b of the upper case 3. In this state, the diaphragm 5 is supported from above by the biasing member 6, and the moving member 7, the screw member 9 screwed to the diaphragm 7, and the holding member 8 held by the screw member 9 are suspended from the diaphragm 5. It looks like it was lowered.

  The substrate 10 is fixed in a state where the front and rear end sides are inserted into the holding groove 44 through the second opening M2 of the lower case 4. As a means for fixing, press fitting into the holding groove 44 or adhesion using an adhesive can be used.

  In addition, about the assembly method of the above-mentioned pressure detection apparatus 1, an example is shown, it is not limited to this, The order of an assembly etc. can be changed suitably. As shown in FIG. 2 and FIG. 3, any assembly method may be adopted as long as each component can be assembled.

  When the pressure detection device 1 is assembled in this way, the first space S <b> 1 is formed by the upper case 3 and the diaphragm 5. The constituent member disposed in the first space S1 is only the urging member 6, and the base 51 of the diaphragm 5 is disposed on the first portion 61 which is the central position of the urging member 6 via the protruding portion 51a and the annular rib 51c. Is fixed.

  In a state where the pressure detection device 1 is assembled, a second space S <b> 2 is formed below the diaphragm 5 in the lower case 4. In the second space S2, a moving member 7, a screw member 9 screwed to the moving member 7, a holding member 8 locked to the screw member 9, and a substrate 10 are disposed. Accordingly, the magnet 13 held by the holding member 8 and the magnetic sensor 12 mounted on the substrate 10 are also disposed in the second space S2.

  Since the first opening M1 and the second opening M2 are formed in the lower case 4, the second space S2 is set to the atmospheric pressure and the equal pressure. On the other hand, the first space S1 becomes a sealed space when the communication portion 34 of the upper case 3 is closed, and the pressure thereof changes depending on the air that passes through the communication portion 34 and flows into the first space S1. Here, for example, as shown in FIG. 2, it is assumed that the pressure in the first space S1 is equal to the atmospheric pressure when the upper surface and the lower surface of the biasing member 6 are horizontal. From this state, when the first space S1 becomes a positive pressure higher than the atmospheric pressure, the volume of the first space S1 tends to expand, so that a force that pushes down the base 51 acts and is displaced downward. Due to this displacement, each deformation portion 63 of the urging member 6 is deformed, and an elastic force is exerted so that the base portion 51 is raised. Then, the base 51 is displaced downward to a position where the pressure of the first space S1 and the elasticity of each deformation portion 63 are balanced. Further, when the first space S1 becomes a negative pressure lower than the atmospheric pressure, the volume of the first space S1 tends to be reduced, so that a force for pulling up the base 51 acts and is displaced upward. Due to this displacement, each deformation portion 63 of the urging member 6 is deformed, and an elastic force is exerted so that the base portion 51 is lowered. Then, the base 51 is displaced upward to a position where the pressure of the first space S1 and the elasticity of each deformation portion 63 are balanced.

  Here, in the diaphragm 5, when the base 51 moves in the vertical direction, the position of the folded portion 53a of the thin portion 53 is deformed so as to be displaced in the vertical direction. In this deformation, the diaphragm 5 is deformed only by the thin portion 53 without substantially deforming the base 51. Further, the moving member 7 moves up and down with the same movement amount according to the vertical movement of the base 51, and as a result, the holding member 8 supported via the screw member 9 and the magnet 13 held by the moving member 7 also move up and down. Move to. Accordingly, the magnet 13 can be displaced in the vertical direction in proportion to the pressure change in the first space S1, and the pressure in the first space S1 is detected by detecting the amount of displacement as described later.

  Next, the 1st adjustment mechanism which the pressure detection apparatus 1 which concerns on this Embodiment has, and the adjustment method by a 1st adjustment mechanism are demonstrated. The first adjusting mechanism includes the columnar portion 71 and the screw member 9 described above, and is provided so that the relative position between the magnet 13 and the magnetic sensor 12 in the moving direction (vertical direction) of the moving member 7 can be adjusted. In this position adjustment, first, a rod-shaped jig (not shown) is inserted into the first opening M1, and the rotation of the holding member 8 is regulated through the jig between the pair of protrusions 83. Since the male screw 71a of the columnar portion 71 and the female screw 91a of the screw member 9 are engaged with each other, the screw member 9 and the holding member 8 are moved in the vertical direction by inserting a tool into the hexagonal hole 91b of the screw member 9 and rotating it. Move to. Since the magnet 13 is held by the holding member 8, the magnet 13 also moves in the vertical direction together with the holding member 8, and the vertical position of the magnet 13 with respect to the magnetic sensor 12 is adjusted. In addition, since the rotation of the holding member 8 is regulated by the jig, even if the screw member 9 is rotated, the locking piece 93 rotates in the through hole 81a, and the magnet 13 faces the magnetic sensor 12 in the left-right direction. Thus, the orientation of the holding member 8 is maintained.

  Next, a second adjustment mechanism included in the pressure detection device 1 according to the present embodiment and an adjustment method using the second adjustment mechanism will be described. The second adjustment mechanism includes a screw member 9 and a holding member 8 that can rotate relative to each other, and is a direction that intersects the moving direction (vertical direction) of the moving member 7 and that connects the poles of the magnet 13 (left and right). Direction), that is, the relative position between the magnet 13 and the magnetic sensor 12 in the front-rear direction (the direction along the arc intersecting with the sheet of FIG. 2) is adjustable. In this position adjustment, first, by inserting a tool into the hexagonal hole 91b, the screw member 9 is restricted from rotating in the circumferential direction of the columnar portion 71, and the screw member 9 and the magnet 13 (holding member 8) are moved up and down. It is assumed that the movement is restricted. In this state, the above-mentioned jig is inserted into the first opening M1, and the protrusion 83 is displaced in the front-rear direction by the jig, so that the holding member 8 around the locking piece 93 of the columnar part 71 and the screw member 9 is obtained. Rotate. Then, the magnet 13 held on the right end side of the holding member 8 moves in the front-rear direction, and the relative position between the magnet 13 and the magnetic sensor 12 is adjusted.

  Next, adjustment of the output of the magnetic sensor 12 will be described with reference to FIG. 5A and 5B are explanatory views of the positional relationship between the magnetic sensor 12 and the magnet 13, FIG. 5A is a front view, and FIG. 5B is a left side view of FIG. 5A. 5C and 5D are graphs showing the relationship between the output of the magnetic sensor 12 and the pressure in the first space S1. In the present embodiment, the output adjustment of the magnetic sensor 12 is performed at the same pressure in the first space S1 and the second space S2 at the stage before the pressure detection by the pressure detection device 1, such as at the time of manufacture or before product shipment. Is done in a state.

  When the pressure detection device 1 is assembled as described above, the magnet 13 is disposed away from the magnetic sensor 12 in the rearward and leftward directions as shown in FIGS. 5A and 5B. In the positional relationship between the magnet 13 and the magnetic sensor 12, the magnetic sensor 12 is configured to increase or decrease the output voltage in proportion to the amount of displacement of the magnet 13 in the vertical direction by detecting the direction of the magnetic flux of the magnet 13. ing. Specifically, the magnetic sensor 12 is configured such that the output voltage increases as the magnet 13 is displaced downward, and the output voltage decreases as the magnet 13 is displaced upward. As described above, since the vertical displacement of the magnet 13 is proportional to the pressure change in the first space S1, the pressure in the first space S1 increases as shown by the solid line in the graphs of FIGS. 5C and 5D. The output voltage increases in proportion to the proportional relationship.

  From the state shown in FIGS. 5A and 5B, the magnet 13 can be moved in the vertical direction by the first adjustment mechanism. When the magnet 13 is moved downward, the output voltage of the magnetic sensor 12 increases. Therefore, in the graph of FIG. 5C, the output voltage of the magnetic sensor 12 is set as indicated by the dotted line positioned above the solid line. On the other hand, when the magnet 13 is moved upward, the output voltage of the magnetic sensor 12 decreases, so that the output voltage of the magnetic sensor 12 is set as shown by the dotted line located below the solid line in the graph of FIG. 5C. Thereby, in the equal pressure state of the first space S1 and the second space S2, the origin adjustment for setting the output voltage to a constant value can be performed by moving the magnet 13 in the vertical direction by the first adjustment mechanism. Further, when manufacturing a plurality of pressure detection devices 1, the output voltage with respect to the pressure to be detected can be kept constant in each pressure detection device 1, and it can be avoided that the output varies for each pressure detection device 1. .

  In addition, the magnet 13 can be moved in the front-rear direction by the second adjustment mechanism from the state shown in FIGS. 5A and 5B. When the magnet 13 is moved forward, the magnet 13 approaches the magnetic sensor 12, so that the output voltage of the magnetic sensor 12 is set as indicated by a dotted line that is steeper than the solid line in the graph of FIG. 5D. On the other hand, when the magnet 13 is moved rearward, the magnet 13 is separated from the magnetic sensor 12, so that the output voltage of the magnetic sensor 12 is set as indicated by a dotted line having a gentler gradient than the solid line in the graph of FIG. 5D. Thereby, the inclination (output voltage per unit pressure) in the graph of FIG. 5D can be adjusted to be constant by moving the magnet 13 in the front-rear direction by the second adjustment mechanism, and this adjustment can be performed for a plurality of pressure detection devices 1. By doing so, it is possible to avoid variation in output for each pressure detection device 1.

  In addition, after the position adjustment by each adjustment mechanism is performed and the output adjustment of the magnetic sensor 12 is completed, the columnar portion 71, the screw member 9, and the holding member 8 that can be relatively displaced in each adjustment mechanism are fixed by an adhesive. The injection of the adhesive is performed by inserting a nozzle (not shown) into the second space S2 through the first opening M1.

  Next, a pressure detection method for the first space S1 by the pressure detection device 1 according to the present embodiment will be described. As described above, when the pressure in the first space S1 is changed by the gas entering and leaving the communication portion 34, the magnet 13 is displaced in the vertical direction in proportion to the pressure change. When the magnet 13 is displaced, the direction of the magnetic flux of the magnet 13 in the magnetic sensor 12 also changes. Due to the change in the direction of the magnetic flux, the output voltage of the magnetic sensor 12 changes, and due to the difference between the output voltage and the output voltage at the time of adjusting the origin, the pressure in the first space S1 is determined from the change characteristics of the output voltage in the magnetic sensor 12. A value is determined.

  As described above, in the pressure detection device 1 according to the present embodiment, since the urging member 6 is a single leaf spring, the diaphragm 51 is inserted into the hole 61a of the urging member 6 after the protrusion 51a is inserted. By disposing 5 in the lower case 4, the assembly of the urging member 6 can be completed, and the assembly workability can be improved as compared with the conventional device using two coil springs. Moreover, not only when the first space S1 is positive and the base 51 is lowered, but also when the first space S1 is negative and the base 51 is raised, the biasing member 6 serving as a leaf spring applies the bias. Can exert power. Thereby, even if the first space S1 becomes not only positive pressure but also negative pressure, the thin portion 53 can be deformed so that the base 51 and the magnet 13 are displaced in proportion to the pressure change. Both pressures can be detected.

  Further, since the urging member 6 is disposed in the first space S1, and the urging member 6 does not have to be disposed in the second space S2, a space can be provided in the second space S2, and the second space S2. The degree of freedom in designing the layout and shape of each member positioned inside can be increased.

  Further, due to the pressure change in the first space S1, in the diaphragm 5, the thin portion 53 is deformed so that the position of the folded portion 53a is displaced and the base portion 51 is displaced up and down, so that the reaction force due to the deformation of the thin portion 53 is suppressed. In addition, the proportionality between the displacement amount of the base 51 and the pressure in the first space S1 can be maintained to increase the accuracy of pressure detection.

  In addition, since the deforming portion 63 of the biasing member 6 is in a positional relationship away from the upper surface of the base portion 51, the deforming portion 63 and the base portion 51 contact each other particularly due to a pressure change that causes the first space S1 to be a negative pressure. Can be prevented. Thereby, it can avoid that the deformation | transformation part 63 deform | transforms into the shape which is not intended, can exert urging | biasing force stably and can perform pressure detection stably.

  Further, the engaging member 72c and the engaging protrusion 51d located outside the first portion 61 are engaged with each other in plan view, so that the moving member 7 is fixed to the diaphragm 5, so that the base 51, the moving body 72, It is possible to prevent the thin-walled portion 53 from being deformed into an undesired shape.

  Further, as a detecting means for detecting the movement of the moving member 7, one that changes the oscillation frequency of the LC resonance circuit with the movement of the moving member 7 can be considered. However, in such a detection means, a situation may occur in which the detection accuracy is reduced due to the resistance of the coil itself constituting the resonance circuit. According to the above embodiment, since the detection means is constituted by the magnet 13 and the magnetic sensor 12, it is possible to prevent such a decrease in detection accuracy. Further, since the magnetic sensor 12 is a GMR element, detection accuracy can be ensured even if the magnetic force of the magnet 13 becomes weak.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the above embodiment, the fluid flowing into the first space S1 is air, but it may be another gas or a liquid such as water or hot water.

  In addition, the diaphragm 5 has a shape having the thin wall portion 53 and the like, but any shape can be adopted as long as it can function as in the above embodiment. However, the configuration having the base 51 and the thin-walled portion 53 as in the above-described embodiment is advantageous because the reaction force of the diaphragm 5 due to a change in detected pressure is less likely to occur.

  Further, the magnetic sensor 12 may be changed to a Hall IC as long as the movement of the moving member 7 can be detected. The magnetic sensor 12 includes a coil (L) and a capacitor (C) connected in parallel to the coil (L) by displacement of the amount of the iron core (core) inserted into the coil (L). You may change into the detection apparatus from which the oscillation frequency of LC resonance circuit fluctuates.

DESCRIPTION OF SYMBOLS 1 Pressure detection apparatus 2 Case 3 Upper case (1st case)
34 Communication part 4 Lower case (second case)
5 Diaphragm 51 Base 51a Protrusion 51c Toroidal rib (protrusion)
52 Peripheral part 53 Thin part 53a Folding part 6 Energizing member 61 1st part 62 2nd part 63 Deformation part 7 Moving member 72 Moving body 12 Magnetic sensor 13 Magnet S1 1st space S2 2nd space

Claims (10)

A pressure detection device capable of detecting both positive pressure and negative pressure,
A housing having a communication portion through which fluid can enter and exit, and a diaphragm that partitions the housing to form a first space and a second space, and can be deformed according to pressure in the first space communicating with the communication portion. A movable member that is disposed in the second space and is movable in accordance with the deformation of the diaphragm, a biasing member that supports the diaphragm so as to be deformable, and a movable member that is disposed in the second space and is movable. Detecting means for detecting
The urging member includes a first part fixed to the diaphragm side, a second part fixed to the housing side, and an elastically deformable deformation provided between the first part and the second part. A leaf spring provided with a portion, disposed in the first space ,
The housing includes a first case including the communication portion, and a second case attached to the first case and accommodating the moving member, and the diaphragm includes the first case and the second case. pressure sensing device and the peripheral portion and the second portion of the biasing member, wherein Rukoto is sandwiched in. The moving member includes a moving body positioned via a gap on an inner peripheral surface of the casing forming the second space,
Said diaphragm has a base portion attached to the movable body, and a thin portion located between the front SL base and the peripheral edge portion,
The thin-walled portion is folded back so as to protrude toward the second space between the outer peripheral surface of the movable body and the inner peripheral surface of the housing, and the position of the folded-back portion is The pressure detection device according to claim 1, wherein the moving member is movable by being displaced by a pressure change in the fluid in the first space. The pressure detecting device according to claim 1, wherein the urging member is formed in a planar shape. The biasing member includes a first portion that forms a central region thereof, and an annular second portion that forms an outer peripheral region thereof, and elastic deformation between the second portion and the first portion. The pressure detecting device according to claim 1, wherein possible deformable portions are provided in series. The pressure detecting device according to claim 2, wherein the thin portion of the diaphragm has a shape that is folded so as to form a U shape, and the folded portion is formed in a lower region thereof. The diaphragm has a projecting portion projecting from the base portion toward the first space, the first portion of the biasing member is supported by the projecting portion, and the deforming portion of the biasing member is separated from the base portion. The pressure detection device according to claim 2, wherein the pressure detection device is separated. The pressure detection according to any one of claims 2 to 6, wherein the moving member is fixed to a base portion of the diaphragm in a region located outside the first portion of the urging member. apparatus. The pressure detection device according to claim 1 , wherein the detection unit includes a magnet that moves together with the moving member, and a magnetic sensor that faces the magnet. The pressure detection device according to claim 8, further comprising a first adjustment mechanism that adjusts a relative position between the magnet and the magnetic sensor in a moving direction of the moving member. 10. The pressure detection device according to claim 8 , further comprising a second adjustment mechanism that adjusts a relative position between the magnet and the magnetic sensor in a direction intersecting a moving direction of the moving member. .

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