JP7434834B2 - sensor unit - Google Patents

Description

The present invention relates to a sensor unit.

For example, a hydraulic control device that is mounted on a vehicle such as an automobile and controls hydraulic pressure is known (see, for example, Patent Document 1). The hydraulic control device described in Patent Document 1 includes an oil passage body having an oil passage through which oil flows, and a plurality of pressure sensors that measure the pressure of the oil flowing in the oil passage, which are arranged in a straight line and connected to each pressure sensor. and a pressure sensor device having a bus bar.

Japanese Patent Application Publication No. 2018-173278

However, in the hydraulic control device described in Patent Document 1, depending on the magnitude of oil pressure, the pressure sensor may be displaced and press the bus bar excessively. In this case, the busbar tries to relieve the stress (internal stress) by bending, but since it is linear as described above, it cannot deform sufficiently, and as a result, the stress does not disappear. There was a problem.

An object of the present invention is to provide a sensor unit that can prevent excessive force from acting on a bus bar.

One aspect of the sensor unit of the present invention is a sensor unit that is used by being installed in a body having a flow path through which fluid can pass, and includes a case having a hollow part, a case housed in the hollow part, and having a terminal. and a pressure sensor that detects the pressure of the fluid passing through the flow path, a plate-shaped bracket that presses the pressure sensor against the body, and a bus bar that is electrically connected to the terminal, the bus bar The bus bar is characterized by having a deformed part extending in the hollow part in a direction intersecting the thickness direction of the bracket, in contact with the terminal, and in which the center line of the bus bar is deformed by curving or bending.

According to one aspect of the sensor unit of the present invention, it is possible to prevent excessive force from acting on the bus bar.

FIG. 1 is a perspective view showing how the sensor unit of the present invention is used. FIG. 2 is an exploded perspective view of the sensor unit shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a view (perspective view) seen from the direction of arrow B in FIG. FIG. 5 is a diagram (plan view) seen from the direction of arrow B in FIG. FIG. 6 is a view (side view) seen from the direction of arrow C in FIG.

Embodiments of the sensor unit of the present invention will be described below with reference to FIGS. 1 to 6. Note that in the following, for convenience of explanation, three mutually orthogonal axes are set as an X axis, a Y axis, and a Z axis. As an example, an XY plane including an X axis and a Y axis is horizontal, and a Z axis is vertical. In this specification, vertical direction, horizontal direction, upper side, and lower side are simply names for explaining the relative positional relationship of each part, and the actual positional relationship etc. is the positional relationship etc. indicated by these names. Other arrangement relationships may also be used.

As shown in FIG. 1, the pressure control device 100 includes a body 20 and a sensor unit 1 installed in the body 20. The pressure control device 100 is mounted, for example, on a vehicle such as an automobile, and is used as a hydraulic control device that controls hydraulic pressure.
As shown in FIG. 3, the body 20 has a flow path 201 therein through which the fluid Q can pass. The body 20 is, for example, an assembly formed by overlapping a plurality of plate-like members. Note that the fluid Q is not particularly limited, and may be transmission oil, for example, when the pressure control device 100 is used as a hydraulic control device for an automobile.

The sensor unit 1 is installed and used on the upper part of the body 20. The sensor unit 1 includes a pressure sensor 2, a bus bar 6, a case 5, a cap 8, a bracket 3, and a positioning section 4. The configuration of each part will be explained below.
Pressure sensor 2 detects the pressure of fluid Q passing through channel 201. The pressure sensor 2 includes a sensor body 23 with a built-in circuit board (not shown), three terminals 21 protruding from the top of the sensor body 23, and a pressure detection element 24 installed at the bottom of the sensor body 23. has.

The sensor main body 23 is a portion having a cylindrical or disk-like external shape. A ring-shaped flange portion 22 is provided on the outer periphery of the sensor body 23 along the circumferential direction. In this embodiment, the flange portion 22 protrudes in a direction perpendicular to the axis of the terminal 21, that is, in a direction parallel to the XY plane.
Each terminal 21 protrudes toward the Z-axis direction and is electrically connected to the circuit board inside the sensor body 23.

The pressure detection element 24 has, for example, a strain gauge, and is configured so that the resistance value of the strain gauge changes depending on the force acting from the fluid Q. The circuit board can convert the resistance value at the pressure detection element 24 into the pressure value of the fluid Q. As shown in FIG. 3, in the present embodiment, the body 20 is provided with a side hole 202 along the Z-axis direction that connects to a flow path 201 parallel to the XY plane. The fluid Q that has passed through the flow path 201 can enter the side hole 202 and press the pressure detection element 24 . At this time, the pressure detection element 24 receives a force from the fluid Q, and the pressure value of the fluid Q is detected as described above.

Furthermore, a ring-shaped packing 203 is arranged between the pressure sensor 2 and the body 20 so as to be concentric with the side hole 202 . Thereby, fluid Q can be prevented from leaking from between the pressure sensor 2 and the body 20. It is preferable that the packing 203 has elasticity and is in a compressed state between the pressure sensor 2 and the body 20. This increases the liquid tightness between the pressure sensor 2 and the body 20, which contributes to preventing leakage of the fluid Q.

A bus bar 6 is arranged on the opposite side of the pressure sensor 2 from the body 20, that is, on the upper side of the pressure sensor 2. The bus bar 6 has a linear shape and is made of a conductive metal material. The bus bar 6 is electrically connected to each terminal 21 of the pressure sensor 2, and includes a current supply bus bar 6A, a grounding bus bar 6B, and an output bus bar 6C, as shown in FIG. The current supply bus bar 6A is used to supply current to the pressure sensor 2. The grounding bus bar 6B is used to ground the pressure sensor 2. The output bus bar 6C is used for outputting the pressure sensor 2. The current supply bus bar 6A, the ground bus bar 6B, and the output bus bar 6C are arranged at intervals in one direction parallel to the XY plane.

Further, an external connector (not shown) is electrically connected to the bus bar 6 . When the bus bar 6 and the external connector are electrically connected, an external current is supplied to the pressure sensor 2 via the current supply bus bar 6A. Further, the pressure sensor 2 is externally grounded via the grounding bus bar 6B. Further, the output of the pressure sensor 2 is transmitted to the outside via the output bus bar 6C.

The bus bar 6 is bent or curved in the middle of the length direction (longitudinal direction), and the other end 65 of the one end 64 and the other end 65 is along the X-axis direction. In this way, the bus bar 6 has a shape that is bent or curved, with one end in its length direction serving as the lateral direction of the bracket 3, and the other end serving as the longitudinal direction of the bracket 3. Thereby, the sensor unit 1 can be downsized at least in the planar direction.

The bus bar 6 is supported and fixed inside the case 5. Thereby, it is possible to prevent the bus bar 6 from being unintentionally deformed and to electrically connect the bus bar 6 to each terminal 21 of the pressure sensor 2 more accurately.
As shown in FIGS. 1 and 2, the case 5 is disposed midway in the longitudinal direction of the elongated bracket 3. As shown in FIGS. Note that, as described later, the bracket 3 is a member that presses the pressure sensor 2 against the body 20. Furthermore, the case 5 includes a fixing portion 50 that is fixed to the bracket 3. This can prevent the case 5 from separating from the bracket 3, thus maintaining the positional relationship between the bus bar 6 and the pressure sensor 2, that is, maintaining the electrical connection between the bus bar 6 and the pressure sensor 2. be able to.

The fixed part 50 has a hollow part 51 that passes through the fixed part 50 in the Z-axis direction. Inside the hollow portion 51, one end 64 of the bus bar 6 in the length direction is exposed. A portion of the pressure sensor 2 is housed below the hollow portion 51, that is, each terminal 21 is exposed. Thereby, each terminal 21 of the pressure sensor 2 and the bus bar 6 electrically connected to each terminal 21 can be protected, and more reliable electrical connection between the bus bar 6 and the pressure sensor 2 is possible.

Furthermore, the case 5 includes a connector portion 52 that continuously extends from the fixing portion 50. The connector portion 52 includes a recess 521 into which the external connector is inserted from the negative side in the X-axis direction. Inside the recess 521, the other end 65 of the bus bar 6 in the length direction is exposed. This enables electrical connection with the external connector with a simple configuration.
The case 5 is preferably made of resin. Thereby, the weight of the sensor unit 1 as a whole can be reduced. Note that the resin material constituting the case 5 is not particularly limited, and for example, polyester such as polybutylene terephthalate can be used.

A cap 8 is removably attached to the fixed part 50 of the case 5. The cap 8 includes a plate portion 81, a protrusion portion 82 that protrudes from the plate portion 81 downward in the thickness direction, that is, toward the negative side in the Z-axis direction, and a side wall that protrudes in the thickness direction along the edge of the plate portion 81. 83.
The plate part 81 can cover the hollow part 51 of the fixing part 50 from above when the cap 8 is attached to the fixing part 50 of the case 5 (hereinafter referred to as the "attached state"). This makes it possible to prevent short-circuits between the terminals 21 and malfunction of the pressure sensor 2 due to foreign matter such as dust entering the hollow portion 51 .

Further, within the hollow portion 51, the plate portion 81 of the cap 8 and one end portion 64 of the bus bar 6 are separated from each other, that is, are in a non-contact state. Thereby, for example, even if the pressure sensor 2 moves slightly in the Z-axis direction due to pressure fluctuations in the fluid Q passing through the flow path 201, the one end portion 64 of the bus bar 6 can deform to follow this movement. At this time, since the plate portion 81 is spaced apart from the one end portion 64, deformation of the one end portion 64 can be allowed. Thereby, the state of electrical connection between the bus bar 6 and each terminal 21 can be suitably maintained.

The protrusion 82 is composed of an elastic piece that can be elastically deformed. In the attached state, the protrusion 82 comes into contact with the outer wall of the fixing part 50, thereby fixing the cap 8 to the fixing part 50. This makes it possible to more reliably prevent the cap 8 from coming off the fixing part 50, thereby preventing the inside of the hollow part 51 from being exposed inadvertently, and thereby reliably protecting the inside of the hollow part 51. Can be done.

Further, the protruding portion 82 made of an elastic piece is provided with a through hole 821 that penetrates in the thickness direction. The through hole 821 can be caught by a claw 501 provided protruding from the outer wall of the fixing part 50. Due to the synergistic effect of the hooking of the through hole 821 with the claw 501 and the contact of the protrusion 82 with the fixed part 50, it is possible to prevent the cap 8 from detaching from the fixed part 50 more reliably. Note that it is preferable that the protruding amount of the claw 501 gradually increases downward, and that the claw 501 has a wedge-like shape when viewed from the X-axis direction.

The side wall portion 83 contacts the outer wall portion (outer peripheral side) of the fixing portion 50 in the attached state. As a result, the fixing force of the cap 8 to the fixing part 50 is increased by the side wall part 83, so that the cap 8 can be prevented from coming off from the fixing part 50 more reliably.
Furthermore, the side wall portion 83 increases the area of the cap 8 that covers the fixing portion 50, making it possible to more reliably prevent foreign matter from entering the hollow portion 51.
Note that the amount of downward protrusion of the side wall portion 83 is smaller than the amount of downward protrusion of the protruding portion 82 in this embodiment, but is not limited thereto; for example, the amount of downward protrusion of the side wall portion 83 is equal to or may be larger than the amount of downward protrusion of the protrusion 82.

Like the case 5, the cap 8 is also preferably made of resin. Thereby, together with the case 5, the weight of the sensor unit 1 as a whole can be reduced. Note that the resin material constituting the cap 8 is not particularly limited, and for example, the same resin material as the case 5 can be used.

As shown in FIGS. 1 to 3, a bracket 3 is placed above the pressure sensor 2. As shown in FIGS. The bracket 3 is composed of a long plate member extending in the X-axis direction. The bracket 3 can press the pressure sensor 2 downward, that is, against the body 20, with the thickness direction parallel to the Z-axis direction.
The bracket 3 has a sensor hole 31 (see FIG. 4) and two bolt holes 32.

The sensor hole 31 is a circular hole that penetrates in the Z-axis direction and into which the pressure sensor 2 is inserted and attached from below. Furthermore, the flange portion 22 of the pressure sensor 2 comes into contact with the edge of the sensor hole 31 . As shown in FIG. 3, when the bracket 3 is fixed to the body 20 via the bolt 30, the pressure sensor 2 can be pressed against the body 20. Thereby, the pressure detection element 24 of the pressure sensor 2 can receive force from the fluid Q.

Further, as shown in FIG. 4, one end portion 64 of the bus bar 6 is exposed from the sensor hole 31. As a result, when electrically connecting the bus bar 6 to each terminal 21 of the pressure sensor 2, the bus bar 6 and each terminal 21 can be viewed from above through the hollow part 51, and therefore the electrical connection work can be easily performed. It can be done more easily.

The two bolt holes 32 are arranged on both sides in the X-axis direction with the sensor hole 31 interposed therebetween. Each bolt hole 32 is a circular hole that penetrates in the Z-axis direction and into which the bolt 30 is inserted from above. As shown in FIG. 3, the male screw 301 of the bolt 30 inserted into each bolt hole 32 is fastened to the female screw 204 provided in the body 20. Thereby, the bracket 3 can be fixed to the body 20. The number of bolt holes 32 arranged is two in this embodiment, but is not limited to this, and may be three or more, for example. Further, the bolt 30 preferably has a thread size of M5 or more and M10 or less, and more preferably M6 or more and M8 or less.

Note that the constituent material of the bracket 3 is not particularly limited, and for example, a metal material such as stainless steel, the same resin material as the case 5, etc. can be used.
Further, in the sensor unit 1, the bracket 3, bus bar 6, and case 5 are preferably integrally molded by insert molding. Thereby, the sensor unit 1 can be easily manufactured.

Further, as shown in FIG. 2, the thickness direction of the bracket 3 and the length direction of the bus bar 6 are perpendicular to each other. Thereby, compared to a configuration in which the thickness direction of the bracket 3 and the length direction of the bus bar 6 are the same, for example, the sensor unit 1 can be made smaller, particularly in the height direction.

The positioning part 4 is a part that positions the bracket 3 with respect to the body 20 in the XY plane direction, around the X axis, around the Y axis, and in the directions around the pressure sensor 2 (around the Z axis).
For example, if the positioning part 4 is omitted, the position and attitude of the bracket 3 with respect to the body 20 may change depending on the skill of the assembler or the like who assembles the sensor unit 1. If the position or attitude of the bracket 3 with respect to the body 20 changes depending on the assembly worker, the bracket 3 may not be positioned accurately and the pressure sensor 2 may not be able to be pressed uniformly against the body 20 with the bracket 3. If the pressure sensor 2 is not pressed evenly, the measured pressure may be inaccurate.
On the other hand, in the sensor unit 1, the bracket 3 is accurately positioned with respect to the body 20 by the positioning part 4, so that the edge of the sensor hole 31 is not displaced with respect to the flange part 22 of the pressure sensor 2. Since the pressure sensor 2 can be pressed against the body 20 evenly, the pressure sensor 2 can be pressed against the body 20 evenly. This allows the pressure sensor 2 to perform accurate measurements.

As shown in FIGS. 1 and 2, in this embodiment, the positioning part 4 has two positioning holes 33 penetrating the bracket 3 in the Z-axis direction, and a positioning pin 41 press-fitted into each positioning hole 333. . This allows the positioning section 4 to have a simple configuration.
The two positioning holes 33 are arranged on both sides in the X-axis direction with the sensor hole 31 interposed therebetween. That is, the sensor hole 31 is arranged between the two positioning holes 33. This allows the two positioning holes 33 to be separated as much as possible, thereby improving the positioning accuracy of the bracket 3 with respect to the body 20.

Although the positioning section 4 has two positioning holes 33, the number of positioning holes 33 is not limited to two, and may be one or three or more, for example.
Further, the diameter of each positioning hole 33 is preferably, for example, 3 mm or more and 8 mm or less, and more preferably 5 mm or more and 6 mm or less.
Further, each positioning hole 33 is a through hole that penetrates the bracket 3 in this embodiment, but is not limited to this, and may be a non-through hole that extends halfway in the thickness direction of the bracket 3.

A positioning pin 41 is press-fitted into each positioning hole 33 . As a result, each positioning pin 41 is in a state of protruding downward. Then, as shown in FIG. 1, each positioning pin 41 is inserted into a positioning hole 205 provided in the body 20 and fitted together. Thereby, the bracket 3 can be accurately positioned with respect to the body 20 in the XY plane direction, around the X axis, around the Y axis, and in the directions around the pressure sensor 2. Note that the fit between the positioning pin 41 and the positioning hole 205 is preferably a "loose fit".

In addition, although the positioning part 4 has the structure which has the positioning hole 33 and the positioning pin 41 in this embodiment, it is not limited to this, and the positioning pin 41 may be abbreviate|omitted. When the positioning pin 41 is omitted, the body 20 is provided with a positioning pin that is inserted into the positioning hole 33 and fitted.

Further, in the positioning part 4, although the positioning pin 41 is configured separately from the bracket 3 in this embodiment, the positioning pin 41 and the bracket 3 are not limited to this and may be configured as a single member. good.
Moreover, in this embodiment, the positioning part 4 is arranged between the two bolt holes 32. This provides an effective configuration, for example, when it is desired to arrange the positioning section 4 close to the sensor hole 31.

As shown in FIGS. 4 and 5, a deformable portion 61 is provided at each one end portion 64 of the bus bar 6 located within the hollow portion 51 of the case 5. As shown in FIGS. Each deformed portion 61 extends in a direction intersecting the thickness direction (Z-axis direction) of the bracket 3, that is, in a direction parallel to the XY plane, and is a portion where the center line O6 of the bus bar 6 is curved or bent and deformed. . Further, as shown in FIGS. 4 and 6, each deformed portion 61 can be contacted by the terminal 21 within the hollow portion 51.

Each deformable portion 61 is provided in the current supply bus bar 6A, the ground bus bar 6B, and the output bus bar 6C, but since they have the same configuration, one deformable portion 61 will be representatively explained below.
The deformed portion 61 has a waveform when viewed from the Z-axis direction, and has a plurality of peaks PK61 corresponding to "peaks" or "troughs" of the waveform. Note that the number of peaks PK61 formed is not particularly limited and is arbitrary as long as it is two or more. Furthermore, the deformed portion 61 has a waveform when viewed from the Z-axis direction (in plan view), but is not limited to this; for example, when viewed from one direction in the XY plane (in side view), the deformed portion 61 has a waveform. You can leave it there.

When pressure sensor 2 receives external force from fluid Q, depending on the magnitude of the external force, it may vibrate (move) in the Z-axis direction and press one end 64 excessively in the Z-axis direction. be. When the one end portion 64 is excessively pressed in the Z-axis direction, it bends (deforms) and tries to eliminate the stress (internal stress), but the deforming portion 61 is omitted, that is, the shape is straight. If it does, it will not be able to bend sufficiently, and as a result, the stress will not be relieved. If such a phenomenon is repeated, metal fatigue will accumulate in the one end portion 64, and there is a possibility that damage or breakage will occur eventually. If one end portion 64 is damaged or broken, it becomes difficult to exchange signals via the bus bar 6.

In contrast, in the sensor unit 1, the bus bar 6 is provided with a deformable portion 61. The deformable portion 61 can be extended in the longitudinal direction by the waveform, and therefore can be sufficiently bent in the Z-axis direction. Thereby, the deformable portion 61 can exhibit a function of alleviating the stress generated at the one end portion 64 when the pressure sensor 2 receives an external force from the fluid Q. The stress relaxation function of the deformable portion 61 can prevent unreasonable force from acting on the one end portion 64, thereby preventing damage or breakage due to accumulation of metal fatigue.

Further, as described above, the bus bar 6 includes a current supply bus bar 6A, a grounding bus bar 6B, and an output bus bar 6C. The deformable portion 61 is provided in each of the current supply bus bar 6A, the ground bus bar 6B, and the output bus bar 6C. As a result, it is possible to prevent excessive force from acting on any of the current supply bus bar 6A, the ground bus bar 6B, and the output bus bar 6C, thereby preventing damage or breakage, and the pressure sensor 2 is It can operate stably.

As shown in FIG. 5, the deformable portion 61 is supported on both sides inside the case 5 (fixed portion 50). As a result, the deformable portion 61 is stably arranged within the hollow portion 51, and the stress relaxation function can be fully exhibited. In this specification, "supported on both sides inside the case 5 (fixed part 50)" means that both ends of the deformed part 61 are fixed at at least two parts inside the fixed part 50 indicated by the two-dot chain line. This means a state in which it is fixed to two portions of the inner wall portion of the portion 50 that are in contact with the hollow portion 51.
As shown in FIG. 4 , the deformed portion 61 has an enlarged width portion 62 in a portion where the terminal 21 comes in contact with the expanded width and is larger than the diameter of the terminal 21 . Further, the widened portion 62 is arranged between adjacent peaks PK61. Further, even if the pressure sensor 2 receives an external force from the fluid Q and the deformable portion 61 is bent, the widened portion 62 can stably maintain the electrical connection between the pressure sensor 2 and the bus bar 6.

Further, as shown in FIGS. 4 and 5, a through hole 66 is formed in the bus bar 6 at a portion located within the hollow portion 51 of the case 5. As shown in FIGS. The through hole 66 is used when integrally molding the bracket 3, bus bar 6, and case 5 by insert molding, and like the deformed portion 61, it also contributes to stress relaxation.

Although the sensor unit of the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to this, and each part constituting the sensor unit may have any configuration that can perform the same function. can be replaced with Moreover, arbitrary components may be added.

Further, the bracket 3 may have two bolt holes 32 arranged between two positioning holes 33.
Further, in the bracket 3, the bolt holes 32 and the positioning holes 33 may be arranged alternately along the longitudinal direction of the bracket 3.
Further, the terminal 21 of the pressure sensor 2 and the bus bar 6 may be joined by, for example, laser welding or the like.

DESCRIPTION OF SYMBOLS 100... Pressure control device, 1... Sensor unit, 2... Pressure sensor, 21... Terminal, 22... Flange part, 23... Sensor body, 24... Pressure detection element, 3... Bracket, 31... Hole for sensor, 32... For bolt Hole, 33... Positioning hole, 4... Positioning part, 41... Positioning pin, 5... Case, 50... Fixed part, 501... Claw, 51... Hollow part, 52... Connector part, 521... Recessed part, 6... Bus bar, 6A... Current supply bus bar, 6B...Grounding bus bar, 6C...Output bus bar, 61...Deformation part, 62...Wide width part, 64...One end part, 65...Other end part, 66...Through hole, 8...Cap, 81...Plate Part, 82...Protrusion, 821...Through hole, 83...Side wall, 20...Body, 201...Flow path, 202...Side hole, 204...Female thread, 203...Packing, 30...Bolt, 301...Male thread, O6...Center Line, PK61...Peak, Q...Fluid

Claims (6)

A sensor unit used by being installed in a body having a flow path through which fluid can pass,
a case having a hollow part;
a pressure sensor that is housed in the hollow part, has a terminal, and detects the pressure of the fluid passing through the flow path;
a plate-shaped bracket that presses the pressure sensor against the body;
a plurality of bus bars electrically connected to the terminal,
The plurality of bus bars extend in a direction intersecting the thickness direction of the bracket, are in contact with the terminals, and have a deformed part in which the center line of the bus bar is curved or bent and deformed,
The deformed portion has a waveform,
The sensor unit is characterized in that the deformable portion is allowed to deform within the hollow portion . The sensor unit according to claim 1 , wherein the deformed portion has an enlarged width portion in a portion where the terminal contacts. The sensor unit according to claim 2 , wherein the widened portion is arranged between adjacent peaks of the waveform. The sensor unit according to claim 1, wherein the deformable portion is supported on both sides by the case. The sensor unit according to any one of claims 1 to 4 , wherein the deformable portion has a function of relieving stress generated in the bus bar when the pressure sensor receives an external force from the fluid. The bus bar is disposed on the opposite side of the body with respect to the pressure sensor, is electrically connected to the pressure sensor, and is used for supplying current to the pressure sensor;
a grounding bus bar disposed on the opposite side of the body with respect to the pressure sensor, electrically connected to the pressure sensor, and used for grounding the pressure sensor;
6. An output bus bar according to claim 1, further comprising an output bus bar disposed on the opposite side of the body with respect to the pressure sensor, electrically connected to the pressure sensor, and used for outputting the pressure sensor. sensor unit.

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