JP4281200B2 - Pressure detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure detection device suitable for use in electronic control of a vehicle engine, for example.
[0002]
[Problems to be solved by the invention]
For example, when performing electronic control of a gasoline engine car, an intake pressure sensor for detecting the pressure in the intake pipe after the throttle valve to indirectly determine the intake air amount, and a pressure drop (decrease in oxygen amount) due to altitude are detected. Thus, two pressure sensors including an atmospheric pressure sensor for correcting the fuel injection amount are used. FIG. 7 shows an arrangement state of both pressure sensors in a conventional vehicle (automobile).
[0003]
That is, in the engine room 1 of the vehicle, an engine 2, an intake pipe 3 for sucking air into the engine 2, a throttle body 4, a surge tank 5 and the like are provided. An intake pressure sensor 6 is attached to the throttle body 4 portion. Although not shown, the intake pressure sensor 6 is configured by disposing a pressure sensor module including a semiconductor pressure sensor or the like in a package, as is well known.
[0004]
On the other hand, an ECU (Electric Control Unit) 8 for controlling the fuel injection amount of the engine is provided in the passenger compartment 7, and an atmospheric pressure sensor 9 is built in the ECU 8. In this case, the atmospheric pressure sensors are conventionally roughly classified into a stand-alone type mounted on the chassis body in the engine room 1 and an IC type built in the ECU 8. Then, an IC type atmospheric pressure sensor 9 that matches the requirements for small size and low cost is the mainstream.
[0005]
By the way, in recent years, it has been considered that the mounting position of the ECU 8 is changed from the interior of the vehicle compartment 7 to the interior of the engine compartment 1 in order to reduce the harness cost. In this case, in order to prevent the ECU 8 from being exposed to water, a sealed structure such as placing the ECU 8 in a dedicated box is required. However, if the airtight structure of the ECU 8 is to be achieved in this way, the above-described IC type atmospheric pressure sensor 9 cannot detect the atmospheric pressure, so it must go back to the times and return to the stand-alone type atmospheric pressure sensor. As a result, there is a problem that goes against the demands for downsizing and cost reduction.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pressure detection device that can detect two kinds of pressures and can be small and inexpensive.
[0007]
[Means for Solving the Problems]
A pressure detection device according to a first aspect of the present invention is disposed in an engine room of a vehicle for engine control, and includes an intake pressure sensor module for detecting intake pressure of the engine and a large amount in one package. An atmospheric pressure sensor module for detecting atmospheric pressure is assembled in two upper and lower stages, and a pressure introduction path for detecting atmospheric pressure is formed in a partition wall that vertically separates the two pressure sensor modules. Further, the present invention is characterized in that a connector part for external connection is provided in the package in a form in which a part of the terminal is shared by two pressure sensor modules. As a result, it is possible to detect two types of pressure, and it is possible to reduce the size and cost.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to engine control of a vehicle will be described with reference to FIGS. First, FIG. 5 schematically shows a specific example of where the pressure detection device 11 according to the present embodiment is mounted with respect to the vehicle (gasoline engine vehicle) 12. Here, the vehicle 12 has an engine room 13 at the front portion and a vehicle compartment 14 at the rear side thereof. In addition to the engine 15, the engine room 13 has air in the engine 15. An intake pipe 16, a throttle body 17, a surge tank 18 and the like are provided.
[0011]
The pressure detection device 11 according to the present embodiment is disposed in the throttle body 17 and detects the pressure (intake pressure) in the intake pipe 16 after the throttle valve and also detects the atmospheric pressure. ing. The pressure detecting device 11 is connected to an engine control ECU (Electoronic Control Unit) 19 disposed in the engine room 13 via a connector harness (not shown), and detection signals of intake pressure and atmospheric pressure are received. It is input to the ECU 19.
[0012]
The ECU 19 performs various controls of the engine 15 centering on the fuel injection amount based on signals from the pressure detection device 11 and signals from other various sensors. The ECU 19 is arranged in a state of being housed in a dedicated box and having a sealed structure.
[0013]
Now, the pressure detection device 11 will be described with reference to FIGS. FIGS. 1 and 2 show the overall configuration of the pressure detection device 11. This pressure detection device 11 includes an atmospheric pressure sensor module 21 and an intake pressure sensor module 22 in one plastic package 20, for example. Each pressure sensor module is constructed in two upper and lower stages.
[0014]
The package 20 is configured by connecting a lower lid portion 24 to a package body 23. As shown in FIG. 3, the package body 23 has a rectangular box shape with both upper and lower sides opened, and has a partition wall portion 25 that divides the interior vertically at an intermediate portion in the height direction. Thus, in the package main body 23, there are provided an upper accommodating portion 23a for accommodating an atmospheric pressure sensor module 21 described later and a lower accommodating portion 23b for accommodating an intake pressure sensor module 22 described later. Further, the right end side in the figure of the partition wall portion 25 is thickened up and down, so that the upper and lower surfaces thereof are terminal arrangement portions 25a and 25b.
[0015]
An atmospheric pressure introduction path 26 as a pressure introduction path is formed in the partition wall portion 25. This atmospheric pressure introduction path 26 extends left and right in the partition wall 25 and has a base end side (right end side in the figure) opened to the upper accommodating portion 23a. As shown in FIG. An opening is formed on the left side surface, which is a portion other than the upper surface of the main body 23 (package 20), and serves as an air introduction port 26a.
[0016]
Further, a connector portion 27 for external connection protruding rightward is provided on the right side wall portion in the figure of the package body 23. This connector part 27 is comprised from the housing 27a integrally formed in the package main body 23, and the terminal 28 integrally provided in the package main body 23 by insert molding. At this time, the terminal 28 is provided with a total of six on the base end side, three on the upper surface of the terminal arrangement portion 25a and three on the lower surface of the terminal arrangement portion 25b. Each of the upper and lower two terminals (Vcc and GND terminals shown in FIG. 4) is made common, and the front end side (inside the housing 27a) has 4 pins.
[0017]
The lower lid portion 24 is configured to integrally close a lower surface opening of the package main body 23 (lower housing portion 23b) and have a cylindrical intake port 29 protruding downward on the lower surface side. An intake pressure introduction path 29a as a pressure introduction path is formed in the intake port 29 so as to extend in the vertical direction, and an upper end portion of the intake pressure introduction path 29a is open to the lower housing part 23b. An O-ring 30 is provided on the outer peripheral surface of the intake port 29.
[0018]
On the other hand, the atmospheric pressure sensor module 21 is configured by mounting a known pressure sensor chip 32 facing the opening in a thin rectangular box-shaped case 31 having an opening on the lower surface. Although not shown in detail, the pressure sensor chip 32 is configured by forming a diaphragm portion on a single crystal silicon substrate and forming a detection circuit in which a piezoresistive element is bridge-connected on the upper surface portion.
[0019]
The terminals of the detection circuit are connected to three electrodes 33 provided on the case 31 by bonding wires, and the three electrodes 33 are provided so as to protrude from the right side surface of the case 31. Further, in order to protect the pressure sensor chip 32 and the electrode 33 and the bonding wire connecting them, the surface portion is covered with a parylene film 34 (deposition film), and the pressure sensor chip 32 and the electrode inside the case 31 are covered. 33. Fluorosilicone gel 35 is applied to the surface of the bonding wire, so that a double protective structure (protective film) is provided.
[0020]
The atmospheric pressure sensor module 21 configured as described above is provided in the upper housing portion 23 a with the lower end portion of the case 31 being hermetically bonded to the upper surface of the partition wall portion 25 of the package 20. At this time, the pressure sensor chip 32 faces the base end of the atmospheric pressure introduction path 26 and detects the pressure (atmospheric pressure) introduced from the atmospheric pressure introduction path 26.
[0021]
Further, the three electrodes 33 (Vcc, Vout1, GND shown in FIG. 4) are connected to the base end portions of the three terminals 28 arranged on the upper surface of the terminal arrangement portion 25a by, for example, welding. It has become. Further, the upper housing portion 23a is filled with a protective member 36 made of, for example, dimethyl silicone rubber having resistance to heat and humidity. In the present embodiment, on the side of the upper housing portion 23a, the package is completed by the protective member 36, and the resin lid on the upper surface of the package body 23 is omitted.
[0022]
On the other hand, in the intake pressure sensor module 22, as in the atmospheric pressure sensor module 21, a pressure sensor chip 38 is disposed in a case 37 having an opening on the lower surface, and is electrically connected to an electrode 39 by a bonding wire. The double protective structure by the parylene film 40 and the fluorosilicone gel 41 is provided. The intake pressure sensor module 22 is provided in the lower housing portion 23 b in a state where the upper surface portion of the case 37 is in close contact with the lower surface of the partition wall portion 25 of the package 20. At this time, the pressure sensor chip 38 faces the upper end portion of the intake pressure introduction passage 29a and detects the intake pressure introduced from the intake port 29.
[0023]
The three electrodes 39 (Vcc, Vout2, GND shown in FIG. 4) are connected to the base end portions of the three terminals 28 arranged on the lower surface of the terminal arrangement portion 25b, for example, by welding. It has become. In this case, as shown in FIG. 4, the Vcc and GND terminals 28 are made common to both pressure sensor modules 21 and 22, and four terminals 28 of Vcc, Vout 1, GND, and Vout 2 are provided in the connector portion 27. Will be provided. Further, the lower housing portion 23b is filled with a protective member 42 made of fluororubber having resistance (chemical resistance) to, for example, gasoline and oil.
[0024]
Here, a procedure for assembling the pressure detecting device 11 having the above configuration will be briefly described with reference to FIG. First, as shown in FIG. 3A, with the package body 23 turned upside down, the intake pressure sensor module 22 is set in a positioning state on the lower surface (upper surface in the figure) of the partition wall portion 25, and the three The electrodes 39 are welded to the base end portions of the terminals 28, respectively. Then, the protective member 42 is filled in the lower housing portion 23b and cured, so that the connection portion between the electrode 39 and the terminal 28 is embedded.
[0025]
Next, as shown in FIG. 3B, the package body 23 is turned upside down to be in a normal state, and the atmospheric pressure sensor module 21 is attached to the upper surface of the partition wall 25 at the lower end of the case 31. Then, the adhesive is cured after the three electrodes 33 are welded to the proximal end portions of the terminals 28, respectively. Then, as shown in FIG. 1, the lower lid 24 is temporarily bonded to the lower surface of the package body 23 with an adhesive, and the protective member 36 is embedded in the upper housing 23a to bury the connection between the electrode 33 and the terminal 28. Fill to fill. Thereafter, the pressure detecting device 11 is completed by curing the adhesive and the protective member 36.
[0026]
Next, the operation of the above configuration will be described. The pressure detection device 11 configured as described above is disposed in the throttle body 17 portion of the engine room 13 of the vehicle 12 as described above. At this time, the intake port 29 is connected directly to the throttle body 17 (or via a rubber hose or the like), and the pressure (intake pressure) in the intake pipe 16 passes through the intake pressure introduction passage 29a to the intake pressure sensor module 22 portion. be introduced. On the other hand, the air inlet 26 a at the tip of the atmospheric pressure introduction path 26 is open to the atmosphere on the side surface of the package 20, and atmospheric pressure is introduced into the atmospheric pressure sensor module 21 through the atmospheric pressure introduction path 26.
[0027]
Then, when the connector harness is connected to the connector portion 27, the pressure detection device 11 is electrically connected to the ECU 19. Thus, the intake pressure sensor module 22 detects the intake pressure in the intake pipe 16 and the detection signal is input to the ECU 19, and the atmospheric pressure sensor module 21 detects the atmospheric pressure and the detection signal is input to the ECU 19. Is done. The ECU 19 controls the fuel injection amount of the engine 15 based on these signals.
[0028]
Although there is a situation where rainwater or the like enters the engine room 13, the atmospheric air introduction port 26 a of the atmospheric pressure introduction path 26 is open on the side surface, so that water or the like is introduced into the engine room 13 through the atmospheric pressure introduction path 26. Invading defects are prevented in advance. Further, since the upper surface side of the package 20 (upper housing portion 23a) is covered with a heat-resistant and moisture-resistant protective member 36, even if the resin lid is omitted, the atmospheric pressure sensor module 21 and its electrical connection are also provided. The part can be protected. The intake pressure sensor module 22 is covered with a chemical-resistant protective member 42, so that the intake pressure sensor 29 can be used even if the intake pressure introduction path 29a is exposed to the gas environment inside the engine 15. The module 22 and its electrical connection can be protected.
[0029]
Here, in the pressure detection device 11, the intake pressure sensor module 22 for detecting the intake pressure and the atmospheric pressure sensor module 21 for detecting the atmospheric pressure are assembled in one package 20 in two upper and lower stages. In other words, since the atmospheric pressure sensor is integrally incorporated in the intake pressure sensor, both the conventional intake pressure sensor 6 and the stand-alone atmospheric pressure sensor are separately incorporated in the engine room 13. Compared to the case, the overall size is small, and the arrangement space is small.
[0030]
In addition, the atmospheric pressure introduction path 26 is formed in the partition wall portion 25, in other words, the portion where the atmospheric pressure introduction path 26 is formed is also used as a partition wall that divides both the pressure sensor units 21 and 22. Therefore, compared with the case where the atmospheric pressure introduction path is formed in a portion other than the partition wall portion 25, a small size (thin shape) is sufficient. Since the atmospheric pressure introduction path 26 extending in the lateral direction is formed in the partition wall portion 25 extending in the horizontal direction, it is a matter of course that the atmospheric pressure introduction path 26 can be easily formed. Furthermore, since the resin lid on the upper surface of the package 20 is omitted, the overall size and thickness can be reduced from this point. Since some of the terminals 28 are shared in the connector portion 27 and 6 pins are reduced to 4 pins, the connector portion 27 can also be reduced in size and thickness.
[0031]
In addition, since the two pressure sensor modules 21 and 22 are assembled in one package 20 as described above, it is possible to reduce the cost compared to the case where separate sensors are provided. By reducing the number of pins, the total cost including the connector harness member can be reduced. Further, the above-described protective member 36 and protective member 42 are also made of different materials, and the protective member 36 on the atmospheric pressure sensor module 21 side is different from the protective member 42 (fluoro rubber) on the intake pressure sensor module 22 side. Cost reduction can also be achieved by using dimethyl silicone rubber that is less expensive.
[0032]
As described above, according to this embodiment, the pressure detection device 11 capable of detecting both the intake pressure and the atmospheric pressure necessary for engine control can be provided in a small size and at a low cost. 6 can be mounted in a space-saving manner as it is. As a result, the sensor for detecting the intake pressure and the atmospheric pressure can be reduced in size and the cost can be reduced, and the request for changing the mounting position of the ECU 19 from the passenger compartment 14 to the engine compartment 13 can be sufficiently met. It is something that can be done.
[0033]
FIG. 6 shows a configuration of a pressure detection device 51 according to another embodiment of the present invention. This pressure detection device 51 is different from the pressure detection device 11 of the above embodiment in the configuration of the atmospheric pressure introduction path 53 formed in the package 52. That is, in this embodiment, the left side wall portion 54a of the package body 54 is formed thick, the atmospheric pressure introduction path 53 extends to the left side of the partition wall portion 55, and is folded at the middle portion of the left side wall portion 54a. It is arranged to be bent and extend downward. According to this, since the air introduction port 53a of the atmospheric pressure introduction path 53 is opened downward, it is possible to more effectively prevent water or the like from entering the inside.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view of a pressure detection device according to an embodiment of the present invention. FIG. 2 is a perspective view showing an external appearance of the pressure detection device. FIG. 4 is a diagram showing an electrical connection relationship of terminals. FIG. 5 is a diagram for explaining a mounting position of a pressure detection device in a vehicle. FIG. 6 is a diagram showing another embodiment of the present invention. Equivalent figure [Fig. 7] Fig. 5 equivalent diagram showing the conventional example [Explanation of symbols]
In the drawings, 11 and 51 are pressure detection devices, 12 is a vehicle, 13 is an engine room, 15 is an engine, 17 is a throttle body, 19 is an ECU, 20 and 52 are packages, and 21 is an atmospheric pressure sensor module (pressure sensor module). , 22 is an intake pressure sensor module (pressure sensor module), 23 and 54 are package bodies, 24 is a lower lid part, 25 and 55 are partition walls, 26 and 53 are atmospheric pressure introduction paths (pressure introduction paths), 26a, 53a is an air inlet, 27 is a connector, 28 is a terminal, 29 is an intake port, 29a is an intake pressure introduction path (pressure introduction path), 31 and 37 are cases, 32 and 38 are pressure sensor chips, and 36 and 42 are A protection member is shown.

Claims (1)

The engine is disposed in an engine room of the vehicle for engine control, and an intake pressure sensor module for detecting the intake pressure of the engine and an atmospheric pressure sensor module for detecting the atmospheric pressure are vertically arranged in one package. A pressure introduction path for detecting atmospheric pressure that opens to the side surface of the package is formed in a partition wall portion that divides the two pressure sensor modules up and down, and is connected to an external connection connector on the package. The pressure detecting device is characterized in that the portion is provided in a form in which a part of the terminal is shared by two pressure sensor modules .

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