JP2001148582A - Structure of waterproof electronic unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproof electronic unit, which is easily assembled, whose manufacture cost is low, whose deterioration of the detection characteristic of a pressure sensor accompanying the introduction of impurity is eliminated, and which withstands long-term use. SOLUTION: In a waterproof electronic unit, a pressure sensor which is loaded on a printed board and in which a pressure detection art is connected to a pressure introducing pipe is stored in a case, in which a waterproof connector is installed by filling it with mold resin. The case is constituted of a body and a cover body which is engaged with the upper part of the body and to which a pressure introducing pipe is shaped integrally. A dynamic pressure room connected to the pressure introducing pipe is installed on the filling face of molding resin on the inner side of the cover body. The structure of the waterproof electronic unit, where the pressure introducing part of the pressure sensor is exposed, is constituted in the dynamic pressure chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION An engine control unit (EC) utilizes a detection signal of a negative pressure in an intake manifold when a vehicle engine such as a motorcycle or an automobile is driven.
U) makes it possible to optimally control the combustion efficiency of the engine. Since this type of control unit is installed in an engine room where rainwater or washing water scatters, it is required to have a waterproof structure. The present invention relates to a structure of a waterproof electronic unit applied to an engine control unit or the like as described above, and more particularly to a waterproof structure in which a printed circuit board on which a pressure sensor is mounted is filled with a mold resin and housed in a sealed structure in a case. The present invention relates to the structure of a type electronic unit.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing the structure of a conventional apparatus. In FIG. 7, Un is a waterproof electronic unit.
Ca is a case of the waterproof electronic unit Un, Mo is a mold resin filled in the case Ca, and Pr is a printed circuit board. The case Ca is made in a pot shape without a lid. Co is a waterproof connector, Pi is a pressure introducing pipe inserted into the waterproof connector Co, Pj is an intermediate pipe, and Se is a pressure sensor.

The pressure sensor Se is mounted on the mounting surface of the printed circuit board Pr, and a lead wire (not shown) is connected via a waterproof connector Co to input and output an input / output current and voltage. The pressure introduction section at the tip of the pressure sensor Se is connected to the pressure introduction pipe Pi via the intermediate pipe Pj. Then, the printed circuit board Pr on which the pressure sensor Se and other electronic components constituting the signal processing circuit and the like are mounted is mounted inside the case Ca, and the waterproof performance is maintained by the mold resin Mo which is completely filled and surrounded. It is supposed to be.

[0004]

As described above, in the conventional waterproof electronic unit, the pressure introducing portion of the pressure sensor Se is connected via the intermediate pipe Pj so as to prevent pressure leakage. Therefore, there is a disadvantage that not only a troublesome manual work for connection is required but also the number of manufacturing steps is increased and the cost is increased. In order to avoid troublesome manual work, it is conceivable to omit the intermediate pipe Pj and extend the pressure introducing portion of the pressure sensor Se to extend outside the case Ca.

[0005] However, when a pressure guiding hose or tube is connected to the end of the extended pressure introducing portion, the moment applied to the pressure sensor Se mounted on the printed circuit board Pr is increased by the extension of the pressure introducing portion. Only increase. For this reason, there is a possibility that soldering of the pressure sensor Se mounted on the printed circuit board Pr may cause a failure, and reliability of electrical connection may not be secured. On the other hand, in a waterproof electronic unit such as an engine control unit that introduces intake negative pressure, there is a possibility that engine oil, gasoline, etc. may be introduced as impurities into the introduced negative pressure air. is there. If such impurities enter the inside of the pressure sensor Se together with the introduced air, there is a problem that the detection of the negative pressure by the pressure sensor Se becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional waterproof electronic unit, and realizes a waterproof electronic unit which is easy to assemble by reducing the number of parts and has a low manufacturing cost. It is something to do. Further, it is possible to realize a waterproof electronic unit that can prevent the inhalation of impurities sucked together with the introduced air from entering the pressure sensor Se, eliminate deterioration of the detection characteristics of the pressure sensor Se, and withstand long-term use. It is intended.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a pressure sensor mounted on a printed circuit board and having a pressure detecting portion connected to a pressure introducing pipe is filled in a case provided with a waterproof connector and filled with a molding resin. In the waterproof electronic unit, a case is fitted to a main body and an upper part of the main body, and a pressure introducing pipe is integrally molded, and a pressure introducing pipe is formed on a filling surface of the mold resin inside the lid. And a pressure-guiding chamber communicating with the pressure-guiding chamber, and a structure of a waterproof electronic unit in which a pressure introducing portion of a pressure sensor is exposed in the pressure-guiding chamber.
Further, in the above means 1, the waterproof electronic unit has a structure in which a rib for partitioning the pressure guiding chamber is provided on the inner surface of the lid. Further, in the above-mentioned means 1 or 2, the structure of the waterproof electronic unit in which the height of the lower end of the rib is set between the pressure introducing portion and the filling surface of the mold resin. Further, in any one of the above means 1 to 3, the structure of the waterproof electronic unit in which the crank portion is formed in the pressure guiding chamber by the rib is constituted.

Further, the present invention provides a waterproof case in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing tube is filled with a mold resin in a case provided with a waterproof connector and housed therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, This structure constitutes the structure of a waterproof electronic unit in which a pressure introducing portion of a pressure sensor is exposed in a pressure guiding chamber and an impurity storing portion is provided on a filling surface of a mold resin.

Further, the present invention provides a waterproof case in which a pressure sensor mounted on a printed circuit board and having a pressure detecting section connected to a pressure introducing pipe is filled with a mold resin in a case provided with a waterproof connector and accommodated therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, The structure of the waterproof electronic unit is configured such that the pressure introducing portion of the pressure sensor is exposed in the pressure guiding chamber and the introduction port of the pressure introducing portion is opened downward.

Further, the present invention provides a waterproofing device in which a pressure sensor mounted on a printed circuit board and having a pressure detecting portion communicated with a pressure introducing tube is filled with a mold resin in a case provided with a waterproof connector and housed therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, An inner cylinder surrounding the pressure lead-out part by immersing the lower end in the mold resin and providing a ventilation path leading to the pressure guide chamber at a position higher than the pressure lead-in part, exposing the pressure introducing part of the pressure sensor in the pressure guiding chamber. And a waterproof electronic unit having a double cylindrical rib having an outer cylinder whose lower end is set at a position higher than the filling surface of the mold resin.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is an explanatory diagram showing a configuration of Embodiment 1 of the present invention.
(A) is a plan view, and (b) is a partial cross-sectional view of (a). In the embodiment of the present invention, the same names are used for most of the members common to the above-described conventional device, but different reference numerals are used, and the members are described in some detail. FIG.
1A and 1B, reference numeral 1 denotes a waterproof electronic unit. Reference numeral 2 denotes a housing of the electronic unit 1. The housing 2 is formed in a square box shape by aluminum die casting, and includes a main body 3 and a lid 4.

The cover 4 has a structure in which the peripheral portion is fitted to the main body 3 and is connected to the upper portion of the main body 3 by closely fitting the fitting portion. Reference numeral 5 denotes a pressure introducing pipe, which is integrally formed on the upper surface of the lid 4. Reference numeral 6 denotes a storage chamber provided inside the main body 3, reference numeral 7 denotes a step formed in the storage chamber 6, and reference numeral 8 denotes a connector having a waterproof structure. Connectors 8 are male and female connectors 81, 8
2 and is disposed on a wall surface that partitions the inside and outside of the housing 2. The two connectors 81 and 82 are detachably connected by a plurality of pins insulated for each signal line.
2 is connected to an input / output conductor.

Reference numeral 9 denotes a printed circuit board fixed to the step 7 with screws or the like, and reference numeral 10 denotes a convex pressure sensor. The pressure sensor 10 is mounted on the mounting surface of the printed circuit board 9 together with other electronic components, and an inlet 11 is opened in the convex protrusion (see FIG. 2C). The inlet 11 extends into the pressure sensor 10 and communicates with the pressure detecting unit inside. The pressure detection unit is configured by, for example, a pressure receiving chamber provided with a pressure receiving element such as a diaphragm. 12 is a mold resin, 13 is a pressure guiding chamber formed inside the lid 4, and 14 is a hose or tube connected to the tip of the pressure introducing pipe 5. The mold resin 12 is injected into the housing chamber 6 of the main body 3 halfway,
The pressure introducing portion at the tip of the pressure sensor 10 is exposed inside the pressure guiding chamber 13.

The waterproof electronic unit 1 according to the first embodiment having the above-described configuration is assembled as follows. First, the printed circuit board 9 on which the pressure sensor 10 is mounted together with another circuit component is inserted into the housing 3 of the main body 3 integrated with the waterproof type connector 8 or the main body 3 to which the waterproof type connector 8 is mounted, It is fixed with fixing screws or adhesive.
The printed circuit board 9 fixed to the main body 3 in the accommodation room 6 is electrically connected to the waterproof connector 8. Combine this with a lid 4 made to fit with the body 3,
A housing 2 is made.

Next, the potting of the liquid mold resin 12, which is solidified by heating or the like, into the storage chamber 6 of the main body 3 is performed. The potting of the mold resin 12 into the storage chamber 6 is performed so that the exposed amount of the pressure introducing portion at the tip of the pressure sensor 10 becomes a predetermined height as shown in the figure. The casing 2 after the potting is heated or the like to solidify the injected mold resin 12. As a method of fitting the lid 4 to the upper portion of the main body 3 and connecting the two to the hermetically sealed structure, an exhaust hole and an injection hole are provided in the lid 4, and the two are joined by an adhesive or the like. A predetermined amount, and molding resin 1 after fitting the two.
There is a method of filling the gap with 2 and sealing by filling the gap, and both are possible.

The waterproof electronic unit 1 assembled in this manner is mounted in the above-described engine room of the vehicle. A hose 14 and the like communicating with the intake manifold of the engine are connected to the distal end of the pressure introducing pipe 5 of the attached waterproof electronic unit 1. The connection of the hose 14 allows the pressure detection unit inside the pressure sensor 10 to communicate with the inside of the intake manifold of the engine. The connector 8 is connected to input / output conductors for supplying power from sensors, control target devices, and batteries of various parts of the vehicle.

Here, when the vehicle engine is driven,
A negative pressure is generated in the intake manifold due to an intake action accompanying the reciprocating motion of the piston. The generated negative pressure is introduced into the pressure guiding chamber 13 inside the lid 4 through the connecting hose 14 and the pressure introducing pipe 5. The air pressure introduced into the pressure guiding chamber 13 is
Further, the pressure is transmitted to the pressure detecting unit inside the pressure sensor 10 and detected by the pressure receiving element. The detected air pressure signal is sent to a processing circuit on the printed circuit board 9 and is converted into an electric signal corresponding to the negative pressure in the intake manifold. The converted electric signal is output to the control device, and the control device utilizes the input electric signal to optimally control the engine.

Usually, such vehicles as motorcycles and automobiles run on roads and the like even in bad weather regardless of fine weather. Further, during maintenance such as during car washing or before vehicle inspection, the inside of the engine room may be washed with high-pressure washing water. Therefore, the electronic unit 1 installed in the engine room or the like is exposed to scattered rainwater, washing water, or the like. However, since the waterproof electronic unit 1 is enclosed in a hermetically sealed structure by the mold resin 12 in the housing 2 and has a literally waterproof structure, intrusion of rainwater, washing water, etc. into the housing 2 is completely completed. Will be blocked. If necessary, a sealing means such as an O-ring is provided at a fitting portion between the main body 3 and the lid 4 to further strengthen the waterproof structure.

In this case, in the first embodiment, since the pressure introducing pipe 5 for guiding the test air pressure to the pressure sensor 10 is formed integrally with the cover 4, the intermediate pipe Pj used in the conventional apparatus is not used. It becomes necessary and the number of parts can be reduced. Further, since the pressure introducing pipe 5 is formed integrally with the lid 4, there is no danger of damaging the soldering portion of the pressure sensor 10 as in the case where the pressure introducing pipe 5 of the conventional device is extended, which is uncertain. There is no inconvenience that lowers the reliability of the device due to the electrical connection. Further, since a troublesome connection work performed while taking into account air leakage through the intermediate pipe Pj can be omitted, there is an advantage that the number of steps is reduced and the cost is suppressed.

Embodiment 2 FIG. 2 is an explanatory view showing the configuration of Embodiment 2, in which (a) and (b) are a plan view and a sectional view similarly to FIG. 1, and (c) is a casing having a different shape. It is sectional drawing using a body. FIG. 2 is different from the first embodiment in that the second embodiment has a structure in which a rib 15 for partitioning the pressure guiding chamber 13 and regulating the volume and shape is provided. The rib 15 is formed on the inner surface of the lid 4 in a vertical direction. In FIG. 2, a pressure guiding chamber 13 having a small internal volume and communicating with the pressure introducing pipe 5 is formed. The lower end of the rib 15 is immersed in the mold resin 12 and surrounds the periphery of the pressure introducing portion of the pressure sensor 10.

Although the structure of the housing 2 is slightly different in FIG. 2 (c), the pressure guiding chamber 13 having a small volume is formed in principle in this modification as in FIGS. 2 (a) and 2 (b). In the second embodiment, the pneumatic circuit for introducing the pneumatic pressure including the pressure guiding chamber 13 has a small volume, the detection sensitivity of the pneumatic pressure is high, and the responsive waterproof electronic unit 1 can be realized. In the second embodiment, the common members having the same reference numerals as those in the first embodiment shown in FIG.

Embodiments 3 to 6 Other embodiments 3 to 6 are shown in FIGS. 3 to 5 except for FIG. 6, a plan view and a cross-sectional view are shown in FIGS. 3A and 3B, similarly to FIG.
As described above, impurities such as gasoline and oil may be introduced together with the negative pressure into the negative air pressure introducing circuit of this type of engine control unit. In the third to sixth embodiments shown in FIG. 3 and subsequent figures, the ribs 15, 18,... That partition the pressure guiding chamber 13 are used to introduce impurities introduced into the pressure guiding circuit into the pressure sensor 10 for some reason. This constitutes a waterproof electronic unit 1 that prevents (suppresses or blocks) intrusion.

In FIG. 3 showing the third embodiment, a rib 16 on the pressure introducing pipe 5 side is provided in the pressure guiding chamber 13 so as to be separated from the pressure sensor 10. Further, near the inlet of the pressure guiding chamber 13 near the pressure introducing pipe 5, a wider filling surface of the mold resin 12 than in FIG. 2 is formed. Then, the expanded filling surface is used as a storage section 17 for storing the impurities.
Therefore, when impurities such as oil heavier than air are introduced from the pressure introducing pipe 5, most of the impurities fall near the inlet of the pressure guiding chamber 13 and are stored in the storage unit 17. According to the third embodiment having such a configuration, the impurities introduced together with the air are stored in the storage portion 17 partitioned by the ribs 16, and the intrusion of the impurities into the pressure sensor 10 is substantially prevented.

FIGS. 4 and 5 showing the fourth and fifth embodiments.
In both figures, the ribs 18 and 19 have the same function as the rib 16 described above. The ribs 18 and 19 shown in FIGS. 4 and 5 face the flow direction of the air flow of the pressure introducing pipe 5, and
Each has a wall and a crank. And
When an impurity is introduced from the pressure introducing pipe 5 together with air, the impurity collides with the rib 18 in the pressure guiding chamber 13 and falls. Further, when impurities are introduced toward the rib 19, the impurity collides with the crank portion formed of the rib 19 in the pressure guiding chamber 13 and falls. In addition, some impurities fall after the introduction direction is changed to the horizontal direction along the crank portion, and all of the impurities are stored in the storage portion 17 as in FIG. 3 and indirectly enter the pressure sensor 10. Is prevented.

FIG. 6 is an enlarged sectional view showing a configuration of a main part according to the sixth embodiment of the present invention. In the sixth embodiment, a double cylindrical rib 21 surrounding the pressure introducing portion of the pressure sensor 10 is formed. 22 and 23 are an outer cylinder and an inner cylinder of the rib 21;
Are a plurality of ventilation holes provided in the inner cylinder and communicating with the pressure guiding chamber 13. As shown in the drawing, a gap is provided between the lower end of the outer cylinder 22 and the filling surface of the mold resin 12, and the lower end of the inner cylinder 23 is immersed in the mold resin 12. The vent hole 24 formed in the inner cylinder 23 is set at a position higher than the pressure introducing portion of the pressure sensor 10.

According to the sixth embodiment, the molding resin 12
Is formed at a depth corresponding to the height h from the filling surface to the vent hole 24, so that even if impurities
Even if the gas is introduced into the pressure sensor 3, the double cylindrical rib 21 prevents impurities from entering the pressure sensor 10. In addition, the pressure sensor 10
The pressure introduction portion may be formed in a U-shape and the introduction port is opened downward, so that intrusion of impurities into the pressure sensor 10 may be suppressed.

In the above-described embodiment of the present invention, the case of an aluminum die-cast housing has been described as an example. However, a resin material (for example, PB
T, PPS, ABS, etc.). Although the control unit for detecting the negative pressure of an engine for a vehicle such as an automobile has been described, the waterproof electronic device according to the present invention may be applied to, for example, marine equipment which is installed below the sea surface and detects air pressure corresponding to the water depth. Unit 1 can be applied. Also, the case where the pressure introducing pipe is integrally formed on the upper surface of the lid that fits into the upper part of the main body of the rectangular box-shaped housing has been illustrated and described.
The pressure introducing pipe may be formed on the side of the lid or the like, and the injection order of the mold resin, the number of ribs and cranks, and the like are not necessarily limited to the embodiment.

[0028]

According to the present invention, a pressure sensor mounted on a printed circuit board and having a pressure detecting section connected to a pressure introducing pipe is filled with a mold resin in a case provided with a waterproof connector and housed therein. In the type electronic unit, a case is formed by fitting a main body and an upper part of the main body to form a pressure introducing tube integrally formed with a lid, and a guide communicating with the pressure introducing tube on the filling surface of the mold resin inside the lid. The pressure chamber was provided, and the structure of the waterproof electronic unit in which the pressure introduction part of the pressure sensor was exposed in the pressure guiding chamber was configured. Further, in the above-described means 1, the structure of the waterproof electronic unit is provided in which a rib for partitioning the pressure guiding chamber is provided on the inner surface of the lid. Further, in the above-mentioned means 1 or 2, the structure of the waterproof electronic unit in which the height of the lower end of the rib is set between the pressure introducing portion and the filling surface of the mold resin is configured. Further, in any one of the above means 1 to 3, the structure of the waterproof electronic unit in which the crank portion is formed in the pressure guiding chamber by the rib is configured. As a result, an intermediate pipe as in the conventional device becomes unnecessary, and the number of parts can be reduced. Further, since the pressure introducing pipe is formed integrally with the lid, there is no possibility that the soldered portion of the pressure sensor is damaged and the reliability of the electronic unit is reduced. Further, since the connection work between the pressure introducing pipe, the intermediate pipe, and the casing is not required, the number of steps is reduced and the production cost can be kept low.

Further, the present invention provides a waterproofing device in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing pipe is filled with a mold resin in a case provided with a waterproof connector and housed therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, A pressure-introducing portion of the pressure sensor was exposed in the pressure-guiding chamber, and a structure of a waterproof electronic unit was provided in which a storage portion for impurities was provided on a filling surface of the mold resin.

Further, the present invention provides a waterproofing device in which a pressure sensor mounted on a printed circuit board and having a pressure detecting section connected to a pressure introducing pipe is filled with a mold resin in a case provided with a waterproof connector and housed therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, The structure of the waterproof electronic unit was constructed in which the pressure introduction part of the pressure sensor was exposed in the pressure guiding chamber and the introduction port of the pressure introduction part was opened downward.

Further, the present invention provides a waterproofing device in which a pressure sensor mounted on a printed circuit board and having a pressure detecting section connected to a pressure introducing tube is filled with a mold resin in a case provided with a waterproof connector and accommodated therein. Type electronic unit,
A case is formed on the main body and a lid body integrally molded with the pressure introducing pipe by fitting the upper part of the main body, and a pressure guiding chamber communicating with the pressure introducing pipe on the filling surface of the mold resin inside the lid body is provided, An inner cylinder surrounding the pressure lead-out part by immersing the lower end in the mold resin and providing a ventilation path leading to the pressure guide chamber at a position higher than the pressure lead-in part, exposing the pressure introducing part of the pressure sensor in the pressure guiding chamber. The waterproof electronic unit has a structure in which a double cylindrical rib having a lower end set at a position higher than the mold resin filling surface is provided on the inner surface of the lid. As a result,
Even if impurities such as oil are introduced into the pressure guiding chamber following the introduction of the test air pressure, most of the introduced impurities are formed on the filling surface of the mold resin by the ribs formed in the pressure guiding chamber. Will be stored in the department. For this reason, the intrusion of impurities into the pressure sensor is prevented, so that the detection of air pressure cannot be disabled.

Therefore, according to the present invention, it is possible to provide a waterproof electronic unit which is easy to assemble, has a low manufacturing cost, and can withstand long-term use without reducing the detection characteristics of the pressure sensor due to the introduction of impurities. Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a second embodiment.

FIG. 3 is an explanatory diagram showing a configuration of a third embodiment.

FIG. 4 is an explanatory diagram showing a configuration of a fourth embodiment.

FIG. 5 is an explanatory diagram showing a configuration of a fifth embodiment.

FIG. 6 is an enlarged sectional view showing a configuration of a main part of a sixth embodiment.

FIG. 7 is a cross-sectional view illustrating a configuration of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waterproof electronic unit 2 Housing 3 Main body 4 Lid 5 Pressure introducing pipe 6 Housing 7 Step 8 Connector 9 Printed circuit board 10 Pressure sensor 11 Inlet 12 Mold resin 13 Pressure guiding chamber 14 Hose (tube) 15,16, 18, 19, 21 Rib 17 Reservoir 22 Outer tube 23 Inner tube 24 Vent 81, 82 Male and female connectors

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeo Nomura 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. F-term (reference) 3J046 AA14 BB10 CA03 4E360 AB31 EA03 GA29 GB99

Claims (7)

[Claims] 1. A waterproof electronic unit in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing pipe is filled and housed in a mold resin in a case provided with a waterproof connector. The case comprises a main body and a lid which is fitted to the upper part of the main body to integrally form the pressure introducing pipe, and communicates with the pressure introducing pipe on the filling surface of the mold resin inside the lid. A structure of a waterproof electronic unit, wherein a pressure guiding chamber is provided, and a pressure introducing portion of the pressure sensor is exposed in the pressure guiding chamber. 2. The structure of the waterproof electronic unit according to claim 1, wherein a rib for partitioning the pressure guiding chamber is provided on an inner surface of the lid. 3. The structure of the waterproof electronic unit according to claim 1, wherein a height of a lower end of the rib is set between a pressure introducing portion and a filling surface of a mold resin. 4. The structure of a waterproof electronic unit according to claim 1, wherein a crank portion is formed in the pressure guiding chamber by the rib. 5. A waterproof electronic unit in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing pipe is filled with a mold resin and housed in a case provided with a waterproof connector. The case comprises a main body and a lid which is fitted to the upper part of the main body to integrally form the pressure introducing pipe, and communicates with the pressure introducing pipe on the filling surface of the mold resin inside the lid. A structure of a waterproof electronic unit, wherein a pressure guiding chamber is provided, a pressure introducing portion of the pressure sensor is exposed in the pressure guiding chamber, and an impurity storage portion is provided on a filling surface of the mold resin. 6. A waterproof electronic unit in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing pipe is filled and housed in a mold resin in a case provided with a waterproof connector. The case comprises a main body and a lid which is fitted to the upper part of the main body to integrally form the pressure introducing pipe, and communicates with the pressure introducing pipe on the filling surface of the mold resin inside the lid. A structure of a waterproof electronic unit, wherein a pressure guiding chamber is provided, a pressure introducing portion of the pressure sensor is exposed in the pressure guiding chamber, and an introduction port of the pressure introducing portion is opened downward. 7. A waterproof electronic unit in which a pressure sensor mounted on a printed circuit board and having a pressure detecting unit communicated with a pressure introducing pipe is filled and housed in a mold resin in a case provided with a waterproof connector. The case comprises a main body and a lid which is fitted to the upper part of the main body to integrally form the pressure introducing pipe, and communicates with the pressure introducing pipe on the filling surface of the mold resin inside the lid. A pressure guiding chamber is provided, and a pressure introducing portion of the pressure sensor is exposed in the pressure guiding chamber, and a ventilation path is provided at a position higher than the pressure introducing portion to communicate with the pressure guiding chamber. A double cylindrical rib comprising an inner cylinder surrounding the pressure deriving portion and an outer cylinder whose lower end is set at a position higher than the filling surface of the mold resin is provided on the inner surface of the lid. Waterproof electronic unit structure.