JP2010090809A - Internal combustion engine pressure detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect the combustion pressure generated in a cylinder. <P>SOLUTION: In this engine, the combustion pressure generated in the cylinder 10 is detected with the pressure sensor 50 arranged at a joining part of a cylinder head 20 and a cylinder block 30. To put it concretely, the pressure sensor 50 is arranged at a sensor notch 42 formed at a gasket member 41 put between the cylinder head 20 and the cylinder block 30. A communication notch 22 for providing communication between the inside of the cylinder 10 and the pressure sensor 50 with a space (pressure introduction port 23) without a restriction is formed on an opposing surface (lower surface) to the pressure sensor 50 at the cylinder head 20. Thus, the communication between the inside of the cylinder 10 and the pressure sensor 50 can be provided with a sufficiently large space. Then, the combustion pressure generated in the cylinder 10 can be accurately detected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine pressure detection device that detects a combustion pressure (in-cylinder pressure) generated in a cylinder of an internal combustion engine with a pressure sensor disposed at a joint between a cylinder head and a cylinder block.

Conventionally, it has been proposed to detect a combustion pressure generated in a cylinder in order to optimally control a combustion state such as ignition timing, emission, output, and fuel consumption in an internal combustion engine (engine). For example, Patent Document 1 discloses a structure in which a pressure sensor for detecting a combustion pressure is embedded in a gasket that is interposed in a joint portion between a cylinder head and a cylinder block in an internal combustion engine and seals both. In this structure, the pressure sensor detects the combustion pressure generated in the cylinder via the air passage that opens to a position facing the inner peripheral surface of the gasket.
JP 2003-20973 A

  However, in the structure described in Patent Document 1 described above, since a sufficiently large air passage cannot be formed on the inner peripheral surface of the gasket, the pressure receiving area of the pressure sensor is small, and the detection accuracy of the combustion pressure is reduced. It becomes a factor.

  The present invention has been made in view of these problems, and an object thereof is to provide a pressure detection device for an internal combustion engine that can accurately detect a combustion pressure generated in a cylinder.

  In order to achieve the above object, the internal combustion engine pressure detection device according to claim 1 of the present invention is similar to the configuration described in Patent Document 1 described above, and the combustion pressure generated in the cylinder of the internal combustion engine is a cylinder. It is detected by a pressure sensor arranged at the joint between the head and the cylinder block.

  The pressure detection device for an internal combustion engine according to claim 1 is similar to the configuration described in Patent Document 1 in the arrangement of the pressure sensor, and for the sensor formed in a gasket interposed between the cylinder head and the cylinder block. It is arranged at the notch. However, in the pressure detection device for an internal combustion engine according to claim 1, the cylinder and the pressure sensor communicate with each other in a space without a restriction on the surface facing the pressure sensor in one of the cylinder head and the cylinder block. A notch for communication is formed.

  For this reason, in the pressure detection device for an internal combustion engine according to the first aspect, compared with the configuration described in Patent Document 1, the inside of the cylinder and the pressure sensor can be communicated with each other in a sufficiently large space. As a result, the combustion pressure generated in the cylinder can be accurately detected. In particular, since the inside of the cylinder and the pressure sensor communicate with each other in a space without an aperture, it is possible to make it difficult to generate deposits (solids) called deposits. That is, if a constriction is formed in the space that communicates the inside of the cylinder and the pressure sensor, the combustion gas that has flowed from the inside of the cylinder is adiabatically expanded and easily cooled, and it is difficult for the combustion gas to flow into the cylinder and It becomes an environment where gas is solidified and deposits are easily generated. On the other hand, in a space without a restriction, the combustion gas flowing in from the cylinder easily flows out into the cylinder, and an environment in which deposits are not easily generated can be obtained.

  By the way, as a structure for arranging a pressure sensor in the notch part for sensors formed in the gasket, the structure which fixed the pressure sensor to the gasket as described in Claim 2, for example is mentioned. In this way, since the pressure sensor can be attached together with the gasket, the assembling work can be easily performed. Further, the communication line for outputting the detection value by the pressure sensor to the outside can be integrated with the gasket, and wiring work can be easily performed. The communication line may be embedded in the gasket or provided on the gasket surface. In the former case, there is an advantage that the original sealing function of the gasket can be hardly damaged. On the other hand, in the latter case, there is an advantage that the attachment work to the gasket becomes easy and an advantage that it becomes easy to find the disconnection of the communication line in the manufacturing process.

  Here, in the configuration in which the pressure sensor is fixed to the gasket, it is conceivable that the pressure sensor floats together with the gasket toward the notch for communication, and the accuracy of the detected pressure deteriorates.

  Therefore, for example, in the pressure detection device for an internal combustion engine according to claim 3, the pressure sensor is not formed with the communication cutout portion of the cylinder head and the cylinder block by the spring provided in the communication cutout portion. It is being pushed toward. According to such a pressure detection device for an internal combustion engine, it is possible to prevent the pressure sensor from being lifted to the communication notch portion side together with the gasket.

  On the other hand, as a configuration for disposing the pressure sensor in the sensor notch formed in the gasket, for example, as described in claim 4, the pressure sensor includes a communication notch for the cylinder head and the cylinder block. The structure fixed to the direction where is not formed is mentioned. According to such a pressure detection device for an internal combustion engine, the pressure sensor can be handled separately from the gasket.

  Next, the internal combustion engine pressure detection device according to the fifth aspect is similar to the internal combustion engine pressure detection device according to the first aspect in that the combustion pressure generated in the cylinder of the internal combustion engine is determined between the cylinder head and the cylinder block. It is detected by a pressure sensor arranged at the joint.

  However, in the pressure detection device for an internal combustion engine according to the fifth aspect, the pressure sensor is disposed in a sensor cutout portion formed on a surface facing one of the cylinder head and the cylinder block. And the notch part for a communication for connecting the inside of a cylinder and a pressure sensor in the space without a restriction | limiting is formed in the gasket interposed between a cylinder head and a cylinder block.

  That is, in the pressure detection device for an internal combustion engine according to claim 1, the space for communicating the inside of the cylinder and the pressure sensor is formed in the cylinder head or the cylinder block, whereas for the internal combustion engine according to claim 4. In the pressure detection device, it is formed in the gap between the cylinder head and the cylinder block. Therefore, the internal combustion engine pressure detection device according to claim 4 can achieve the same effect as the internal combustion engine pressure detection device according to claim 1.

  By the way, as a configuration for disposing the pressure sensor in the sensor cutout formed in the cylinder head or the cylinder block, the pressure sensor is provided in the communication cutout as described in claim 6, for example. The structure fixed with the spring is mentioned. If it does in this way, a pressure sensor can be fixed by simple work. Further, for example, as described in claim 7, there is a configuration in which the pressure sensor is fixed to the sensor notch with a screw. In this way, the pressure sensor can be fixed relatively firmly.

  On the other hand, in the configuration in which the pressure sensor is arranged in the sensor notch formed in the Linder head or the cylinder block in this way, the communication line for outputting the detection value by the pressure sensor to the outside is referred to as the cylinder head or the cylinder block. It is conceivable to perform wiring through a gasket. In this case, for example, as described in claim 8, if the communication line is configured to be separable by the connector, the assembling work can be easily performed as compared with the configuration incapable of being separated.

  For example, in the pressure detection device for an internal combustion engine according to claim 9, the pressure sensor includes a transmitter for wirelessly transmitting the detection value and a power generation element for generating electric power for driving the transmitter. According to such a pressure detecting device for an internal combustion engine, a complicated wiring work can be omitted, and therefore the assembling work can be easily performed. In addition, as a power generation element, a piezoelectric element, a thermocouple, etc. can be used, for example.

  Here, for example, if the receiver for receiving the detection value wirelessly transmitted from the transmitter is provided in the gasket as described in claim 10, the distance from the transmitter to the receiver can be shortened. Thus, the power required for wireless transmission can be reduced.

By the way, since the inside of the cylinder of the internal combustion engine becomes very high temperature, it is preferable that the pressure sensor is configured not to become high temperature.
For example, in the pressure detection device for an internal combustion engine according to claim 11, the pressure sensor causes the heat of the pressure sensor to escape to the cooling water flowing in the cooling water flow path formed inside the cylinder head or the cylinder block. It has. According to such a pressure detecting device for an internal combustion engine, the pressure sensor can be efficiently cooled using the cooling water.

  For example, in the pressure detection device for an internal combustion engine according to claim 12, the pressure sensor is provided at a position away from the fuel injection direction. According to such a pressure detection device for an internal combustion engine, it is possible to make the pressure sensor difficult to reach a high temperature as compared with the case where the pressure sensor is provided at a position close to the fuel injection direction. This is because the region where the fuel is injected becomes high temperature due to the occurrence of a flame.

  In this case, for example, if the pressure sensor is provided at a position close to the fuel injection direction in addition to the position away from the fuel injection direction, the cylinder is based on the detection values of the plurality of pressure sensors. It is possible to estimate the pressure distribution inside.

  Further, for example, in the pressure detection device for an internal combustion engine according to claim 14, the pressure sensor is provided at a position away from the glow plug. According to such a pressure detection device for an internal combustion engine, it is possible to make the pressure sensor difficult to reach a high temperature as compared with the case where the pressure sensor is provided near the glow plug. This is because the glow plug is hot and the vicinity of the glow plug is also hot.

  On the other hand, in the pressure detection device for an internal combustion engine according to claim 15, for example, a pressure sensor is provided for each of the plurality of cylinders of the internal combustion engine, and the pressure sensors of adjacent cylinders are arranged close to each other. According to such a pressure detection device for an internal combustion engine, communication lines of pressure sensors of adjacent cylinders can be combined into one, and wiring can be simplified.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is an explanatory diagram of an engine (specifically, a four-cylinder engine) according to the first embodiment. FIG. 1A is a partial cross-sectional view of a joint portion between a cylinder head 20 and a cylinder block 30, and FIG. It is A sectional drawing of a).

  As shown in FIG. 1A, the engine of the present embodiment includes a pressure sensor integrated gasket 40 between the cylinder head 20 and the cylinder block 30 as in the configuration described in Patent Document 1 described above. .

  That is, the pressure sensor integrated gasket 40 is interposed between the cylinder head 20 and the cylinder block 30 in the engine, and is clamped and fixed with a bolt or the like to seal the cylinder head 20 and the cylinder block 30. It is. Originally, the gasket has a function of maintaining the combustion pressure generated in the cylinder (combustion chamber) 10 and a lubricating oil path, a cooling water path (not shown), etc. (not shown) communicating between the cylinder head 20 and the cylinder block 30. And a function of forming the passage without leakage. On the other hand, the pressure sensor integrated gasket 40 has a function of detecting a combustion pressure (cylinder pressure) in addition to such an original function.

Specifically, the pressure sensor integrated gasket 40 includes a gasket member 41, a pressure sensor 50, and a lead wire 60.
The gasket member 41 is a sheet-like seal member made of an inorganic filler, a synthetic rubber binder, and the like, and having a gasket original function. The gasket member 41 is positioned near the cylinder 10 of each cylinder on the upper surface (the surface on the cylinder head 20 side) ( In FIG. 3, a sensor cutout 42 that is a disk-shaped recess for placing the pressure sensor 50 is formed.

  The pressure sensor 50 includes a pressure sensor element 52 built in a disk-shaped (button type) casing 51 and is embedded in a sensor cutout 42 of the gasket member 41. As the pressure sensor element 52, for example, a type that is detected by a surface acoustic wave, a type that is detected by a piezoelectric effect, or the like is used.

The lead wire 60 is for sending the value detected by the pressure sensor 50 to the outside, and is embedded in the gasket member 41.
On the other hand, on the surface (lower surface) of the cylinder head 20 facing the pressure sensor 50, a communication notch 22 is formed over the inner peripheral surface 21 facing the cylinder (combustion chamber) 10. Thereby, a space (hereinafter referred to as “pressure introduction port 23”) is formed between the cylinder head 20 and the pressure sensor 50, and the pressure sensor 50 is cylindrical through the air layer in the pressure introduction port 23. It is in contact with 10 of the combustion gases. That is, the pressure sensor 50 detects the combustion pressure generated in the cylinder 10 through the pressure inlet 23. In order to fully exhibit the function of the pressure inlet 23, the height (the distance from the pressure receiving surface (upper surface) of the pressure sensor 50 to the lower surface of the cylinder head 20) is set to the thickness of the pressure sensor integrated gasket 40. The above is preferable.

  Further, as shown in FIG. 1B, the shape of the communication cutout portion 22 (pressure introduction port 23) viewed from the direction of the cylinder central axis is a shape that exposes the entire pressure receiving surface of the pressure sensor 50. Yes. Moreover, it has a shape without a restriction so that the inflowing gas does not easily expand, and the space width gradually decreases as the distance from the cylinder central axis increases. Specifically, the pressure introduction port 23 has an angle α of an extension surface of the inlet end surface with respect to the inner peripheral surface 21 of the cylinder head 20 to the cylinder 10 of less than 90 °, and the cross-sectional area increases as the distance from the cylinder central axis increases. Gradually decreases.

On the other hand, the position of the pressure sensor 50 in each cylinder is considered so as to avoid a particularly high temperature region in the cylinder 10 as much as possible.
Specifically, for example, as shown in FIG. 2A, in the case of an engine in which fuel is sprayed (injected) in a certain direction (a cross direction as viewed from the direction of the cylinder center axis in FIG. 2A), the pressure The sensor 50 is preferably installed at a position as far as possible from the spray tip position 73. This is because the area where the fuel is sprayed becomes high temperature due to the occurrence of a flame. In the example of FIG. 2A, the pressure sensor 50 is installed at an intermediate position (for example, any one of the four illustrated positions) between the spray tip positions 73 adjacent to each other.

  For example, as shown in FIG. 2B, in the case of an engine including a glow plug 74, the pressure sensor 50 is preferably installed at a position away from the glow plug 74. This is because the glow plug 74 has a temperature of 1000 ° C. or higher, and thus the vicinity of the glow plug 74 is at a high temperature. In the example of FIG. 2 (b), the pressure sensor 50 has a position where the angle β with respect to the glow plug 74 as viewed from the direction of the cylinder central axis is larger than 90 ° (for example, any one of the two positions shown in the figure) Two positions). Of course, the position is not limited to the illustrated position. For example, the glow plug 74 may be installed at a position opposite to the glow plug 74 (position of angle β = 180 °).

  It is also possible to install a plurality of pressure sensors 50 for one cylinder. Specifically, for example, as shown in FIG. 2C, if the pressure sensor 50 is installed at both a position close to the fuel spray tip position 73 and a position as far as possible from the spray tip position 73, 2 It is possible to estimate the pressure distribution in the cylinder 10 based on the detection values of the two pressure sensors 50.

On the other hand, FIG. 3 is a plan view of the pressure sensor integrated gasket 40. Reference numeral 43 denotes a seal surface.
As shown in the figure, the pressure sensor 50 of each cylinder is connected to an ECU (electronic control unit) 71 outside the engine via a lead wire 60, and a detection value by the pressure sensor 50 is connected via a lead wire 60. It is sent to the ECU 71.

  Here, the pressure sensor 50 of each cylinder is disposed at a position close to each other in each set including two cylinders. For this reason, the lead wires 60 of the two adjacent pressure sensors 50 can be combined into one, and wiring from the pressure sensor integrated gasket 40 to the ECU 71 can be simplified. Here, if the lead wires 60 of the four pressure sensors 50 are to be combined into one, the length of the lead wires 60 embedded in the pressure sensor integrated gasket 40 needs to be excessively increased. In the case where the lead wires 60 of the two pressure sensors 50 are combined into one as described above, the length of the lead wire 60 can be shortened to the minimum necessary.

  As described above, the engine of the first embodiment has a configuration in which the combustion pressure generated in the cylinder 10 is detected by the pressure sensor 50 disposed at the joint between the cylinder head 20 and the cylinder block 30. Specifically, the pressure sensor 50 is disposed in a sensor cutout 42 formed in a gasket member 41 interposed between the cylinder head 20 and the cylinder block 30. A communication notch 22 for communicating the cylinder 10 and the pressure sensor 50 in a space (pressure introduction port 23) without a restriction is formed on the surface (lower surface) of the cylinder head 20 facing the pressure sensor 50. Is formed.

  For this reason, according to the engine of this embodiment, the cylinder interior 10 and the pressure sensor 50 can be communicated with each other in a sufficiently large space. As a result, the combustion pressure generated in the cylinder 10 can be detected with high accuracy. In particular, since the cylinder interior 10 and the pressure sensor 50 are communicated with each other through the pressure inlet 23 without restriction, it is possible to make it difficult to generate deposits. That is, if a restriction is formed at the pressure inlet 23, the combustion gas flowing in from the cylinder 10 is adiabatically expanded and is easily cooled, and is less likely to flow out into the cylinder 10 so that the combustion gas is solidified. This makes it easy to generate deposits. On the other hand, at the pressure inlet 23 without restriction, the combustion gas flowing in from the cylinder 10 easily flows out into the cylinder 10 immediately, and an environment in which deposits are not easily generated can be obtained. In particular, the pressure introduction port 23 is not limited to a throttle, but can be formed larger than the case where it is formed on the inner peripheral surface of the gasket as described in Patent Document 1 described above. Can be made difficult to generate.

  Further, since the pressure sensor 50 is fixed to the gasket member 41, the pressure sensor 50 can be attached together with the gasket member 41 (as the pressure sensor integrated gasket 40), so that the assembly work can be easily performed. Moreover, since the lead wire 60 for outputting the detection value by the pressure sensor 50 to the outside is also integrated with the gasket member 41, wiring work can be easily performed. In particular, since the lead wire 60 is embedded in the gasket member 41, the original sealing function of the gasket can be made difficult to be impaired.

  In addition, the communication cut-out portion 22 of the cylinder head 20 can be formed by a simple process that cuts the thickness of the cylinder head 20, and thus can be realized at a lower cost than a configuration in which a hole is formed in the cylinder head 20. be able to.

[Second Embodiment]
Next, the engine of the second embodiment will be described.
FIG. 4A is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the second embodiment. As shown in the figure, the engine of the second embodiment differs from the engine of the first embodiment (FIG. 1 (a)) only in the shape of the pressure inlet 23 in the height direction. That is, in the engine of the second embodiment, the height of the pressure inlet 23 formed on the surface (bottom surface) facing the pressure sensor 50 in the cylinder head 20 is formed so as to gradually decrease as the distance from the cylinder central axis increases. Has been. For this reason, compared with the structure of 1st Embodiment with the constant height of the pressure inlet 23, the effect which makes it difficult to produce | generate a deposit can be heightened further.

[Third Embodiment]
Next, an engine according to a third embodiment will be described.
FIG. 4B is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the third embodiment. As shown in the figure, the engine of the third embodiment is different from the engine of the first embodiment (FIG. 1A) only in that a fixing spring 72 is provided. That is, in the engine of the third embodiment, the pressure sensor-integrated gasket 40 (specifically, the pressure sensor 50) is connected to the cylinder by the fixing spring 72 provided in the communication notch 22 (pressure inlet 23). It is pressed to the block 30 side. For this reason, it can prevent that the edge part (pressure sensor 50) near the cylinder 10 in the pressure sensor integrated gasket 40 floats to the pressure inlet 23 side (upward). As a result, it is possible to prevent the pressure from being accurately detected (deterioration of detection accuracy) due to the generation of a space on the side opposite to the pressure receiving surface of the pressure sensor 50. The fixing spring 72 is provided so as to hold down a portion other than the pressure receiving surface of the pressure sensor 50 in the pressure sensor integrated gasket 40 (a portion that does not hinder pressure detection). In addition, as the fixing spring 72, a shape (for example, a linear shape) that does not obstruct gas flow at the pressure inlet 23 is used.

[Fourth Embodiment]
Next, an engine according to a fourth embodiment will be described.
FIG. 5A is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the fourth embodiment. As shown in the figure, the mounting position of the pressure sensor 50 differs between the engine of the fourth embodiment and the engine (FIG. 1A, etc.) of the first to third embodiments described above.

  Specifically, in the engines of the first to third embodiments, the pressure sensor 50 is disposed in a sensor cutout 42 formed in the gasket member 41. That is, the pressure sensor 50 is arranged in a gap formed between the cylinder head 20 and the cylinder block 30 (originally a space where a gasket exists). And the pressure introduction port 23 is formed by forming the notch part 22 for communication in the surface (lower surface) facing the pressure sensor 50 in the cylinder head 20.

  On the other hand, in the engine of the fourth embodiment, a pressure sensor 50 is provided in the sensor notch 24 formed on the surface (lower surface) of the cylinder head 20 facing the cylinder block 30, and the cylinder head 20, the cylinder block 30, The pressure inlet 46 is formed in the gap formed between the two (originally the space where the gasket exists). That is, the fourth embodiment is configured such that the mounting position of the pressure sensor 50 and the position of the pressure inlet are reversed from those of the first to third embodiments.

  The engine of the fourth embodiment includes a gasket 44 separate from the pressure sensor 50 in place of the pressure sensor integrated gasket 40 of the first to third embodiments. As shown in FIG. 6, the shape of the gasket 44 facing the pressure sensor 50 as viewed from the direction of the cylinder central axis is the same as the notch 22 for communication (FIG. 1B) of the first embodiment. A communication cutout 45 having the same shape is formed. That is, the pressure inlet 46 having the same shape as the pressure inlet 23 of the first embodiment is formed.

Further, the pressure introduction port 46 is provided with a fixing spring 72 (similar to the third embodiment) for fixing the pressure sensor 50 to the sensor notch 24 of the cylinder head 20.
On the other hand, the lead wire 60 is embedded in the cylinder head 20 and the gasket 44, and the outer surface is covered with an insulator. If a cooling water passage formed inside the cylinder head 20 is used as a part of the buried path of the lead wire 60 inside the cylinder head 20, the processing of the buried path can be simplified.

  As described above, in the engine of the fourth embodiment, the pressure sensor 50 is disposed in the sensor cutout 24 formed on the surface (lower surface) of the cylinder head 20 facing the cylinder block 30. The gasket 44 interposed between the cylinder head 20 and the cylinder block 30 is formed with a communication notch 45 for communicating the cylinder 10 and the pressure sensor 50 in a space without any restriction.

  That is, in the engine of the first embodiment, the cylinder head 20 has a space communicating with the cylinder 10 and the pressure sensor 50, whereas in the engine of the fourth embodiment, the cylinder head 20 and the cylinder block 30. It is formed in the gap. For this reason, the engine of the fourth embodiment can achieve the same effects as the engine of the first embodiment.

  In particular, in the engine of the fourth embodiment, the pressure sensor 50 is fixed by the fixing spring 72 provided in the communication notch 45 (pressure inlet 46). Can be fixed by simple work.

[Fifth Embodiment]
Next, an engine according to a fifth embodiment will be described.
FIG. 5B is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the fifth embodiment. As shown in the figure, in the engine of the fifth embodiment, when compared with the engine of the fourth embodiment (FIG. 5A), the pressure sensor 50 is arranged not on the cylinder head 20 side but on the cylinder block 30 side. Is different. That is, in the engine of the fifth embodiment, the pressure sensor 50 is disposed in the sensor notch 31 formed on the surface (upper surface) of the cylinder block 30 facing the cylinder head 20, and is fixed by the fixing spring 72. Has been.

For this reason, according to the engine of 5th Embodiment, the effect similar to the engine of 4th Embodiment can be acquired.
[Sixth Embodiment]
Next, an engine according to a sixth embodiment will be described.

  FIG. 5C is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the sixth embodiment. As shown in the figure, the engine of the sixth embodiment is not fixed by the fixing spring 72 but is fixed by screws as compared with the engine of the fourth embodiment (FIG. 5A). The point is different.

  That is, in the engine of the sixth embodiment, the pressure sensor 50 is formed with a male screw portion 53 extending upward from the upper surface thereof, and the male screw of the pressure sensor 50 is formed in the sensor cutout portion 24 of the cylinder head 20. A female screw portion 25 that is screwed with the portion 53 is formed. For this reason, the pressure sensor 50 can be screwed to the sensor cutout 31 without using the fixing spring 72.

For this reason, according to the engine of the sixth embodiment, the pressure sensor 50 can be fixed relatively firmly.
[Seventh Embodiment]
Next, an engine according to a seventh embodiment will be described.

  FIG. 7 is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the seventh embodiment. As shown in the figure, the engine of the seventh embodiment is different from the engine of the fourth embodiment (FIG. 5A) in that the lead wire 60 is configured to be separable by a connector.

  That is, in the engine of the seventh embodiment, the lead wire 60 embedded in the cylinder head 20 and the pressure sensor 50 are connected by the connectors 26 and 54. The lead wire 60 embedded in the cylinder head 20 and the lead wire 60 embedded in the gasket 44 and the pressure sensor 50 are connected by the connectors 27 and 47.

  For this reason, according to the engine of the seventh embodiment, the assembly work can be easily performed as compared with the configuration in which the lead wire 60 cannot be separated. Each connector is not limited to the configuration in which the protruding portion is inserted into the hole portion as shown in FIG. 7, and may be a simple configuration in which the metal plate is simply brought into contact.

[Eighth Embodiment]
Next, an engine according to an eighth embodiment will be described.
FIG. 8A is a partial cross-sectional view of a joint between the cylinder head 20 and the cylinder block 30 in the engine of the eighth embodiment. As shown in the figure, when the engine of the eighth embodiment is compared with the engine of the sixth embodiment (FIG. 5C), the pressure sensor 50 is connected to the transmitter 81 instead of the lead wire 60. The difference is that the power generation piezoelectric element 55 is provided.

  That is, in the engine of the eighth embodiment, the detected value by the pressure sensor 50 is wirelessly transmitted by the transmitter 81 to the outside (receiver outside the engine). The driving power for the transmitter 81 is generated by the power generation piezoelectric element 55. Specifically, the piezoelectric element for power generation 55 is configured to be continuously deformed by a continuous change of the combustion pressure in the cylinder 10 and to generate electric power along with this deformation. Note that the transmission by the transmitter 81 can be performed periodically (for example, every cycle), thereby reducing the power consumption.

  For this reason, according to the engine of 8th Embodiment, since the complicated wiring operation | work of the lead wire 60 can be abbreviate | omitted, an assembly operation can be performed easily. A thermocouple or the like can be used as the power generation element.

[Ninth Embodiment]
Next, an engine according to a ninth embodiment will be described.
FIG. 8B is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the ninth embodiment. As shown in the figure, the engine of the ninth embodiment differs from the engine of the eighth embodiment (FIG. 8A) in that a receiver 82 is embedded in the gasket 44. Note that communication from the receiver 82 is performed by wire (a lead wire embedded in the gasket 44).

For this reason, according to the engine of the eighth embodiment, the distance from the transmitter 81 to the receiver 82 can be shortened, and the power required for wireless transmission can be reduced.
[Tenth embodiment]
Next, the engine of 10th Embodiment is demonstrated.

  FIG. 9 is a partial cross-sectional view of a joint portion between the cylinder head 20 and the cylinder block 30 in the engine of the tenth embodiment. As shown in the figure, the engine of the tenth embodiment is different from the engine of the eighth embodiment (FIG. 8A) in that the pressure sensor 50 is actively cooled. .

  That is, in the engine of the tenth embodiment, the pressure sensor 50 is a rod-shaped member extending upward from the upper surface thereof, and includes a heat conductor 56 formed of a metal having a high thermal conductivity. On the other hand, an insertion port 28 for inserting the heat conductor 56 of the pressure sensor 50 is formed in the sensor cutout portion 24 of the cylinder head 20, and this insertion port 28 is formed inside the cylinder head 20. The cooling water passage 29 is penetrated. For this reason, the upper end portion of the heat conductor 56 protrudes into the cooling water passage 29 and is cooled by the cooling water. As a result, the pressure sensor 50 is cooled. In the example of FIG. 9, the transmitter 81 is provided inside the heat conductor 56, but is not limited to this.

  For this reason, according to the engine of the tenth embodiment, the pressure sensor 50 can be efficiently cooled using the cooling water. In particular, since the heat conductor 56 penetrates the cooling water passage 29, the design can be made without strictly considering the thickness of the cylinder head 20. Of course, the same configuration can be made using the cooling water passage on the cylinder block side.

[Modification]
As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form, without being limited to the said embodiment.

  For example, in the first to third embodiments, the configuration in which the communication cutout portion 22 (pressure introduction port 23) for communicating the in-cylinder 10 and the pressure sensor 50 is formed in the cylinder head 20 is illustrated. However, the present invention is not limited to this, and the cylinder block 30 may be formed.

  Moreover, in the said 1st-3rd embodiment, although the structure which fixed the pressure sensor 50 to the gasket member 41 was illustrated, it is not limited to this, The pressure sensor 50 is comprised separately from the gasket member 41. May be. Specifically, in the configuration in which the pressure introduction port is formed in the cylinder head 20, the pressure sensor 50 is fixed to the cylinder block 30 side. Conversely, in the configuration in which the pressure introduction port is formed in the cylinder block 30, the pressure sensor 50 is provided. Fix to the cylinder head 20. In this way, the pressure sensor 50 and the gasket can be handled separately.

  Furthermore, in each said embodiment, although the lead wire 60 was illustrated the structure embedded inside the gasket member 41 (or gasket 44), it is not limited to this, The gasket member 41 (or gasket 44) is not limited to this. It may be provided on the surface. In this way, it is easy to attach the lead wire 60 to the gasket member 41 (or gasket 44), and it is easy to find the disconnection of the lead wire 60 in the manufacturing process.

  Moreover, in the said 4th-7th embodiment, although the structure which embedded some lead wires 60 in the gasket 44 was illustrated, it is not limited to this, It passes only the cylinder head 20 or the cylinder block 30. You may comprise.

It is explanatory drawing of the engine of 1st Embodiment, (a) is a fragmentary sectional view of the junction part of a cylinder head and a cylinder block, (b) is A sectional drawing of (a). It is explanatory drawing which illustrated the position which installs a pressure sensor. It is a top view of the pressure sensor integrated gasket of a 1st embodiment. It is a fragmentary sectional view of the joined part of the cylinder head and cylinder block in the engine of the 2nd and 3rd embodiments. It is a fragmentary sectional view of the joined part of the cylinder head and cylinder block in the engine of the 4th-6th embodiment. It is a top view of the pressure sensor integrated gasket of a 4th embodiment. It is a fragmentary sectional view of the joined part of a cylinder head and a cylinder block in an engine of a 7th embodiment. It is a fragmentary sectional view of the junction part of the cylinder head and cylinder block in the engine of 8th, 9th embodiment. It is a fragmentary sectional view of the joined part of a cylinder head and a cylinder block in an engine of a 10th embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... In-cylinder, 20 ... Cylinder head, 21 ... Inner peripheral surface, 22 ... Communication notch part, 23 ... Pressure inlet, 24 ... Sensor notch part, 25 ... Female thread part, 26, 27, 47, 54 ... Connector, 28 ... Insertion port, 29 ... Cooling water passage, 30 ... Cylinder block, 31 ... Sensor notch, 40 ... Pressure sensor integrated gasket, 41 ... Gasket member, 42 ... Sensor notch, 43 Reference numeral 44 ... Gasket 45 ... Communication cutout 46 ... Pressure inlet 50 ... Pressure sensor 51 ... Housing 52 ... Pressure sensor element 53 ... Male screw part 55 ... Piezoelectric element for power generation, 56 ... Thermal conductor, 60 ... Lead wire, 71 ... ECU, 72 ... Spring for fixing, 73 ... Spray tip position, 74 ... Glow plug, 81 ... Transmitter, 82 ... Receiver

Claims (15)

A pressure detection device for an internal combustion engine that detects a combustion pressure generated in a cylinder of the internal combustion engine with a pressure sensor arranged at a joint between a cylinder head and a cylinder block,
The pressure sensor is disposed in a sensor notch formed in a gasket interposed between the cylinder head and the cylinder block,
A communication notch for communicating the inside of the cylinder and the pressure sensor in a space without a restriction is formed on a surface facing the pressure sensor in one of the cylinder head and the cylinder block. A pressure detecting device for an internal combustion engine. The pressure sensor for an internal combustion engine according to claim 1, wherein the pressure sensor is fixed to the gasket. The pressure sensor is pressed by a spring provided in the notch for communication to a side of the cylinder head and the cylinder block where the notch for communication is not formed. Item 3. The pressure detection device for an internal combustion engine according to Item 2. 2. The internal combustion engine pressure detection device according to claim 1, wherein the pressure sensor is fixed to one of the cylinder head and the cylinder block in which the notch for communication is not formed. 3. A pressure detection device for an internal combustion engine that detects a combustion pressure generated in a cylinder of the internal combustion engine with a pressure sensor arranged at a joint between a cylinder head and a cylinder block,
The pressure sensor is disposed in a sensor cutout formed on a surface facing one of the cylinder head and the cylinder block.
The gasket interposed between the cylinder head and the cylinder block is formed with a notch for communication for communicating the inside of the cylinder and the pressure sensor in a space without a restriction. Pressure detector for internal combustion engine. The pressure sensor for an internal combustion engine according to claim 5, wherein the pressure sensor is fixed by a spring provided in the notch for communication. The pressure detection device for an internal combustion engine according to claim 5, wherein the pressure sensor is fixed to the notch for the sensor with a screw. The communication line for outputting the detection value by the pressure sensor to the outside is wired via the cylinder head or the cylinder block and the gasket, and is configured to be separable by a connector. The pressure detection device for an internal combustion engine according to any one of claims 5 to 7. The pressure sensor is
A transmitter for wirelessly transmitting a detection value;
A power generation element for generating power for driving the transmitter;
The pressure detection device for an internal combustion engine according to any one of claims 5 to 8, further comprising: The internal combustion engine pressure detection device according to claim 9, wherein a receiver for receiving a detection value wirelessly transmitted from the transmitter is provided in the gasket. The said pressure sensor is equipped with the heat conductor for releasing the heat | fever of the said pressure sensor to the cooling water which flows through the cooling water flow path formed in the inside of the said cylinder head or the said cylinder block. Item 11. The pressure detection device for an internal combustion engine according to any one of Items 10 to 10. The pressure detection device for an internal combustion engine according to any one of claims 1 to 11, wherein the pressure sensor is provided at a position distant from a fuel injection direction. The pressure sensor for an internal combustion engine according to claim 12, wherein the pressure sensor is provided at a position away from the fuel injection direction and a position close to the fuel injection direction. The pressure detection device for an internal combustion engine according to any one of claims 1 to 13, wherein the pressure sensor is provided at a position away from the glow plug. The pressure sensor is provided in each of a plurality of cylinders of the internal combustion engine, and the pressure sensors of adjacent cylinders are arranged close to each other. 15. The pressure detection device for an internal combustion engine according to the item.