JP2019044638A - Data transmission device of internal combustion engine - Google Patents

Abstract

To provide a data transmission device of an internal combustion engine which achieves high power generation performance.SOLUTION: A data transmission device of an internal combustion engine includes: a sensor provided at a piston; a transmission part which is provided at a connecting rod connected to the piston and transmits data measured by the sensor; a power generation part which is provided at the connecting rod and supplies electric power to the transmission part; and a cover which covers the power generation part. The power generation part generates electric power by thermoelectric effect using a temperature difference between the connecting rod and a crank chamber in which the connecting rod is housed. The cover covers a crank chamber side surface of the power generation part and has a cavity which penetrates through the cover along an extension direction of the connecting rod.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a data transmission device for an internal combustion engine.

  For stable operation of the internal combustion engine, it is important to measure the temperature and behavior of the piston. There is known a technology in which a sensor is provided on a piston and data of a physical quantity detected by the sensor is transmitted (for example, Patent Document 1).

JP, 2012-207642, A

  Such a transmitter includes a transmitter that transmits data detected by the sensor, and a power supply that supplies power to the transmitter. In the technique of Patent Document 1, a battery is used as a power source. However, when the battery capacity is exhausted, power generation is difficult, and it takes a lot of time to replace the battery. Therefore, it is an object of the present invention to provide a data transmission device for an internal combustion engine with high power generation performance.

  The above object is to provide a sensor provided on a piston, a transmitting unit provided on a connecting rod connected to the piston and transmitting data measured by the sensor, and provided on the connecting rod to supply power to the transmitting unit A power generation unit, and a cover covering the power generation unit, wherein the power generation unit generates the electric power by a thermoelectric effect using a temperature difference between the connecting rod and a crank chamber in which the connecting rod is accommodated; The cover can cover the surface on the crank chamber side of the power generation unit, and can be achieved by a data transmission device of an internal combustion engine having a cavity penetrating the cover along the extension direction of the connecting rod.

  It is possible to provide a data transmission device for an internal combustion engine with high power generation performance.

FIG. 1 is a schematic view illustrating a data transmission apparatus. FIG. 2A is a perspective view illustrating the cover. FIG. 2B is a perspective view illustrating the power generation unit. FIG. 2C is a side view illustrating the power generation unit. FIG.2 (d) is a perspective view of the state which attached the electric power generation part and the cover to the connecting rod. Fig.3 (a) and FIG.3 (b) are sectional drawings which illustrate a connecting rod, an electric power generation part, and a cover. FIG. 4 is an enlarged view of the cover. FIG. 5 is a flow chart illustrating the steps of assembling the data transmission apparatus. FIG. 6 is a flowchart illustrating the operation of the data transmission apparatus.

(Embodiment)
Hereinafter, the data transmission device 100 of the internal combustion engine of the present embodiment will be described with reference to the drawings. The data transmission device 100 is applied to an engine 10 (internal combustion engine). The engine 10 is, for example, a gasoline engine mounted on a car. FIG. 1 is a schematic view illustrating the data transmission apparatus 100. As shown in FIG. The Z direction is the vertical direction, and the X direction and the Y direction are orthogonal to the Z direction.

  As shown in FIG. 1, a combustion chamber 12 and a crank chamber 14 are formed in a cylinder block 11 of the engine 10. A piston 16 is disposed in the combustion chamber 12, and a connecting rod 18 is disposed in a crank chamber 14 of the engine 10. The piston 16 and the connecting rod 18 reciprocate in the vertical direction (Z direction) by the rotation of a crankshaft (not shown).

  The data transmission device 100 includes a sensor 20, a transmission unit 22, a power generation unit 24, and a cover 30. The two sensors 20 are, for example, thermocouples, provided on the piston 16 to measure the temperature of the piston 16. Each of the two sensors 20 outputs temperature information and the like. Also, for example, one of the sensors 20 may be a thermocouple and the other may be a gap sensor. In this case, temperature information and displacement information are output.

  The transmission unit 22 and the power generation unit 24 are provided on the connecting rod 18. The transmitting unit 22 is electrically connected to the sensor 20 and performs wireless communication with the antenna 25. The transmitting unit 22 converts the data detected by the sensor 20 into analog data or converts it into analog-digital data, and transmits the analog data.

  The antenna 25 receives data. The receiving unit 26 outside the cylinder block 11 is electrically connected to the antenna 25 by a wire drawn out of the cylinder block 11, and acquires data from the antenna 25. The receiving unit 26 includes, for example, a filter that removes noise from data, an amplifier that amplifies a signal of data, and an analog / digital conversion circuit that mutually converts an analog signal and a digital signal. The receiver 26 converts the data into digital data.

  The analysis unit 28 is, for example, a computer such as a personal computer, and is electrically connected to the reception unit 26. The analysis unit 28 converts data into physical characteristic values (such as temperature), and stores the data in a storage device such as a hard disk drive (HDD: Hard Disc Drive). Also, the user can view the temperature data of the piston 16 on a display or the like.

  The power generation unit 24 is provided on the connecting rod 18 and supplies power to the transmission unit 22 through the wiring 23. The cover 30 covers the power generation unit 24 and is fixed to the connecting rod 18 by, for example, a bolt.

  FIG. 2A is a perspective view illustrating the cover 30. FIG. Inside the cover 30, a cavity 32 is provided which penetrates the cover 30 in the Z direction. A cavity 33 is formed on the −Y side of the cover 30.

  An inclined portion 34 is formed on the + Z side end and the −Z side end of the + Y side surface of the cover 30. The inclined portion 34 is inclined to the −Y side from the outside to the center side of the cover 30. A plate 35 is attached to the + Z side and the −Z side of the cover 30 by welding or the like. The plate 35 is inclined from the outside to the center of the cover 30 so as to face the + Y direction. The inclined portion 34 and the plate 35 form an end 31 whose width decreases along the Z-axis toward the center of the cover 30.

  FIG. 2 (b) is a perspective view illustrating the power generation unit 24. FIG. 2C is a side view illustrating the power generation unit 24. The power generation unit 24 illustrated in FIG. 2B and FIG. 2C is a thermoelectric element. A plurality of electrodes 24c are provided on the surface of the substrate 24a facing the substrate 24b, and a plurality of electrodes 24d are provided on the surface of the substrate 24b facing the substrate 24a. A plurality of semiconductors 24p and 24n are sandwiched between the two substrates 24a and 24b. The p-type semiconductor 24p and the n-type semiconductor 24n are in contact with the electrodes 24c and 24d. The semiconductors 24p and 24n are alternately arranged and connected in series. When a temperature difference occurs between the substrates 24a and 24b, an electromotive force is generated by the Seepeck effect, and current flows through the plurality of electrodes 24c and 24d. A wire 23 is connected to each of the one electrode 24 c and the one electrode 24 d, and power is supplied to the transmission unit 22 through the wire 23.

  FIG. 2D is a perspective view of the power generation unit 24 and the cover 30 attached to the connecting rod 18. 3 (a) and 3 (b) are cross-sectional views illustrating the connecting rod 18, the power generation unit 24 and the cover 30, and FIG. 3 (a) shows the connecting rod 18 rising while FIG. 3 (b) shows the connecting rod 18. FIG. In FIGS. 3A and 3B, the electrodes 24c and 24d and the wiring 23 are omitted.

  As shown in FIG. 2D to FIG. 3B, the substrate 24 a of the power generation unit 24 is fixed to the connecting rod 18. The substrate 24 b faces away from the connecting rod 18, is fitted into the cavity 33 of the cover 30, and is exposed to the cavity 32. The cover 30 is disposed such that the cavity 32 is along the Z direction.

  As shown in FIG. 1, the connecting rod 18 is connected to the piston 16, and heat is transferred from the combustion chamber 12 to the connecting rod 18 through the piston 16. As shown in FIG. 2 (d) to FIG. 3 (b), the substrate 24a is close to the connecting rod 18, so the heat transmitted from the connecting rod 18 causes a high temperature. On the other hand, the substrate 24 b is a surface far from the connecting rod 18 and is exposed to the cavity 32 of the cover 30. Therefore, the temperature of the substrate 24b is lower than that of the substrate 24a. The power generation unit 24 generates power when a temperature difference is generated between the substrates 24a and 24b. The generated power is supplied from the power generation unit 24 to the transmission unit 22 through the wiring 23.

  When the connecting rod 18 ascends as shown by arrow A1 in FIG. 3A, air flows downward in the cavity 32 of the cover 30 as shown by arrow A2. When the connecting rod 18 is lowered as shown by the arrow A3 in FIG. 3 (b), air flows upward in the cavity 32 as shown by the arrow A4. Thereby, heat exchange between the substrate 24b and the atmosphere in the crank chamber 14 is promoted, and the temperature of the substrate 24b becomes lower than that of the substrate 24a. By the temperature difference becoming large, the power generation performance of the power generation unit 24 is improved.

質量保存の法則により次の数３が成り立つ。

数３を変形すると数４が導き出される。

Ｓ２＜Ｓ１であるため、空洞３２を通る空気の速度Ｖ２は、端部３１に流入する空気の速度Ｖ１より大きくなる。したがって、空洞３２に露出する基板２４ｂと空気との熱交換が促進され、電極間の温度差が大きくなる。この結果、発電性能が向上する。 FIG. 4 is an enlarged view of the cover 30. As shown in FIG. 4, the cross-sectional area S1 in the XY plane of the inlet of the cover 30 (the outermost part of the end 31) is larger than the cross-sectional area S2 of the cavity 32. The density of air is set to a constant value ρ in the cover 30. The flow rate Q1 of air at the end 31 is represented by equation 1, and the flow rate Q2 in the cavity 32 is represented by equation 2.

The following equation 3 is established by the law of mass conservation.

By transforming Equation 3, Equation 4 is derived.

Since S2 <S1, the velocity V2 of the air passing through the cavity 32 is greater than the velocity V1 of the air flowing into the end 31. Therefore, heat exchange between the substrate 24b exposed to the cavity 32 and the air is promoted, and the temperature difference between the electrodes becomes large. As a result, power generation performance is improved.

  FIG. 5 is a flow chart illustrating the process of assembling the data transmission apparatus 100. The assembly is performed by, for example, a vehicle mechanic and a user before assembling the engine. As shown in FIG. 5, for example, the user first attaches the sensor 20 to the piston 16 (step S10). The transmitter 22 is attached to the connecting rod 18 (step S12). The cover 30 is attached to the power generation unit 24 (step S14), and the power generation unit 24 is attached to the connecting rod 18 (step S16). The sensor 20, the transmission unit 22, and the power generation unit 24 are connected to one another (step S18). The piston 16 and the connecting rod 18 are assembled, and these are assembled to the engine 10 (step S19).

  FIG. 6 is a flowchart illustrating the operation of the data transmission apparatus 100. It is assumed that the engine 10 has started operation. The connecting rod 18 becomes high temperature with the operation of the engine 10, and a temperature difference is generated between the substrate 24a and the substrate 24b of the power generation unit 24. Thus, the power generation unit 24 generates power (step S20). The power is supplied to the transmitter 22. The sensor 20 detects data on the temperature of the piston 16 (step S22). The transmission unit 22 acquires data on temperature from the sensor 20 and transmits the data to the antenna 25 (step S24). The receiving unit 26 receives data via the antenna 25 (step S26), and performs, for example, analog / digital conversion. The analysis unit 28 receives data from the reception unit 26, converts the data into physical property values and the like (step S28), and displays and stores the result (step S30). The physical characteristic value is, for example, a temperature difference between the sensors 20, a temperature at each of the sensors 20, a displacement of the piston 16, or the like.

  As described above, according to the present embodiment, the transmission unit 22 and the power generation unit 24 are provided on the connecting rod 18, and the cover 30 covers the power generation unit 24. The substrate 24 a of the power generation unit 24 is located on the connecting rod 18 side, and the substrate 24 b is exposed to the cavity 32 of the cover 30. As the engine 10 operates, the temperature of the connecting rod 18 rises, causing a temperature difference between the substrate 24 a and the substrate 24 b, and the power generation unit 24 can generate power by the thermoelectric effect. Since the power generation unit 24 generates power while the engine 10 operates and a temperature difference occurs, it is not necessary to replace the power generation unit 24 such as a battery. Therefore, the power generation performance is improved.

  As shown in FIGS. 3A and 3B, the flow of air through the cavity 32 of the cover 30 makes the temperature of the substrate 24b lower than that of the substrate 24a. In particular, since the end 31 of the cover 30 is tapered, the air flow velocity V2 is increased in the cavity 32, and heat exchange between the substrate 24b and the air is promoted. Therefore, the power generation performance is improved. Further, the power generation unit 24 can be protected from oil or the like by the cover 30.

  The shape of the cover 30 may be changed. For example, even if the cover 30 has a tubular shape having a constant cross-sectional area, air flows inside the cover 30, and the substrate 24b is cooled by the air. However, if the cross-sectional area of the end portion of the cover 30 is small, the pressure loss of the air increases and the flow velocity decreases. In order to increase the flow velocity of air in the cover 30, it is preferable that the cross-sectional area S1 of the end 31 of the cover 30 be larger than the cross-sectional area S2 of the central part of the cover 30. For example, S1 may be 1.5 times or more, twice or more of S2, or the like. The angle of inclination of the end 31 may vary, and the end 31 may be curved.

  Power can be generated by attaching a rotary generator to the connecting rod. However, when engine oil etc. adhere to the eccentric rotor of a rotary generator, power generation may be inhibited. Further, in order to suppress the influence of the centrifugal force of the eccentric rotor on the motion of the connecting rod and the piston, the mounting position of the rotary generator is limited to the side closer to the lower end of the connecting rod. The power generation unit 24 of the present embodiment is a thermoelectric element and does not significantly affect the motion of the connecting rod. Further, the size and shape of the power generation unit 24 can be changed according to the shape of the substrates 24a and 24b, the arrangement of the semiconductors 24p and 24n, and the like. Therefore, the degree of freedom of the mounting position of the power generation unit 24 is high. For example, the power generation unit 24 may be provided on the surface (the surface on the + Y side) to which the transmission unit 22 of the connecting rod 18 is attached, or may be provided on the other surface. The power generation unit 24 may be provided on the upper side or the lower side of the transmission unit 22.

  Power can also be generated using a spring and a piezoelectric element. However, there is a risk that the power generation performance may be reduced due to the engine speed. The power generation unit 24 can generate power if there is a temperature difference between the substrates 24 a and 24 b regardless of the number of revolutions of the engine.

  The temperature stored in the analysis unit 28 is used as information for operating the engine stably. The sensor 20 may be a thermistor other than the thermocouple. The sensor 20 may be a sensor that measures physical quantities other than temperature, such as a gap sensor that measures the distance between the piston 16 and the inner wall of the cylinder block 11, for example.

  The antenna 25, the receiving unit 26, and the analyzing unit 28 may be integrated. The receiving unit 26 and the analyzing unit 28 may perform wired communication or wireless communication. The analysis unit 28 may be an ECU (Engine Control Unit) mounted on a vehicle other than a personal computer. The engine 10 may be a diesel engine or the like other than a gasoline engine.

  Although the preferred embodiments of the present invention have been described above in detail, the present invention is not limited to the specific embodiments, and various modifications may be made within the scope of the subject matter of the present invention described in the claims. Changes are possible.

Reference Signs List 10 engine 11 cylinder block 12 combustion chamber 14 crank chamber 16 piston 18 connecting rod 20 sensor 22 transmission unit 24 power generation unit 24a, 24b substrate 24c, 24d electrode 24p, 24n semiconductor 25 antenna 26 reception unit 28 analysis unit 30 cover 31 end 32, 33 cavity 34 slope 35 plate 100 data transmitter

Claims (1)

A sensor provided on the piston,
A transmitting unit provided on a connecting rod connected to the piston and transmitting data measured by the sensor;
A power generation unit provided in the connecting rod and supplying power to the transmission unit;
And a cover covering the power generation unit,
The power generation unit generates the electric power by a thermoelectric effect using a temperature difference between the connecting rod and a crank chamber in which the connecting rod is accommodated.
The data transmission device for an internal combustion engine, wherein the cover covers a surface on the crank chamber side of the power generation unit, and has a cavity penetrating the cover along the extension direction of the connecting rod.

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