JP6521429B2 - Powertrain structure of vehicle - Google Patents

Description

  The present invention relates to a powertrain structure of a vehicle in which a torque transmission mechanism that transmits torque between an engine and a transmission is interposed.

  2. Description of the Related Art Conventionally, there is known a power train that transmits torque by interposing a torque transmission mechanism in a torque transmission path between an engine and a transmission (in the case of a series hybrid vehicle, an electric motor incorporated in the transmission). When the torque transfer mechanism is a torque limiter mechanism, when a torque exceeding the preset limit torque is input, the frictional engagement element slips, and the transmission of the excessive torque is prevented.

  In general, the torque transfer mechanism is covered by a housing, but the bottom of this housing is an opening to ensure air permeability, discharge of intruded water and interference with parts laid out in the periphery. There are those that are notched. If the opening is notched in the bottom of the housing, moisture can easily enter the housing due to traveling on a rainy day, traveling on snow, traveling in a flooded channel, or the like. Then, when the intruded water adheres to the torque transmission mechanism and the state is continued, rusting may occur in each component of the torque transmission mechanism over time.

  In particular, in the torque limiter mechanism, when rusting occurs in each component, sticking occurs or the friction coefficient of the frictional engagement element changes. As a result, since the actual limit torque fluctuates, the torque limiter does not operate even if the excessive torque exceeding the preset limit torque is input, or the torque limiter operates with less than the preset limit torque. Cause a problem.

  Therefore, according to Patent Document 1 (Japanese Patent Laid-Open No. 2010-167837), when a moisture sensor or the like detects water in the housing, or immediately after the main switch is turned off, the motor generator is driven to generate torque. Technology that suppresses the sticking of the frictional engagement element due to rusting by resonating the torque transmission path where the limiter is disposed, thereby forcibly operating the torque limiter and relatively rotating the frictional engagement element It is disclosed.

Unexamined-Japanese-Patent No. 2010-167837

  However, in the technique disclosed in the above-mentioned document, the torque transmission mechanism is made to resonate to prevent sticking of the frictional engagement element provided in the torque limiter due to rusting, but the torque transmission path is Resonating causes noise and vibration to be promoted, resulting in a loss of comfort. Furthermore, if the humidity sensor or the like is deteriorated, it may be difficult to correctly detect water entering into the housing, which may cause a malfunction.

  Further, immediately after the system is stopped, vibrating the torque transmission path constantly causes unnecessary wear of the battery, which causes a problem of shortening the battery life. Furthermore, although the rusting of the frictional engagement element occurs over time, the resonance point of the torque transfer path is likely to change due to parts replacement, aging, etc., and the resonant operation of the torque transfer mechanism is guaranteed over the long term It is difficult, there is a problem in the service life, and there is a limit in obtaining high reliability.

  In view of the above circumstances, the present invention has a simple structure, does not require electrical control, and can suppress rusting of a torque transmission mechanism for a long time to achieve long life and high reliability. The purpose is to provide a train structure.

  According to the present invention, an engine, a transmission, a torque transmission mechanism disposed on a torque transmission path between the engine and the transmission to transmit torque between the engine and the transmission, and the torque And a housing accommodating the transmission mechanism and having an opening formed at the bottom thereof, wherein the opening is provided in a side portion of the housing and an exhaust pipe extending from the engine is disposed. A heat dissipating member is disposed below the portion, and an end of the heat dissipating member is joined to the exhaust pipe.

  According to the present invention, the heat dissipation member is disposed below the opening formed in the bottom of the housing that accommodates the torque transmission mechanism, and the end of the heat dissipation member is joined to the exhaust pipe. The heat absorbed from the tube is dissipated into the housing through the opening, whereby the water adhering to the torque transfer mechanism can be evaporated. As a result, rusting of the torque transmission mechanism can be suppressed. Furthermore, since the heat dissipating member is simply provided, the structure can be manufactured at low cost without the need for electrical control. Further, long-term suppression of rusting of the torque transmission mechanism can achieve long life and high reliability.

The schematic block diagram which shows the powertrain of the hybrid vehicle by 1st Embodiment Same as the power train The same, III-III schematic sectional drawing of FIG. The same IV, IV schematic cross section of FIG. The schematic sectional view of FIG. 4 equivalent according to the second embodiment

  Hereinafter, an embodiment of the present invention will be described based on the drawings.

First Embodiment
1 to 4 show a first embodiment of the present invention. A hybrid vehicle 1 is shown in FIG. In this hybrid vehicle 1, an engine 2 is mounted on the front of the vehicle body, and a transmission 3 is continued to the rear of the engine 2. Reference numeral 11f is a front wheel, and 11r is a rear wheel.

  The transmission 3 has a transmission case 3a, and a limiter housing 3b is integrally formed at the front of the transmission case 3a. The front end of the limiter housing 3b is open, and the open end is coupled to the cylinder block rear surface 2a of the engine 2 to form a storage space therein. Furthermore, an opening 3c is formed in the bottom of the limiter housing 3b.

  The engine 2 shown in the present embodiment is a horizontally opposed type or V-type engine, and as shown in FIGS. 1 to 3, cylinder heads 2b are provided in banks disposed on the left and right sides in the vehicle width direction. An exhaust pipe 5 is communicated with an exhaust port formed in 2 b through an exhaust manifold 4. The respective exhaust pipes 5 pass on both sides of the limiter housing 3b, are gathered at the rear of the transmission case 3a, and extend rearward.

  Further, as shown in FIG. 4, the limiter housing 3b is disposed on the bottom of the vehicle body of the hybrid vehicle 1 and at the front of the opening of the floor tunnel 1a formed at the center in the vehicle width direction. Exhaust pipes 5 are respectively disposed in the vicinity of the skirts on both sides of 1a. Since the exhaust pipe 5 in the vicinity of the opening front of the floor tunnel 1a is near the downstream end of the exhaust manifold 4, in other words, near the upstream end of the exhaust pipe 5, relatively high temperature exhaust heat is circulated during traveling Ru.

  Further, a heat radiation plate 6 as a horizontally long heat radiation member is disposed below the opening 3c formed in the bottom surface of the limiter housing 3b. The heat dissipating plate 6 is formed of a material having rigidity and a relatively high thermal conductivity, such as iron, aluminum or stainless steel. As shown in FIGS. 3 and 4, the heat dissipating plate 6 has a width W covering the entire opening 3c, and both left and right ends 6a in the vehicle width direction are joined to the exhaust pipes 5 by means such as welding. It is done.

  Furthermore, a central heat dissipating portion 6b and a central portion of the heat dissipating plate 6, that is, a portion located below the opening 3c and a portion located on the both sides between the exhaust pipe 5 and the limiter housing 3b Left and right heat radiation parts 6c are respectively formed. A large surface area is secured in each of the heat radiating portions 6b and 6c by bending such as corrugating (wave-forming).

  Moreover, as shown to FIG. 2, FIG. 3, the oil pan 2c of the engine 2 is facing the front of the center thermal radiation part 6b. Therefore, since the traveling wind at the time of traveling is blocked by the oil pan 2c, it is difficult to reach the central heat radiating portion 6b, and the heat from the central heat radiating portion 6b is easily radiated upward. On the other hand, the left and right heat radiating portions 6c are exposed between the exhaust pipe 5 and the limiter housing 3b, and are easier to cool than the central heat radiating portion 6b by traveling wind from the front when traveling.

  Exhaust heat flowing through the exhaust pipe 5 tends to fluctuate due to the influence of the engine load, and the temperature rises when the engine load is high. Therefore, the exhaust heat at high speed traveling is likely to be high temperature, and the torque limiter mechanism 7 described later contained in the limiter housing 3b operates more frequently due to load fluctuation at high speed operation, and heat generation tends to occur. Therefore, by adjusting the heat radiation area of the central heat radiating portion 6b and the left and right heat radiating portions 6c, it is possible to adjust the amount of heat radiated from the central heat radiating portion 6b into the limiter housing 3b through the opening 3c.

Next, the basic internal structure of the transmission 3 will be briefly described. As shown in FIGS. 2 and 3, two motors of a first motor generator MG1 and a second motor generator MG2 applied to the series-parallel hybrid vehicle 1 are disposed in the transmission case 3a. A motor shaft 13 provided to the first motor generator MG1 is connected to a power split mechanism 15 disposed at the front in the transmission case 3a, and further extends forward from the power split mechanism 15 A torque limiter mechanism 7 is interposed in a torque transmission path between the transmission input shaft 15 a and the output shaft 2 d of the engine 2.

  The torque limiter mechanism 7 transmits torque by the frictional force holding the frictional engagement element, and when the torque exceeding the preset limit torque is input, the frictional engagement element slips and rotates relative to the Transmission of excessive torque between the engine 2 and the transmission 3 is prevented. The torque limiter mechanism 7 may be provided with a damper function to suppress torque fluctuation between the engine 2 and the transmission 3.

  On the other hand, the second motor generator MG2 is disposed at the rear of the transmission case 3a, and is connected to the front wheel output shaft 9 via a first gear train 8 consisting of a drive gear 8a and a driven gear 8b. . The front wheel output shaft 9 is connected to a front wheel shaft 12 supporting the left and right front wheels 11 via a differential mechanism 10 integrally including a final reduction gear. The first gear train 8 is always rotating during traveling.

Furthermore, a second gear train in which power split mechanism 15 connected to transmission input shaft 15a and motor shaft 13 of first motor generator MG1 are connected to front wheel output shaft 9 by drive gear 14a and driven gear 14b. It is connected continuously via 14. The power split mechanism 15 distributes the output of the engine 2 to the first motor generator MG1 and the front wheel output shaft 9 at a predetermined ratio, and a so-called series-parallel hybrid system is constructed.

  That is, when power split mechanism 15 shuts off power transmission between output shaft 2d of engine 2 and second gear train 14 to construct a torque transmission path on the side of first motor generator MG1, first motor generator MG1 is a generator , And the front wheel 11 is driven by only the output of the second motor generator MG2 and is in a series hybrid mode.

  On the other hand, the power split mechanism 15 mechanically connects the output shaft 2d of the engine 2 to the drive gear 14a of the second gear train 14 so that the front wheels 11 have both the engine 2 and the output of the second motor generator MG2. It becomes a driven parallel hybrid mode. In addition, although the forward / backward switching mechanism etc. are provided in the transmission case 3a, description of these is abbreviate | omitted.

  Next, the operation of the present embodiment having such a configuration will be described. The output of the engine 2 is a shift of the power split mechanism 15 housed in the transmission case 3a via the torque limiter mechanism 7 housed in the limiter housing 3b formed at the front of the transmission 3 from the output shaft 2d. It is transmitted to the machine input shaft 15a.

When the traveling mode is set to the series hybrid mode, basically, power split device 15 cuts off between output shaft 2 d of engine 2 and drive gear 14 a of second gear train 14, and outputs shaft 2 d and output shaft 2 d . The motor shaft 13 of the first motor generator MG1 is provided continuously. As a result, the first motor generator MG1 performs power generation operation by the driving force of the engine 2.

Further, when the traveling mode is set to the parallel hybrid mode, the power split mechanism 15 mechanically connects the output shaft 2 d of the engine 2 to the drive gear 14 a of the second gear train 14 and sets the front wheel 11 f to the engine 2. It drives with both the output of 2nd motor generator MG2. At that time, when there is a surplus in the output of the engine 2, a part of the output of the engine 2 is distributed to the first motor generator MG1 by the power split mechanism 15, and the first motor generator MG1 is operated to generate power.

  When an excessive torque equal to or greater than the preset limit torque is input to the torque limiter mechanism 7 provided between the engine 2 and the power split mechanism 15, the torque limiter mechanism 7 slips and rotates relative to the torque limiter mechanism 7. And torque transmission above the limit torque is interrupted.

  On the other hand, when the engine 2 operates, the temperature of the exhaust gas rises in proportion to the combustion temperature. The exhaust gas is led from the exhaust port provided in the cylinder head 2b, through the exhaust manifold 4, through the exhaust pipe 5, to the rear of the vehicle body and discharged. As the exhaust gases pass through the exhaust manifold 4 and the exhaust pipe 5, they are heated by the exhaust heat.

  By the way, as shown in the present embodiment, in the case where the opening 3c is notched on the bottom of the limiter housing 3b accommodating the torque limiter mechanism 7, the inside of the limiter housing 3b can be traveled on a rainy day, on snow, waterway travel, etc. Moisture can easily penetrate into the Then, when the moisture that has entered the limiter housing 3b adheres to each component of the torque limiter mechanism 7 and the state continues and the adhesion of the moisture is repeated, rusting easily occurs with time.

  In the present embodiment, the horizontally long rectangular heat dissipation plate 6 is disposed below the limiter housing 3b, with the left and right end portions 6a joined to the exhaust pipe 5, and the central heat dissipation portion 6b formed at the portion facing the opening 3c. It is done. The limiter housing 3 b is connected to the rear end of the engine 2, and the exhaust pipe 5 at a position corresponding to the limiter housing 3 b is directly downstream of the exhaust manifold 4, and exhaust gas having high temperature exhaust heat flows .

  Therefore, the exhaust pipe 5 in the vicinity of the limiter housing 3b is heated to a high temperature, a part of the heat is received by the heat radiation plate 6, and a large amount of heat is radiated from the central heat radiation portion 6b. The heat radiated from the central heat radiating portion 6b heats the inside of the limiter housing 3b, and the heat evaporates the water attached to the torque limiter mechanism 7.

  By the way, inside the floor tunnel 1a of the vehicle 1 being traveled, a traveling wind is passing from the front to the rear, and the central heat radiation portion 6b is cooled by the traveling wind. However, as shown in FIGS. 2 and 3, since the oil pan 2c is disposed in front of the central heat radiating portion 6b, most of the traveling air flowing in the direction of the central heat radiating portion 6b is blocked by the oil pan 2c. The cooling by the traveling wind is suppressed accordingly.

  Therefore, the heat radiated from the central heat radiation portion 6b can be efficiently transferred to the inside of the limiter housing 3b through the opening 3c, and the water adhering to the torque limiter mechanism 7 can be evaporated at an early stage. As a result, rusting of the torque limiter mechanism 7 is suppressed, and a long life can be realized accordingly. Furthermore, since the lower part of the opening 3c is covered with the heat dissipation plate 6, the amount of water entering the limiter housing 3b from the opening 3c can be suppressed.

  On the other hand, as shown in FIG. 3, since the space between the exhaust pipe 5 and the limiter housing 3b is located on the outer side in the vehicle width direction from the side surface of the oil pan 2c, the traveling wind easily flows along the floor tunnel 1a. The left and right heat radiating portions 6c formed at the relevant portion of the heat radiating plate 6 are positively cooled by the passage of the traveling wind. Therefore, by adjusting the heat radiation area of the central heat radiation part 6b and the heat radiation area of the left and right heat radiation parts 6c, it is possible to adjust the heat radiation amount of the central heat radiation part 6b at the time of high speed traveling.

  That is, at the time of high speed traveling, since the acceleration / deceleration operation is repeated a relatively large number of times, the operation frequency of the torque limiter mechanism 7 increases and frictional heat is easily generated. At this time, if the inside of the limiter housing 3b is heated by the heat radiation from the central heat radiation portion 6b, the fade resistance of the torque limiter mechanism 7 is reduced. Therefore, by actively radiating heat from the left and right heat radiation portions 6c of the heat radiation plate 6 at high speed traveling, it is possible to reduce the amount of heat radiation from the central heat radiation portion 6b and to prevent a decrease in fade resistance.

  As described above, according to the present embodiment, the exhaust heat flowing through the exhaust pipe 5 is received by the heat dissipation plate 6 and dissipated from the central heat radiating portion 6b facing downward of the limiter housing 3b to adhere to the torque limiter mechanism 7 Since the moisture is evaporated, electrical control is not required, rusting of the torque transmission mechanism can be suppressed for a long period of time, and long life can be realized, and high reliability can be obtained. Furthermore, the heat dissipating plate 6 is simply added, and it can be easily mounted on existing vehicles, so that high versatility can be obtained. Further, since the heat dissipating plate 6 can be formed from a sheet metal material, it can be manufactured inexpensively, and the cost can be reduced.

Second Embodiment
FIG. 5 shows a second embodiment of the present invention. In the first embodiment described above, the exhaust pipe 5 is disposed on the left and right sides of the transmission 3, but the exhaust pipe 5 shown in the present embodiment may be a serial engine or a horizontally opposed type (V type An embodiment in which the left and right exhaust pipes are assembled as an engine and disposed on one side (right side in the vehicle width direction in the drawing) of the transmission 3 is shown.

  In addition, since it is the structure similar to 1st Embodiment except the arrangement | sequence of the exhaust pipe 5, it demonstrates using the same code | symbol and abbreviate | omits the description by drawing. The same components as those of the first embodiment of the heat dissipating plate 6 are denoted by the same reference numerals and the description thereof is omitted.

  That is, one end 6a of the heat dissipation plate 6 is joined to the exhaust pipe 5 by means such as welding, and the other end 6d is welded to the side surface of the limiter housing 3b (or the transmission case 3a). It is fixed by means such as bolting. Alternatively, a bracket may be fixed to the side surface of the limiter housing 3b and fastened to the bracket. The material of the heat radiation plate 6 and the shape of the central heat radiation portion 6b are the same as those of the first embodiment.

  However, since the right heat radiating portion 6 c formed on the heat radiating plate 6 is set according to the exhaust heat quantity of the exhaust gas passing through the single exhaust pipe 5, it is larger than the left and right heat radiating portions 6 c shown in the first embodiment. It has a surface area.

  Thus, in the present embodiment, when the exhaust pipe 5 is disposed only on one side of the transmission 3, one end 6a of the heat dissipation plate 6 is joined to the exhaust pipe 5, and the other end 6d is By fixing to the side surface of the limiter housing 3b (or the transmission case 3a), the exhaust pipe 5 can be applied even when arranged on only one side, and higher versatility can be obtained.

The present invention is not limited to the above-described embodiments. For example, the invention is applicable to a vehicle in which the engine output shaft 2d is connected to the input shaft 15a of the transmission 3 via the torque limiter mechanism 7. Vehicles are not limited to hybrid vehicles.

1 ... hybrid vehicle,
1a ... floor tunnel,
2 ... engine,
2c ... oil pan,
2d: output shaft,
3 ... Transmission,
3a ... Transmission case,
3b ... limiter housing,
3c ... opening,
5 ... Exhaust pipe,
6 ... Heat dissipation plate,
6a ... end,
6b: central radiator,
6c ... left and right heat sink,
7 ... Torque limiter mechanism,
13: Motor shaft,
15 ... Power split mechanism,
15a ... Transmission input shaft MG1 ... First motor generator,
MG2 ... second motor generator,
W ... width

Claims (5)

Engine and transmission,
A torque transmission mechanism disposed in a torque transmission path between the engine and the transmission for transmitting torque between the engine and the transmission;
A housing that accommodates the torque transfer mechanism and has an opening at the bottom;
In a powertrain structure of a vehicle, an exhaust pipe extending from the engine is disposed on a side of the housing.
A heat dissipation member is disposed below the opening,
A powertrain structure of a vehicle, wherein an end of the heat dissipation member is joined to the exhaust pipe. 2. The powertrain structure of a vehicle according to claim 1, wherein a heat dissipating portion is formed at a portion of the heat dissipating member facing the opening. 3. The powertrain structure of a vehicle according to claim 2, wherein another heat radiating portion is formed between the exhaust pipe of the heat radiating member and the housing. The exhaust pipe is disposed on the left and right of the housing,
Powertrain structure for a vehicle according to any one of claims 1 to 3, characterized in that both end portions of the heat radiating member is bonded to the each exhaust pipe. The exhaust pipe is disposed at one side of the housing,
Powertrain structure of a vehicle according to any one of claims 1 to 3, one end portion of the heat radiating member is joined to the exhaust pipe, the other end, characterized in that it is fixed to the housing.

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