JP2016145596A - Temperature increase device and temperature increase method of automatic transmission fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently increase the temperature of automatic transmission fluid (ATF(R)).SOLUTION: A temperature increase device of ATF includes a heat exchanger 400 configured to circulate engine cooling water to perform heat exchange between itself and ATF, and a compression coil spring 500 comprising a shape memory alloy deforming (expanding/contracting) according to the temperature of ATF. The heat exchanger 400 is disposed in a vertically movable manner at the bottom part of an oil pan 320 of an automatic transmission 300. Also, the compression coil spring 500 is interposed between the oil pan 320 and the heat exchanger 400, and vertically moves the position of the heat exchanger 400 to the oil pan 320 with temperature change of ATF.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an ATF temperature raising device and an ATF temperature raising method for promoting the temperature rise of an automatic transmission fluid (ATF; registered trademark).

  In an automatic transmission mounted on an automobile, since the viscosity of ATF at a low temperature is high, friction loss during warm-up is large, which is one of the causes of a reduction in fuel consumption of the automobile. For this reason, as described in Japanese Patent Application Laid-Open No. 2012-127456 (Patent Document 1), a heat exchanger is disposed inside the oil pan, and engine cooling water is circulated therein, thereby increasing the temperature of the ATF. Techniques that promote this have been proposed.

JP 2012-127456 A

  However, since ATF has a large volume change due to temperature, the heat exchanger disposed in the oil pan does not always increase the temperature of the ATF efficiently. In other words, since the oil level of the ATF goes up and down according to the temperature change, the positional relationship between the ATF and the heat exchanger changes. For example, the upper part of the heat exchanger protrudes upward from the oil level of the ATF. The heat of engine cooling water will not be used effectively.

  Accordingly, an object of the present invention is to provide an ATF temperature raising device and an ATF temperature raising method in which a heat exchanger disposed in an oil pan can efficiently raise ATF. .

  For this reason, the ATF temperature raising device is arranged at the bottom of the oil pan of the automatic transmission so as to be movable up and down, circulates engine cooling water and exchanges heat with the ATF, A temperature-sensitive member that deforms according to temperature and moves the position of the heat exchanger relative to the oil pan up and down.

  Also, the ATF temperature raising method is such that the heat exchanger fixed to the bottom of the oil pan of the automatic transmission is moved up and down by a temperature-sensitive member that deforms according to the temperature of the ATF, so that the heat exchanger Heat exchange is performed between the introduced engine cooling water and the ATF to promote the temperature increase of the ATF.

  According to the present invention, the heat exchanger disposed inside the oil pan can efficiently raise the ATF.

It is a perspective view which shows an example of an engine and an automatic transmission. It is a side view showing an example of an engine and an automatic transmission. It is a bottom view which shows an example of the mounting state of a heat exchanger. It is a perspective view which shows an example of the mounting state of a heat exchanger. It is sectional drawing which shows an example of the mounting state of a heat exchanger. It is a perspective view which shows the modification of a heat exchanger. It is a piping diagram which shows an example of the path | route of engine cooling water and ATF. It is sectional drawing explaining the oil level of ATF in an oil pan.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 show an example of an engine and an automatic transmission mounted on an automobile.

  An electronically controlled automatic transmission 300 incorporating a torque converter and a planetary gear mechanism is detachably fastened to one end face of the engine 100 by a plurality of fasteners 200 including bolts and washers. The output of the engine 100 is transmitted to the planetary gear mechanism via the torque converter of the automatic transmission 300. The engine 100 is, for example, a diesel engine or a gasoline engine such as an in-line 3 cylinder, an in-line 4 cylinder, an in-line 6 cylinder, a V-type 6 cylinder, or a V-type 8 cylinder, and is mounted vertically with respect to the vehicle.

  Engine 100 can also be mounted horizontally with respect to the vehicle. The automatic transmission 300 is not limited to a transmission incorporating a torque converter and a planetary gear mechanism, and may be a known transmission such as CVT (Continuously Variable Transmission) or DCT (Dual Clutch Transmission).

  An oil pan 320 is detachably fastened to a lower portion of the automatic transmission 300 by a fastener (not shown) for storing ATF used for gear lubrication and control valve operation. The oil pan 320 has, for example, a substantially box shape with an upper surface opened, and is manufactured by pressing a thin steel plate. The oil pan 320 closes the opening that opens at the lower portion of the automatic transmission 300, and holds the ATF at a portion partitioned by the peripheral wall and the bottom wall. In addition, the shape of the oil pan 320 is not limited to a substantially box shape having an upper surface opened, and may be, for example, an irregular shape having an upper surface opened.

  Further, a heat exchanger 400 that circulates cooling water (engine cooling water) of the engine 100 and promotes the temperature rise of the ATF is provided inside the oil pan 320, specifically, near the bottom of the oil pan 320. It is arranged to be movable.

  As shown in FIGS. 3 to 5, the heat exchanger 400 includes a pair of heat exchange members 420 that extend substantially in parallel while being separated from each other by a predetermined distance, and a pair of both ends in the longitudinal direction of the heat exchange member 420. A connecting member 440. Note that FIG. 3 shows the automatic transmission 300 from which the oil pan 320 is removed in order to explain the mounted state of the heat exchanger 400.

  As the heat exchanging member 420, for example, a fin tube heat radiating pipe having a substantially rectangular parallelepiped shape in which fins are formed around a tube through which engine coolant flows can be used. The connection member 440 is made of, for example, a substantially hat-shaped thin steel plate with a central portion protruding downward in a side view, and a heat exchange member 420 is fixed to the upper surface of the central portion by brazing or the like. Here, both end portions of the connecting member 440, that is, portions extending substantially parallel to the central portion function as attachment portions A for attaching the heat exchanger 400 to the oil pan 320, and a circular hole having a substantially circular shape here. Is formed. The connecting member 440 is not joined to the oil pan 320 because the heat exchanger 400 can move up and down with respect to the oil pan 320. The connecting member 440 can also be formed by joining a plurality of members by welding or the like.

  As shown in FIG. 6, the connecting member 440 may be a linear plate member having a substantially U-shaped (substantially channel-shaped) cross section with an open bottom surface. In this case, the upper surfaces of both ends of the connecting member 440 are fixed to the lower surface in the longitudinal direction of the heat exchange member 420 by brazing or the like. Further, separate mounting members 442 functioning as mounting portions A are fixed to the outer side surfaces of the heat exchange members 420 in the longitudinal direction by brazing or the like. The mounting member 442 is made of, for example, an equilateral mountain-shaped steel having a substantially L shape in a side view, and is disposed so that one surface thereof is substantially parallel to the upper surface and the lower surface of the heat exchange member 420 and the one surface is located above. ing. A circular hole having a substantially circular shape is formed on one surface of the attachment member 442. In short, in the heat exchanger 400 shown in FIG. 6, the heat exchange member 420 is a main structural member, and a separate mounting member 442 that functions as the mounting portion A is attached thereto.

  Returning to FIGS. 3 to 5, at one end of the pair of heat exchange members 420, a cooling water introduction pipe 460 that introduces engine cooling water into one heat exchange member 420, and engine cooling from the other heat exchange member 420. A cooling water outlet pipe 462 for leading water is connected to each other. The cooling water introduction pipe 460 and the cooling water outlet pipe 462 are, for example, an oil pan 320 via a flexible tube 464 made of metal or synthetic resin so as to enable relative displacement between the oil pan 320 and the heat exchanger 400. Respectively.

  The other ends of the pair of heat exchange members 420 are in communication with each other via a communication pipe 466 that introduces engine coolant discharged from one heat exchange member 420 to the other heat exchange member 420. Here, the cooling water introduction pipe 460, the cooling water outlet pipe 462, and the communication pipe 466 can be made of, for example, iron so as to contribute to heat exchange with the ATF.

  Heat exchanger 400 is arranged inside oil pan 320 such that the pair of heat exchange members 420 are substantially parallel to a crankshaft (not shown) of engine 100. Note that the heat exchanger 400 is not limited to the shape shown in FIGS. 3 to 5, and may have other shapes that can be disposed inside the oil pan 320.

  At the bottom surface of the oil pan 320, specifically, at four locations facing each attachment portion A of the heat exchanger 400, the base end portion of the substantially cylindrical pin member 480 that stands up vertically from the bottom surface is brazed or the like. Are fixed to each other. For example, a circular hole of each attachment portion A of the heat exchanger 400 is fitted to each pin member 480 so as to be relatively displaceable via a compression coil spring 500 made of a shape memory alloy. Here, the heat exchanger 400 is prevented from being detached from the pin member 480 by, for example, fitting a snap ring into a circumferential groove formed at the tip of the pin member 480. Further, the compression coil spring 500 has a natural length when the ambient temperature is lower than a predetermined temperature, and has a characteristic that when the ambient temperature exceeds the predetermined temperature, the entire length gradually increases as the temperature rises. The compression coil spring 500 is an example of a temperature sensitive member that deforms according to the ATF temperature.

  According to such a configuration, since the heat exchanger 400 is disposed inside the oil pan 320, for example, an ATF pipe that leads the ATF from the oil pan 320 to an external heat exchanger becomes unnecessary. The pressure loss due to the high-viscosity ATF flowing through the ATF pipe can be reduced. For this reason, the load of the oil pump which circulates ATF reduces, and it can contribute to a fuel consumption improvement.

  Further, since the heat exchanger 400 is fixed to the bottom surface of the oil pan 320, for example, when the oil pan 320 is removed from the automatic transmission 300 during inspection and maintenance, the heat exchanger 400 integrated with the heat pan 400 is removed. Can be removed together. For this reason, the man-hour required for the inspection maintenance of the heat exchanger 400, etc. can be reduced.

FIG. 7 shows an example of the engine coolant and ATF paths.
The coolant outlet 102 of the engine 100 is connected to the coolant inlet 122 of the radiator 120 via the first coolant pipe 110. A cooling water outlet 124 of the radiator 120 is connected to a water pump 140 attached to the cooling water inlet 104 of the engine 100 via a second cooling water pipe 130. Here, the water pump 140 can be driven by the output of the engine 100 or the electric motor, for example.

  The first cooling water pipe 110 and the second cooling water pipe 130 are communicated with each other via a bypass pipe 150 that bypasses the radiator 120. A thermostat 160 that opens and closes the flow path of the engine cooling water according to the temperature of the engine cooling water (cooling water temperature) is provided in the second cooling water pipe 130 positioned between the radiator 120 and the connection portion of the bypass pipe 150. It is arranged. The thermostat 160 closes the flow path when the cooling water temperature is equal to or lower than the warm-up completion temperature, and when the cooling water temperature exceeds the warm-up completion temperature, the opening degree of the flow path gradually increases toward the full opening as the cooling water temperature rises. To do.

  Therefore, since the flow path is closed by the thermostat 160 while the engine 100 is warmed up, the engine cooling water does not pass through the radiator 120 and the engine 100 can be warmed up in a short time. On the other hand, when the warm-up of the engine 100 is completed, the flow path is opened by the thermostat 160, so that the engine cooling water passes through the radiator 120, and the engine cooling water can be maintained in an appropriate temperature range. Note that the thermostat 160 may be disposed in the first cooling water pipe 110 located between the radiator 120 and the connection place of the bypass pipe 150. In addition, the bypass pipe 150 can be integrated with the radiator 120.

  The first cooling water pipe 110 located between the cooling water outlet 102 of the engine 100 and the connection location of the bypass pipe 150 is connected to the cooling water introduction pipe 460 of the heat exchanger 400 via the third cooling water pipe 170. It is communicated to. The second cooling water pipe 130 positioned between the water pump 140 and the bypass pipe 150 is connected to the cooling water outlet pipe 462 of the heat exchanger 400 through the fourth cooling water pipe 180. Yes. Accordingly, a part of the engine cooling water that has passed through the engine 100 is introduced into the heat exchanger 400 through the third cooling water pipe 170, and heat exchange with the ATF of the oil pan 320 is performed to raise the temperature of the ATF. . Then, the engine coolant that has exchanged heat with the ATF in the heat exchanger 400 is returned to the upstream of the water pump 140 through the fourth coolant pipe 180.

  The automatic transmission 300 is provided with an ATF cooler 340 that suppresses the ATF from exceeding the allowable temperature. The ATF cooler 340 can be disposed in the vicinity of the radiator 120 as shown in FIG. The ATF at the lower part of the oil pan 320 is sucked up by, for example, an oil pump 350 disposed between the engine 100 and the automatic transmission 300, and is adjusted to a predetermined pressure. Supplied to. The ATF that has passed through the control valve 360 and the torque converter 370 is introduced into the ATF inlet 342 of the ATF cooler 340 via the first ATF pipe 380 connected to the ATF outlet 302 of the automatic transmission 300. The ATF introduced into the ATF cooler 340 is cooled by exchanging heat with the atmosphere, and then is passed through the second ATF pipe 382 connected to the ATF outlet 344 to the ATF inlet 304 of the automatic transmission 300. Returned.

  The first ATF pipe 380 and the second ATF pipe 382 communicate with each other via a bypass pipe 384 that bypasses the ATF cooler 340. The second ATF pipe 382 positioned between the ATF cooler 340 and the connection place of the bypass pipe 384 is provided with a thermostat 390 that opens and closes the ATF flow path in accordance with the ATF temperature (ATF temperature). . The thermostat 390 closes the flow path when the ATF temperature is lower than or equal to the allowable temperature, and when the ATF temperature exceeds the allowable temperature, the opening degree of the flow path is gradually increased toward the full opening as the ATF temperature increases.

  Therefore, when the ATF temperature is equal to or lower than the allowable temperature, since the thermostat 390 closes the flow path, the ATF does not pass through the ATF cooler 340 and does not hinder the temperature increase of the ATF. On the other hand, when the ATF temperature exceeds the allowable temperature, the flow path is opened by the thermostat 390, so that the ATF is introduced into the ATF cooler 340, is cooled by exchanging heat with the outside air, and the ATF temperature falls below the appropriate temperature range. Can be maintained. The thermostat 390 can also be disposed in the first ATF pipe 380 located between the ATF cooler 340 and the connection place of the bypass pipe 384. Further, the bypass pipe 384 can be integrated with the ATF cooler 340.

Next, the temperature raising action of ATF by the heat exchanger 400 will be described.
Immediately after the cold start of the engine 100 or the like, the ATF temperature of the automatic transmission 300 is equal to or lower than a predetermined temperature, so the volume of the ATF is small, and as shown by the solid line in FIG. The surface is low. Further, immediately after the cold start of the engine 100 or the like, the atmospheric temperature of the compression coil spring 500 is also equal to or lower than a predetermined temperature, so that the compression coil spring 500 receives the weight of the heat exchanger 400 and contracts from its natural length. As shown in FIG. 5, the position of the heat exchanger 400 in the oil pan 320 is also low. For this reason, the heat exchanger 400 can be positioned below the oil level of the ATF by appropriately setting the arrangement position of the heat exchanger 400 when it is cold.

  Since the flow path is closed by the thermostat 160 when the engine 100 is warmed up, the engine coolant does not pass through the radiator 120 but circulates through the bypass pipe 150, and the temperature rises in a short time. The ATF of the oil pan 320 performs heat exchange with the heat exchanger 400 that circulates the engine cooling water, and therefore the temperature rises slightly after the cooling water temperature rises. When the ATF temperature rises, the viscosity of the ATF decreases and the internal friction of the automatic transmission 300 decreases, so that fuel efficiency can be improved.

  Further, when the ATF temperature rises, the volume of ATF increases, and the oil level of ATF rises as shown by the broken line in FIG. When the ATF temperature exceeds a predetermined temperature, the total length of the compression coil spring 500 gradually increases as the temperature rises, so that the position of the heat exchanger 400 in the oil pan 320 gradually increases. Therefore, by appropriately setting the characteristics of the compression coil spring 500, the position of the heat exchanger 400 can be changed following the ATF temperature, and the heat exchanger 400 is always positioned below the oil level of the ATF. Can be made. If the heat exchanger 400 is always located below the oil level of the ATF, for example, the upper part of the heat exchanger 400 does not go upward from the oil level of the ATF, and the heat of the engine cooling water is effectively used. Thus, the ATF can be effectively heated.

  When the warm-up of the engine 100 is completed, the flow path is opened by the thermostat 160, so that the engine coolant passes through the radiator 120 and the temperature thereof is maintained in an appropriate temperature range. Although this cooling water temperature is lower than the appropriate temperature of the ATF, the ATF temperature can be further increased by lubricating the gears of the automatic transmission 300, and the ATF temperature in the automatic transmission 300 can be raised to the appropriate temperature. At this time, by appropriately setting the capacity of the ATF cooler 340 and the operating characteristics of the thermostat 390, when the ATF of the oil pan 320 rises from an appropriate temperature, the ATF passes through the ATF cooler 340 and the ATF temperature is within an appropriate range. Can be maintained within.

  The temperature-sensitive member is not limited to the compression coil spring 500 made of a shape memory alloy, and a known member that deforms (extends or contracts) according to temperature, such as bimetal or wax, can be used.

300 automatic transmission 320 oil pan 400 heat exchanger 500 compression coil spring (temperature-sensitive member)

Claims (5)

A heat exchanger that is arranged at the bottom of the oil pan of the automatic transmission so as to be movable up and down, and circulates engine coolant to exchange heat with the automatic transmission oil;
A temperature-sensitive member that deforms according to the temperature of the automatic transmission oil and moves the position of the heat exchanger relative to the oil pan up and down;
A temperature raising device for an automatic transmission oil characterized by comprising: The temperature sensing member moves the position of the heat exchanger relative to the oil pan upward as the temperature of the automatic transmission oil increases.
The temperature raising device for automatic transmission oil according to claim 1. The temperature sensitive member is a compression coil spring made of a shape memory alloy interposed between the oil pan and the heat exchanger.
The temperature raising device for an automatic transmission oil according to claim 1 or 2, characterized in that The heat exchanger is fixed to the bottom surface of the oil pan.
The temperature raising device for automatic transmission oil according to any one of claims 1 to 3. A heat exchanger fixed to the bottom of the oil pan of the automatic transmission so as to be movable up and down is moved up and down by a temperature-sensitive member that deforms according to the temperature of the automatic transmission oil, and the engine coolant introduced into the heat exchanger Heat exchange between the automatic transmission fluid and the automatic transmission fluid to promote the temperature rise of the automatic transmission fluid,
A method for raising the temperature of an automatic transmission oil characterized by the above.