JP5724392B2 - Transmission cooling device - Google Patents

Description

  The present invention relates to a transmission cooling device that achieves a high cooling effect with low fuel consumption and low cost and does not prevent warm-up.

  The transmission transmits the rotation of the engine to the drive wheel shaft at a gear ratio selected from a plurality of gear ratios. A plurality of gears are combined in the case of the transmission. In the case, oil is circulated in order to reduce friction between the gears and friction between the gear and the shaft that rotatably holds the gear. For example, at the bottom of the case, oil accumulates so that at least a part of the gear is immersed, and when the gear that is partially immersed in the oil rotates, the oil is scraped up and the surrounding members are oiled. Is bathed. Oil circulates from the member to the bottom of the case. This lubrication method is called oil bath lubrication.

  Also, a lubrication method is adopted in which oil is sucked up from the bottom of the case by an oil pump and pumped to the circulation path, and oil is supplied from the circulation path to the gears and shaft.

JP 2008-303918 A

  By the way, oil is effective not only for lubrication but also for cooling. That is, a heat source such as a gear in the case loses heat to the oil, heat is transferred from the hot oil that has fallen to the bottom of the case to the case, and is radiated from the case to the outside. Further, since the oil scraped up by the gear is splashed on the inner surface of the case, the oil heat propagates to the case while the oil flows down the inner surface of the case. The heat source is cooled by the oil thus cooled being raked up or circulated by an oil pump.

  If the expected cooling effect cannot be obtained, further cooling measures are taken. For example, when the amount of oil is increased, the heat capacity of the entire oil increases, so that a temporary temperature increase due to high-load operation or the like can be suppressed. Further, when an oil cooler is installed outside the case, hot oil is taken out from the case to the oil cooler, and the oil cooled by the oil cooler is returned to the case, an excellent cooling effect is maintained for a long time.

  However, when the amount of oil is increased, the gear is immersed deeply in the oil, so that the stirring loss due to the work of stirring the oil by the gear increases and the fuel consumption deteriorates. In addition, the installation of the oil cooler increases the cost of parts. Therefore, these cooling measures are not preferable.

  On the other hand, at the time of starting from a state where the engine and the transmission are at the same temperature as the outside temperature, that is, a so-called cold start, it is necessary to warm up to a temperature at which the engine and the transmission operate smoothly. At this time, if the cooling effect of the oil is working, it will hinder warm-up.

  Therefore, an object of the present invention is to provide a transmission cooling device that solves the above-described problems, provides a high cooling effect with low fuel consumption and low cost, and does not prevent warm-up.

  To achieve the above object, the present invention provides a plurality of gears that are meshed and rotated, a case that stores the plurality of gears and that stores oil at the bottom so that at least a part of the gears are immersed, A cooling device that cools oil in a transmission including an oil pump that sucks up oil from the bottom and pumps the oil, a transfer path that extracts and transfers a part of the oil pumped by the oil pump, and a transfer path that is transferred through the transfer path. An oil discharge member that discharges the oil to the inner surface of the case, an oil temperature sensor that detects the temperature of the oil, and the oil discharge from the oil discharge member is suppressed when the temperature detected by the oil temperature sensor is below a threshold value An oil release suppressing member is provided.

  The oil discharge member may include a pipe that is disposed along the inner surface of the case and has a flow hole that allows oil to flow down.

  The oil discharge member may include a nozzle that is disposed to face the inner surface of the case and injects oil toward the inner surface of the case.

  A diffusion guide for diffusing oil released to the inner surface may be provided on the inner surface of the case.

  The transmission has a plurality of main gears and a main shaft disposed at an upper portion in the case, and a plurality of counter gears meshed with the main gear and partially immersed in oil. The oil discharge member may discharge oil to a surface of the inner surface of the case opposite to a surface facing the scraping side of the counter gear.

  A relief valve may be provided for extracting oil from the outlet of the oil pump to the transfer path when the oil pressure at the outlet of the oil pump becomes a threshold value or more.

  A check valve for preventing the oil from flowing back in the transfer path may be provided.

  The oil release suppressing member may include a valve for extracting oil from the transfer path to the bottom of the case.

  The oil release suppression member starts suppression when the temperature detected by the oil temperature sensor falls below the threshold when the oil release from the oil release member is not suppressed, and the oil release from the oil release member If the temperature detected by the oil temperature sensor exceeds a threshold value for hysteresis higher than the threshold value, the suppression may be stopped.

  The present invention exhibits the following excellent effects.

  (1) Low fuel consumption and low cost.

  (2) A high cooling effect can be obtained.

  (3) Warm-up is not hindered.

It is a block diagram of the transmission and transmission cooling device which show one Embodiment of this invention. It is sectional drawing which looked at the transmission and transmission cooling device of FIG. 1 in the cross section along the side surface of a gearwheel. It is a one part block diagram of the case of the transmission and transmission cooling device which show other embodiment of this invention. It is a flowchart which shows the control procedure of the transmission cooling device of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a transmission 101 to which the present invention is applied includes a plurality of gears 102, 103, 104 that are meshed and rotated, and a plurality of gears 102, 103, 104 that are housed in one gear 103. A case 105 that accumulates oil D in the bottom 105 a so that the part is immersed, and an oil pump 107 that sucks up the oil D from the bottom 105 a of the case 105 and pumps it to the circulation path 106.

  The transmission 101 according to the present embodiment has an input gear 102 and an input shaft 108 disposed at an upper portion in a case 105, and a plurality of main gears 104 having different numbers of teeth, and is on the same axis as the input shaft 108. A main shaft 109 disposed at an upper portion in the case 105 and a plurality of counter gears 103 having different numbers of teeth meshing with the main gear 104 and partially immersed in oil, are parallel to the input shaft 108 and the main shaft 109. And a countershaft 110 disposed at a lower portion in 105.

  The input shaft 108 is connected to a crankshaft (not shown) via a clutch (not shown). The input gear 102 is integrally attached to the input shaft 108. The five counter gears 103 of the counter shaft 110 are integrally attached to the counter shaft 110. One counter gear 103 is always meshed with the input gear 102, and four main gears 104 are always meshed with the four counter gears 103. Therefore, when the input shaft 108 rotates, the input gear 102, all the counter gears 103, the counter shaft 110, and all the main gears 104 rotate.

  The main gear 104 is rotatably attached to the main shaft 109. The main shaft 109 is provided with a mechanism (not shown) that locks each main gear 104 to the main shaft 109. When any of the main gears 104 is selectively locked, the locked main gear 104 is locked. The main shaft 109 rotates with the rotation 104, and the rotation of the input shaft 108 is transmitted to the main shaft 109. The gear ratio of the transmission 101 is determined by the gear ratio between the main gear 104 selected at this time and the counter gear 103 engaged therewith.

  The circulation path 106 guides the oil D pumped from the oil pump 107 to a lubrication site such as a tooth surface of the main gear 104 or a friction site of the main gear 104 and the main shaft 109. As the circulation path 106, piping may be provided inside or outside the case 105 from the oil pump 107 to the vicinity of the lubrication site, but here, a groove that penetrates through the main shaft 109 and opens near the lubrication site. And has a structure in which piping is provided from the oil pump 107 to the inlet of the groove.

  The transmission cooling device 1 according to the present invention takes out a part of the oil D that is pumped to the circulation path 106 by the oil pump 107, and is located above the oil surface indicated by the one-dot chain line, for example, the same as the top of the main gear 104. A transfer path 2 for transferring to a high position, an oil discharge member 3 for discharging oil D transferred through the transfer path 2 to the inner surface of the case 105, an oil temperature sensor 4 for detecting the temperature of the oil D, and an oil temperature An oil release suppression member 5 that suppresses oil release from the oil release member 3 when the temperature detected by the sensor 4 is equal to or lower than a threshold value is provided. In addition, although the transfer path 2 is branched and installed from the circulation path 106, the oil discharge member 3 may be installed inside the case 105 or may be installed outside.

  In the present embodiment, the oil discharge member 3 includes a pipe 7 that is disposed along the inner surface of the case 105 and has a flow hole 6 through which oil D flows down. The pipe 7 extends in parallel with the main shaft 109 at a position close to the upper surface of the case 105, and a plurality of flow-down holes 6 are formed at appropriate intervals.

  As shown in FIG. 2, the counter gear 103 always rotates in the same rotational direction. Here, the rotation direction of the counter gear 103 is shown counterclockwise. The input gear 102 and the main gear 104 that mesh with the counter gear 103 rotate in the clockwise direction opposite to the counter gear 103. FIG. 2 shows a state in which the oil D that has been scraped up is splashed on the inner surface of the case 105. Since the counter gear 103 rotates counterclockwise, the oil D is scraped rightward. Of the inner surface of the case 105, the right side surface in the figure faces the scraping side of the counter gear 103. Oil D is splashed on the right side as shown. This surface is called a splash surface 111.

  In the present embodiment, the oil release member 3 is configured to release the oil D to the left side of the figure, which is the opposite side of the counter gear 103 facing the scraping side (the splashing surface 111). This surface is called a non-bounce surface 112. The tube 7 has a semicircular cross section along the non-splashing surface 112. The flow down hole 6 is opened toward the bottom 105 a of the case 105 so that the oil D flows down along the inner surface of the case 105.

  As shown in FIG. 1, in this embodiment, the transmission cooling device 1 allows oil D from the circulation path 106 to the transfer path 2 when the oil pressure in the circulation path 106 connected to the outlet of the oil pump 107 exceeds a threshold value. A relief valve 8 is provided. The relief valve 8 is a valve configured such that the outlet side is opened when the pressure on the inlet side is about to exceed a threshold value. The relief valve 8 serves to keep the oil pressure in the circulation path 106 below a threshold value and supply the extracted oil D to the transfer path 2.

  The transmission cooling device 1 includes a check valve 9 that prevents the oil D from flowing back in the transfer path 2. Specifically, the transfer path 2 is a branch path 10 at the outlet of the relief valve 8, and a check valve 9 is inserted into one of the branch paths 10 on the way to the pipe 7.

  In the present embodiment, the oil release suppressing member 5 has a valve 11 that extracts the oil D of the transfer path 2 to the bottom 105 a of the case 105. The valve 11 is connected to the other one of the branch paths 10. The outlet of the valve 11 is arranged toward the bottom 105a of the case 105, or is connected to the middle of the suction pipe 113 that is piped from the inlet of the oil pump 107 to the bottom 105a of the case 105.

  Hereinafter, the operation of the transmission cooling device 1 of the present invention will be described.

  Since the plurality of gears 102, 103, and 104 are always meshed and rotated in the transmission 101 while the vehicle after the warm-up is completed, the friction between the gears 102, 103, and 104, the main gear 104, and the main shaft are rotated. Oil D is circulated to relieve friction with 109. When the counter gear 103, which is partially immersed in the oil D accumulated in the bottom 105a of the case 105, rotates, the oil D is scraped up and oil bath lubrication is performed. Oil D sucked from the bottom 105 a of the case 105 by the oil pump 107 is pumped to the circulation path 106 and supplied to a lubrication site such as a tooth surface of the main gear 104 and a friction portion of the main gear 104 and the main shaft 109. The

  At this time, the heat sources such as the gears 102, 103, 104, etc. in the case 105 are deprived of heat by the oil D, and heat propagates from the hot oil D that has fallen to the case bottom 105 a to the case 105, Heat is released to the outside. In addition, since the oil D scraped up by the counter gear 103 is splashed on the splashing surface 111, the heat of the oil D propagates to the case 105 while the oil D flows down the splashing surface 111. The heat source is cooled by the oil D thus cooled being raked up or circulated by an oil pump.

  However, in the prior art, the oil D is transferred to the inner surface of the case 105 only by scooping up by the counter gear 103, and the oil D does not splash on the non-splashing surface 112 of the inner surface of the case 105. Did not contribute to cooling.

  In the present invention, a part of the oil D pumped by the oil pump 107 to the circulation path 106 is transferred to the upper part from the oil surface by the transfer path 2, and the oil D transferred by the transfer path 2 is transferred to the case 105 by the oil discharge member 3. Released to the inner surface. Thereby, more oil D flows down the inner surface of the case 105, and a high cooling effect is obtained. Moreover, in the present embodiment, since the oil release member 3 is configured to release the oil D to the non-splashing surface 112, the non-splashing surface 112 contributes to cooling, and a higher cooling effect is achieved. can get. As a result, the oil cooler installed in the prior art is omitted or reduced in size, the cost of parts is reduced, and the work of transferring oil to the oil cooler is unnecessary or reduced, improving fuel efficiency. To do.

  Further, in the present embodiment, the relief valve 8 is connected to the circulation path 106 that has been conventionally pumping the oil D, whereby a part of the oil D is extracted into the transfer path 2 and discharged from the oil discharge member 3. . For this oil transfer, work surplus in the oil pump 107 is used, and no special pumping means is added, so that an increase in parts cost can be suppressed and fuel consumption can be prevented from deteriorating.

  In the present embodiment, since the pipe 7 as the oil discharge member 3 extends in parallel with the main shaft 109 at a position close to the upper surface of the case 105, the oil D flows down over a wide area of the inner surface of the case 105. High cooling effect can be obtained.

  Next, the operation of the transmission cooling device 1 when the vehicle cold starts will be described.

  If the oil cooling effect is active before the warm-up is completed at the cold start, the warm-up is hindered. In the transmission cooling device 1 of the present invention, when the temperature detected by the oil temperature sensor 4 is equal to or lower than the threshold value, the oil release suppression member 5 suppresses oil release from the oil release member 3. Specifically, since the valve 11 connected to the branch path 10 extracts the oil D in the transfer path 2 to the inlet of the oil pump 107 or the bottom 105a of the case 105, the oil D is transferred from the check valve 9 to the pipe 7. Oil release is suppressed. Thus, when the oil temperature is equal to or lower than the threshold value, the oil D does not flow down to the non-splashing surface 112 and warm-up is not hindered.

  In the present embodiment, since the check valve 9 is inserted in the transfer path 2, the transfer path 2 is obtained when there is no oil supply from the relief valve 8 or when the oil D is extracted by the oil discharge member 3. Thus, the oil D is prevented from flowing back and air is prevented from entering the transfer path 2. As a result, bubbles are not generated in the oil D accumulated in the bottom 105a of the case 105, and bubbles are not generated in the oil D flowing down from the pipe 7 to the non-splashing surface 112.

  Next, another embodiment of the present invention will be described.

  FIG. 3 shows the transmission cooling device 31. However, the members of the transmission 101 housed in the case 105 are omitted. Further, the same members as those of the transmission cooling device 1 among the members of the transmission cooling device 31 are omitted.

  As shown in FIG. 3, the oil discharge member 3 of the transmission cooling device 31 is disposed so as to face the non-splashing surface 112 of the case 105, and has a nozzle 12 that injects oil D toward the non-splashing surface 112. Have. The nozzle 12 is connected to the transfer path 2 and diffuses and jets the oil D from the transfer path 2 as fine oil droplets or mist. The nozzle 12 preferably has a wide-angle injection range so that the oil D is widely injected onto the non-splashing surface 112. The number of nozzles 12 is not limited to one, and a plurality of nozzles 12 may be arranged. The nozzle 12 may be arranged in an upward or obliquely upward posture at a low position close to the oil surface as shown, or may be arranged in a relatively horizontal posture at a high position.

  The oil D sprayed from the nozzle 12 to the non-splashing surface 112 flows down while heat is taken away by the case 105. Further, since the oil D injected from the nozzle 12 diffuses widely in the case 105, it contributes to the lubrication of the gears 102, 103, and 104.

  As shown in FIG. 3, the transmission cooling device 31 includes a diffusion guide 13 that diffuses the discharged oil D on the inner surface of the case 105. The diffusion guide 13 is formed such that a rib or a recessed groove raised from the inner surface of the case 105 extends with a horizontal or gentle inclination. The diffusion guide 13 functions to diffuse the oil D about to flow down along the inner surface of the case 105 in the lateral direction. As a result, the oil D flows down over a wider area of the inner surface of the case 105, and a high cooling effect is obtained. The diffusion guide 13 may be formed on either the splash surface 111 or the non-splash surface 112. There may be a plurality of diffusion guides 13.

  The flowchart of FIG. 4 shows the control procedure of the transmission cooling devices 1 and 31 having hysteresis in the oil temperature determination.

  This control procedure is repeatedly executed at appropriate time intervals.

  In step S1, it is determined whether the valve 11 of the oil release inhibiting member 5 is open or closed. When the valve 11 is closed, the oil release suppressing member 5 does not suppress the oil release from the oil releasing member 3, so the process proceeds to step S2. When the valve 11 is open, the oil release suppression member 5 suppresses oil release from the oil release member 3, and thus the process proceeds to step S3.

  In step S2, it is determined whether or not the temperature t detected by the oil temperature sensor 4 is equal to or less than a threshold value t1. When the temperature t exceeds the threshold value t1, the current control procedure ends. When the temperature t is equal to or lower than the threshold value t1, the control procedure of this time is ended after the valve 11 is opened in step S4.

  In step S3, it is determined whether the temperature t detected by the oil temperature sensor 4 exceeds the hysteresis threshold t2 (t1 <t2). When the temperature t is equal to or lower than the hysteresis threshold t2, the current control procedure is terminated. If the temperature t exceeds the hysteresis threshold t2, the control procedure of this time is ended after the valve 11 is closed in step S5.

  By executing the above control procedure, the oil release suppression member 5 does not suppress oil release from the oil release member 3, but suppresses the suppression when the temperature detected by the oil temperature sensor 4 is equal to or less than the threshold value t1. When the oil release from the oil release member 3 is suppressed and the temperature detected by the oil temperature sensor 4 exceeds the hysteresis threshold t2, the suppression is stopped.

  In the control procedure where the threshold is only one of t1 and if the oil temperature is equal to or lower than the threshold t1, the oil release is immediately suppressed, and when the oil temperature exceeds the threshold t1, the suppression is stopped immediately. In some cases, hunting (chattering) in which oil release suppression and suppression stop are frequently repeated is likely to occur. However, according to the control procedure of FIG. 4, the oil temperature determination has hysteresis in the temperature range of t2−t1, and thus hunting is prevented.

DESCRIPTION OF SYMBOLS 1 Transmission cooling device 2 Transfer path 3 Oil discharge member 4 Oil temperature sensor 5 Oil discharge suppression member 6 Downflow hole 7 Pipe 8 Relief valve 9 Check valve 10 Branch path 11 Valve 12 Nozzle 13 Diffusion guide

Claims (9)

A plurality of gears rotated in mesh with each other; a case in which the plurality of gears are housed and in which oil is stored at the bottom so that at least a part of the gears are immersed; and an oil pump that sucks and pumps oil from the bottom of the case; In the cooling device for cooling the oil of the transmission equipped with
A circulation path for supplying oil that is pumped by the oil pump to a power transmission member in the case;
A part of the oil pumped by the oil pump is taken out, and a transfer path for transferring the oil into the case through a path different from the circulation path ,
An oil release member for releasing the oil transferred in the transfer path to the inner surface of the case;
A transmission cooling device, comprising: a relief valve for extracting oil from an outlet of the oil pump to the transfer path when an oil pressure at an outlet of the oil pump becomes a threshold value or more .   2. The transmission cooling device according to claim 1, wherein the oil discharge member has a pipe formed along the inner surface of the case and formed with a flow-down hole through which oil flows down.   2. The transmission cooling device according to claim 1, wherein the oil discharge member includes a nozzle that is disposed to face the inner surface of the case and injects oil toward the inner surface of the case.   The transmission cooling device according to any one of claims 1 to 3, further comprising: a diffusion guide for diffusing oil discharged to the inner surface of the case. The transmission has a plurality of main gears and a main shaft disposed at an upper portion in the case, and a plurality of counter gears meshed with the main gear and partially immersed in oil. And a countershaft disposed on the
The transmission cooling according to any one of claims 1 to 4, wherein the oil discharge member discharges oil to a surface of the inner surface of the case opposite to a surface facing the scraping side of the counter gear. apparatus. The transmission cooling device according to claim 1, further comprising a check valve that prevents backflow of oil in the transfer path. An oil temperature sensor that detects the temperature of the oil;
The transmission cooling device according to any one of claims 1 to 6, further comprising an oil discharge suppression member that suppresses oil discharge from the oil discharge member when a temperature detected by the oil temperature sensor is equal to or lower than a threshold value. . The transmission cooling device according to claim 7, wherein the oil release suppressing member has a valve for extracting oil from the transfer path to the bottom of the case. The oil release suppression member starts suppression when the temperature detected by the oil temperature sensor falls below the threshold when the oil release from the oil release member is not suppressed, and the oil release from the oil release member 9. The transmission cooling device according to claim 7 , wherein when the temperature is suppressed, the suppression is stopped when the temperature detected by the oil temperature sensor exceeds a hysteresis threshold higher than the threshold.

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