JP2007170499A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection accuracy of the temperature of a clutch plate. <P>SOLUTION: In an automatic transmission provided with a multiple plate clutch mechanism, a lubricating oil supply means supplying lubricating oil from an inner side of the clutch plate to the clutch plate, a detection means formed on an circumference wall of the clutch drum, provided at a discharge port discharging lubricating oil in a radial direction and an outside of the circumference wall of the clutch drum, and detecting oil temperature of lubricating oil discharged from the discharge port, is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automatic transmission, and more particularly to a temperature detection technique for a clutch plate of a multi-plate clutch mechanism.

  In general, in an automatic transmission, a plurality of sets of planetary gears for obtaining a gear ratio of each gear stage are used. Further, for switching at least a part of each gear stage, a multi-plate clutch mechanism that performs fastening between rotating elements (sun gear, ring gear, carrier) of each set of planetary gears is used. Here, the clutch plate of the multi-plate clutch mechanism generates heat due to friction during fastening or during release. When the heat generation amount is high, the facing material provided in the sliding portion of the clutch plate is seized, and a sufficient fastening force cannot be obtained at the time of fastening.

  In view of this, there has been proposed a control for detecting the temperature of lubricating oil supplied into the automatic transmission and changing the shift time when the oil temperature is changed (Patent Document 1). Patent Document 1 discloses that when the oil temperature is high, the amount of heat generated by the clutch plate tends to be high, and the shift time is shortened. Further, it is disclosed that the oil temperature of the lubricating oil is detected by providing an oil temperature sensor in the hydraulic circuit.

Japanese Patent Publication No. 6-33815

  However, the thing of patent document 1 detects the oil temperature in a hydraulic circuit, and estimates the temperature of a clutch plate, and since the lubricating oil in a hydraulic circuit circulates each part of an automatic transmission, The detection accuracy of the temperature of the clutch plate is not necessarily high.

  Accordingly, an object of the present invention is to improve the detection accuracy of the temperature of the clutch plate.

  According to the present invention, the clutch drum, the clutch hub provided inside the clutch drum, and the rotational direction of the clutch drum and the clutch hub between the peripheral wall of the clutch drum and the peripheral wall of the clutch hub. In an automatic transmission comprising a multi-plate clutch mechanism having a plurality of clutch plates arranged in a row, and a lubricant supply means for supplying lubricant to the clutch plate from the inner side of the clutch plate, A discharge port that is formed in the peripheral wall of the clutch drum and discharges the lubricating oil in a radial direction, and an oil temperature of the lubricating oil that is provided outside the peripheral wall of the clutch drum and is discharged from the discharge port. An automatic transmission comprising a detecting means for detecting is provided.

  According to the automatic transmission of the present invention, the detecting means detects the temperature of the lubricating oil discharged from the discharge port. Since the lubricating oil discharged from the discharge port passes through the clutch plate, the oil temperature substantially coincides with the temperature of the clutch plate. Therefore, the detection accuracy of the temperature of the clutch plate can be improved.

  The present invention further includes a support member that supports the detection means, and the support member is provided on an outer surface of the peripheral wall of the clutch drum in a transmission case of the automatic transmission that houses the clutch drum. It is possible to adopt a configuration including a fixing portion fixed to a facing portion, and an extending portion extending from the fixing portion toward the outer surface and having the detection means disposed at the tip thereof. According to this configuration, the detection means can be stably disposed at a position closer to the discharge port, and the temperature detection accuracy of the clutch plate can be improved.

  Moreover, in this invention, the said discharge port can employ | adopt the structure currently formed in the center part of the said rotating shaft direction among the arrangement | sequence areas of the said clutch plate. When the amount of heat generated by the clutch plate is high as a whole, the temperature distribution of the plurality of clutch plates is not necessarily uniform, and the clutch plate located at the center side compared to the clutch plates located at both ends in the rotation axis direction is It tends to be relatively hot. This is because the clutch plate located on the center side is relatively poor in heat dissipation compared to the clutch plates located on both ends in the rotation axis direction. According to the above configuration, the lubricating oil that has passed through the clutch plate located on the center side is discharged from the discharge port, and the detection means detects the temperature of the lubricating oil, so that the temperature distribution of the plurality of clutch plates is If the temperature is not uniform, the temperature of the clutch plate that is the highest temperature can be detected.

  In the present invention, the multi-plate clutch mechanism may employ a configuration in which the operation is controlled in accordance with the oil temperature detected by the detection means. According to this configuration, the operation reliability of the multi-plate clutch mechanism can be improved by controlling the multi-plate clutch mechanism based on the oil temperature detected by the detection means.

  Further, in the present invention, it is possible to employ a configuration in which transmission means for transmitting the oil temperature information detected by the detection means to a control unit of an engine to which the automatic transmission is connected is provided. According to this configuration, engine control based on the oil temperature detected by the detection means is enabled.

  As described above, according to the present invention, the accuracy of detecting the temperature of the clutch plate can be improved.

  FIG. 1 is a cross-sectional view of a main part of an automatic transmission A according to an embodiment of the present invention. The automatic transmission A has a transmission case 1 constituting its outer wall, and a torque converter chamber 2 is formed at an end thereof. A torque converter (not shown) including a pump impeller 2a is disposed in the torque converter chamber 2. The engine output is input to the pump impeller 2a. An oil pump 3 is connected to the pump impeller 2a, and the oil pump 3 pumps the lubricating oil by the rotational force of the pump impeller 2a.

  The torque converter has a turbine facing the pump impeller 2a, and a turbine shaft 4 is connected to the turbine. The turbine shaft 4 is rotated by the rotational force of the turbine. In FIG. 1, a line L <b> 1 indicates an axis of the turbine shaft 4, and the turbine shaft 4 is illustrated in an upper half portion. An oil passage 4 a for lubricating oil is formed in the turbine shaft 4, and the lubricating oil pumped from the oil pump 3 via the hydraulic control device is discharged from the oil passage 4 a into the transmission case 1.

  The automatic transmission A has a planetary gear 10 disposed around the turbine shaft 4 and enclosed in the transmission case 1. The planetary gear 10 includes a ring gear 11, a sun gear 12, and a pinion 13 that meshes with the inner teeth of the ring gear 11 and the outer teeth of the sun gear 12. The ring gear 11 is connected to the turbine shaft 4 via a connecting member 11a, and rotates around the line L1 together with the turbine shaft 4. The sun gear 12 is fixed to the transmission case 1. The sun gear 12 is loosely fitted to the turbine shaft 4 and is disposed so as to be rotatable around the line L1. A carrier 14 is rotatably supported on the pinion 13, and the carrier 14 is disposed so as to be rotatable around a line L1.

  The automatic transmission A also includes a multi-plate clutch mechanism 20 disposed around the turbine shaft 4 and enclosed in the transmission case 1. The multi-plate clutch mechanism 20 includes a clutch drum 21 and a clutch hub 22 provided inside the clutch drum 21. The clutch drum 21 and the clutch hub 22 are rotatably arranged around the turbine shaft 4 and the rotation axis direction is the line L1 direction. The clutch drum 21 is connected to the carrier 14 and rotates according to the rotation of the carrier 14. The clutch hub 22 is connected to a rotating element of a subsequent planetary gear (not shown).

  Between the peripheral wall 21a of the clutch drum 21 and the peripheral wall 22a of the clutch hub 22, a plurality of clutch plates 23, 24 arranged in the rotational axis direction (line L1 direction) of the clutch drum 21 and the clutch hub 22 are arranged. Has been. Four clutch plates 23 are provided, all of which are held by the clutch drum 21. Four clutch plates 24 are also provided, all of which are held by the clutch hub 22. A disc spring 25 is provided on the right side of the rightmost clutch plate 23 in FIG. Further, a retaining ring 26 and a retainer 27 for restricting movement of the clutch plates 23 and 24 are provided on the left side of the leftmost clutch plate 23.

  A part of the piston member 28 is in contact with the disc spring 25. The piston member 28 is provided so as to be slidable in the direction of the line L1, moves to the left in FIG. 1 using the lubricating oil supplied from the turbine shaft 4 as hydraulic oil, and moves to the right in FIG. 1 by the bias of the spring 28a. Move to. When the piston member 28 moves to the left in FIG. 1, the clutch plates 23 and 24 are pressed by the piston member 28 via the disc spring 25, and are sandwiched between the piston member 28 and the retaining ring 26. It will be in a fastening state. This fastening state is released when the piston member 28 moves to the right in FIG.

  A part of the lubricating oil supplied from the turbine shaft 4 is supplied to the clutch plates 23 and 24 from the inner side of the clutch plates 23 and 24. An arrow in FIG. 1 shows an example of a supply path of lubricating oil to the clutch plates 23 and 24, and the oil path including the oil pump 3 and the oil path 4 a extends from the inner side of the clutch plates 23 and 24 to the clutch plate 23. , 24 functions as a lubricating oil supply means for supplying lubricating oil. The supplied lubricating oil functions as a cooling medium for the clutch plates 23 and 24.

  Here, in the present embodiment, a plurality of discharge ports 21 b are provided in the peripheral wall 21 a of the clutch drum 21. The discharge port 21b is an opening for discharging the lubricating oil supplied to the clutch plates 23 and 24 in the radial direction (outward of the clutch drum 21).

  The automatic transmission A is provided with a temperature detection unit 30 that detects the temperature of the lubricating oil supplied to the clutch plates 23 and 24. The temperature detection unit 30 is fixed to a portion 1 a of the transmission case 1 that faces the outer surface of the peripheral wall 21 a of the clutch drum 21. FIG. 2 is an enlarged view around the temperature detection unit 30 (partially broken). The arrows in FIG. 2 show examples of the lubricating oil movement paths around the clutch plates 23 and 24. The temperature detection unit 30 is provided outside the peripheral wall 21a of the clutch drum 21, and includes a temperature sensor 33 that detects the temperature of the lubricating oil discharged from the discharge port 21b, a support member 31 that supports the temperature sensor 33, Is provided.

  In the case of this embodiment, the temperature sensor 33 is a sensor that converts a temperature into an electric signal, and examples thereof include a thermocouple and a thermistor. The support member 31 has a cylindrical shape with a hole formed in the center thereof, and extends to the outer surface of the peripheral wall 21a of the clutch drum 21 from the fixed portion 31a fixed to the portion 1a of the transmission case 1 and the fixed portion 31a. Extending portion 31b. The fixing portion 31a passes through the portion 1a of the transmission case 1, and is fixed to the portion 1a by screw fastening or an adhesive. A temperature sensor 33 is disposed at the tip of the extended portion 31b in the central hole of the support member 31. The signal line of the temperature sensor 33 passes through the remaining part of the hole and is filled with the resin material 32.

  Therefore, in this embodiment, the temperature sensor 33 detects the temperature of the lubricating oil discharged from the discharge port 21b. Since the lubricating oil discharged from the discharge port 21 b passes through the clutch plates 23 and 24, the oil temperature substantially matches the temperature of the clutch plates 23 and 24. Therefore, the detection accuracy of the temperature of the clutch plates 23 and 24 can be improved.

  Further, by supporting the temperature sensor 33 on the transmission case 1 with the support member 31, the temperature sensor 33 can be stably disposed at a position closer to the discharge port 21b. For this reason, the oil temperature of the lubricating oil immediately after being discharged from the discharge port 21b can be detected, and the temperature detection accuracy of the clutch plates 23 and 24 can be improved.

  Here, when the amount of heat generated by the clutch plates 23 and 24 is high as a whole, the temperature distribution of the plurality of clutch plates 23 and 24 is not necessarily uniform, and the clutch plates 23 and 24 positioned at both ends in the direction of the line L1. Compared to the clutch plates 23 and 24 located on the center side, the temperature tends to be relatively high. This is because the clutch plates 23 and 24 located on the center side are relatively poor in heat dissipation compared to the clutch plates 23 and 24 located on both ends.

  In the present embodiment, the discharge port 21b is provided at least in the central portion Sc in the direction of the line L1 (FIG. 1) in the arrangement region S of the clutch plates 23 and 24, and the temperature sensor 33 is provided in the central portion Sc. It is disposed at a position facing the discharge port 21b. According to this configuration, the lubricating oil passing through the clutch plates 23 and 24 located on the center side is discharged from the discharge port 21b of the central portion Sc, and the temperature sensor 33 detects the temperature of the lubricating oil. When the temperature distribution of the clutch plates 23 and 24 is not uniform, the temperature of the clutch plates 23 and 24 on the center side that becomes the highest temperature can be detected.

  Next, control based on the detection result of the temperature sensor 33 will be described. FIG. 3 is a block diagram showing the configuration of the control unit 50 of the automatic transmission A. The control unit 50 includes a CPU 51, an EEPROM 52 storing a control program executed by the CPU 51, a RAM 53 storing a calculation result of the CPU 51, an input / output interface (I / OIF) 54 functioning as an interface to an external device, an engine And a communication interface (communication IF) 55 for the control unit (ECU).

  Connected to the I / OIF 54 are various sensors provided in a vehicle on which the automatic transmission A is mounted, and various control valves that control the hydraulic system of the automatic transmission A. The control valve includes a control valve for controlling the operation of the multi-plate clutch mechanism 20 (supply / cutoff of hydraulic oil to the piston 28). The sensor also includes a temperature sensor 33. The CPU 51 controls each control valve based on detection results of various sensors obtained via the I / OIF 54 and information such as an engine control state from the ECU.

  As an example of control of the operation of the multi-plate clutch mechanism 20, changing the shift time according to the oil temperature detected by the temperature sensor 33 can be mentioned. For example, when the oil temperature is higher than a predetermined threshold, the heat generation amount of the clutch plates 23 and 24 is assumed to be large, and the control for reducing the heat generation amount, for example, the slip control time of the clutch plates 23 and 24 is normally set. It is shorter than it is, and complete fastening or full release is early. Such control can improve the reliability of the operation of the multi-plate clutch mechanism 20.

  In addition, since the control unit 50 includes the communication IF 55, information on the oil temperature detected by the temperature sensor 33 can be transmitted to the ECU (transmission means). The ECU can control the engine torque based on the received oil temperature information. For example, when the oil temperature is higher than a predetermined threshold value, the heat generation amount of the clutch plates 23 and 24 is assumed to be large, and control for reducing the engine torque is performed. As a result, the amount of heat generated by the clutch plates 23 and 24 can be reduced even in engine control.

It is principal part sectional drawing of the automatic transmission A which concerns on one Embodiment of this invention. It is an enlarged view of the periphery of the temperature detection unit 30 (partially broken). 3 is a block diagram of a control unit 50 of the automatic transmission A. FIG.

Explanation of symbols

A automatic transmission 1 transmission case 10 planetary gear 20 multi-plate clutch mechanism 21 clutch drum 21b discharge port 22 clutch hubs 23 and 24 clutch plate 30 temperature detection unit 33 temperature sensor 50 control unit

Claims (5)

A plurality of clutch drums, a clutch hub provided inward of the clutch drum, and a plurality of rows arranged in the direction of the rotation axis of the clutch drum and the clutch hub between the peripheral wall of the clutch drum and the peripheral wall of the clutch hub A multi-plate clutch mechanism having a clutch plate,
Lubricating oil supply means for supplying lubricating oil to the clutch plate from the inner side of the clutch plate;
In an automatic transmission with
A discharge port formed in the peripheral wall of the clutch drum and configured to discharge the lubricating oil in a radial direction;
Detecting means provided outside the peripheral wall of the clutch drum for detecting the temperature of the lubricating oil discharged from the discharge port;
An automatic transmission characterized by comprising: Furthermore,
A support member for supporting the detection means;
The support member is
Of the transmission case of the automatic transmission that houses the clutch drum, a fixed portion that is fixed to a portion facing the outer surface of the peripheral wall of the clutch drum;
An extending portion extending from the fixed portion toward the outer surface, and having the detection means disposed at a tip thereof;
The automatic transmission according to claim 1, further comprising: The outlet is
3. The automatic transmission according to claim 1, wherein the automatic transmission is formed at a central portion in the direction of the rotation axis in an arrangement region of the clutch plates.   The automatic transmission according to any one of claims 1 to 3, wherein the operation of the multi-plate clutch mechanism is controlled according to the oil temperature detected by the detection means.   The automatic according to any one of claims 1 to 4, further comprising a transmission unit that transmits information on the oil temperature detected by the detection unit to a control unit of an engine to which the automatic transmission is connected. transmission.

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