JP2007170500A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection accuracy of temperature of a clutch plate while improving layout properties and assembly properties of a sensor detecting temperature of the 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 rotation speed sensor provided on an outside of a circumference wall of a clutch drum and detecting rotation speed of the clutch drum with using the clutch drum as a detected rotor, and a support member supporting the rotation speed sensor, a temperature sensor 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, and the temperature sensor is supported by the support member. <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. In controlling an automatic transmission, it is known that the number of rotations of a rotating element in the automatic transmission is detected by an electromagnetic pickup type rotation number sensor or the like (Patent Document 1). It is also known that the rotational speed of the multi-plate clutch mechanism is controlled by detecting the rotational speed of the clutch drum using such a rotational speed sensor as the detected rotor.

  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 2). Patent Document 2 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.

JP-A-9-96354 Japanese Patent Publication No. 6-33815

  However, since the thing of patent document 2 detects the oil temperature in a hydraulic circuit and estimates the temperature of a clutch plate, 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. In order to increase the detection accuracy of the temperature of the clutch plate, it is desirable to provide a temperature sensor in the vicinity of the clutch plate. However, the vicinity of the clutch plate has a complicated configuration, and the arrangement site becomes a problem.

  Accordingly, an object of the present invention is to improve the detection accuracy of the temperature of the clutch plate while improving the layout and assembly of the sensor for detecting 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. A multi-plate clutch mechanism, a lubricating oil supply means for supplying lubricating oil to the clutch plate from the inner side of the clutch plate, and an outer periphery of the peripheral wall of the clutch drum. An automatic transmission comprising a rotation speed sensor that detects the rotation speed of the clutch drum using the clutch drum as a detected rotor, and a support member that supports the rotation speed sensor. A discharge port formed in the peripheral wall for discharging the lubricating oil in a radial direction; and an outer side of the peripheral wall of the clutch drum Provided, and a temperature sensor for detecting the oil temperature of the lubricating oil discharged from the discharge port, an automatic transmission wherein the temperature sensor is characterized in that it is supported by the supporting member.

  According to the automatic transmission of the present invention, the temperature sensor 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 temperature sensor is supported by the support member together with the rotational speed sensor, and these sensors can be integrated into one unit. Therefore, the layout property and assembly property of the temperature sensor can be improved.

  In the present invention, the support member includes a fixing portion that is fixed to a portion of the transmission case of the automatic transmission that houses the clutch drum that faces the outer surface of the peripheral wall of the clutch drum, and the fixing portion. It is possible to employ a configuration that includes an extending portion that extends toward the outer surface from which the temperature sensor is disposed. According to this configuration, both the rotation speed sensor and the temperature sensor can be stably supported. In particular, the temperature sensor 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.

  Moreover, in this invention, the structure which connected the said rotation speed sensor and the said temperature sensor in series is employable. According to this configuration, the signal lines from the sensor can be reduced, and the number of circuit terminals and the number of harnesses can be reduced.

  As described above, according to the present invention, the accuracy of detecting the temperature of the clutch plate can be improved while improving the layout and assembly of the sensor that detects the temperature of the clutch plate.

  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 sensor unit 30. The sensor 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 sensor 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 sensor unit 30 is provided outside the peripheral wall 21a of the clutch drum 21, and includes a rotational speed sensor 34 that detects the rotational speed of the clutch drum 21 using the clutch drum 21 as a detected rotor, and an outer side of the peripheral wall 21a of the clutch drum 21. And a temperature sensor 33 that detects the temperature of the lubricating oil discharged from the discharge port 21b, and a rotation speed sensor 34 and a support member 31 that supports the temperature sensor 33.

  The rotation speed sensor 34 includes a cylindrical core 34a, a cylindrical permanent magnet 34b disposed at the upper end of the core 34a, and a coil 34c provided around the core 34a. It is a sensor. By forming irregularities on the outer surface of the peripheral wall 21a of the clutch drum 21 at an equal pitch in the circumferential direction, the distance between the lower end surface of the core 34a and the outer surface of the peripheral wall 21a of the clutch drum 21 changes. The magnetic flux passing through the core 34a changes, and the coil 34c generates a voltage corresponding to the change in the magnetic flux.

  The irregularities formed at equal pitch on the outer surface of the peripheral wall 21a of the clutch drum 21 can be formed for the rotational speed sensor 34, but the clutch plate 23 is usually engaged with the peripheral wall 21a of the clutch drum 21. Splines to be joined are formed, and irregularities associated with the formation of the splines are formed at equal pitches in the circumferential direction. Therefore, this unevenness may be used. In this embodiment, an electromagnetic pickup type rotational speed sensor is used as the rotational speed sensor 34. However, other types of rotational speed sensors may be used as long as they are non-contact type and can convert the rotational speed into an electrical signal. be able to.

  The temperature sensor 33 is a sensor that converts temperature into an electrical signal, and examples thereof include a thermocouple and a thermistor. The support member 31 has a cylindrical shape, and includes a fixed portion 31a fixed to the portion 1a of the transmission case 1, and an extending portion 31b extending from the fixed portion 31a toward the outer surface of the peripheral wall 21a of the clutch drum 21. . 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. The temperature sensor 33 is disposed in the opening at the tip of the core 34a, and its signal line extends upward through the core 34a and the permanent magnet 34b. The inside of the support member 31 is filled with a resin material 32, and the rotation speed sensor 34 and the temperature sensor 33 are fixed.

  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, the temperature sensor 33 is supported by the support member 31 together with the rotational speed sensor 34, and these sensors are integrated into one unit to constitute a sensor unit 30. By adopting a configuration in which the sensor unit 30 is fixed to the transmission case 1, it is avoided that these sensors interfere with the internal mechanism of the automatic transmission A, and the rotation speed sensor 34 and the temperature sensor 33 are separately provided. Compared with the arrangement, the layout and assembly of the temperature sensor 33 can be improved. In addition, both the rotation speed sensor 34 and the temperature sensor 33 can be stably supported on the transmission case 1 by the support member 31. In particular, the temperature sensor 33 can be stably disposed at a position closer to the discharge port 21b, the oil temperature of the lubricating oil immediately after being discharged from the discharge port 21b can be detected, The detection accuracy of the temperature of 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 detection results of the temperature sensor 33 and the rotation speed sensor 34 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). Further, the sensor includes a temperature sensor 33 and a rotation speed sensor 34. 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.

  Examples of control of the operation of the multi-plate clutch mechanism 20 include slip control according to the detection result of the rotation speed sensor 34, and changing the shift time according to the oil temperature detected by the temperature sensor 33. 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.

  Further, since the control unit 50 includes the communication IF 55, the information on the oil temperature detected by the temperature sensor 33 can be transmitted to the ECU. 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.

<Other embodiments>
It is desirable that the rotation speed sensor 34 and the temperature sensor 33 have their signal lines connected in series. By doing in this way, the signal line from the sensor unit 30 to the control unit 50 can be reduced (reduction from four to two), and the number of circuit terminals and the number of harnesses can be reduced. FIG. 4A is a diagram showing a circuit example of these signal processes when the temperature sensor 33 and the rotation speed sensor 34 are connected in series.

  When the electromagnetic pickup type rotational speed sensor is used as the rotational speed sensor 34 as described above, the electrical signal as an output thereof is a sine wave having a period corresponding to the rotational speed of the clutch drum 21. Further, when a thermocouple is used as the temperature sensor 33, the output electric signal is a voltage signal corresponding to the oil temperature. Therefore, the output waveform of the electrical signal when the rotation speed sensor 34 and the temperature sensor 33 are connected in series is a sine wave offset by the output voltage Va of the temperature sensor 33 as shown in FIG. In addition, the example of the figure shows the case where the output voltage of the temperature sensor 33 is constant (the oil temperature is constant).

  Thus, signal processing is performed by the filter circuit 56a, and a rectangular signal based on the detection result of the rotation speed sensor 34 is generated from the output signals of the rotation speed sensor 34 and the temperature sensor 33 (FIG. 4C). A signal (offset voltage Va) based on the detection result of the sensor 33 is generated (Fig. 4 (d)) The rectangular signal in Fig. 4 (c) is counted by the counter circuit 56b and output to the I / OIF 54. Thus, the clutch drum 4 (d) is converted into a digital signal by an A / D (analog / digital) converter 56c and output to the I / OIF 54. Thus, lubrication is performed. The oil temperature of the oil (the temperature of the clutch plate) is detected.

  When other types of sensors are used as the rotation speed sensor 34 and the temperature sensor 33, they can be connected in series based on the same concept. For example, a case where a thermistor is employed as the temperature sensor 33 will be described. Since the resistance value of the thermistor changes with temperature, the electric value of the electric signal input to the filter 56a changes instead of the offset voltage Va as shown in FIG. 4B. Therefore, the detection result of the thermistor can be extracted by providing a circuit for detecting the current value.

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 sensor unit 30 (partially broken). 3 is a block diagram of a control unit 50 of the automatic transmission A. FIG. (A) is a figure which shows the example of a signal processing circuit of the temperature sensor 33 and the rotation speed sensor 34, (b) is an example of the signal waveform input into the filter 56a, (c) is the signal waveform input into the counter 56b. An example, (d) shows an example of a signal waveform input to the A / D converter 56c.

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 Sensor unit 31 Support member 33 Temperature sensor 34 Rotational speed sensor 50 Control unit

Claims (4)

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;
A rotational speed sensor that is provided outside the peripheral wall of the clutch drum and detects the rotational speed of the clutch drum using the clutch drum as a detected rotor;
A support member for supporting the rotational speed sensor;
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;
A temperature sensor that is provided outside the peripheral wall of the clutch drum and detects the temperature of the lubricating oil discharged from the discharge port;
With
The automatic transmission, wherein the temperature sensor is supported by the support member. 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 that extends from the fixed portion toward the outer surface, and the temperature sensor is disposed at the 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 rotational speed sensor and the temperature sensor are connected in series.

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