JP2007100886A - Belt-type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt-type continuously variable transmission which does not have influence on operation of the transmission at the time of detecting the number of revolutions of pulleys, eliminates the necessity for securing a space for newly installing a member in order to detect the number of revolutions by sensors, and further eliminates increase in size and weight more than necessary of the transmission itself and a man-hour for production. <P>SOLUTION: In the belt-type continuously variable transmission, detection of the number of revolutions respectively of primary and secondary pulleys are conducted by using rotation-transmitting members placed for transmission of the power of an engine. Thus, a space-securing for newly providing a member for detecting the number of revolutions by a sensor is not necessary, and increase in size and weight of the transmission itself and increase in man-hour for production is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a belt-type continuously variable transmission, and more particularly to an arrangement of a rotational speed sensor for detecting the rotational speeds of a primary pulley and a secondary pulley of the belt-type continuously variable transmission.

  An example of such a belt-type continuously variable transmission is described in Patent Document 1, and its configuration is shown in FIG.

  The belt type continuously variable transmission 30 shown in the figure shifts the power rotation transmitted from the engine 31 as a power source to the primary pulley 33 via the torque converter 32 and transmitted to the secondary pulley 35 by the V belt 34. Then, it is output to the output shaft 36 and transmitted to drive wheels (not shown). The primary pulley 33 forms a V-shaped pulley groove with a fixed flange 37 that rotates integrally with the input shaft 36 and a movable flange 38 that faces the fixed flange 37, and the flange 38 is pivoted on the back of the movable flange 38 by hydraulic pressure. A first cylinder chamber 39 that is displaced in the direction is provided. The secondary pulley 35 forms a V-shaped pulley groove with a fixed flange 40 that rotates integrally with the output shaft 36 and a movable flange 41 that faces the fixed flange 40, and the flange 41 is attached to the back surface of the movable flange 41 by hydraulic pressure. A second cylinder chamber 42 that is displaced in the axial direction is provided.

  The first cylinder chamber 39 and the second cylinder chamber 42 are respectively supplied with hydraulic pressure from a hydraulic control unit 44 that is a transmission actuator based on a command (target transmission ratio) from the CVT control unit 43. The first cylinder chamber 39 is supplied with hydraulic pressure in accordance with a command from the CVT control unit 43, the second cylinder chamber 42 is supplied with line pressure accordingly, and the primary pulley is driven by the hydraulic pressure supplied to the first cylinder chamber 39. By changing the groove width of the 33, the clamping pressure on the V belt 34 is controlled to change the speed, and the power rotation from the engine is performed in accordance with the contact friction force between the V belt 34 and the pulleys 33 and 35. Communicated.

  By the way, in the illustrated belt type continuously variable transmission 30, a first rotational speed sensor 45 for detecting the rotational speed Npri of the primary pulley 33 is disposed in the vicinity of the first cylinder chamber 39. The rotational speed of the outer peripheral wall 39a is detected. Usually, when the rotation number of a rotating body is detected by a rotation sensor, a large number of uneven portions are formed on the surface of the rotating body facing the rotation sensor. This is because the number of rotations is detected based on magnetic and optical changes that occur when these uneven portions (in other words, gaps between adjacent convex portions) pass in front of the sensor.

  Therefore, it is necessary to form a large number of uneven portions for detecting the rotational speed on the outer peripheral wall 39a of the first cylinder chamber 39. However, as shown in the figure, the outer peripheral wall 39a of the first cylinder chamber 39 is a surface that seals and slides with the outer peripheral surface of the vertical wall 39b of the movable flange 38. Therefore, very high processing accuracy is required for the outer peripheral wall 39a and the vertical wall 39b of the first cylinder chamber 39, but when forming an uneven part for detecting the rotational speed, in order to form the uneven part It is necessary to make the outer peripheral wall 39a thicker, and the outer wall 39a deteriorates the accuracy of the seal and sliding surface with the vertical wall 39b due to the processing of the concave and convex portions, and the sealing performance of the first cylinder chamber 39 is lowered. Therefore, there is a possibility that the movable flange 38 does not operate normally or that the movable flange 38 is not smoothly slid, which may affect the speed change operation.

On the other hand, the second rotation speed sensor 46 for detecting the rotation speed Nsec of the secondary pulley 35 is disposed in the vicinity of the fixed flange 40, and detects the rotation speed of the fixed flange 40. In this case, it is necessary to newly provide a rotation detection member 47 having a concavo-convex portion formed on the outer periphery in the radial direction so as to face the second rotation speed sensor 46 on the outer peripheral side in the radial direction of the fixed flange 40. This also necessitates an increase in the axial width of the fixed flange 40 in order to arrange the rotation detection member 47, thereby increasing the size and weight of the transmission itself, and further providing the rotation detection member 47. As a result, the man-hour for manufacturing increases.
JP 2004-116638 A

  In view of the above-described problems of the prior art, the present invention does not affect the operation of the transmission when detecting the number of rotations of the pulley, and a new member is provided for detecting the number of rotations by the sensor. It is an object of the present invention to provide a belt-type continuously variable transmission that does not require a sufficient space for the transmission, and that can further prevent the transmission itself from increasing in size, weight, and manufacturing man-hours. It is what.

For this purpose, the belt-type continuously variable transmission according to the first invention is
An input-side primary pulley, an output-side secondary pulley, and a belt spanned between the primary pulley and the secondary pulley;
Power rotation from a power source is input to the primary pulley, the power rotation is transmitted to the secondary pulley via the belt, and the power rotation is shifted at a predetermined gear ratio to transfer from the secondary pulley to the drive wheel. An output belt type continuously variable transmission,
A first rotation transmission member disposed in direct connection with the primary pulley between the power source and the primary pulley to transmit power rotation from the power source to the primary pulley on the input side;
In order to transmit the rotation from the secondary pulley on the output side to the drive wheel, a continuously variable rotation transmission member is provided between the secondary pulley and the drive wheel, and a second rotation transmission member arranged in direct connection with the secondary pulley. In the transmission,
A first rotation speed sensor for detecting the rotation speed of the primary pulley is disposed in the vicinity of the first rotation transmission member;
A second rotation speed sensor for detecting the rotation speed of the secondary pulley is disposed in the vicinity of the second rotation transmission member.

The belt-type continuously variable transmission according to the second invention is the one according to the first invention, wherein the first and second rotation transmission members both have a large number of irregularities on the outer periphery in the radial direction.
The first and second rotational speed sensors are arranged to face the concave and convex portions of the first and second rotation transmission members, respectively.

The belt-type continuously variable transmission according to the third invention is the one according to the second invention, further comprising a forward / reverse switching mechanism having a clutch or a brake engaging member, disposed between the power source and the primary pulley.
The first rotation transmission member is the clutch of the forward / reverse switching mechanism or the clutch drum of a brake engagement member.

The belt-type continuously variable transmission according to the fourth invention is the one according to the third invention, further comprising an output gear directly connected to the secondary pulley for transmitting the output from the secondary pulley to the drive wheel.
The second rotation transmission member is the output gear.

Further, the belt-type continuously variable transmission according to the fifth invention is the one according to the third invention or the fourth invention, wherein the forward / reverse switching mechanism comprises a planetary gear mechanism comprising a sun gear, a planetary gear carrier and a ring gear.
At least one of the three elements of the planetary gear mechanism is connected to the clutch drum, and at least one of the other elements is connected to the clutch drum when the clutch or brake engaging member is engaged. It is what.

  The belt-type continuously variable transmission according to the first aspect of the present invention is a first rotation that is directly connected to the primary pulley to transmit the power rotation from the power source to the primary pulley when measuring the rotation speed of each of the primary pulley and the secondary pulley. A first rotation speed sensor is provided in the vicinity of the transmission member, and the rotation speed of the first rotation transmission member is measured by the first rotation speed sensor to obtain the rotation speed of the primary pulley and output from the secondary pulley. A second rotation speed sensor is provided in the vicinity of the second rotation transmission member directly connected to the secondary pulley to transmit the rotation to the driving wheel, and the rotation of the second rotation transmission member is performed by the second rotation speed sensor. The number of rotations of the secondary pulley is determined by measuring the number.

  That is, since the rotation speed is measured using a rotation transmission member provided to transmit power from the engine, a space for arranging a new member for detecting the rotation speed by the sensor. As a result, it is possible to prevent an increase in the size and weight of the transmission itself and the man-hours for manufacturing.

  The belt-type continuously variable transmission according to the second aspect of the invention measures the rotational speed by using a large number of uneven portions of the first and second rotation transmission members described above on the outer periphery in the radial direction. Therefore, it is not necessary to provide uneven portions on these rotation transmission members, and it is possible to effectively prevent an increase in man-hours and costs for manufacturing the transmission.

  In this case, as in the third aspect of the invention, the first rotation transmission member is a clutch drum that engages with a clutch or brake engagement member that is provided in a forward / reverse switching mechanism that is disposed between the power source and the continuously variable transmission; In addition, as in the fourth aspect of the invention, the second rotation transmission member is preferably an output gear for transmitting the output from the secondary pulley to the drive wheel.

  Further, as in the fifth invention, the forward / reverse switching mechanism includes a planetary gear mechanism including three elements of a sun gear, a planetary gear carrier, and a ring gear, and at least one of these elements is connected to the clutch drum, and the other elements. When at least one element is connected to the clutch drum when the clutch or brake is engaged, the primary pulley rotation speed can be detected during forward travel, and the primary pulley can be determined from the gear ratio of the planetary gear mechanism during reverse travel. It is possible to detect the number of rotations.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows a belt-type continuously variable transmission according to the present invention. In the illustrated belt type continuously variable transmission 1, a primary pulley 2 and a secondary pulley 3 are arranged so that their V grooves are aligned, and a V belt 4 is stretched over the V grooves of these pulleys 2 and 3. An engine 5 as a power source is coaxially arranged with respect to the primary pulley 2, and a torque converter 6 having a lock-up clutch and a forward / reverse switching mechanism 7 are sequentially arranged between the engine 5 and the primary pulley 2 from the engine 5 side. Deploy. The forward / reverse switching mechanism 7 includes a clutch 7a and a brake 7b, which are starting friction elements, and a planetary gear mechanism 7c that shifts and outputs the rotation from the torque converter 6.

  The planetary gear mechanism 7c is a double-pinion planetary gear mechanism that includes a sun gear 7sg, two pinion gears 7p1 and 7p2, a carrier 7cr that supports these pinion gears, and a ring gear 7rg. As shown in the figure, the output shaft of the torque converter 6 rotates integrally with the sun gear 7sg of the planetary gear mechanism 7c and the clutch drum 7d of the clutch 7a, and the carrier of the clutch drum 7d and the planetary gear mechanism 7c is engaged by fastening the clutch 7a. Rotates together with 7cr. The brake 7b is disposed on the outer periphery of the ring gear 7rg of the planetary gear mechanism 7c, and the rotation of the ring gear 7rg is suppressed by fastening the brake 7b. Further, the carrier 7cr of the planetary gear mechanism 7c is connected to the primary pulley 2.

  The rotation of the primary pulley 2 transmitted from the engine 5 via the torque converter 6 and the forward / reverse switching mechanism 7 is transmitted to the secondary pulley 3 via the V belt 4. It is transmitted to drive wheels (not shown) through the directly connected output shaft 8, output gear set 9, and differential gear device 10.

  In order to change the rotation transmission ratio (transmission ratio) between the primary pulley 2 and the secondary pulley 3 during the power transmission, one of the flanges forming the V grooves of the primary pulley 2 and the secondary pulley 3 is fixed. The flanges 2a and 3a are used, and the other flanges 2b and 3b are movable flanges that can be displaced in the axial direction. These movable flanges 2b and 3b move in the direction toward the fixed flanges 2a and 3a by the thrust generated by supplying the primary pulley pressure Ppri and the secondary pulley pressure Psec to the primary pulley chamber 2c and the secondary pulley chamber 3c, respectively. Then, the V belt 4 is sandwiched between the flanges of the pulleys to enable power transmission between the primary pulley 2 and the secondary pulley 3.

  The speed change in the power transmission described above is performed by changing the widths of the V grooves of both pulleys 2 and 3 by the differential pressure between the primary pulley pressure Ppri and the secondary pulley pressure Psec generated corresponding to the target gear ratio. This is achieved by realizing the target gear ratio by continuously changing the winding arc diameter of the V-belt 4 around the pulleys 2 and 3.

  The primary pulley pressure Ppri and the secondary pulley pressure Psec are controlled by the shift control hydraulic circuit 11. The shift control hydraulic circuit 11 is controlled by a signal from the transmission controller 12. Therefore, the transmission controller 12 has a signal from the primary pulley rotation speed sensor 13 for detecting the primary pulley rotation speed Npri, a signal from the secondary pulley rotation speed sensor 14 for detecting the secondary pulley rotation speed Nsec, and an engine output rotation speed No. A signal from the engine output speed sensor 15 for detecting the actual pressure, a signal from the primary pulley pressure sensor 16 for detecting the actual primary pulley pressure Ppri, a secondary pulley pressure sensor 17 for detecting the actual secondary pulley pressure Psec, and depression of the accelerator pedal A manual shift switch 19 detects a selection from a signal from an accelerator pedal stroke sensor 18 for detecting a stroke, a manual shift mode giving priority to a shift by a driver's operation, or an automatic shift mode according to a shift command from the transmission controller 12. Signal from the inhibitor Selection range signal from switch 20, signal from brake switch 21 that detects the depression of the brake pedal, signal from economy mode switch 22 for the driver to demand driving that emphasizes fuel efficiency, and engine that controls engine 5 Signals related to transmission input torque from the controller 23 (engine speed Ne, fuel injection time, etc.) are input.

  In the illustrated belt type continuously variable transmission 1, a primary pulley rotational speed sensor 13, which is a first rotational speed sensor that detects the rotational speed Npri of the primary pulley 2, is used as a clutch that constitutes the clutch 7 a of the forward / reverse switching mechanism 7. The drum (first rotation transmission member) 7d is arranged to face the outer periphery in the radial direction. On the outer periphery of the clutch drum 7d constituting the clutch 7a, an uneven portion (not shown) for engaging with the friction plate is already formed. That is, the primary pulley rotation speed sensor 13 is arranged opposite to the uneven portion to detect the rotation speed Npri of the primary pulley 2.

  The clutch drum 7d that constitutes the clutch 7a is always rotated by the engagement of the clutch 7a or the brake 7b both when the vehicle is moving forward and when the vehicle is moving backward. Therefore, by detecting the rotation speed of the clutch drum 7d, The rotation speed Npri of the primary pulley 2 can be detected. Note that the rotational speed Npri of the primary pulley 2 during reverse travel can be obtained by considering the gear ratio of the planetary gear mechanism 7c of the forward / reverse switching mechanism 7 in the detection value of the primary pulley rotational speed sensor 13.

  That is, while the clutch 7a is engaged and the brake 7b is released, the primary pulley 2 rotates in the same direction as the output rotation from the engine 5, so the vehicle moves forward. Therefore, the rotation speed Npri of the primary pulley 2 when the vehicle moves forward can be detected by the primary pulley rotation speed sensor 13 disposed on the outer periphery of the clutch drum 7d. Conversely, when the clutch 7a is released while the brake 7b is engaged, the primary pulley 2 rotates in the direction opposite to the output rotation from the engine 5, and the vehicle moves backward. Therefore, the rotation speed Npri of the primary pulley 2 can be detected even when the vehicle is moving backward by the primary pulley rotation speed sensor 13 disposed on the outer periphery of the clutch drum 7d.

  On the other hand, the secondary pulley rotational speed sensor 14 which is a second rotational speed sensor for detecting the rotational speed Nsec of the secondary pulley 3 is a gear 9a (second rotational speed) directly connected to the output shaft 8 in the output gear set 9. It arrange | positions facing the outer periphery (tooth surface) of a transmission member. That is, the teeth formed on the gear 9 are used as an uneven portion for detecting the rotational speed, and the rotational speed Nsec of the secondary pulley 3 is obtained from the rotational speed of the gear 9a using this tooth.

  In other words, both the rotation speed Npri of the primary pulley 2 and the rotation speed Nsec of the secondary pulley 3 are detected by using an existing rotation transmission member having an uneven portion on the outer peripheral surface. Therefore, it is not necessary to secure a space for newly providing a member to detect the rotation speed, and as a result, it is possible to prevent an increase in the size and weight of the transmission itself and the man-hours for manufacturing.

  Further, the slippage of the torque converter 6 or the torque converter 6 is locked up from the rotation speed Npri of the primary pulley 2 detected by the primary pulley rotation speed sensor 13 and the engine output rotation speed No detected by the engine output rotation speed sensor 15. When slipping occurs during the operation, it is possible to detect such slipping.

  As described above, the belt-type continuously variable transmission according to the present invention uses the rotation transmission member provided for transmitting the power from the engine when detecting the rotation speeds of the primary pulley and the secondary pulley. Therefore, it is not necessary to secure a space for arranging a new member in order to detect the rotation speed by the sensor, and as a result, the size and weight of the transmission itself and the man-hours for manufacturing increase. Can be prevented.

  In the above embodiment, the planetary gear mechanism of the forward / reverse switching mechanism is of a double pinion type, but the present invention is not limited to this double pinion type planetary gear mechanism.

It is a figure which shows schematically the structure of the belt-type continuously variable transmission by this invention. It is a figure which shows schematically the structure of the conventional belt-type continuously variable transmission.

Explanation of symbols

1,30 Belt type continuously variable transmission
2, 33 Primary pulley
3, 35 Secondary pulley
4,34 V belt
5,31 engine
6, 32 Torque converter
7 Forward / reverse switching mechanism
8, 36 Output shaft
9 Output gear set
10 Differential gear unit
11 Shift control hydraulic circuit
12 Transmission controller
13 Primary pulley speed sensor
14 Secondary pulley speed sensor
15 Engine output speed sensor
16 Primary pulley pressure sensor
17 Secondary pulley pressure sensor
18 Accelerator pedal stroke sensor
19 Manual shift switch
20 Inhibitor switch
21 Brake switch
22 Economy mode switch
23 Engine controller
37 Fixing flange of primary pulley 33
38 Movable flange of primary pulley 33
39 First cylinder chamber
40 Fixed flange of secondary pulley 35
41 Movable flange of secondary pulley 35
42 Second cylinder chamber
43 CVT control unit
44 Hydraulic control section
45 First speed sensor
46 Second speed sensor
47 Rotation detection member of fixed flange 40

Claims (5)

An input-side primary pulley, an output-side secondary pulley, and a belt spanned between the primary pulley and the secondary pulley;
Power rotation from a power source is input to the primary pulley, the power rotation is transmitted to the secondary pulley via the belt, and the power rotation is shifted at a predetermined gear ratio to transfer from the secondary pulley to the drive wheel. An output belt type continuously variable transmission,
A first rotation transmission member disposed in direct connection with the primary pulley between the power source and the primary pulley to transmit power rotation from the power source to the primary pulley on the input side;
In order to transmit the rotation from the secondary pulley on the output side to the drive wheel, a continuously variable rotation transmission member is provided between the secondary pulley and the drive wheel, and a second rotation transmission member arranged in direct connection with the secondary pulley. In the transmission,
A first rotation speed sensor for detecting the rotation speed of the primary pulley is disposed in the vicinity of the first rotation transmission member;
A belt-type continuously variable transmission, wherein a second rotation speed sensor for detecting the rotation speed of the secondary pulley is disposed in the vicinity of the second rotation transmission member. 2. The continuously variable transmission according to claim 1, wherein each of the first and second rotation transmission members has a large number of uneven portions on a radially outer periphery.
The belt-type continuously variable transmission, wherein the first and second rotational speed sensors are arranged to face the concave and convex portions of the first and second rotation transmission members, respectively. The continuously variable transmission according to claim 2, further comprising a forward / reverse switching mechanism having a clutch or a brake engaging member disposed between the power source and the primary pulley.
The belt-type continuously variable transmission, wherein the first rotation transmission member is a clutch drum that engages with the clutch or brake engagement member of the forward / reverse switching mechanism. The continuously variable transmission according to claim 3, further comprising an output gear directly connected to the secondary pulley for transmitting the output from the secondary pulley to the drive wheel.
The belt type continuously variable transmission, wherein the second rotation transmission member is the output gear. The continuously variable transmission according to claim 3 or 4, wherein the forward / reverse switching mechanism includes a planetary gear mechanism including three elements of a sun gear, a planetary gear carrier, and a ring gear.
At least one of the three elements of the planetary gear mechanism is connected to the clutch drum, and at least one of the other elements is connected to the clutch drum when the clutch or brake engaging member is engaged. A belt-type continuously variable transmission.

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