JPS61105345A - Pulley structure for belting type stepless transmission - Google Patents

Abstract

PURPOSE:To make each actuation of both first and second pistons performable so smoothly, by installing the first piston fitly in a first cylinder tube and a boss part of a movable pulley, while locking the second piston to the boss part, and keeping the slide resistance between both these first and second pistons constant. CONSTITUTION:A boss part 48 is extendedly installed in a movable flange 37, and a first piston 50 is attached to an end face of the boss part. A second piston 52 is installed in an outer circumference of the boss part 48 free of slide motion together with the first piston each and, after being connected to this second piston 52, a cylinder 52a is fitted in an outer circumference of the first piston 50 free of slide motion. Thus, a pressure chamber 55 is partitively formed between the first piston 50 and an end cover 53 while another pressure chamber 56 between the second piston 52 and the movable flange 37, respectively, whereby hydraulic pressure in an arrow (e) is fed to these pressure chambers as shown in an arrow (fg) so that the slide resistance between these first and second pistons comes to being constant, thus their actuations become smoothed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a pulley structure for a continuously variable transmission.

(Prior art) Generally, in the pulley structure of a continuously variable transmission, a winding is provided inside the first cylinder and the first cylinder in order to increase the force that moves the movable pulley toward the fixed pulley. It has two cylinders, a second cylinder and a second cylinder.

As a conventional boob structure of this type of continuously variable transmission, for example, the one shown in European Patent Publication No. 0051918 is known. The pulley structure of the continuously variable transmission disclosed in this publication includes a first cylinder tube fixed to a movable pulley, a second cylinder tube whose one end is fixed to the fixed booby side and inserted into the first cylinder tube. 1st
A first piston that is slidably inserted into the cylinder tube and engages with the other end of the second cylinder tube, a second piston that is slidably inserted into the second cylinder tube, and one end of which is continuous with the second piston. A sleeve whose other end is fixed to the movable pulley and is slidably inserted into the first piston, and by introducing pressure oil into the first cylinder tube and the second cylinder tube, the first piston and the sleeve are slidably inserted into the first piston. The second pistons are actuated in opposite directions to move the movable pulley toward the fixed pulley.

However, the pulley structure of such a conventional continuously variable transmission has the following problems. First, only the other end of the sleeve is fixed to the movable pulley, and since it overhangs on the right side, it is easy to rotate (fall down) using the other end as a fulcrum. Further, a second piston is integrally connected to one end of the sleeve. Therefore, when the sleeve rotates (falls down) using the other end as a fulcrum, the second piston presses the second cylinder tube in the radial direction with an external force F1. As a result, a frictional force μF occurs between the second cylinder tube and the second piston, resulting in a problem in that the second piston does not operate smoothly. Further, when the sleeve rotates (falls down) using the other end as a fulcrum, the first piston receives a reaction force F2=Fixz that is expanded in the radial direction by the sleeve because the sleeve is inserted into the first piston.

/ it is pressed with 2. (Here, il is the length of the sleeve, and 2□ is the distance from the other end of the sleeve to the first piston.) Moreover, the first piston is separated from the second cylinder tube. Therefore, the first piston moves in the radial direction by being pressed by the sleeve, and large frictional forces μF2 are generated between the first piston and the first cylinder tube and between the first piston and the sleeve. do. As a result, there was a problem in that the first piston did not operate smoothly.

(Object of the invention) This invention was made by focusing on the above-mentioned problems.
It is an object of the present invention to provide a pulley structure for a continuously variable transmission that can maintain constant sliding resistance of a first piston and a second piston.

(Structure of the Invention) In order to achieve this object, the structure of the present invention includes a pulley shaft provided with a fixed pulley, a movable pulley whose boss portion is slidably attached to the pulley shaft, and a movable pulley fixed to the movable pulley. a first cylinder tube supported by the pulley shaft and insertable into the first cylinder tube; a first piston slidably fitted in the first cylinder tube and the boss portion; a second piston fixedly engaged with the second piston and slidably inserted into the second cylinder tube;
A first cylinder chamber is defined between the movable pulley, the first cylinder tube, and the first piston, and introduces oil for pressing the first piston toward the second piston;
a second piston defined between the cylinder tube and the second piston;
The second cylinder chamber introduces oil that presses the piston toward the first piston.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

Figures 1, 2, and 3 show an embodiment of the transmission type continuously variable transmission of the present invention, in which 1 indicates a transmission case, 2 indicates a front cover, and 3 indicates a rear cover. The following power transmission train is assembled in the space obtained by combining the two with bolt marks 61 to form a continuously variable transmission.

That is, the main axis 01, sub-axis 0□, intermediate axis 03, and output axis 04 are arranged as shown in Fig. 2, and engine power is input onto the main axis 01 as shown in Fig. 1. A fluid coupling 4, a double pinion type planetary gear set 5, and a primary pulley 6 are arranged sequentially from the side (right side in FIG. 1), and a secondary boot U? and an output gear 8, a beam reduction gear 9 and a final drive pinion 10 are provided on the intermediate axis 03, and a final drive ring gear 11 and a differential gear 12 are provided on the output axis 04.

The fluid coupling 4 is connected to the engine crankshaft via a coupling cover 13, and includes a pump impeller 14 driven by the engine, a turbine runner 15 facing the pump impeller 14, and a lock that directly connects the pump impeller and the turbine runner as appropriate. It consists of an amplifier clutch 16. A pump drive shaft 17 is welded to the pump impeller 14 and is supported within the pump housing 18 via a bearing 19, thereby rotatably supporting the pump impeller 14.

The empty space of the pump housing 18 is closed by a pump cover 21 attached to this with bolts 20, and the pump cover 2
1 to the transmission case 1, and attach it to the transmission case with bolts 22. A normal gear pump 23 is housed in the cavity of the pump housing 18, and a shaft 1 is attached to this gear pump.
7, the pump is always driven by the engine, and oil for speed change control, hydraulic oil for the fluid coupling 4, and oil for lubricating various parts are provided by the oil discharged from the gear pump 23. Incidentally, the gear pump holder takes in and discharges the reservoir in the oil pan 29 shown in FIG. 2.

Turbine runner 15 is riveted to turbine hub 24, which is splined to input shaft 25. The input shaft 25 passes through a fixed sleeve 26 which is fixed to the pump cover 21, and is rotatably supported within this sleeve via a bushing 27.

The lock-up clutch 16 is slidably fitted onto the turbine hub 24, and is drivingly connected to the turbine hub 24 via a torsion spring 28, and is connected to the clutch facing 16a via a compression ring 28 as shown in FIG. When the clutch facing 16a is brought into pressure contact with the compression cover 13 as shown in FIG. A lock-up condition transmitted to the input shaft 25 shall be provided. Note that when the lock amplifier clutch 16 is in the released position shown in FIG. becomes.

Oil passages for supplying hydraulic oil to the fluid coupling 4 and performing lock-up control thereof are indicated by arrows a and b.

When hydraulic oil is supplied and discharged in the directions shown by these arrows to cause a DC flow of hydraulic oil to the fluid coupling 4, the dynamic pressure causes the lock-up clutch 16 to be in the release position shown in FIG. When engine power is transmitted to the input shaft in this state, and hydraulic oil is supplied and discharged in the opposite direction as shown by arrows a and b, and the hydraulic oil flows through the fluid coupling 4, the lock-up clutch is activated by the dynamic pressure. 16 is connected as shown in FIG.
to communicate.

The double pinion type planetary gear set 5 includes a sun gear 30 integrally molded on the input shaft 25, an internal gear 31, an inner pinion 32 that meshes with the sun gear 30, and an outer pinion 33 that meshes with the inner pinion and the internal gear 31. A common pinion carrier 34 rotatably supports pinions 32, 33. The primary boo IJ 6 is composed of a fixed flange 35 that abuts the input shaft 25 coaxially and is rotatable relative to the fixed flange 35, and a movable flange 37 that is movable in the axial direction on a pulley shaft 36 integrated with the fixed flange 35. The above pinion carrier 34
is spline-coupled to a fixed flange 35 on the one hand, and can be drive-coupled to the input shaft 5 as appropriate by means of a forward clutch 38 on the other hand.

The forward clutch 38 is a well-known wet type multi-disc clutch, and has a clutch drum 39 spline-coupled to the input shaft, a drive plate spline-fitted into the clutch drum 39, and a driven plate spline-fitted onto the pinion carrier 34, which are arranged alternately. Clutch pack 4
0, and a piston 41 that presses between these drive plates and the driven plates. The piston 41 is hydraulically actuated by the supply of hydraulic pressure shown by arrow C to press the drive plate and the driven plate into frictional engagement, and engages the forward clutch 38. As a result of this engagement, the forward clutch 38 moves the pinion carrier 34 into the input shaft. 25. Further, the internal gear 31 can be appropriately fixed by a reverse brake 42, and this reverse brake is arranged by alternating between a fixed plate spline-fitted into the gear case 1 and a braked plate spline-fitted to the outer periphery of the internal gear 31. This is a well-known wet multi-disc brake composed of a brake pack 43 that is arranged and a piston 44 that presses between a fixed plate and a braked plate.

The piston 44 is hydraulically actuated by the supply of hydraulic pressure indicated by arrow d so as to press the fixed plate and the braked plate into frictional engagement, and the internal gear 31 can be fixed by operating the reverse brake 42.

Fixed flange 35 of primary pulley 6 and pulley shaft 3
6 is rotatably supported on the transmission case 1 and rear cover 3 by bearings 45 and 46, and the movable flange 37 is drive-coupled to the pulley shaft 36 by a ball spline 47 so that it can move easily in the axial direction on the pulley shaft 36. do. For this purpose, a boss portion 48 extending away from the fixed flange 35 is provided on the movable flange 37, and a first piston 50 is attached to the end surface of the boss portion with a port 49. A cylindrical body 51 is welded to the outer periphery of the movable flange 37, and is slidably fitted to the inner periphery of the cylindrical body and the outer periphery of the boss portion 48, respectively.
A piston 52 is provided, connected to the second piston 52, and a cylinder 52a is slidably fitted to the outer periphery of the first piston 50.
The insertion opening is closed with an end cover 53 fitted onto the pulley shaft 36, and the end of the insertion opening is welded to the end cover 53. Thus, a pressure chamber 55 is defined between the first piston 50 and the end cap 53, and a pressure chamber 56 is defined between the second piston 52 and the movable flange 37.
An oil passage for supplying the hydraulic pressure as shown by arrow fg is formed. In addition, the carrier case 3 that constitutes a part of this oil passage
The hydraulic pressure transfer section between the pulley shaft 36 and the pulley shaft 36 is
end face opening and pulley shaft bearing protrusion 3a of rear case 3
It has a communication chamber 58 defined by a separate plate 57 fitted therein, and the separate plate 57 has its punched protrusion 57a inserted into the corresponding recess 3b of the rear case 3 to prevent rotation.

Similarly to the primary pulley 6, the secondary pulley 7 is composed of a fixed flange 59, a pulley shaft 62 integrated with the fixed flange 59, and a movable flange 63 that is movable in the axial direction on this pulley shaft. 6
and place it in the opposite direction. The fixed flange 59 and pulley shaft 62 are rotatably supported at three points by bearings 64 to 66 on the rear cover 3, transmission case 1, and front cover 2, and bearings 64 and 65 are placed between the rear cover 3 and the transmission case 1. The secondary pulley 7 is centered with respect to the primary pulley 6 by means of shims 69 and 70 provided in the axial direction. Movable flange 63
The boss portion 71 is extended in a direction away from the fixed flange 59, and the boss portion is drive-coupled to the pulley shaft 62 by a ball spline 72, so that the movable flange 63 can be easily moved along the axis on the pulley shaft 62. drivingly coupled thereto for movement in the direction. A screw 73t is engaged with the pulley shaft 62 and is slidably fitted into a cylinder 74 whose outer periphery is welded to the outer periphery of the movable flange 63 to define a pressure chamber 75. A spring 76 compressed between this and the piston 73 biases the fixed flange 59 in the direction. In addition, an annular plate 77 is provided at the tip of the cylinder 74 so as to extend radially inward, an oil reservoir 78 is set, and the pressure chamber 7
The centrifugal force exerted on the oil leaked from 5 into the oil reservoir through the pores and stored therein is balanced with the hydraulic pressure in the pressure chamber 75 to prevent the piston 73 from being deformed by the hydraulic pressure in the pressure chamber 75. To prevent. An oil passage is formed to supply oil pressure to the pressure chamber 75 as indicated by the arrow i, and the oil pressure transfer portion between the carrier cover 3 and the pulley shaft 62 is a part of this oil passage. is constituted by an end face opening of the pulley shaft 62 and a groove 79 fitted into the rear case 3.

A belt 80 is passed between the primary pulley 6 and the secondary pulley 7 so that power can be transferred between the two pulleys.
A well-known method such as that described in Japanese Patent No. 653 may be used.

The output gear 8 is spline-coupled to the pulley shaft 62 between bearings 65 and 66, and the reduction gear 9 is meshed with the output gear 8. The reduction gear 9 and the final drive pinion 10 are integrated, and these are mounted on a bearing 81.8.
2, it is rotatably supported by the transmission case 1 and the front cover 2. The transmission case 1 and the front cover 2 further rotatably support a case 85 of the differential gear 12 via bearings 83 and 84.
At the same time, the final drive ring gear 11 is coaxially connected with bolts 86, and the final drive ring gear 1
1 is brought into mesh with the final drive pinion 10. The differential gear set to be assembled into the case 85 includes a pinion mate shaft passing through the case 85 in the vertical direction in FIG. Since this is a well-known device consisting of a pair of side gears, a description thereof will be omitted, and only the output shafts 92 and 93, which are individually drivingly connected to both side gears, are shown by two-dot chain lines. When using the continuously variable transmission of the present invention in a vehicle, these output shafts are
coupled to its drive wheels.

Next, the lubrication method for each part will be explained. A portion of the hydraulic fluid removed from the fluid coupling 4 in the direction opposite to the arrow a is transferred to the forward clutch 38 and the planetary gear set 5 as shown by the arrow j-m.
, the reverse brake 42, and the belt 80, it is possible to thoroughly lubricate these components including the adjacent black bearings. Further, an oil collection plate 88 is attached to the lower part of the expanded protrusion 3a of the rear case 3 by bolts 87 to form an oil reservoir 89 (in the illustrated example, it is shown facing downward, but is set upward), Splashed lubricating oil is stored in this and guided through the through hole 90 to lubricate the bearing 43. Furthermore, a lubrication hole 91 is formed in the transmission case 1 so as to communicate with a suitable oil passage formed in the pump cover 21, and the opening thereof is directed toward the output gear 8, so that the oil is directed to the output gear as shown by arrow n. 8 to squirt. This jetted oil is scattered by the output gear 8 and supplied to the bearing 65, and if this bearing is located relatively inside where it is difficult to supply lubricating oil, it can be reliably lubricated.

The fluid coupling 4, the operation of the above embodiment will be explained next, transmits engine power to the input shaft 25 in the compressed state or lockup state as described above, and transmits the engine power to the sun gear 3.
0 is rotating together with the input shaft 25. Here, oil pressure c,
d is not supplied, the forward clutch 38 and the reverse brake 42
If none of these are activated, the input shaft and sun gear 3
The zero rotation is not transmitted to the pinion carrier 34, resulting in a neutral state in which the primary pulley 6 does not rotate.

By the way, when the forward clutch 38 is actuated by the hydraulic pressure C, the pinion carrier 34 is drive-coupled to the input shaft 25, and the rotation of the input shaft 25 is directly transmitted to the primary pulley 6 via the pinion carrier 34, which is transferred to the human power shaft 25.
Rotate integrally with. The rotation of primary pulley 6 is ■
The engine power is transmitted to the secondary pulley 7 via the belt 80, and then to the differential gear 12 via the pulley shaft 62, output gear 8, reduction gear 9, final drive pinion 10, and final drive ring gear 11. The output can be distributed in the forward direction from the shafts 92 and 93.

When the reverse brake 42 is operated by the hydraulic pressure d, the internal gear 31 is fixed, the rotation of the sun gear 30 is reversed and transmitted to the nion carrier 34, and the primary pulley 6 is rotated in the opposite direction to the input shaft 25 via this pinion carrier. is rotated to This reverse rotation of the primary pulley 6 is transmitted to the differential gear 12 through the same transmission path as described above, but since the primary pulley 6 is now reversed, the engine power is distributed from both output shafts 92 and 93 to the reverse rotation. It can be output.

The speed change during power transmission in the above two modes is as follows:
The belt 80 is wound by changing its diameter. That is, by removing the hydraulic pressure e, the movable flange 37 of the primary pulley 6 is brought to the position farthest from the fixed flange 35, as shown in the upper half of FIG. With the movable flange 63 of the secondary pulley 7 working together in the position shown in the lower half of FIG. The diameter of the hook is minimized, and the diameter of the hook around the secondary pulley 7 is maximized. Therefore, the rotation transmission ratio (speed ratio) from the primary pulley 6 to the secondary pulley 7
is set to the minimum, and the lowest gear selection state is obtained.

From this state, the hydraulic pressure e is supplied to the pressure chambers 55 and 56, and the movable flange 37 is moved to the limit position shown in the lower half of FIG. The movable flange 59 is moved toward the fixed flange 35, and at the same time, while removing the hydraulic pressure, the V-belt 80 is wound around the movable flange 59. 59, the V-belt 80 changes its state of winding around both pulleys 6.7 toward the limit state shown by the two-dot chain line in FIG. In other words, the diameter of the V-belt 80 is gradually increased when it is wrapped around the primary pulley 6, and the diameter is gradually decreased when it is wrapped around the secondary pulley 7, and during this time the rotation transmission ratio (speed ratio) from the primary pulley 6 to the secondary pulley 7 is continuously maintained. It is possible to increase the transmission speed to a continuously variable speed.

Incidentally, in the continuously variable transmission which conversely decreases the gear ratio, the movable flange 37 is moved to the left in this figure from the position shown in the lower half of FIG. The V-belt 80 is wound around both pulleys 6.7 by moving leftward in this figure from the position shown in FIG. can get.

(Effects of the Invention) As explained above, according to the present invention, the first cylinder tube is fixed to the movable pulley, the first piston is fitted to the boss portion of the first cylinder tube and the movable pulley, and the second piston is fixed to the movable pulley. is fixed to the boss, the sliding resistance between the first piston, the first cylinder tube, and the boss is maintained constant, and the sliding resistance between the second piston and the second cylinder tube is maintained constant. As a result, the effect of smooth operation of the first piston and the second piston is obtained.

[Brief explanation of drawings]

FIG. 1 shows an automatic transmission to which an embodiment of the continuously variable transmission pulley structure according to the present invention is attached, and FIG.
-01-0□-0, -04-B sectional view taken along the arrows; FIG. 2 is a view taken along the nn arrow of FIG. 1; and FIG. 3 is an enlarged view of the main part of FIG. 1--Transmission case, 2--Front cover, 3--Rear cover, 4--Fluid coupling, 5--Double binion type planetary gear set, 6-- -Primary pulley, 7.----Secondary pulley, 8..-1--Output gear, 9..--111 Reduction gear 1 10.--Final drive pinion, 11.
−111・Final drive ring gear, 12・−−
---Differential gear, 25----- Single power shaft, 30--11--Sun gear, 31-- Internal gear, 32-- Inner pinion, 33-- 111 outer pinion, 34--binion carrier, 38--one forward clutch, 39--clutch drum, 40--clutch pack, 41--piston, 42----1 reverse brake, 43---1 brake pack, 44---1 piston, 80---V belt.

Claims (1)

[Claims] A pulley shaft provided with a fixed pulley, a movable pulley whose boss portion is slidably attached to the pulley shaft, a first cylinder tube fixed to the movable pulley, and a first cylinder tube supported by the pulley shaft. a second insertable cylinder tube; a first piston slidably fitted in the first cylinder tube and the boss portion; and a first piston fixedly engaged with the boss portion and slidably inserted in the second cylinder tube. two pistons, a first cylinder chamber defined between the movable pulley, the first cylinder tube, and the first piston and into which oil for pressing the first piston toward the second piston is introduced; a pulley shaft and the second cylinder; A wrap-type continuously variable transmission characterized by comprising: a second cylinder chamber defined between the tube and the second piston, into which oil is introduced to press the second piston toward the first piston. pulley structure.