JPH0260525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicular continuously variable transmission for a horizontal engine using a V-belt type continuously variable transmission.

[Prior Art] When a vehicle is equipped with a continuously variable transmission for a horizontal engine in which the engine is placed horizontally with respect to the vehicle body, the continuously variable transmission is connected to the input shaft, output shaft, counter shaft, differential shaft, etc. It is composed of four axes such as a shear shaft, and because the axial dimension is shortened, it is advantageous in terms of freedom of mounting the continuously variable transmission to the engine and vehicle body, but the configuration is complicated. There is a drawback. On the other hand, a continuously variable transmission constructed of two shafts, an input shaft and an output shaft, is disclosed in, for example, Japanese Patent Laid-Open No. 57-29845.

[Problems to be Solved by the Invention] However, in the above-mentioned continuously variable transmission, a wet brake is provided as a starting device at the rear of the output shaft, which is the second shaft of the V-belt continuously variable transmission.
The transmission torque is large at the time of starting (half-clutch state), and a large heat capacity of the brake is required. For this reason, there is a problem in that the number of discs in the wet brake increases and the axial dimension increases.In addition, to solve this problem, if the starting device is disposed on the first shaft, the axial direction of the first shaft increases. The problem is that the size increases, and it is difficult to mount the continuously variable transmission within the space restricted by the engine and the vehicle body.

The present invention solves the above problems, and includes:
An object of the present invention is to provide a continuously variable transmission for a vehicle, which can shorten the axial dimension of the continuously variable transmission composed of two shafts and can be easily mounted even in the case of a horizontally mounted engine.

[Means for Solving the Problems] To achieve this, the continuously variable transmission for vehicles of the present invention includes an input pulley that is provided on an input shaft having a hollow portion and whose effective diameter is variable by a servo mechanism, and an input pulley that is provided in parallel with the input shaft. a continuously variable transmission consisting of an output pulley whose effective diameter is variable by a servo mechanism provided on an output shaft disposed on an output shaft, and a V-belt that transmits power between the input pulley and the output pulley; and the input pulley and the engine. A fluid coupling disposed between the output shafts, a forward/reverse switching mechanism disposed on the engine side of the output pulley, and a shaft connected to the forward/reverse switching mechanism and disposed concentrically with the output shaft. It is characterized by comprising a differential mechanism having.

[Operation and Effects of the Invention] The present invention includes a fluid coupling disposed between an input pulley and an engine output shaft, and a forward/reverse switching mechanism disposed on the engine side of the output pulley. It is possible to shorten the axial dimension of a continuously variable transmission consisting of the following, making it easier to install it even in the case of a horizontally mounted engine.

[Example] Next, the present invention will be explained based on an example shown in FIG.

1 is the engine, 10 is the transmission case, 11 is the output shaft (crankshaft) of the engine, 2 is the V-belt continuously variable transmission, and 3 is the fluid arranged between the engine and the V-belt continuously variable transmission. In this embodiment, a fluid coupling with a direct coupling clutch is used.

4 is a forward/reverse switching mechanism, and 5 is a differential mechanism.

The V-belt type continuously variable transmission 2 includes a hollow input shaft 21 with a closed end near the engine, which is arranged in series on the same axis as the engine output shaft, and a V-belt which is arranged parallel to the input shaft. Input pulley 2 installed on the hollow output shaft 22 and input shaft 21 of the continuously variable transmission
3. An output pulley 24 provided on a hollow output shaft 22, a V-belt 25 that transmits power between the input pulley 23 and the output pulley 24, a servo mechanism 26 that changes the effective diameter of the input pulley 23, and an output pulley 24.
It consists of a servo mechanism 27 that changes the effective diameter of the input pulley, and a cam mechanism 28 provided on the input pulley.

The input shaft 21 has a hollow shaft center and a bearing 2.
11 and 212, the engine is rotatably supported by the transmission case 10, and the engine is connected to the alligator stage 2.
13, on the other side, an outer peripheral spline 214 and a tip screw 215 are formed.

The output shaft 22 has a hollow shaft center, and in this embodiment is formed integrally with a sleeve of a fixed flange, which will be described later, and is rotatably supported by the transmission case 10 by bearings 221 and 222.

The input pulley 23 has one end (the right end in the figure) connected to the stage 21 of the input shaft via a thrust bearing 216.
3, and an outer circumferential spline 23 on the outer periphery of the other end.
1 and a sleeve-shaped portion 23 provided with a keyway 232
3, and a slit 234 formed integrally with the sleeve-shaped portion 233 and on the outer periphery for detecting the rotational speed of the input shaft.
A fixed flange 23A consisting of a flange portion 235 provided around the fixed flange 23A, a key groove 236 that is fitted onto the sleeve portion 233 of the fixed flange 23A so as to be freely displaceable in the axial direction, and that corresponds to the key groove 232 of the fixed flange on the inner peripheral wall. A movable flange 23B consisting of a sleeve-shaped hub part 238 in which a driven screw 237, which is a first screw, is formed on the outer peripheral wall thereof, and a flange part 239 formed integrally with the hub part 238, and a key groove. 232 and 236, the other is an alligator tube from the outer periphery of the ball key 230 and the movable flange 23B for allowing the fixed flange 23A and the movable flange 23B to displace in the axial direction and rotate integrally around the axes. A band brake 6 consisting of a brake drum 23C formed in a shape and a double-wrap type brake band 23D wound around the outer periphery of the brake drum 23C.
Consisting of

The output pulley 24 has a keyway 241, a spline 242, a screw 243, and a spline 2 on the outer periphery.
A fixed flange 24A consisting of a sleeve-shaped part 244 formed integrally with the output shaft 22 and a flange part 245 formed integrally with the sleeve-shaped part 244, and a sleeve part 244 of the fixed flange 24A. A key groove 2 is fitted on the outside so as to be freely displaceable in the axial direction, and a key groove 2 corresponding to the key groove 241 is provided on the inner periphery.
450, and a sleeve-shaped hub portion 247 having a driven screw 246, which is a first screw, formed on the outer periphery.
and a flange portion 248 formed integrally with the hub portion 247, and a ball key inserted into the key grooves 241 and 2450 for integrally rotating the fixed flange 24A and the movable flange 24B. Consists of 240.

The V-belt 25 is connected to the input pulley 23, respectively.
and working surfaces 251 and 252 that contact the V-shaped working surfaces formed by the fixed flange 23A, fixed flange 24A, movable flange 23B, and movable flange 24B of the output pulley 24 to form a friction surface.
are provided on both sides.

The input pulley servo mechanism 26 has a driven screw 261 which is a second screw screwed into the driven screw 237 of the movable flange 23B of the input pulley formed on the inner periphery, and one end is connected to the driven screw 261 via a thrust bearing 265, which will be described later. The other cam race 287 of the cam mechanism
A sleeve 262 that is a driver of a movable flange that is in contact with the case 10 , a wet multi-plate electromagnetic downshift brake 263 that is provided between the sleeve 262 and the case 10 and brakes the sleeve 262 , and a sleeve 2
Cylindrical spring guide 2 arranged around the outer periphery of 62
64, the spring guide 264 and the sleeve 26
A first upshift spring 266 is disposed between the spring guide 2 and the engine end is connected to the movable flange 23B, and the other end is connected to the other end of the cylindrical spring guide 264. A second upshift spring 267 is disposed on the outer periphery and has an engine-side end connected to the engine-side end of the spring guide 264 and a second upshift spring 267 connected to the other side end of the sleeve 262 .

The output pulley servo mechanism 27 includes a sleeve 272, which is a driver, and a sleeve 272, which is a driver, on the inner circumference of which a drive screw 271, which is a second screw that is screwed into the driven screw 246 of the movable flange 24B, is formed, and the sleeve 272 and the case 10. a wet multi-plate electromagnetic upshift brake 273 that fixes the upshift, a torsion coil spring 274 for downshift connected with both ends connected between the sleeve 272 and the movable flange 24B, and a spline 242 of the output shaft. A spline is formed to fit into the movable flange 24B.
One side is in contact with the end face of the sleeve 272 via the bearing 275, and the other side is in contact with the nut 276 via the inner race of the bearing 221.
and a support ring 277 that supports the sleeve 272 in the axial direction.

The cam mechanism 28 is connected to the input shaft 2 as shown in FIG.
The inner peripheral spline 281 is fixed in the axial direction by a snap ring 218 externally fitted on the input shaft 21 and a nut 217 screwed onto the screw 215 formed at the end of the input shaft. It consists of one cam race 282 formed, the other cam race 287, a tapered roller 288 interposed between these cam races, and a cover ring 289 of the roller 288.
The movable flange 23B is sandwiched between the working surfaces 292 and 286 of the movable flange 23A and the fixed flange 23A, and changes the pressing force that presses the movable flange 23B in the right direction in the figure in response to the rotational displacement of the input shaft 1 and the fixed flange 23A.

Next, the operation of this V-belt type continuously variable transmission will be explained.

(a) When driving at constant speed, brakes 263 and 273 are released on both sides.

Torque is transmitted through the input shaft 21 → one race 282 of the cam mechanism → tapered roller 288
→The other race 287→Input pulley 23→V belt 25→Output pulley 24→Output shaft 22 in this order. The magnitude of the torque transmitted by the V-belt 25 is proportional to the clamping force applied to the V-belt 25.
The pinching pressure is brought into contact with the other cam race 287 via the movable pulley 23B and the sleeve 262 screwed with the movable pulley, and the input pulley moves slightly in the rotational direction due to the principle of the cam mechanism, and is moved in the axial direction by the tapered roller 288. Acting clamping force
Fc changes in proportion to the transmitted torque, as shown in FIG. Surface, movable flange 23B and fixed flange 2
The contact pressure with the working surface of 3A changes, changing the clamping pressure on the contact surface. In Figure 3, F1 is the required clamping pressure at which the V-belt does not slip at the highest gear ratio, F2 is the required clamping pressure at which the V-belt does not slip at the lowest gear ratio, and F0 is the required clamping pressure at which the V-belt does not slip at the lowest gear ratio. The clamping pressure, Fs, indicates the clamping pressure due to the spring. From the graph in Figure 3, in the V-belt continuously variable transmission using the cam mechanism 28, the clamping pressure and the transmission torque are directly proportional even when the transmission torque is 5 kg or less, reducing the generation of unnecessary clamping pressure with the V-belt pulley. I see that it is possible.

(b) Upshifting is performed by engaging the brake 273.

The sleeves 262 and 272 rotate relative to the sleeve portions 238 and 247 of the movable flange, and the movable flange 23B is displaced in a direction (to the right in the figure) that increases the effective diameter of the input pulley 23.
The movable flange 24B is displaced in a direction that reduces the effective diameter of the output pulley 24 (to the right in the figure), and the speed ratio is reduced. The brake 273 is released when the gear ratio reaches the control set value.

During this upshift, the torsion spring 274 of the servo mechanism of the output pulley is twisted and energy is stored.

(c) A downshift is performed by engaging the brake 263.

When the brake 263 is engaged, the sleeve 262
is fixed and the movable flange 23B is input to the input pulley 23.
is displaced in the direction of decreasing effective diameter (to the left in the figure),
Torsion spring 274 is attached to sleeve 272
is rotated and returned, and the movable flange 24B is displaced in the direction of increasing the effective diameter of the output pulley (to the left in the figure). The displacement of the movable flange 23B of the input pulley 23 is controlled by the cam mechanism.
This is done against the pressing force of 3B. When the gear ratio reaches the control set value, the brake 263 is released. During this downshift, the first and second upshift springs 266 and 267 of the input pulley servo mechanism 26 are twisted to store energy.

In this V-belt type continuously variable transmission, if the electromagnetic brakes of the brakes 263 and 273 fail and the brakes become inapplicable, the vehicle can run with the same speed ratio as before the failure. Therefore, it is possible to prevent the gear ratio from being changed inadvertently due to oil pressure leakage in the case of a V-belt continuously variable transmission in which the gear ratio is changed by a hydraulic servo, resulting in excellent safety.

The fluid coupling 3 is provided between the input pulley 23 and the engine 1, and includes a drive plate 31 having an engine starting ring gear 311 welded to its outer periphery and connected to the output shaft 11 of the engine by a bolt 312. A front cover 32 is fastened to the front cover 32 with bolts 321, the outer periphery is welded to the front cover, and a metal bearing 33 is attached to the output shaft 35 of a fluid coupling in the center.
A pump impeller 33 is welded to a pump hub 335 that is rotatably supported via a pump hub 335 and whose gap with the output shaft 35 is sealed via an oil seal 332, and is disposed between the pump impeller and the front cover 32. turbine runner 34,
The output shaft 3 of the fluid coupling is formed integrally with the input shaft 21 of the V-belt type continuously variable transmission, and the input shaft 21 is hollow and the engine is closed.
5. Turbine and direct coupling clutch hub 3 spring-fitted to the engine-side end of the output shaft 35
6. Damper spring 371 and spring plate 3 riveted on the outer periphery of the hub 36
72, a weight 373 attached to the outer periphery of the spring plate 372, a spring 374 arranged around the outer periphery of the weight 373, and a friction material 375 of a centrifugal lock-up clutch arranged outside the weight 373. It has a centrifugal direct coupling clutch 37, and an oil seal 101 seals between the outer periphery of the pump hub 335 and the side wall of the automatic transmission case 10. In this fluid coupling 3, the hollow engine output shaft 11 is used as a supply oil passage 111 for cooling hydraulic oil, and the engine oil supplied from the engine oil pump is passed through a recess provided at the end of the oil passage 111. Front cover 1 in place 112
Center piece 3 with center hole welded to the center of 2
The output is supplied into the front cover 32 through the center hole 23 of the output shaft 35 and connects the inside of the fluid coupling between the turbine and direct coupling clutch hub 36 of the output shaft 35 and the pump hub 335 with the hollow part of the output shaft 35. The oil returns to the oil pan of the engine via the shaft hollow part 350 and the hollow part 210 of the input shaft 21 of the V-belt continuously variable transmission, through the drain 12 provided on the rear cover 110 of the automatic transmission case.

The forward/reverse switching mechanism 4 includes a dog clutch 41
(brake device), a first simple planetary gear set 43, and a second simple planetary gear set 45.

The dog clutch 41 includes a fork 411 linked to an operating lever, a brake sleeve 413 that is engaged with the fork and slid in the axial direction, a first gear (spline piece) 415, a second gear (spline piece) 417, and a sleeve. 413
and a second gear 417.

The first planetary gear set 43 has a sun gear shaft 430 spline-fitted to a front spline 249 provided on the output shaft 22 of the V-belt continuously variable transmission.
The sun gear 431 formed above is connected to the second gear 417 of the dog clutch 41 and
Ring gear 433 and dog clutch 41 connected to sun gear 451 of planetary gear set 45
The second planetary gear set 45 consists of a carrier 435 connected to the first gear 415 and a second ring gear 453, and a planetary gear 437. The carrier 45 is spline-fitted to a spline 459 provided on an output sleeve 450 connected to the carrier 45.
5 and a planetary gear 457. This forward/reverse switching mechanism 41 is configured so that the sleeve 413 of the dog clutch 41 is moved to the second gear 4 manually or automatically.
17 and the ring gear 433 and sun gear 451 are fixed to the case 10, the set gear ratio is moved forward, and the sleeve 413 is engaged with the first gear 4.
Carrier 435 and ring gear 4 meshed with 15
53 is fixed to the case 10, it becomes a backward movement at the set gear ratio. The operation of this dog clutch 41 is to fix the input pulley with the band brake 6 in the V-belt continuously variable transmission and stop the rotation of the output shaft 22 of the V-belt continuously variable transmission due to the drag in the fluid coupling 3. It is done in a state where
This band brake 6 is operated by a known servo mechanism that utilizes the engine's intake negative pressure.

The differential mechanism 5 has an output sleeve 450, which is the output shaft of the forward/reverse switching mechanism 4, as an input shaft, a gear box 52 integrally connected to the input shaft 450, and small differential gears 53, 54. Large differential gears 55 and 56 meshing with the small gears, one output shaft 57 spline-fitted to the large differential gear, and the output shaft first and second sun gears 431 of the V-belt continuously variable transmission. , 451, and the other output shaft 58 inserted through the output leaf 450.
Consisting of

13 and 14 are constant velocity joints provided at the ends of the output shafts 57 and 58 of the differential mechanism 5.

As described above, the continuously variable transmission for vehicles of the present invention has the following features: A) Since a fluid coupling is used as the starting device,
No control is required for starting, the starting is smooth, the heat capacity is large, engine torque fluctuations can be absorbed, and transmission of engine vibration into the vehicle interior and vibrations caused by transmission torque fluctuations can be prevented.

B) Since a centrifugal lock-up clutch is used in the fluid coupling, slip losses in the fluid coupling can be eliminated.

C) The centrifugal lock-up clutch engages itself by centrifugal force, so it does not require any external control, and has a simple structure and low cost. In addition, compared to conventional stepped transmissions, continuously variable transmissions are essentially mechanisms that do not have a shift shock, so there is no need to release the lock-up clutch each time a gear is changed. The lock-up clutch combination has great advantages.

D) Since the engine oil discharged from the engine oil pump is used to cool the fluid coupling, there is no need for a dedicated oil pump in the transmission, resulting in low cost and no power loss.

E) Since it uses a dog clutch of the type used in manual transmissions, it is lightweight, compact, low cost, and has no drag resistance.

F) Since it has a two-shaft structure and the dimension in the direction of the input shaft can be significantly shortened, the turning radius of the vehicle can be reduced. Furthermore, the number of constant velocity joints can be reduced.

G) Since a torsional coil spring and an electromagnetic brake are used as the speed change control mechanism, a hydraulic friction transmission device is not used as in conventional automatic transmissions, making it simple and low cost.

H) Since no oil pump, valve body, etc. are used, the machining process for forming oil passages can be significantly reduced compared to conventional automatic transmissions, resulting in low cost and high productivity.

I) When a double winding type brake band is adopted as in the embodiment shown in FIG. 1, the torque capacity is larger than that of a normal single winding type, so the servo mechanism can be made lighter and more compact.

J) By using an electromagnetic brake and torsion spring as the servo mechanism of the V-belt continuously variable transmission, compared to using a hydraulic servo,
The radial dimension can be reduced, and by using a dog clutch as the engagement element of the forward/reverse switching mechanism, the outer diameter of this portion can also be reduced.

K) By adopting the above-mentioned servo mechanism and dog clutch, it is possible to control gear shifts without using hydraulic pressure, eliminating the need for a hydraulic control circuit for hydraulic control and eliminating the need for oil passage formation, simplifying the structure and reducing manufacturing costs. Costs can be reduced and maintenance can be facilitated.

L) The dog clutch and electromagnetic brake can be easily operated both manually and automatically, so they can be controlled manually or automatically with the same configuration.

It has the following effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the continuously variable transmission for a vehicle according to the present invention, FIG. 2 is an enlarged view of the cam mechanism, and FIG. 3 is a graph for explaining the function of the cam mechanism. DESCRIPTION OF SYMBOLS 1... Engine, 2... Continuously variable transmission, 3... Fluid coupling, 4... Forward/forward switching mechanism, 5... Differential mechanism, 21... Input shaft, 23... Input pulley, 24
...output pulley, 25...V belt, 26, 27...servo mechanism, 28...cam mechanism, 23A, 24A...fixed flange, 23B, 24B...movable flange.

Claims (1)

[Claims] 1. An input pulley that is provided on an input shaft having a hollow part and whose effective diameter is variable by a servo mechanism, an input pulley that is provided on an output shaft that is arranged in parallel to the input shaft and whose effective diameter is variable by a servo mechanism A continuously variable transmission comprising a variable output pulley and a V-belt that transmits power between the input pulley and the output pulley; a fluid coupling disposed between the input pulley and the engine; and an engine for the output pulley. A vehicle-use vehicle comprising: a forward/reverse switching mechanism disposed on the side; and a differential mechanism having a shaft connected to the forward/reverse switching mechanism and disposed concentrically with the output shaft. gearbox. 2. The continuously variable transmission for a vehicle according to claim 1, wherein the forward/reverse switching mechanism comprises first and second planetary gear sets and a dog clutch that selectively fixes the components thereof. Machine. 3. An input pulley that is installed on an input shaft having a hollow part and whose effective diameter is variable by a servo mechanism, and an output pulley that is installed on an output shaft that is arranged in parallel to the input shaft and whose effective diameter is variable by a servo mechanism. , a continuously variable transmission consisting of a V-belt that transmits power between an input pulley and an output pulley; a fluid coupling disposed between the input pulley and the engine; and a fluid coupling disposed on the engine side of the output pulley. a differential mechanism having a forward/reverse switching mechanism and a shaft connected to the forward/reverse switching mechanism and disposed concentrically with the output shaft; a flange and a movable flange; a drive mechanism that displaces the movable flange in the axial direction; and a drive mechanism that is provided on at least one of the input shaft or the output shaft and that makes the clamping force between the fixed flange and the movable flange and the V-belt proportional to the transmission torque of the V-belt. A continuously variable transmission for a vehicle, characterized by comprising a cam mechanism that causes the transmission to occur. 4. The drive mechanism includes a driver screwed onto the movable flange, a spring that rotates the driver, and a brake that brakes the driver. Continuously variable transmission for vehicles.