JPH0333943B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuously variable transmission mainly used in automobiles, which is composed of a V-belt continuously variable transmission mechanism and a forward/reverse switching mechanism, and particularly relates to the structure of the forward/reverse switching mechanism. be.

When continuously variable transmissions are used in automobiles, they have the advantage of not requiring a speed change operation or being able to select an arbitrary reduction ratio depending on conditions such as load, and various proposals have been made in the past.

For example, Japanese Patent Publication No. 56-66557 proposes a continuously variable transmission comprising a torque converter, a V-belt type continuously variable transmission, and a forward/reverse switching mechanism. In this proposal, the known V-belt type is used, in which the width of the tapered V-belt groove of the drive and driven pulleys of the V-belt is made variable, thereby steplessly changing the rotation radius of the belt by the pulley along the taper. The continuously variable transmission mechanism is driven by the engine via the torque converter, and the torque converter and V
A continuously variable transmission is constructed in which a forward/reverse switching mechanism is interposed between the belt type continuously variable transmission mechanism or between the V belt type continuously variable transmission mechanism and the output shaft. As a result, sudden shifts such as when starting are performed mainly by the torque converter, and normal gradual shifts are performed by a V-belt type continuously variable transmission mechanism, and a forward/reverse switching mechanism with a planetary gear device is used to switch between forward and backward movements. ing. The proposed forward/reverse switching mechanism uses a brake provided on the ring gear to switch forward/reverse forward/reverse, and a clutch that engages and disengages the sun gear and carrier. Since the above-mentioned brake and clutch are arranged in parallel in the axial direction on the side of the planetary gear system, the axial dimension becomes long, which goes against the desire to shorten the axial dimension as much as possible in order to make the car more compact. . Furthermore, the brakes and clutches arranged in parallel in the axial direction are easy to mold and assemble the forward/reverse switching mechanism because the accommodating parts of the case that accommodate them are formed with opening directions facing each other. There is also a desire to simplify the process because it is easily damaged.

In view of the above circumstances, an object of the present invention is to provide a continuously variable transmission that is compact and has a simple structure by shortening the axial dimension of the forward/reverse switching mechanism and simplifying the arrangement structure of the brake and clutch. shall be.

The continuously variable transmission of the present invention includes a V-belt type continuously variable transmission mechanism and a forward/reverse switching mechanism having a planetary gear device connected in series to the mechanism, and an input shaft and an output shaft of the forward/reverse switching mechanism. One of the elements is directly connected to one element of the sun gear, carrier, and ring gear of the planetary gear apparatus, and the other is directly connected to one of the two elements, and the rotation of the element is prevented by the remaining elements of the planetary gear apparatus. In addition to providing a multi-plate brake that reverses the rotation of the input shaft and transmits it to the output shaft, the rotation of the input shaft is directly coupled by controlling the connection of two of the three elements mentioned above. In a continuously variable transmission provided with a multi-plate clutch for transmitting a signal to an output shaft, the multi-plate clutch is located on an axial side of the planetary gear device, and an opening of a clutch drum of the multi-plate clutch is on the side of the planetary gear device. The multi-disc brake is disposed in a radially outward direction of the multi-disc clutch or the planetary gear set in the same direction as the opening side of the clutch drum of the multi-disc clutch. The device is characterized in that it is disposed within an open housing portion of the case.

According to the present invention, since the multi-disc brake is disposed radially outward of the multi-disc clutch or the planetary gear device, the axial dimension of the forward/reverse switching mechanism can be shortened, resulting in a compact continuously variable transmission. machine can be realized. Furthermore, since the multi-disc brake and multi-disc clutch have their housing portions and clutch drums open in the same direction, the case that accommodates and supports these multi-disc brakes and multi-disc clutch has surfaces that face each other. This makes it possible to improve the formability of the case, improve the ease of assembling the forward/reverse switching mechanism, and realize a continuously variable transmission with a simple structure. can.

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 are schematic diagrams showing the main parts of an embodiment of the present invention. Figure 1 shows the connection between the carrier and ring gear in a forward/reverse switching mechanism where the clutch is used to control the connection, and Figure 2 shows the connection between the sun gear and the ring gear. This shows the case of controlling the coupling of ring gears.

In the embodiment shown in FIG. 1, the input shaft 3 of the V-belt type continuously variable transmission mechanism 10 is a damper 2 (this may be a fluid coupling or a torque converter instead of a damper).
It is driven by engine 1 via. Cylinder 11 integrated with fixed flange 11 on this drive shaft
A piston chamber 13 is formed by a piston 12a integrated with a movable flange 12 that is slidably inserted into the cylinder 11a only in the axial direction.
In this embodiment, balls 14 are inserted into grooves extending in the axial direction provided on the outer circumference of the fixed flange and the inner circumference of the movable flange so that the movable flange 12 can move in the axial direction and rotate at the same time as the fixed flange 11. I have to. By applying hydraulic pressure, air pressure, etc. to the piston chamber 13, the piston 12a is pushed and returned, and the movable flange 12 is moved in the axial direction, and the movable flange 12 and the fixed flange 11 are moved.
The groove width of the drive pulley can be controlled. The pulley on the driven side is similar to the drive side pulley, and has a cylinder 15a integrated with the fixed flange 15.
A piston 16a integrated with the movable flange 16 is slidably inserted only in the axial direction by a ball 18, and the groove width of the driven pulley consisting of the movable flange 16 and the fixed flange 15 is changed by the oil pressure, air pressure, etc. of the piston chamber 17. can be controlled. The above movable flanges 12, 16 and fixed flange 1
1 and 15 both have tapers that widen in the radial direction, and the radius of rotation of the V-belt 19 by the pulley changes as the groove width of the pulley is controlled. By appropriately controlling the groove width, a stepless reduction ratio can be obtained.

Output shaft 4 of the V-belt type continuously variable transmission mechanism 10
is directly connected to the carrier 22 of the forward/reverse switching mechanism 20, and rotates the carrier 22 and the planetary double pinion gear 23. In this embodiment, a double pinion gear is used as the planetary gear, but this gear is directly connected to either the forward or reverse gear to prevent a drop in efficiency in the planetary part.
Because the gear ratio of the continuously variable transmission mechanism can be used in both forward and reverse directions, a forward to reverse gear ratio of about 1.0 is good, so a double pinion gear is used because it is easy to set the forward to reverse gear ratio close to 1.0.
(With a single pinion gear, it is very difficult to set the above gear ratio close to 1.0.) The ring gear 24 is stacked radially so that the brake 27 is on the outside and the clutch 26, which controls the coupling with the carrier, is on the inside. When the clutch 26 is engaged, the ring gear 24 and the carrier 22
The sun gear 25 also rotates the same as the carrier 22 and is outputted via the output shaft 5. That is, when the clutch 26 is engaged, the planetary portions are directly connected and the input rotation and output rotation are in the same direction. Next, when the clutch 26 is released and the brake 27 is engaged, the sun gear 25 rotates in the opposite direction to the carrier 22 and is outputted via the output shaft 5. As described above, a continuously variable transmission capable of continuously variable speed in both forward and reverse directions is obtained.

The embodiment shown in FIG. 2 is the same as the embodiment shown in FIG. 1 except that the coupling between the ring gear 24 and the sun gear 25 is controlled by a clutch 26, and the same parts are given the same numbers and their explanations will be omitted. . The rotation of the carrier 22, which is directly connected to the output shaft 4 of the V-belt continuously variable transmission mechanism 10, is such that when the clutch 26 is engaged, the sun gear and ring gear rotate at the same time, so the carrier also rotates at the same time and the planetary part is directly connected. The input rotation and output rotation of the forward/reverse switching mechanism 20 become the same. Next, when the clutch 26 is released and the brake 27 is engaged, the sun gear 25 rotates in the opposite direction to the carrier 22. Therefore, according to this embodiment as well, a continuously variable transmission capable of continuously variable speed in both forward and reverse directions can be obtained. In this embodiment as well, the brake 27 and the clutch 26 are provided on the ring gear so as to overlap inside and outside in the radial direction.

3 and 4 are upper half sectional views showing details of the forward/reverse switching mechanism 20 in the schematic diagrams of FIGS. 1 and 2, respectively.

In FIG. 3, the V-belt type continuously variable transmission mechanism 10
The output shaft 4 of is directly connected to a carrier 22, and this carrier 22 and a planetary double pinion 23
(only part shown) and transmits rotation to. Of this double pinion, the outer pinion 23 is the ring gear 2
4, and an inner pinion (not shown) meshes with sun gear 25. A brake 27 is provided on the ring gear 24 via a flange portion 24a. Also, the clutch drum 2 coupled to the ring gear 24
6c is stacked on the inside of the brake 27 in the radial direction, and the clutch 2 is placed on the inside of this clutch drum 26c.
6 is provided. Brake 27 is ring gear 24
between the flange portion 24a and the case 29, which are connected to the ring gear
Brake the rotation of 4. The clutch 26 is located between a clutch drum 26c connected to the ring gear 24 and a drum 22a connected to the carrier 22, and engages and disengages the two. That is, the brake 27
When the clutch 26 is activated (engaged), the ring gear 24 is fixed and rotation is prevented, and when the clutch 26 is activated (engaged), the ring gear 24 and the carrier 22 are engaged and rotate at the same time. The brake 27 is engaged when the piston 27b is pushed by the hydraulic pressure generated in the cylinder of the case 29 by oil from the brake oil hole 27a, and the clutch 26 is engaged by the oil from the brake oil hole 27a.
The piston 26b is pushed into engagement by the hydraulic pressure generated within the clutch drum 26c by the oil from the clutch drum 26a. Further, the ring gear 24 is supported in the thrust direction by a case 29 via a bearing 28.

In the forward/reverse switching mechanism 20 configured as described above, when the brake 27 is engaged, the ring gear 24
is fixed, so after the rotation of the input shaft 4 is transmitted to the carrier, the sun gear 25 is rotated in the opposite direction to the input shaft 4 via the double pinion 23. Then,
When the brake 27 is engaged, the rotation of the input shaft 4 is reversed and transmitted to the output shaft 5. When the clutch 26 is engaged, the ring gear 24 and the carrier 22 are directly connected and rotate at the same time, so the sun gear 25 also rotates together with them. In other words, the rotations of the input shaft 4 and the output shaft 5 are exactly the same.

In the embodiment shown in FIG. 4, the clutch 26 includes a clutch drum 26c coupled to the ring gear 24.
and a drum 25a that is coupled to the sun gear 25, and engages and disengages the two, that is, the drum 25a that is coupled to the clutch drum 26c via the clutch 26 (in the embodiment shown in FIG. 3, the drum 25a is coupled to the carrier 22). 3) is the same as the embodiment shown in FIG. 3, except that it is connected to the sun gear 25. Therefore, the same parts as in the example of FIG. 3 are given the same numbers, and the explanation of the structure will be omitted. In this embodiment, when the brake 27 is engaged, the ring gear 24
is fixed, and the rotation of the input 4 is reversed and transmitted to the output shaft 5 as in the example of FIG. When the clutch 26 is engaged, the ring gear 24 and sun gear 25
are directly connected, so ring gear 24 and sun gear 2
5 and carrier 22 all rotate at the same time, and the input shaft 4 and output shaft 5 rotate at the same time.

As described above, by engaging the clutch or brake, switching between forward and reverse rotation can be performed. In the above embodiment, the shaft directly connected to the carrier was used as the input shaft, and the shaft directly connected to the sun gear was used as the output shaft, but by reversing this, the carrier side could be used as the output shaft and the sun gear side as the input shaft, allowing both forward and reverse movement. There is no problem since the input/output gear ratio is approximately 1:1.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams showing the main parts of an embodiment of the present invention, and FIGS. 3 and 4 are upper half sectional views of the forward/reverse switching mechanism, respectively. 1... Engine, 2... Damper, 3... Input shaft, 4... Continuously variable transmission mechanism output shaft, 5... Output shaft,
10... V-belt type continuously variable transmission mechanism, 11, 15...
...fixed flange, 12,16...movable flange,
13, 17... Piston chamber, 14, 18... Ball, 19... V belt, 20... Forward/forward switching mechanism, 22... Carrier, 23... Double pinion gear, 24... Ring gear, 25... Sun gear,
26...Clutch, 26c...Clutch drum,
27...brake, 28...bearing, 29...
…Case.

Claims (1)

[Scope of Claims] 1. A V-belt continuously variable transmission mechanism and a forward/reverse switching mechanism having a planetary gear device connected in series to the mechanism, wherein either an input shaft or an output shaft of the forward/reverse switching mechanism is provided. One of the elements is directly connected to one element of the sun gear, carrier, and ring gear of the planetary gear apparatus, and the other is directly connected to one of the other two elements, and the rotation of the element is prevented by the remaining elements of the planetary gear apparatus. In addition to providing a multi-plate brake that reverses the rotation of the input shaft and transmits it to the output shaft, the above 3.
In a continuously variable transmission equipped with a multi-plate clutch that directly transmits the rotation of an input shaft to an output shaft by controlling the coupling of two of the two elements, the multi-plate clutch The clutch drum of the multi-disc clutch is supported by a case and disposed on the axial side of the planetary gear device with an opening of the clutch drum opening toward the planetary gear device, and the multi-disc brake is arranged on the multi-disc brake. A continuously variable transmission characterized in that the continuously variable transmission is disposed in a housing portion of the case that opens in the same direction as the opening side of the clutch drum of the multi-disc clutch at a radially outer side of the clutch or the planetary gear set.