JPS6113032A - Speed change gear - Google Patents

Abstract

PURPOSE:To make the start of a turbine ever so smooth, by installing a centrifugal lockup clutch, frictionally engaging the pump side in time of dead slow, in the side of the turbine of a hydraulic coupling. CONSTITUTION:A drive plate 2 at the end part of a crankshaft 1 is locked to the side of a cover member 5 being solidly installed together with a pump 4 of a hydraulic coupling 3. A centrifugal lockup clutch 7 is coupled with a turbine 6 of the hydraulic coupling 3, and when a revolving speed of the turbine 6 becomes more than the specified one, it frictionally engages the cover member 5. Therefore, not only smooth starting is performable but also lockup clutch is able to automatically operate owing to centrifugal force, thereby dispensing with control over hydraulic pressure or the like utterly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transmission suitable as an automobile transmission, and particularly to a starting mechanism thereof.

Prior art and its problems As described in Japanese Patent Application Laid-Open No. 58-42862,
By mutually moving the movable sheave of the driving pulley and the movable sheave of the driven pulley, the pulley ratio (speed ratio)
A transmission device is known that includes a V-belt type continuously variable transmission with variable speed and a fluid coupling between the continuously variable transmission and an engine.

The fluid coupling is provided with a lock amplifier device for start control that operates before the pulley ratio of the continuously variable transmission starts to change to a higher speed. In other words, since the V-belt continuously variable transmission can have a larger gear ratio than a conventional automatic transmission, the engine speed is sufficiently high even at extremely low vehicle speeds of about 5 km/h, and at this point the lock amplifier is activated. Not only does this not cause any problems, but it is also advantageous to run the lock amplifier at as low a speed as possible when considering fuel efficiency and power performance. From this point of view, the above lockup device is provided.

However, since the above-mentioned lock amplifier device is operated by a hydraulic control valve for controlling the continuously variable transmission, not only is the control complicated, but the lock-up vehicle speed is unstable due to fluctuations in oil temperature. There was a problem.

Purpose of the Invention The present invention has been made in view of such conventional problems.
The purpose is to provide a transmission device that can perform a smooth start and that does not require control of hydraulic pressure or the like.

Structure of the Invention In order to achieve the above object, the present invention provides a centrifugal lock-up clutch on the turbine side of a fluid coupling that frictionally engages with the pump side at extremely low speeds. In other words, in the present invention, when the turbine side of the fluid coupling starts to rotate, the lock-up clutch is automatically activated by the centrifugal force, so there is no need to control oil pressure or the like. Because it is installed on the side,
Direct connection conditions are not affected by engine speed.

If this lock-up clutch is installed on the pump side, it will operate according to the engine speed, so if you operate the choke or dry-inject while the engine is stopped, the engine speed will increase and the lock-up clutch will lock up. There is a problem where the amplifier clutch activates and the vehicle starts moving. The present invention does not have this problem.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an example of a transmission according to the present invention, and this transmission is composed of a starting mechanism A and a continuously variable transmission B. As shown in FIG.

First, to explain the starting mechanism A, a drive plate 2 is coupled to the end of the crankshaft 1 of the engine, and the drive plate 2 is fixed to the side surface of a cover member 5 provided integrally with the pump 4 of the fluid coupling 3. ing. on the other hand,
A centrifugal lock-up clutch 7 is connected to the turbine 6 of the fluid coupling 3, and this lock-up clutch 7 comes into frictional engagement with the cover member 5 when the rotational speed of the turbine 6 exceeds a predetermined value. There is.

A continuously variable transmission B is provided behind the starting mechanism A, and this continuously variable transmission B includes a driving pulley 20, a driven boolean IJ 30, and a non-&IV belt 40 wound between these pulleys. It is equipped with The driving pulley 20 and the driven pulley 30 each include fixed sheaves 22, 32 fixed to a shaft 21.31, and a movable sheave 23.33 that is movable in the axial direction with respect to the shaft 21.31, By pressing this movable sheave 23.33 from behind with an actuating means 24.34, the pulley diameter can be varied. The actuation means 24, 34 include a hydraulic cylinder controlled by a hydraulic control valve, a centrifugal actuator that displaces the movable sheave by centrifugal force, and a torque cam that generates a sheave thrust commensurate with the input torque.

Here, the configuration of the starting mechanism A will be explained in detail with reference to FIGS. 2 and 3. The inner diameter part of the turbine 6, the inner diameter part of the clutch plate 8 of the lock-up clutch 7, and the boss 9 are connected by a beam head 10, and the boss 9 is fixed integrally with the drive shaft 21. The clutch plate 8 is formed into a disk shape, and a pair of side plates 11 are provided on both sides of the outer peripheral portion of the clutch plate 8 so as to be slidable in the circumferential direction. Between this side plate 11,
Two clutch shoes 12 having friction material 13 on the outer peripheral surface
a and 12b are arranged, and this clutch shoe 12
3 and 12b are rotatably pivoted at one end by a support shaft 14. A return spring 15 is stretched between the free end side end of one clutch shoe and the support shaft 14 of the other clutch shoe, and this return spring 15 causes the clutch shoes 12a, 12b to move inwardly toward each other. energized. Clutch shoes 12a, 12b due to centrifugal force
When the friction material 13 overcomes the return spring 15 and rotates outward, the friction material 13 comes into pressure contact with the inner peripheral surface of the cover member 5 of the fluid coupling 3, and the pump 4 and the turbine 6 are directly connected.

The lock-up clutch 7 is provided with a torsional damper 16 in order to absorb shock in the rotational direction when the clutch is directly engaged. This torsional damper 16 is inserted into a hole 17 provided in the clutch plate 8, and is held on both sides by holes 18 in the side plate 11. Therefore, when the friction material 13 of the clutch shoes 12a, 12b comes into pressure contact with the inner peripheral surface of the pump 4 and the shock acts on the side plate 11 via the support shaft 14, the side plate 11 and the clutch plate 8 rotate relative to each other. , the torsional damper 16 is compressed and the shock is absorbed.

In this embodiment, a lock-up clutch 7 is shown in which the pump 4 and the turbine 6 are directly connected by rotating the clutch shoes 12a and 12b, which are pivotally connected at one end, outward by centrifugal force. It is not limited to.

-Next, the operation of the transmission having the above configuration will be explained. When the engine rotates, the pump 4 of the fluid coupling 3 also rotates, and oil pumped by the hydraulic pump flows into the fluid coupling 3, and as the pump 140 rotates, the turbine 6 also begins to rotate. When the rotation speed of the turbine 60 reaches a predetermined value, the lock-up clutch 7 and the cover member 5 are directly connected, and from then on, the engine power from the crank shirt l-1 is transferred to the fluid coupling 3.
Drive plate 2. It is transmitted to the drive shaft 21 via the cover member 5 and the lock-up clutch 7. The power transmitted to the drive shaft 21 has its gear ratio changed by the continuously variable transmission B, and is transmitted to the driven shaft 31.

Effects of the Invention As is clear from the above explanation, according to the present invention, a centrifugal lock-up clutch is provided on the turbine side of the fluid coupling that frictionally engages with the pump side at extremely low speeds, so that smooth starting can be achieved. In addition, since the lock-up clutch is automatically operated by centrifugal force, there is no need to control hydraulic pressure or the like. Moreover, since the lock-up clutch is installed on the turbine side, the conditions for direct connection are determined by the boolean ratio and vehicle speed, regardless of the engine speed, and there is no problem such as the lock-up clutch accidentally operating while the vehicle is stopped.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram of an example of a transmission according to the present invention, FIG. 2 is a detailed sectional view of its starting mechanism, and FIG. 3 is a partially cutaway side view of a centrifugal lock amplifier clutch. A... Starting mechanism, B... Continuously variable transmission, 3... Fluid coupling, 4... Pump, 6... Turbine, 7... Lock-up clutch, 20... Drive side pulley , 21・
... Drive shaft, 23... Movable sheave, 30... Driven pulley, 31... Driven shaft, 33... Movable sheave, 4
o...V Held.

Claims (1)

[Claims] (1) Equipped with a V-belt type continuously variable transmission in which the pulley ratio is variable by mutually moving the movable sheave of the driving pulley and the movable sheave of the driven pulley, and the continuously variable transmission and the engine are What is claimed is: 1. A transmission having a fluid coupling between the fluid coupling and the transmission, characterized in that a centrifugal lock-up clutch is provided on the turbine side of the fluid coupling and frictionally engages with the pump side at extremely low speeds.