JPS6145166A - Hydraulic device of v-belt stepless speed change gear - Google Patents

Abstract

PURPOSE:To decrease aberation of pulley ratio control oil pressure by providing an oil pressure chamber for cancelling oil pressure generated in a cylinder chamber by centrifugal force and connecting the chamber to a lubricating oil path. CONSTITUTION:When a driven pulley 10 is rotated, oil pressure is generated in a cylinder chamber 18 according to centrifugal force, so that a movable sheave 13 is pushed to a fixed sheave 12 by force of F1 by the oil pressure. On the other hand, oil pressure is generated in balance chambers 20, 21 rotated in a body with the cylinder chamber 18 by centrifugal force, so that the balance chamber 20 on inside diameter side pushes the movable sheave 13 to the left by force of F2 by the oil pressure, and the balance chamber 21 on back side pushes the movable sheave 13 to the right by force of F3. Further, low-pressure lubricating oil is supplied to the balance chamber 20 on inside diameter side from an oil pump 26 through an orifice 27 by an oil path 28. Thus, some oil in the cylinder chamber is prevented from leaking out to the balance chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydraulic system for a V-belt continuously variable transmission suitable as an automobile transmission.

Prior art and its problems Conventionally, as described in Japanese Patent Laid-Open No. 58-42862, a cylinder chamber for moving the movable sheave in the axial direction by hydraulic pressure is provided behind the movable sheave of the driving pulley and the driven pulley. One that is integrated is known. However, in this structure, even when no hydraulic pressure is acting on the cylinder chamber, when the movable sheep rotates, hydraulic pressure is generated in the cylinder chamber due to centrifugal force, causing the movable sheep to malfunction.

In order to solve this problem, a balance chamber (auxiliary chamber) is installed behind the fixed piston in the cylinder chamber, and oil leaks from the cylinder chamber into the balance chamber through a small hole. A system has been proposed that cancels out the hydraulic pressure caused by centrifugal force.

However, in this case, since some of the oil in the cylinder chamber is led to the balance chamber, the oil pressure in the cylinder chamber decreases, causing errors in pulley ratio control, and the filling and discharging of oil into the balance chamber becomes difficult. It is expected that this will not be carried out smoothly and there will be a delay in achieving the desired balance effect.

Purpose of the Invention The present invention has been made in view of such conventional problems.
The purpose is to provide a hydraulic system for a V-belt type continuously variable transmission that does not cause deviation in the hydraulic pressure for controlling the pulley ratio in the cylinder chamber and can quickly fill and discharge oil into the balance chamber.

Structure of the Invention In order to achieve the above object, the present invention provides a hydraulic balance chamber at least on the back side of the fixed piston of the hydraulic cylinder chamber for canceling out the hydraulic pressure generated in the cylinder chamber due to centrifugal force, and the hydraulic balance chamber A lubricating oil passage is connected to the oil pump via an orifice. That is, the balance chamber and the cylinder chamber are not communicated with each other, and oil is supplied to the balance chamber through an independent lubricating oil passage.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an example of a continuously variable transmission according to the present invention. It is equipped with The drive-side pulley 1 has a fixed sheave 3 fixed to the drive shaft 2 and a movable sheave 4 that is movable relative to the drive shaft 2, making the pulley diameter variable. A torque cam 5 and a torsion spring 6 are provided to provide a sheave thrust commensurate with the torque.

The driven pulley 10 also has a fixed sheave 12 fixed to the driven shaft 11 and a movable sheave 13 that is movable in the axial direction with respect to the driven shaft 11, similarly to the driving side boolean IJ1.

The configuration of the driven pulley 10 will be explained in detail according to FIG.
The fixed sheave 12 is spline-engaged with the end portion of the driven shaft 11 and coupled with a rotation stopper 14. A vertical groove 15 is formed on the inner peripheral surface of the movable sheave 13.
5 and a vertical groove 16 provided on the outer peripheral surface of the driven shaft 11, the movable sheave 13
is movable only in the axial direction with respect to the driven shaft 11. A hydraulic cylinder chamber 18 is integrally provided at the back of the movable sheave 13, and by controlling the hydraulic pressure acting on this cylinder chamber 18 with a hydraulic pulley ratio control means 19, the movable sheave 13 is moved in the axial direction. , the pulley ratio (speed ratio) between the driving side and the driven side can be changed steplessly. In Fig. 2, the upper half of the driven shaft 11 is the driven pulley 1.
The pulley diameter of 0 is the minimum, and the lower half shows the maximum boolean IJe.

The specific configuration of the hydraulic pulley ratio control means 19 includes, for example, a pitot tube that detects the engine rotation speed, a cam that interlocks with the throttle opening, and a pitot tube as described in Japanese Patent Laid-Open No. 58-42862. The hydraulic control valve may be configured to control the pulley ratio based on the /lb pressure signal from the cam and the cam displacement signal, or any other hydraulic control method may be used.

By the way, even when the oil pressure to the cylinder chamber 18 is zero, oil pressure is generated in the cylinder chamber 18 due to centrifugal force based on the rotation of the driven side boo 910, and this oil pressure moves the movable sheave 13 and changes the pulley ratio. There is a risk of In order to eliminate this imbalance in the pulley ratio, hydraulic balance chambers 20 and 21 are provided on the inner diameter side and rear side of the cylinder chamber 18. The cylinder chamber 18 and the inner balance chamber 20 are partitioned by a diaphragm 22, the cylinder chamber 18 and the rear balance chamber 21 are partitioned by a fixed piston 23 fixed to the driven shaft 11, and the cylinder chamber 18 and the rear balance chamber 21 are partitioned by a fixed piston 23 fixed to the driven shaft 11. It is separated from the outside by a diaphragm 24. Cylinder chamber 1
Hydraulic pressure is applied to 8 through an oil passage 25 from the hydraulic pulley ratio control means 19, and a one-way radial balance chamber 20
A lubricating oil passage 2B that supplies low-pressure lubricating oil from an oil pump 26 through an orifice 27 communicates with the balance chambers 20 and 21, and both balance chambers 20 and 21 communicate with each other through a communication passage 29 provided in the fixed piston 23. There is.

Here, the function of the balance chambers 20, 21 will be explained with reference to FIG. Now, when the driven pulley 10 is rotating and the hydraulic pressure acting on the cylinder chamber 18 is zero, hydraulic pressure corresponding to the centrifugal force is generated in the cylinder chamber 18, and this hydraulic pressure causes the movable sheave 13 to respond to the force of Fl. Fixed sheave 1
Pushed towards the 2nd side (leftward in Figure 3). On the other hand, cylinder chamber 1
Hydraulic pressure is also generated by centrifugal force in the balance chambers 20 and 21 that rotate, and this oil pressure causes the balance chambers 20 and 21 on the inner diameter side to rotate.
pushes the movable sheave 13 to the left in Figure 3 with the force of F2, and the rear balance chamber 21 pushes the movable sheave 13 to the third position with the force of F3.
Push to the right in the figure. At this time, since the sum of the areas of the hydraulic pressure working surface of the cylinder chamber 18 and the hydraulic pressure working surface of the inner diameter side balance chamber 20 is set to be approximately equal to the hydraulic pressure working surface of the back side balance chamber 21, the hydraulic pressure due to the centrifugal force is Balanced with
The pulley ratio will not go out of order.

In addition, although the case where the hydraulic pressure acting on the cylinder chamber 8 is zero is described above, even when some hydraulic pressure is acting on the cylinder chamber 18 from the hydraulic pulley ratio control means 19, the hydraulic pressure fluctuation due to centrifugal force may occur. Minutes can be balanced on the left and right in the same way as above.

As mentioned above, the balance chamber 20.21 and the cylinder chamber 18
are completely separated by the diaphragm 22 and fixed piston 23, and the balance chamber 20.21 is completely separated from the cylinder chamber 18.
Since a separate lubrication oil passage 28 is in communication with the oil passage 25 to There is no need to worry about it occurring. Furthermore, since the oil pump 26 is also driven at the same time as the engine is started, the balance chamber 20
．． 21 is immediately filled with lubricating oil, and the desired balancing effect can be exerted. Therefore, there is no delay as in the conventional case.

In the above embodiment, in addition to the back side of the fixed piston 23,
A balance chamber 20 is also provided on the inner diameter side, and the purpose of this balance chamber 20 is to eliminate the imbalance between the hydraulic surface of the cylinder chamber 18 and the hydraulic surface of the rear balance chamber 21. If the area of the hydraulic surface is set to be approximately equal to that of the balance chamber 21, the inner diameter balance chamber 20 is not necessary.

Further, although the driving pulley 1 is provided with a torque cam 5 as a mechanical tension loading means and the driven pulley lO is provided with a hydraulic pulley ratio control means 19, in contrast to this, the driving pulley 1 is provided with a hydraulic pulley ratio control means 19. A hydraulic pulley ratio control means may be provided on the drive side pulley 10, a mechanical tension loading means may be provided on the driven pulley 10, and a hydraulic pulley ratio control means may be provided on both the drive side and drive side pulleys.

Advantages of the Invention As is clear from the above explanation, according to the present invention, the balance chamber and the cylinder chamber are not communicated with each other, and oil is supplied to the balance chamber through an independent lubricating oil passage. There is no fear that the oil pressure in the cylinder chamber will drop and the pulley ratio control will be out of order, and the balance chamber can be quickly filled and discharged with oil, providing an excellent balance effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a V-belt type continuously variable transmission according to the present invention, FIG. 2 is a detailed sectional view of a driven pulley, and FIG. 3 is a schematic diagram showing the function of a balance chamber. 1... Drive side pulley, 5... Torque cam, 10...
- Drive side pulley, 13... Movable sheave, 18... Hydraulic cylinder chamber, 19... Hydraulic pulley ratio control means, 2
0.21... Hydraulic balance chamber, 22.24... Diaphragm, 23... Fixed piston, 26... Oil pump, 27... Orifice, 28... Lubrication oil path.

Claims (1)

[Claims] (1) In a V-belt continuously variable transmission in which a hydraulic cylinder chamber for moving the movable sheave in the axial direction is integrally provided in at least one of the movable sheaves of the driving pulley or the driven pulley, the hydraulic cylinder chamber A hydraulic balance chamber for canceling the hydraulic pressure generated in the cylinder chamber by centrifugal force is provided at least on the back side of the fixed piston, and a lubricating oil path is communicated from the oil pump to the hydraulic balance chamber via an orifice. Hydraulic system for V-belt continuously variable transmission.