JPH09329209A - Hydraulic actuator - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To properly operate a hydraulic actuator by preventing a response delay of a change in centrifugal hydraulic pressure when the rotational speed of a hydraulic actuator operating by a command hydraulic pressure and a centrifugal hydraulic pressure acting on a control hydraulic chamber changes. Let A drive pulley D of a belt type continuously variable transmission
The movable pulley half 4 of the _DR has the command hydraulic pressure acting on the control hydraulic chamber 12, the control hydraulic chamber 12, and the canceller hydraulic chamber 1.
4 and the effective centrifugal oil pressure corresponding to the difference of the centrifugal oil pressures acting on No. 4. Radial ribs 4 ₃ , 9 ₃ , 1 on the movable pulley half 4, piston 9 and cylinder 10 which form the inner wall surfaces of the control hydraulic chamber 12 and the canceller hydraulic chamber 14.
By forming 0 ₂ , the hydraulic oil in the control hydraulic chamber 12 and the canceller hydraulic chamber 14 follows the change in the rotation speed of the drive pulley D _DR without delay, and a desired centrifugal hydraulic pressure is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a command hydraulic pressure of hydraulic oil supplied to a control hydraulic chamber formed on the outer periphery of a rotary shaft and a centrifugal hydraulic pressure acting on the hydraulic oil present in the control hydraulic chamber. The present invention relates to a hydraulic actuator that drives a movable member facing a control hydraulic chamber.

[0002]

2. Description of the Related Art One in which a gear ratio of a belt type continuously variable transmission is controlled by a hydraulic actuator is disclosed in JP-A-4-8394.
It is known from Japanese Patent No.

In the above-mentioned conventional type, the movable pulley half of the pulley of the belt type continuously variable transmission is exposed to the control hydraulic chamber, and the hydraulic pressure acting on the control hydraulic chamber is changed to change the movable pulley half. Is to be brought into contact with and separated from the fixed pulley half body.

[0004]

By the way, since the hydraulic oil existing in the control hydraulic chamber rotates by being dragged by the inner wall surface of the control hydraulic chamber, a hydraulic pressure (centrifugal hydraulic pressure) is generated by a centrifugal force. This centrifugal hydraulic pressure acts to assist the hydraulic pressure (command hydraulic pressure) of the hydraulic oil supplied from the hydraulic control device into the control hydraulic chamber, so that the sum of the estimated centrifugal hydraulic pressure and control hydraulic pressure becomes equal to the target hydraulic pressure. , The command hydraulic pressure is set to be smaller by the centrifugal hydraulic pressure in advance.

However, when the rotation speed of the pulley changes, the rotation speed of the hydraulic oil in the control oil pressure chamber does not immediately follow and a time lag occurs, so that the centrifugal oil pressure during that time greatly differs from the estimated value and the desired target oil pressure is obtained. There was a problem that could not be obtained.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reliably generate a centrifugal hydraulic pressure and operate a hydraulic actuator accurately even if the rotational speed of the hydraulic actuator changes.

[0007]

In order to achieve the above object, the invention described in claim 1 provides a command hydraulic pressure of hydraulic oil supplied to a control hydraulic chamber formed on the outer periphery of a rotary shaft, and the control. In a hydraulic actuator that axially drives a movable member facing the control hydraulic chamber by a centrifugal hydraulic pressure that acts on hydraulic oil that is present in the hydraulic chamber, a rotary member that forms an inner wall surface of the control hydraulic chamber has a circumferential direction. It is characterized in that a plurality of concavo-convex portions arranged at are formed.

In addition to the configuration of claim 1, the invention described in claim 2 provides a command according to the rotational speed of the rotating member such that the sum of the command hydraulic pressure and the centrifugal hydraulic pressure matches the target hydraulic pressure. Characterized by determining the hydraulic pressure.

In addition to the structure of claim 1, the invention described in claim 3 is provided with a canceller hydraulic chamber for canceling centrifugal hydraulic pressure acting on the control hydraulic chamber, and an inner wall surface of the canceller hydraulic chamber is constituted. A plurality of uneven portions arranged in the circumferential direction are formed on the rotating member.

The invention described in claim 4 is characterized in that, in addition to the structure of claim 1, the concavo-convex portion is formed radially outward of the control hydraulic chamber.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 to 7 show a first embodiment of the present invention. FIG. 1 is a vertical sectional view of a drive pulley of a belt type continuously variable transmission, and FIG. 2 is a view taken along the line 2-2 in FIG. 3 and 4 of FIG. 1
-3 line arrow view, FIG. 4 is a 4-4 line arrow view of FIG. 1, FIG. 5 is a graph showing the centrifugal hydraulic pressure of the control hydraulic chamber and the canceller hydraulic chamber, and FIG. 6 is the distribution of the effective centrifugal hydraulic pressure and the command hydraulic pressure. FIG. 7 is a graph showing the ratio, and FIG. 7 is a graph showing changes in the effective centrifugal oil pressure depending on the presence or absence of ribs.

As shown in FIG. 1, the drive pulley P _DR of the belt type continuously variable transmission includes a sleeve 2 which is fitted to the outer periphery of the input shaft 1 so as to be relatively rotatable. Sleeve 2
A fixed pulley half body 3 is integrally formed on the outer circumference of the movable pulley half body 4 facing the fixed pulley half body 3 by a ball spline 5 so as to be axially slidable and non-rotatable. To be done. Belt contact surface 3 ₁ of fixed pulley half 3 and belt contact surface 4 of movable pulley half 4
_{Between 1} and 2, there are a large number of pushing pieces 7 on two straps 6 and 6.
The metal endless belt 8 equipped with ... is wound around. still,
The metal endless belt 8 is also wound around a driven pulley (not shown) forming a pair with the drive pulley P _DR .

A disk-shaped piston 9 is fixed to the outer circumference of the sleeve 2, and a substantially cylindrical cylinder 10 into which the piston 9 is slidably fitted is fixed to the outer circumference of the movable pulley half body 4. . By sealing the sliding surface of the piston 9 and the cylinder 10 with the seal member 11, the control hydraulic chamber 12 surrounded by the movable pulley half 4, the piston 9, the cylinder 10 and the sleeve 2 is defined. The return spring 13 is compressed between the movable pulley half body 4 and the piston 9 in order to urge the movable pulley half body 4 toward the fixed pulley half body 3 to clamp the metal endless belt 8 with a predetermined set load. Set up. A canceller hydraulic chamber 14 is formed between the piston 9 and the outer end of the cylinder 10 curved inward in the radial direction in order to cancel the centrifugal hydraulic pressure that acts on the hydraulic oil in the control hydraulic chamber 12. The inner peripheral surface of the canceller hydraulic chamber 14 is open, and the hydraulic oil scattered in the casing of the belt type continuously variable transmission enters the canceller hydraulic chamber 14 through the opening and is retained therein by centrifugal force.

As can be seen by referring also to FIG.
The piston 9 is a press-formed metal plate material,
A shaft hole 9 into which the sleeve 2 is fitted₁Along with
The return spring 13 comes into contact with the middle portion in the radial direction.
Annular spring seat 9 ₂Equipped with. Spring
9₂12 ribs 9 on the outside in the radial direction_ThreeIs radiated
It is formed in a shape. Rib 9_Three… Formed by press molding
And the canceller that protrudes to the control hydraulic chamber 12 side.
The hydraulic chamber 14 side is recessed.

Referring to FIG. 3 together, it is apparent that
The cylinder 10 is formed by press-molding a metal plate material, and the opening 10 ₁ of the canceller hydraulic chamber 14 is formed in the inner periphery thereof, and 12 cylinders radially extending in the radial middle portion and projecting toward the canceller hydraulic chamber 14 side. Ribs 10 ₂ are formed by press molding.

As can be seen by referring also to FIG.
A shaft hole 4 ₅ that fits into the outer circumference of the sleeve 2 is formed on the inner circumference of the movable pulley half 4 made of a cast product or a forged product. The spring seat 4 ₂ on the right side surface of the movable pulley half 4 facing the spring seat 9 _second piston 9 is formed, 12 ribs 4 ₃ radially extending radially outwardly of the spring seat 4 ₂ … Is projected.

Returning to FIG. 1, the hydraulic oil discharged by the hydraulic pump 15 is regulated by the linear solenoid valve 16 and then, via the four-way valve 17, the control hydraulic chamber 12 of the drive pulley P _DR.
And the control hydraulic chamber (not shown) of the driven pulley P _DN . The linear solenoid valve 16 and the four-way valve 1
7 is controlled by an electronic control unit U to which a signal from an input shaft rotation speed sensor 18 that detects the rotation speed of the input shaft 1 is input.

Then, the shaft is provided inside the input shaft 1.
Oil passage 1 formed in the radial and radial directions ₁, 1₂,sleeve
Oil passage 2 formed in 2 in the radial direction₁And movable pulley half
Oil passage 4 formed in 4 in the radial direction_FourThrough the linear
The hydraulic oil regulated by the solenoid valve 16 is used to control the hydraulic pressure chamber.
12, the movable pulley half 4 is supplied to the fixed pulley 12.
The drive pulley P is moved by moving in a direction approaching the half body 3._DRof
The groove width is reduced and the metal endless belt 8 moves radially outward.
Then, the gear ratio changes to the TOP side.

At this time, the centrifugal oil pressure acting on the working oil existing in the control oil pressure chamber 12 acts to assist the command oil pressure of the working oil supplied to the control oil pressure chamber 12, and the centrifugal oil pressure inside the canceller oil pressure chamber 14 is increased. Centrifugal oil pressure acting on the hydraulic oil existing in the counter oil acts to oppose the command hydraulic pressure of the hydraulic oil supplied to the control hydraulic chamber 12. That is, by canceling the centrifugal oil pressure acting on the control oil pressure chamber 12 by the centrifugal oil pressure acting on the canceller oil pressure chamber 14, the influence of the centrifugal oil pressure is minimized and the accuracy of the gear ratio control of the belt type continuously variable transmission is reduced. Is improving.

To further explain this, as shown in FIG. 5, since the volume of the control hydraulic chamber 12 is larger than the volume of the canceller hydraulic chamber 14, the centrifugal hydraulic pressure acting on the control hydraulic chamber 12 acts on the canceller hydraulic chamber 14. The effective centrifugal oil pressure, which is larger than the centrifugal oil pressure that is generated and corresponds to the difference, acts to assist the command oil pressure of the hydraulic oil supplied to the control oil pressure chamber 12. Therefore, as shown in FIG. 6, the target hydraulic pressure to be applied to the control hydraulic chamber 12 is set to the drive pulley P _DR.
The effective centrifugal oil pressure preset according to the rotation speed of
The command hydraulic pressure to be supplied to the control hydraulic chamber 12 by the hydraulic control device is divided, and a value obtained by subtracting a preset effective centrifugal hydraulic pressure from the target hydraulic pressure is used as the command hydraulic pressure to be supplied to the control hydraulic chamber 12 by the hydraulic control device. To do. That is, the command hydraulic pressure is determined so that the sum of the command hydraulic pressure and the effective centrifugal hydraulic pressure becomes equal to the target hydraulic pressure.

Since the effective centrifugal oil pressure shown in FIG. 6 is set as a value when the drive pulley P _DR is rotating in a steady state, the effective centrifugal oil pressure is changed when the rotation speed of the drive pulley P _DR changes. The hydraulic pressure will be very different from the actual value. This is because the hydraulic oil in the control hydraulic chamber 12 and the canceller hydraulic chamber 14 rotates by being dragged by the frictional force received from the wall surfaces of the control hydraulic chamber 12 and the canceller hydraulic chamber 14, so that the rotation speed of the drive pulley P _DR changes. Even if the rotation speed of the hydraulic oil is not immediately followed, a time lag occurs.

However, in this embodiment, the movable pulley half 4 and the piston 9 forming the wall surface of the control hydraulic chamber 12 are formed with ribs 4 ₃ ... 9 ₃ ... Since ribs 9 ₃ ..., 10 ₂ ... That extend in the radial direction are formed on the piston 9 and the cylinder 10 that form the wall surface of 14, the rib 4 is formed when the rotational speed of the drive pulley P _DR changes.
₃ ..., 9 ₃ ..., 10 _{2 The} hydraulic oil pushed or blocked is restricted from slipping on the drive pulley P _DR , and the rotational speed of the hydraulic oil rotates the drive pulley P _DR without a time lag. It comes to follow the speed. As a result, the effective centrifugal oil pressure when the rotation speed of the drive pulley P _DR changes becomes substantially equal to that when the drive pulley P _DR rotates in a steady state, and the command oil pressure is not particularly corrected. , The side pressure of the drive pulley P _DR can be appropriately controlled.

FIG. 7 shows the ribs 4 ₃ ..., 9 ₃ ..., 10 ₂ ...
Is a graph showing the effect of, the ratio of the centrifugal hydraulic pressure to the target hydraulic pressure of the control hydraulic chamber 12 increases and the ratio of the command hydraulic pressure decreases when the rotation speed of the drive pulley P _DR is increased. At this time, in the drive pulley P _DR having ribs, the target hydraulic pressure is secured because the centrifugal hydraulic pressure increases without a time lag, but in the drive pulley P _DR having no ribs, there is a time lag in the increase of the centrifugal hydraulic pressure, so the target hydraulic pressure is secured. It can be seen that the hydraulic pressure drops temporarily and the target hydraulic pressure cannot be secured.

Since the movable pulley half 4, the piston 9 and the cylinder 10 are provided with the ribs 4 ₃ ..., 9 ₃ ..., 10 ₂ ..., the movable pulley half 4, the piston 9 and the cylinder 10 are formed. The rigidity can be improved.
Further, since the ribs 4 _3, ..., 9 ₃ facing the control oil pressure chamber 12 are formed radially outward of the center position of the control oil pressure chamber 12 in the radial direction, the ribs 4 _3, ... Thus, the rotation of the hydraulic oil that greatly contributes to the centrifugal oil pressure can be made to follow the rotation of the drive pulley P _DR .

Further, since the ribs 4 ₃ of the movable pulley half 4 and the ribs 9 _{3 of the} piston 9 are arranged radially outward of both ends of the return spring 13 housed in the control hydraulic chamber 12, these ribs are arranged. The return spring 13 can be positioned using 4 ₃ ... 9 ₃ . Further, since the canceller hydraulic chamber 14 is arranged outside the right half of the control hydraulic chamber 12 in the radial direction, these control hydraulic chambers 12 are
In addition, the dimension of the drive pulley P _{DR in} the axial direction can be reduced as compared with the case where the canceller hydraulic chambers 14 are arranged side by side in the axial direction.

Next, a second embodiment in which the present invention is applied to a starting clutch of a belt type continuously variable transmission will be described with reference to FIG.

The starting clutch C is connected to the drive pulley P _DR of the belt type continuously variable transmission and rotates with the driven pulley P _{DN which} rotates and the output shaft 22.
The rotation of the output shaft 22 is transmitted to the output gear 24 supported on the outer periphery of the output shaft 22 via needle bearings 23.

The clutch outer 2 is attached to the left end of a sleeve 35 that is splined to the outer periphery of the output shaft 22.
5 are fixed, and a plurality of clutch discs 27 ... And a plurality of clutch plates 28 ... Are alternately arranged between the clutch outer 25 and the clutch inner 26 integrally connected to the output gear 24. A partition wall 29 is fixed to the right end of the sleeve 35, and a piston 30 is slidably fitted between the partition wall 29 and the clutch outer 25.

A control oil pressure chamber 31 is defined between the piston 30 and the clutch outer 25. The control oil pressure chamber 31 has a feed pipe 32 and an output shaft 22.
By supplying the hydraulic oil through the oil passage 22 ₁ of the sleeve 35 and the oil furnace 35 ₁ of the sleeve 35, the piston 30 moves to the right and the clutch discs 27 ... And the clutch plates 28 ... Engage. Piston 3
0 and has canceller oil chamber 34 which is mounted under compression is defined a return spring 33 between the partition 29, the oil passage 35 of the oil passage 22 _2, 22 ₃ and the sleeve 35 of the output shaft 22 to the canceller oil chamber 34 Hydraulic fluid is supplied via ₂ . The centrifugal hydraulic pressure generated by the hydraulic oil in the control hydraulic chamber 31 is canceled by the centrifugal hydraulic pressure generated by the hydraulic oil in the canceller hydraulic chamber 34.

A plurality of radially extending ribs 25 _1, ... Are integrally formed when the clutch outer 25 is press-molded, and a plurality of radially extending ribs 30 _1, ... Are radially formed when the piston 30 is press-molded. It is integrally formed. The ribs 30 ₁ are projected toward the control hydraulic chamber 31 and are recessed toward the canceller hydraulic chamber 34, and the ribs 25 ₁ are recessed toward the control hydraulic chamber 31. It functions to rotate the hydraulic oil in the chambers 31 and 34 following the rotation of the clutch outer 25, the partition wall 29 and the piston 30.

Thus, also in the second embodiment, the effective centrifugal hydraulic pressure corresponding to the difference between the centrifugal hydraulic pressure acting on the control hydraulic chamber 31 and the centrifugal hydraulic pressure acting on the canceller hydraulic chamber 34 is
It is preset according to the rotation speed of the output shaft 22, and the magnitude of the command hydraulic pressure is controlled so that the sum of the effective centrifugal hydraulic pressure and the command hydraulic pressure supplied to the control hydraulic chamber 31 becomes equal to the target hydraulic pressure. . Then, when the rotational speed of the output shaft 22 changes, the hydraulic oil in the control hydraulic chamber 31 and the canceller hydraulic chamber 34 is ribs 25 _1, ...
For rotation in accordance with the rotation speed of the output shaft 22 at 30 ₁ ... action, it is possible to accurately control the engaging force of the starting clutch C holds the size of the effective centrifugal hydraulic pressure to a desired value.

Also in the second embodiment, the rib 25
By forming ₁ ..., 30 ₁ ..., the rigidity of the clutch outer 25 and the piston 30 can be improved.

Although the embodiments of the present invention have been described in detail above, the present invention can be modified in various ways without departing from the scope of the invention.

For example, in the embodiment, the drive pulley D _DR and the starting clutch C of the belt type continuously variable transmission are exemplified as the hydraulic actuator, but the present invention can be applied to any other hydraulic actuator.

[0036]

As described above, according to the invention described in claim 1, since the rotating member forming the inner wall surface of the control hydraulic chamber is formed with the plurality of uneven portions arranged in the circumferential direction. When the rotation speed of the rotating member changes, the rotation speed of the hydraulic oil in the control hydraulic chamber can be changed without delay.
As a result, a desired centrifugal hydraulic pressure can be generated in the control hydraulic chamber to control the hydraulic actuator accurately.

According to the second aspect of the present invention,
Since the command hydraulic pressure is determined according to the rotational speed of the rotating member so that the sum of the command hydraulic pressure and the centrifugal hydraulic pressure matches the target hydraulic pressure,
Even if the rotational speed of the rotating member fluctuates and the centrifugal oil pressure changes,
It is possible to prevent fluctuations in the target hydraulic pressure.

According to the invention described in claim 3,
A canceller hydraulic chamber that cancels centrifugal hydraulic pressure acting on the control hydraulic chamber is provided, and a plurality of uneven portions arranged in the circumferential direction are formed on the rotating member that constitutes the inner wall surface of the canceller hydraulic chamber. The centrifugal oil pressure acting on the canceller oil pressure chamber can be canceled by the centrifugal oil pressure acting on the canceller oil pressure chamber. It is possible to change it, and thereby, it is possible to generate a desired centrifugal oil pressure in the canceller oil pressure chamber and accurately control the oil pressure actuator.

According to the invention described in claim 4,
Since the uneven portion is formed on the outer side in the radial direction of the control hydraulic chamber, the rotation of the hydraulic oil on the outer side in the radial direction of the control hydraulic chamber, which greatly contributes to the centrifugal hydraulic pressure, can be effectively made to follow the rotation of the rotating member. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a drive pulley of a belt type continuously variable transmission.

FIG. 2 is a view taken along the line 2-2 of FIG.

FIG. 3 is a view taken along the line 3-3 of FIG.

FIG. 4 is a view taken in the direction of arrows 4-4 in FIG. 1;

FIG. 5 is a graph showing centrifugal hydraulic pressures in a control hydraulic chamber and a canceller hydraulic chamber.

FIG. 6 is a graph showing a distribution ratio of effective centrifugal oil pressure and command oil pressure.

FIG. 7 is a graph showing changes in effective centrifugal oil pressure with and without ribs.

FIG. 8 is a vertical sectional view of a starting clutch according to the second embodiment.

[Explanation of symbols]

2 Sleeve (rotating shaft) 4 Movable pulley half (movable member, rotating member) 4 ₃ Rib (uneven portion) 9 Piston (rotating member) 9 ₃ rib (uneven portion) 10 Cylinder (rotating member) 10 ₂ rib (uneven portion) 12) Control hydraulic chamber 14 Canceller hydraulic chamber 25 Clutch outer (rotating member) 25 ₁ Rib 30 Piston (movable member) 31 ₁ Rib (uneven portion) 31 Control hydraulic chamber 34 Canceller hydraulic chamber 35 Sleeve (rotating shaft)

Claims (4)

[Claims] 1. A command hydraulic pressure of hydraulic oil supplied to a control hydraulic chamber (12, 31) formed on the outer periphery of a rotary shaft (2, 35) and an operation existing in the control hydraulic chamber (12, 31). Due to the centrifugal oil pressure acting on the oil, the control oil pressure chamber (12,
31) In the hydraulic actuator for driving the movable members (4, 30) facing the rotating member (4, 9, 25, 30) forming the inner wall surface of the control hydraulic chamber (12, 31), the hydraulic actuator is arranged in the circumferential direction. A hydraulic actuator characterized in that a plurality of concavo-convex portions (4 ₃ , 9 ₃ , 25 ₁ , 30 ₁ ) arranged are formed. 2. The rotating member (4, 9, 25, 30) so that the sum of the command hydraulic pressure and the centrifugal hydraulic pressure matches the target hydraulic pressure.
The hydraulic actuator according to claim 1, wherein the command hydraulic pressure is determined according to the rotation speed of the hydraulic actuator. 3. A canceller hydraulic chamber (1) for canceling centrifugal hydraulic pressure acting on the control hydraulic chamber (12, 31).
4, 34) are provided, and the canceller hydraulic chambers (14, 3)
Rotating member (9, 10, 30) that constitutes the inner wall surface of 4)
A plurality of uneven portions which are arranged in the circumferential direction (9 _3, 1
0 ₂ , 30 ₁ ) are formed.
The hydraulic actuator described. 4. The hydraulic actuator according to claim 1, wherein the concave and convex portions (4 ₃ , 9 ₃ ) are formed radially outward of the control hydraulic chamber (12).