JPH1151180A - Fluid pressure actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure actuator simple in structure, favourable in positional precision and small in hammering sound. SOLUTION: A piston 101 is arranged in the inside of a cylinder 100, hydraulic oil is supplied to a first piston oil chamber 111 and a second piston oil chamber 112 through a first oil hole 108 and a second oil hole 109 by a hydraulic oil supply discharge change-over valve 120 or hydraulic oil is drawn out from there. A cutout 113 is formed on an edge of the outside on a right end of the piston 101. Depth A in the axial direction of the cutout 113 is sufficiently smaller than a diameter D of the second oil hole 109 but slightly larger than a distance B between a right end part of the second oil hole 109 and a side wall surface 114 of the cylinder 100. An opening area of the second oil hole 109 is radically reduced immediately before the piston 101 makes contact with a side wall of the cylinder 100, and discharge resistance is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulically operated actuator.

[0002]

2. Description of the Related Art Fluid pressure actuators for moving an actuated body to a predetermined position by fluid pressure are used in various fields. For example, in an automatic transmission using a synchronizer, a fluid pressure actuator is used to switch the position of a sleeve of the synchronizer (see Japanese Patent Application Laid-Open No. 9-42387). It is important for an actuator used in such a device to surely move a sleeve of a synchronous device, which is an actuated body, to a predetermined position. The position accuracy is ensured by making contact with the side wall of the cylinder accommodating the piston.

[0003]

In order to move the piston, the working fluid is supplied to one of two fluid chambers in a cylinder defined by the piston, and the working fluid is removed from the other. As described in the above publication, a large force is required to move the sleeve of the synchronizer, and the pressure of the working fluid to be sent is high. As a result, the piston collides with the cylinder side wall at a high speed, and a tapping sound is generated. There was a problem of doing. In order to solve this problem, a cushioning material such as rubber is interposed between the piston and the side wall of the cylinder, or an accumulator is provided in the working fluid supply mechanism so that the piston comes into contact with the side wall of the cylinder. Although it is conceivable to reduce the pressure, in the former case, there is a problem that the accuracy of the stop position of the piston is reduced, and in the latter case, there is a problem that the structure becomes complicated and costs increase. The present invention has been made in view of the above problems, and has as its object to provide a fluid pressure actuator having a good positional accuracy, a simple structure, and low noise.

[0004]

According to the first aspect of the present invention, a cylinder having a side wall at an axial end, a piston slidably disposed in the cylinder, and an operating rod coupled to the piston And supplying the working fluid to one of two fluid chambers in the cylinder defined by the piston, discharging the working fluid from the other, and moving the piston until it comes into contact with the axial end side wall of the cylinder. An actuator for moving a body to be actuated coupled to an operating rod, wherein the discharge port for discharging the working fluid is a variable discharge port whose opening area decreases as the piston approaches the end side wall of the cylinder. Is done. In the actuator configured as described above, as the piston approaches the side wall, the opening area of the discharge port is reduced, the resistance increases, and the speed at which the piston comes into contact with the side wall decreases.

According to a second aspect of the present invention, in the first aspect of the present invention, the variable discharge port is formed on a circular cross-sectional hole formed in a peripheral wall of the cylinder close to the end side wall, and the end portion on the side of the cylinder side wall. Is a variable discharge port formed by passing a piston having a notch at the outer peripheral edge of the hole. B, the axial depth from the end face of the piston notch on the cylinder side wall side is A,
Then, an actuator is provided in which D is sufficiently larger than A and A is slightly larger than B.
In the actuator configured as described above, the variable discharge port is provided with a notch at the outer peripheral edge of the end portion on the cylinder side wall side on the circular cross section formed in the peripheral wall of the cylinder close to the axial side wall. The diameter of the hole is D, the distance from the side wall of the cylinder to the side closest to the side wall of the cylinder is B, and the depth of the notch of the piston is the axial depth from the end face of the piston. When A, D is sufficiently larger than A, and A is slightly larger than B.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing the overall configuration of a twin clutch type transmission including an actuator to which the present invention is applied. An output shaft 10 of an engine (not shown) is connected to a front cover 21 of the torque converter 2, and the front cover 21 is connected to a pump impeller 22 and a turbine 23 which are connected via a fluid flow, or a lock-up clutch 24. The input shaft 30 of the twin clutch type automatic transmission 1 is connected to the output shaft 20 of the torque converter 2 so as to be integrally rotatable.

The input shaft 30 is connected to a first clutch input disk C1 _{i of} the first clutch C1 and a second clutch input disk C2 _{i of} the second clutch C2 which constitute the clutch C. The first clutch output shaft 40 and the second clutch output shaft 50 are connected to the first clutch output disk C1 _o of the first clutch C1 and the second clutch output disk C2 _o of the second clutch C2, respectively. Coaxially connected to the outside. The sub shaft 60 and the output shaft 70 are arranged in parallel to these shafts. The drive output shaft 80 of the differential device FG is also arranged in parallel with the input shaft 30.

A torque converter 2 is connected to the first clutch output shaft 40.
, A first speed drive gear I ₁ and a third speed drive gear I ₃ are fixedly connected. The second clutch output shaft 50, from the side of the torque converter 2, a fourth speed drive gear I _4, the auxiliary shaft drive gear I _s, the second speed drive gear I ₂ are fixedly connected. The countershaft 60, toward the side of the clutch C on the side of the torque converter 2, the auxiliary shaft driven gear O _S, reverse synchronizer DR, reverse drive gear I _R is disposed.

On the output shaft 70, from the side of the torque converter 2 toward the side of the clutch C, the final drive gear I _F ,
The first speed driven gear O _1, first synchronizer D1, the third-speed driven gear O _3, fourth speed driven gear O _4, the second synchronizer D2, driven gear O ₂ and the second gear is disposed. The final drive gear _IF is fixed to the output shaft 70 and acts as an input gear of the differential FG,
It is always meshed with a final driven gear O _F that rotates about a drive output shaft 80 of the.

[0010] First speed driven gear O₁Is first speed driven
Gear O₁And third-speed driven gear O _ThreeIs the third speed drive
Gear I_ThreeWith the output shaft by the first synchronizer D1.
70 is selectively coupled. 2nd speed driven gear O_TwoIs
2nd speed drive gear I_TwoAnd the fourth-speed driven gear O _FourIs
4th speed drive gear I_FourAnd the second synchronizing device D
2 selectively coupled to the output shaft 70. Counter shaft drib
Gear O_SIs fixed to the counter shaft 60 and the counter shaft drive gear
YaI_SIs always engaged. And reverse drive gear I
_RIs the first speed driven gear O₁, Always meshing with the reverse
It is selectively connected to the countershaft 60 by the position D3.

The first synchronizing device D1 comprises a first hub H1 fixedly connected to the output shaft 70, a first sleeve S1 mounted on the outer peripheral end thereof so as to be slidable in the axial direction, and a synchronizer ring R. That is, the first sleeve S1 is selectively moved and the first speed clutch gear G ₁ fixedly connected to the first speed driven gear O ₁ or the third speed gear G ₃ fixedly connected to the third speed driven gear O 3. Speed clutch gear G
_Third , the first driven gear O ₁ or the third driven gear O ₃ is connected to the first output shaft 70 by engaging the output shaft 70 via the synchronizer ring R.

Similarly, the second synchronizing device D2 comprises a second hub H2 fixedly connected to the output shaft 70, a second sleeve S2 axially slidably mounted on the outer peripheral end thereof,
Synchronizer ring R, and the second sleeve S2
And move selectively, or second-speed clutch gear G _2, which is fixedly coupled to the second speed driven gear O _2, 4
Speed driven gear O ₄ to allowed to connect the second speed driven gear O ₂ or the fourth speed driven gear O ₄ to the output shaft 70 by engaging the fourth speed clutch gear G ₄ which are fixedly connected. The third synchronizing device D3 is composed of a third hub H3 fixedly connected to the countershaft 60, a third sleeve S3 axially slidably mounted on an outer peripheral end thereof, and a synchronizer ring R. made, by moving the third sleeve S3 selectively, allowed to connect the reverse drive gear I _R to countershaft 60 by engaging the reverse clutch gear G _R which is fixedly coupled to the reverse drive gear I _R.

The first sleeve S1 of the first synchronization device D1, the second sleeve S2 of the second synchronization device D2, and the third synchronization device D3
Of the first shift fork Y1, the second shift fork Y2, and the third shift fork Y
3, the actuator is moved by a first actuator ACT1, a second actuator ACT2, and a third actuator ACT3. The present invention relates to the internal structure of these actuators.

In the twin clutch type transmission constructed as described above, the synchronizing device is operated to complete the gear combination of the desired speed stage, and the clutch connected to the gear combination is engaged to rotate the input shaft. Is transmitted at the gear ratio of the desired speed stage to the output shaft. However, the combination of the clutch and the synchronizer for obtaining each speed stage is not relevant to the point of the present invention, and is therefore omitted.

FIG. 2 is a sectional view showing the internal structure of the first actuator ACT1 in FIG. The second
Actuator ACT2, third actuator ACT3
Has the same structure. Referring to FIG. 2, a piston 101 is provided inside a cylinder 100 of the first actuator ACT1.
The operating rod 102 is fixed to the piston 101 by a bolt 103, and the shift fork Y 1 is fixed to the operating rod 102 by a bolt 104. Reference numeral 105 denotes a spring. The left end of the spring 105 in the figure contacts the stopper 106 whose position is regulated by the snap ring 106, and the right end contacts the piston 101. Biased in the direction. Therefore, when the hydraulic oil is not supplied, that is, when the engine is stopped, the piston 101
Is being brought located far right in the figure, the sleeve S1 (see FIG. 1) moves to the first speed driven gear O ₁ side, so to complete the connection of the gear for the first speed stage, be provided for the next start it can.

The first oil hole 108 is provided in the first piston oil chamber 111.
The hydraulic fluid is used to supply the hydraulic oil to the first piston oil chamber 111 or to drain the hydraulic oil from the first piston oil chamber 111. Similarly,
The second oil hole 109 is used to supply hydraulic oil to the second piston oil chamber 112 or to drain hydraulic oil from the second piston oil chamber 112. The switching of the supply and discharge of the hydraulic oil is performed by a hydraulic oil supply and discharge switching valve 120.
130 is an oil pump and 140 is a drain. In FIG. 1, the hydraulic oil supply / discharge switching valve 120 is configured such that the hydraulic oil pumped by the oil pump 130
And the hydraulic oil in the first piston oil chamber 111 is discharged to the drain 140. In addition, 1
Reference numeral 10 denotes an oil hole for sending lubricating oil for lubricating the sliding surface of the piston 101.

As a feature of the present invention, the piston 1
A notch 113 is formed on the outer edge of the right end of No. 01. The axial depth A of the notch 113 is the second oil hole 10
9 is sufficiently smaller than the diameter D of the second oil hole 10.
9 is slightly larger than the distance B between the right end of the cylinder 9 and the side wall surface 114 of the cylinder 100.

In FIG. 2, hydraulic oil is supplied to the second piston oil chamber 112, and the piston 101 is at the left end position in the figure, that is, at the position where the gear connection for the third speed stage is completed. Then, when the hydraulic oil supply / discharge switching valve 120 is switched to supply hydraulic oil to the first piston 111 and withdraw hydraulic oil from the second piston oil chamber 112, the piston 101 is moved to the right in the figure, and as shown in FIG. After passing through the illustrated state, as shown in FIG. 4, it comes into contact with the side wall surface 114 of the cylinder 100 to complete the gear connection for the first speed stage.

FIG. 5 shows that the piston 101 approaches the side wall surface 114 of the cylinder 100,
13 shows a change from when the bottom 115 of the thirteen reaches the left end of the second oil hole 109 to when the piston 101 comes into contact with the side wall surface 114 of the cylinder 100. The cross section shows the opening width of the diameter portion of the second oil hole 109, and the dashed line shows the opening area (area). FIG. 6 is a graph showing the change of the aperture ratio, and (A), (B), (C), (D), and (E) on the horizontal axis of FIG. The positions of the end face of the piston at the positions (B), (C), (D) and (E) are shown.

Thus, in the actuator of the present invention,
Immediately before the piston 101 comes into contact with the side wall surface 114 of the cylinder 100, the opening area of the second oil hole 109 from which the hydraulic oil is drained is reduced, and the discharge resistance increases. As a result, the moving speed of the piston decreases, 101 is the cylinder 10
The hitting sound when contacting the side wall surface 114 of the “0” is reduced.

On the other hand, FIG. 7 shows an example of a notch in the prior art, and as shown, the axial depth A of the notch is as large as the diameter D of the second oil hole 109. The right end of the second oil hole 109 and the cylinder 1
00 is much larger than the distance B between the side wall surfaces 114. As a result, the piston 101 moves to the side wall surface 11 of the cylinder 100.
The change of the opening of the second oil hole 109 until it comes close to and comes into contact with 4 is as shown in FIG. 8, and the change of the opening ratio is as shown in FIG.

Therefore, the piston 101 is
2 until the hydraulic fluid comes into contact with the side wall surface 114 of the second
The opening area of the oil hole 109 is hardly changed, and the discharge resistance does not increase. As a result, the moving speed of the piston is not reduced, and the piston 101 comes into contact with the side wall surface 114 of the cylinder 100 at a high speed to generate a tapping sound. large.

[0023]

According to the present invention, it is possible to reduce the tapping noise when the piston comes into contact with the side wall of the cylinder by appropriately forming the notch in the outer edge of the end of the piston on the side that comes into contact with the side wall of the cylinder. Can be achieved only with a low cost. Also, there is no sacrifice in positional accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a twin clutch type transmission including an actuator according to the present invention.

FIG. 2 is a sectional view of the actuator according to the invention in an operating position.

FIG. 3 is a sectional view of the actuator according to the present invention in an operating position different from that of FIG. 2;

FIG. 4 is a cross-sectional view of the actuator according to the present invention in an operation position different from FIGS.

FIG. 5 is a diagram showing a change in an opening area of a hole for discharging hydraulic oil when a piston approaches a side wall of a cylinder.

FIG. 6 is a graph showing the change in FIG. 5;

FIG. 7 is a diagram showing an example of the structure of a conventional actuator.

FIG. 8 is a diagram showing a change in the opening area of a hole for discharging hydraulic oil when a piston approaches a side wall of a cylinder in the prior art of FIG. 7;

FIG. 9 is a graph showing the change in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Twin clutch type transmission ACT1 ... 1st actuator 100 ... Cylinder 101 ... Piston 102 ... Operating rod 104 ... Shift fork 105 ... Spring 108 ... 1st oil hole 109 ... 2nd oil hole 110 ... Lubrication oil hole 113 ... Notch 114 ... Cylinder side wall 120 ... Hydraulic oil supply / discharge switching valve

Claims (2)

[Claims] 1. A cylinder having a side wall at an axial end, a piston slidably disposed in the cylinder, and a working rod coupled to the piston, wherein a cylinder defined by the piston is provided. An actuator that supplies a working fluid to one of the two fluid chambers, discharges the working fluid from the other, moves the piston until it comes into contact with an axial end wall of a cylinder, and moves an object to be actuated coupled to an operating rod. An actuator characterized in that the discharge port for discharging the working fluid is a variable discharge port whose opening area decreases as the piston approaches the end wall of the cylinder. 2. A piston provided with a notch at an outer peripheral edge of an end on the side of the cylinder side wall passes over a hole having a circular cross section formed on a peripheral wall of the cylinder in which the variable discharge port is close to the end side wall. The diameter of the hole is D, the distance from the side wall of the cylinder to the side closest to the side wall of the cylinder is B, the end face of the notch of the piston on the side of the cylinder side of the piston. 2. The actuator according to claim 1, wherein D is sufficiently larger than A and A is slightly larger than B, where A is a depth in the axial direction from A. 3.