JP3447487B2 - Composite hydraulic actuator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound hydraulic actuator suitable for controlling intake / exhaust valve opening / closing timing of an internal combustion engine.

[0002]

5 and 6 are sectional views for explaining the schematic structure and operation of a conventional rotary hydraulic actuator, FIG. 5 is a sectional view orthogonal to an axis, and FIG. 6 is an axial direction sectional view.
In the figure, 1 is a casing 1a and a drive side bracket 1.
b is an airtight container composed of a rear bracket 1c, 2 is an output shaft rotatably supported by both brackets 1b and 1c via a bearing 13, 3 is a rotating body formed integrally with the output shaft 2, and 4 is a rotating body. A sluice valve which is integrally coupled to the body 3 and whose outer surface slides on the inner surface of the casing 1a and whose both end surfaces slide on the inner surfaces of the brackets 1b and 1c while sliding, is a sluice valve in the hermetically sealed container 1. It is configured to be divided into one pressure chamber 5 and a second pressure chamber 6. Reference numeral 7 denotes an oil intake / exhaust passage of the first pressure chamber 5, 8 an oil intake / exhaust passage of the second pressure chamber 6, which are connected to an electromagnetic hydraulic control valve 9 for switching four ports and three positions by piping. 9a to 9d indicate ports of the hydraulic control valve 9, and the port 9a is connected to the hydraulic pump 10.
The port 9b is provided in the oil intake / exhaust passage 7 of the first pressure chamber 5 and the port 9b.
c is connected to the oil suction / discharge passage 8 of the second pressure chamber 6 by piping, and the port 9d is connected by a return pipe 12 to the oil tank 11 at normal pressure. In addition, 14 is an oil seal.

In the conventional rotary hydraulic actuator constructed as above, when the electromagnetic hydraulic control valve 9 operates and the ports 9a and 9b communicate with each other and 9c and 9d communicate with each other, the hydraulic pressure of the hydraulic pump 10 increases. 5 to flow into the first pressure chamber 5, the oil in the second pressure chamber 6 is discharged to the oil tank 11 through the return pipe 12, and the sluice valve 4 moves in the direction of the solid arrow in FIG. The cam shaft of the internal combustion engine (not shown) is operated by being pushed by and rotating counterclockwise together with the output shaft 2. Also, the hydraulic control valve 9 is the port 9
When a and 9c are communicated with each other and ports 9b and 9d are communicated with each other, the hydraulic pressure of the hydraulic pump 10 passes through the oil suction / discharge passage 8 and the second pressure chamber 6
Oil of the first pressure chamber 5 is discharged to the oil tank 11 through the return pipe 12, the sluice valve 4 is pushed in the direction of the dotted arrow in FIG. 5, and is rotated clockwise with the output shaft 2. Operates the camshaft of an internal combustion engine. Furthermore, the hydraulic control valve 9
When both ports 9b and 9c are closed, the pressures in the first pressure chamber 5 and the second pressure chamber 6 are evenly held, and the output shaft 2 is configured to stop rotating and hold its position. There is.

[0004]

As described above, in the conventional rotary hydraulic actuator, the hydraulic control valve 9 is used.
By the operation, the rotation direction of the output shaft 2 and the stop position can be controlled and the position at the stop position can be maintained, and the opening / closing timing of the intake / exhaust valve can be controlled by operating the cam shaft of the internal combustion engine. Such an actuator for controlling intake and exhaust valves of an internal combustion engine requires a large driving force and good responsiveness,
In addition, a wide control range and high controllability with respect to changes in the operating conditions of the internal combustion engine are required. In the rotary hydraulic actuator as described above, the driving force of the output shaft 2 is determined by the area of the sluice valve 4, that is, the internal volume of each of the first and second pressure chambers 5 and 6, but the internal volume of each pressure chamber is However, the increase of the actuator not only makes the actuator larger but also lowers the responsiveness, and it is difficult to achieve both high driving force and good responsiveness.

The present invention has been made in order to solve the above problems, and a sufficient driving force and good responsiveness can be obtained without increasing the size of the actuator, and a wide control range and high controllability are also obtained. It is an object of the present invention to obtain a hydraulic actuator suitable for controlling intake / exhaust valve opening / closing timing of an internal combustion engine.

[0006]

SUMMARY OF THE INVENTION A hydraulic actuator according to the present invention includes a closed container composed of a bracket and a casing, a rotatably held inside the closed container, and a sluice valve having an outer diameter and a first valve having an inner diameter. A rotating body having a helical spline, first and second pressure chambers formed between the inner surface of the closed container and the outer surface of the rotating body, and divided by a sluice valve of the rotating body; A gear piston having a second helical spline that meshes with one helical spline, and a third helical spline having a third helical spline having a twist in the opposite direction to the first helical spline in the inner diameter, and a third helical spline of the gear piston. An output shaft that has a fourth helical spline that meshes with it on the outer diameter and is rotatably supported by the bracket of the closed container, and the rotating body and the output shaft in the closed container. And the third and fourth pressure chambers divided by the gear piston, and the sluice valve to which hydraulic pressure is applied in the rotational direction and the gear piston to which hydraulic pressure is applied in the axial direction both drive the output shaft. It is a thing.

The first pressure chamber and the second pressure chamber are controlled by the first hydraulic control valve, and the third pressure chamber and the fourth pressure chamber are controlled by the second hydraulic control valve. The controllability, responsiveness, and driving force are thereby improved. Furthermore, by configuring the first pressure chamber and the second pressure chamber, and the third pressure chamber and the fourth pressure chamber to be controlled by a common hydraulic control valve, the control range and response can be controlled by one hydraulic system. It is designed to enhance the sexuality and driving force. Furthermore, the first pressure chamber is connected to either the third pressure chamber or the fourth pressure chamber, and the second pressure chamber is connected to the other of the third pressure chamber or the fourth pressure chamber. Thus, the control range, the driving force and the responsiveness are enhanced while simplifying the piping.

[0008]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. 1 to 3 show the configuration of Embodiment 1 of the present invention. FIG. 1 is a sectional view orthogonal to the axis of a compound hydraulic actuator, FIG. 2 is an axial sectional view, and FIG. 3 is a hydraulic control system. FIG. In the figure, 15 is a casing, 16 is a drive side bracket, 17 is a rear bracket, and these are combined to form a closed container 18. Reference numeral 19 denotes a rotating body that is rotatably held in the closed container 18. A helical spline 19a is provided on the inner circumference of the rotating body 19, and sluice valves 20a and 20b are provided on the outer circumference at symmetrical positions. Airtight container 18 and rotating body 19
Hydraulic chambers 21a and 21b are provided at symmetrical positions between the outer peripheral portions. The hydraulic chambers 21a and 21b form a closed chamber independent of each other by the closed container 18 and the rotating body 19, and the inner surface and both sides of the closed container 18 are formed. By the sluice valves 20a and 20b which slide and rotate on the surface, the first pressure chamber 22
a and 22b and second pressure chambers 23a and 23b,
The first pressure chambers 22a and 22b are provided at symmetrical positions, and are communicated with each other by a hydraulic passage (not shown).
3a and 23b are also provided at symmetrical positions and are connected to each other by a hydraulic passage.

An output shaft 24 is rotatably supported by both brackets 16 and 17 constituting the hermetically sealed container 18 via bearings 36. A helical spline 25 is provided on the outer periphery of the output shaft 24 in the hermetically sealed container 18. Is provided, and the helical spline 25 is the helical spline 19 of the rotating body 19.
It is configured to have the same pitch as that of a and the twisting direction is opposite. A gear piston 26 has a helical spline 26a that meshes with the helical spline 19a of the rotating body 19 on its outer circumference, and a helical spline 26b that meshes with the helical spline 25 of the output shaft 24 on the inner circumference. A space formed between the inner diameter of the rotating body 19 and the outer diameter of the output shaft 24 is divided therein to form a third pressure chamber 27 and a fourth pressure chamber 28.

The supply of hydraulic pressure to each of the first to fourth pressure chambers is as shown in FIG. In FIG. 3, 29 is a normal pressure oil tank, 30 is a hydraulic pump for increasing the pressure of oil in the oil tank 29, 31 and 32 are hydraulic control valves, and a port 31a of the hydraulic control valve 31 is a hydraulic pump 3
0, the port 31b to the first pressure chambers 22a and 22b,
The port 31c is connected to the second pressure chambers 23a and 23b, the port 31d is connected to the return pipe 33a, and the port 32a of the hydraulic control valve 32 is connected to the hydraulic pump 30, the port 32b is connected to the third pressure chamber 27, and the port 32c is connected to the first pressure chamber. The four pressure chambers 28 and the port 32d are connected to the return pipe 33b, respectively.

In the combined hydraulic actuator according to the first embodiment of the present invention configured as described above, the port 31a and the port 31b communicate with each other by the operation of the spool (not shown) of the hydraulic control valve 31, and the port 31c and the port 31d. Are communicated with each other, the hydraulic pressure of the hydraulic pump 30 is supplied to the first pressure chambers 22a and 22b via the ports 31a and 31b, and the second pressure chambers 23a and 23b pass through the ports 31c and 31d and the return pipe 33a to maintain normal pressure. Oil tank 2
9 is connected to the first pressure chamber 22 in FIG.
a and 22b and the second pressure chambers 23a and 23b, a pressure difference is generated, the sluice valves 20a and 20b receive a force in the direction of the solid line arrow in FIG. 1, and the rotating body 19 is connected to the gear piston by a helical spline. The output shaft 24 is rotated clockwise via 26 to operate, for example, a cam shaft of an internal combustion engine. In addition, the ports 31a and 31c of the hydraulic control valve 31
When the port 31b and the port 31d are communicated with each other, the hydraulic pressure is supplied to the second pressure chambers 23a and 23b, and the first pressure chambers 22a and 22b are connected to the oil tank 29 at normal pressure. The output shaft 24 rotates in the direction of the dotted arrow in the figure. Then, when the ports 31b and 31c are closed, the hydraulic pressures of the first and second pressure chambers become equal and the output shaft 24 is held at that position.

On the other hand, when the ports 32a and 32b are communicated with each other and the ports 32c and 32d are communicated with each other by the operation of the spool (not shown) of the hydraulic control valve 32, the hydraulic pressure is supplied to the third pressure chamber 27 and the fourth pressure chamber 28. Is a normal pressure oil tank 2
9 is connected to the gear piston 26 in FIG.
Is applied in the direction of the solid arrow in the figure. Then, the rotating body 19 is replaced by the first pressure chamber 22a, 22b or the second pressure chamber 23.
Since the gear piston 26 is held by the hydraulic pressures a and 23b, the gear piston 26 moves in the solid line direction while rotating the output shaft 24 in accordance with the twist angle of the helical spline meshing with the inner and outer surfaces thereof. Similarly, port 32 of hydraulic control valve 32
When a and 32c are connected and ports 32b and 32d are connected, hydraulic pressure is supplied to the fourth pressure chamber 28, and the third pressure chamber 2
Since 7 is connected to the oil tank 29 of normal pressure, the gear piston 26 moves in the direction of the dotted arrow in the figure, and as a result, the output shaft 24
Is driven in the opposite direction, and when the ports 32b and 32c are closed, the pressures of the third pressure chamber 27 and the fourth pressure chamber 28 become equal and the position of the output shaft 24 is maintained.

As described above, according to the combined hydraulic actuator of Embodiment 1 of the present invention, the driving force of the rotating body 19 by the first pressure chambers 22a and 22b and the second pressure chambers 23a and 23b, Third pressure chamber 27 and fourth pressure chamber 28
Output shaft 2 due to both the pressing force of the gear piston 26 due to
4 is driven to rotate, the hydraulic control valves 31 and 32 are operated by a control device (not shown) to rotate the rotor 1.
9 and the force of the gear piston 26 can be reciprocated or individually operated. When reciprocated, the force applied to the output shaft 24 is doubled to increase the driving force and increase the rotation speed. In addition, the control range can be expanded by adding the control range, and further, the drive control of the output shaft 24 can be performed finely by performing the individual operation, and therefore the size is particularly increased. Without doing so, it is possible to obtain a hydraulic actuator excellent in driving force, responsiveness, and controllability.

The port 31b of the hydraulic control valve 31 is also provided.
To the first pressure chambers 22a and 22b and the third pressure chamber 27, and the port 31c to the second pressure chambers 23a and 23b and the fourth pressure chamber 2.
8 is connected to the pipe 8 and the hydraulic control valve 32 is eliminated, it is possible to operate the rotary body 19 and the gear piston 26 in a harmony manner by the hydraulic control valve of one system. And a hydraulic actuator having a wide control range.

Embodiment 2. FIG. 4 is a sectional view showing the structure of the compound hydraulic actuator according to the second embodiment of the present invention. In this embodiment, the first pressure chamber 22
hydraulic passage 3 that connects a and 22b with the third pressure chamber 27
4, and the hydraulic passage 35 that connects the second pressure chambers 23a and 23b to the fourth pressure chamber 28 is provided in the rotating body 19. In the hydraulic actuator according to the second embodiment configured as described above, the oil pressure control valve supplies oil to the first hydraulic chambers 22a and 22b at the same time to the third hydraulic chamber 27, and also to the second hydraulic chambers 23a and 23b. Since refueling is also provided to the fourth hydraulic chamber 28, the rotary body 19 and the gear piston 26 can be operated in a harmony manner by a series of hydraulic valves and a series of piping, and the driving force can be simplified while simplifying the hydraulic piping. It is possible to obtain a hydraulic actuator having excellent responsiveness and a wide control range. In the embodiment of the present invention, the sluice valves are provided at two locations on the outer circumference of the rotating body, but one or two or more locations may be provided if necessary, and the number of sluice valves is not limited. .

[0016]

As described above, according to the combined hydraulic actuator of the present invention, the drive force of the sluice valve by the first pressure chamber and the second pressure chamber, and the third pressure chamber and the fourth pressure chamber. Since both the pressing force of the gear piston and the output shaft are applied to the output shaft, by operating these with a two-series hydraulic control valve, driving force and responsiveness can be improved and a wide control range can be achieved without increasing the size. In this way, it is possible to perform fine drive control, and it is possible to improve the drive force and responsiveness and expand the control range even when using a single hydraulic control valve. Furthermore, by connecting the first pressure chamber and the third pressure chamber and the second pressure chamber and the fourth pressure chamber, it is possible to improve the driving force and responsiveness while simplifying the hydraulic piping, and obtain a wide control range. Thus, it is possible to obtain an excellent hybrid hydraulic actuator.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of the first embodiment of the present invention.

FIG. 3 is a system diagram of hydraulic control according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a conventional rotary hydraulic actuator.

FIG. 6 is an explanatory diagram showing a configuration of a conventional rotary hydraulic actuator.

[Explanation of symbols]

15 casing, 16, 17 bracket, 18 closed container, 19 rotating body, 19a, 25, 26a, 26b
Helical spline, 20a, 20b Gate valve, 22
a, 22b first pressure chamber, 23a, 23b second pressure chamber, 24 output shaft, 26 gear piston, 27 third pressure chamber, 28 fourth pressure chamber, 31, 32 hydraulic control valve,

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Claims (4)

(57) [Claims] 1. A closed container constituted by a bracket and a casing, a rotating body rotatably held in the closed container and having a sluice valve in an outer diameter portion and a first helical spline in an inner diameter portion, and an inner surface of the closed container. Between the first pressure chamber and the second pressure chamber which are arranged between the outer surface of the rotor and the outer surface of the rotor and which are divided by the sluice valve of the rotor, and the second diameter which meshes with the first helical spline of the rotor on the outer diameter portion. A gear piston having a helical spline and a third helical spline having a twist in the opposite direction to the second helical spline in the inner diameter portion,
An output shaft that has a fourth helical spline that meshes with the third helical spline of the gear piston in the outer diameter portion and is rotatably supported by the sealed container, and in the sealed container between the rotating body and the output shaft. A composite hydraulic actuator comprising a third pressure chamber and a fourth pressure chamber that are configured and divided by a gear piston. 2. The first pressure chamber and the second pressure chamber are controlled by the first hydraulic mechanism, and the third pressure chamber and the fourth pressure chamber are controlled by the second hydraulic mechanism. The hybrid hydraulic actuator according to claim 1. 3. The combined hydraulic actuator according to claim 1, wherein the first pressure chamber and the second pressure chamber, and the third pressure chamber and the fourth pressure chamber are controlled by a common hydraulic mechanism. . 4. The first pressure chamber communicates with the third pressure chamber or the fourth pressure chamber, and the second pressure chamber communicates with the other of the fourth pressure chamber and the third pressure chamber. The hybrid hydraulic actuator according to claim 1 or 3.