JP2723329B2 - Electric / hydraulic pressure converter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electro-hydraulic converter, and more particularly to an electro-hydraulic converter including a high temperature range within a use temperature range.

(Prior Art) In general, electric-to-hydraulic pressure converters are provided in various hydraulic operating systems as being interposed in a hydraulic supply / discharge circuit of a hydraulic actuator and controlling the operating pressure of the hydraulic actuator in accordance with an input electric signal. It is provided in. Among them, an electric / hydraulic pressure converter which is used in combination with an actuator for controlling a control surface of an aircraft or the like, requires a particularly high durability in a high temperature region because its use environment temperature greatly changes.

Conventional electric-hydraulic converters of this type include, for example, a spool that is moved by an electromagnetic solenoid based on an operating position detection signal of a hydraulic cylinder, and a pair of load sides that communicate with a pair of hydraulic chambers of the hydraulic cylinder. In some actuator systems including an electric-to-hydraulic converter, a liquid supply and discharge circuit outside the electric-to-hydraulic converter, such as a return side, is controlled. A means for cooling the liquid is added to the circuit so that the durability of the electric-to-hydraulic converter, various seals, and the like is not easily reduced when used in a high temperature range.

(Problems to be Solved by the Invention) However, in such a conventional electric-to-hydraulic pressure conversion device, since the configuration is indirectly cooled by the external liquid cooling means, electric components inside the device are The internal temperature tends to increase due to heat generation of the sliding parts and the like, and its characteristics (for example, the thrust of the spool) tend to decrease at high temperatures. For this reason, since it is necessary to obtain a reliable operation at high temperatures, a large-sized electric / hydraulic converter having a larger output than required at room temperature has to be used.

In addition, the structure of the entire actuator system has been complicated due to the necessity of securing an installation space for the cooling means and mounting the cooling means.

In view of the above, the present invention provides a small-sized electric / liquid converter that forms an orifice hole in a spool, circulates liquid in the electric / hydraulic pressure conversion device, cools the internal device, and provides stable output even at high temperatures. It is intended to provide a pressure conversion device.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a manifold having a pair of load-side ports communicating with a hydraulic chamber of a hydraulic actuator, a hydraulic pressure introduction port and a hydraulic pressure discharge port. And a pair of annular passages which are provided in the manifold so as to be axially displaceable and which are always in communication with the load side port between the manifold and the manifold. A pressure introducing port, by connecting a hydraulic pressure discharging port to the other, a spool capable of adjusting supply and discharge of hydraulic pressure to the load side port, and a driving means for driving the spool, provided inside the manifold, A liquid passage having an orifice in the spool, and a part of the liquid introduced into one of the annular passages is passed through the liquid passage. The fluid is recirculated to the hydraulic pressure discharge port through the passage, and the manifold is formed with a communication passage communicating with the liquid passage and the hydraulic pressure discharge port near the driving means. You may.

(Operation) In the present invention, a liquid passage having an orifice is formed in a spool for controlling the supply and discharge of the liquid pressure to and from the load side port, and a part of the liquid introduced into the manifold from the liquid pressure introduction port is used as the liquid passage. Through to the hydraulic outlet port. Therefore, without adding a cooling means outside as in the past,
Internal cooling is performed by the circulating liquid circulating in the liquid passage, and a small electric-to-hydraulic conversion device that can obtain a stable output even at a high temperature is obtained.

In addition, if the communication passage that connects the liquid passage and the hydraulic pressure discharge port is formed in the manifold in the vicinity of the driving unit, the driving unit can be sufficiently cooled.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a view showing one embodiment of an electric-hydraulic converter according to the present invention, and shows an example in which the present invention is applied to a hydraulic cylinder device.

First, the configuration will be described. In FIG. 1, reference numeral 11 denotes a hydraulic cylinder device. The hydraulic cylinder device 11 controls the supply and discharge of hydraulic oil (liquid) to and from the hydraulic cylinder body 12 (hydraulic actuator). Adjusting means 13 (electric / hydraulic converter) and a control circuit for controlling the adjusting means 13
It consists of fourteen. The hydraulic cylinder body 12 has a piston 22 slidably provided in a cylinder barrel 21, and the piston 22 is caused to stroke by a differential pressure between hydraulic chambers 23A and 23B defined by the piston 22, Piston 22 projecting outward from one end of cylinder barrel 21
The rod portion 22a is connected to an unillustrated control surface operation unit of the aircraft. The adjusting means 13 includes a manifold 31 and a spool 32 housed in the manifold 31.The manifold 31 has a pair of load sides communicating with a pair of hydraulic chambers 23A and 23B of the hydraulic cylinder body 12. Port 33A, 33B
A hydraulic pressure introduction port 34 for introducing hydraulic pressure from a hydraulic pressure supply means such as an oil horn (not shown) and a hydraulic pressure discharge port 35 for discharging hydraulic pressure to an oil tank or the like (not shown) are formed.
Each of these ports 33A, 33B, 34, 35 is open to a spool storage chamber 36 formed at the center of the manifold 31, respectively, and has openings 41A, 41B, opening 42, and openings 43A, 43B, respectively. Has formed. The spool 32 has three land portions 32a, 32b, and 32c that are axially separated from each other.These land portions define a pair of annular passages 37A and 37B in the spool storage chamber 36. Is the opening 41A
However, openings 41B are always in communication with 37B. When the spool 32 is displaced in the axial direction from the position shown in FIG.
a, 32b, and 32c, one of the openings 43A and 43B and the opening 42 are opened, and the other of the openings 43A and 43B is closed, for example, from the hydraulic pressure introduction port 34 to the annular passage 37A. The introduced hydraulic pressure is supplied to the hydraulic chamber 23A, and the hydraulic pressure is discharged from the hydraulic chamber 23B through the annular passage 37B.

Reference numeral 51 denotes a drive unit housed in the manifold 31 and driving the spool 32.The drive unit 51 is connected to a shaft 52 coaxially fixed to the spool 32 and to the spool storage chamber 36 attached to the shaft 52. Hole 54 (communication passage) formed
And a set of electromagnetic coils 55A, 55B mounted on the manifold 31 so as to be positioned on both sides of the permanent magnet 53 in the axial direction of the shaft 52, Is provided. These electromagnetic coils 55A and 55B are connected to a control circuit 14, which detects piston position from a differential transformer 56 interposed between the cylinder barrel 21 and the piston 22 of the hydraulic cylinder body 12. An electromagnetic coil 55 based on a deviation signal between a signal (feedback signal) and a command signal C from the outside.
A and 55B are selectively excited, whereby the spool 32 is axially displaced by a required amount via the permanent magnet 53 and the shaft 52.

Further, the spool 32 is formed in a bottomed cylindrical shape having a bottom portion on the side of the land portion 32a, and forms an annular passage 61 (liquid passage) between itself and the shaft 52. The annular passage 61 communicates with the annular passage 37A through an orifice hole 62 formed between the land portion 32a and the land portion 32b of the spool 32, and communicates with the hole 54 and the manifold 31 formed near the driving means 51. It communicates with the hydraulic pressure discharge port 35 via the passage 63. When hydraulic pressure is introduced into the annular passage 37A through the hydraulic pressure introduction port 34, liquid flows from the annular passage 37A into the annular passage 61 through the orifice hole 62, and the liquid flows from the annular passage 61 to the hole 54 and the communication passage 63. Through hydraulic outlet port
Reflux to 35.

 Next, the operation will be described.

When the command signal C is input to the control circuit 14, the control circuit 14
Is an electromagnetic coil 55 based on a deviation signal between the position detection signal of the differential transformer 56 and the command signal C, which is a feedback signal.
A and 55B are selectively excited to apply electromagnetic thrust to the permanent magnet 53 to displace the spool 32, thereby controlling supply and discharge of hydraulic pressure to and from the hydraulic pressure chambers 23A and 23B.

Now, for example, if the spool 32 is displaced to the left in the figure from the neutral position shown in FIG. 1, the opening of the hydraulic pressure introduction port 34 increases according to the amount of displacement, and the annular passage The hydraulic pressure is supplied to the hydraulic chamber 23B through the 37B and the load port 33B, and the hydraulic pressure is discharged from the hydraulic chamber 23A to the hydraulic discharge port 35 through the load port 33A and the annular passage 37A. Then, the piston 22 is moved by the pressure difference between the hydraulic chambers 23A and 23B.
Strokes leftward in FIG. 1 to change the steering angle of the control surface.

On the other hand, if the spool 32 is displaced to the right in FIG. 1, the hydraulic pressure is supplied to the hydraulic pressure chamber 23A through the supply / discharge path opposite to the above-described case, and the hydraulic pressure is supplied from the hydraulic pressure chamber 23B. As a result, the piston 22 strokes rightward in FIG. At this time, a part of the liquid introduced into the annular passage 37A by the liquid pressure in the annular passage 37A flows into the annular passage 61 through the orifice hole 62, and returns to the hydraulic pressure discharge port 35 through the hole 54 and the communication passage 63. At this time, the liquid immediately after being introduced from the outside through the inside of the manifold 31 is circulated, so that the inside of the manifold 31 is cooled.
The vicinity of the electromagnetic coils 55A and 55B is sufficiently cooled. Therefore, even in a high-temperature environment, a stable driving force of the driving means 51 can be obtained and a required output can be exhibited. It does not need to be a device. Further, since it is not necessary to rely on an external cooling means for cooling the electric-to-hydraulic conversion device as in the prior art, the cooling means of the system including the hydraulic cylinder device 11 can be eliminated or the system can be downsized. The structure can be simplified.

FIG. 2 is a view showing another embodiment of the electric / hydraulic converter according to the present invention.

In the figure, 71 is a manifold, 72 is a manifold
71 is a sleeve that is housed in 71 and guides the spool 32 slidably, and the manifold 71 has load-side ports 73A, 73B,
It has a hydraulic pressure introduction port 74 and hydraulic pressure discharge ports 75A, 75B. The sleeve 72 communicates with the hydraulic pressure introduction port 74, and is opened and closed by the land 32b of the spool 32;
It has ports 82A and 82B communicating with the hydraulic pressure discharge ports 75A and 75B, and the ports 82A and 82B
It is opened when closing 1 and can be closed by the lands 32a and 32c. The annular passage 6 serving as a liquid passage is provided through one of the ports 82A and 82B.
1 communicates with one of the hydraulic pressure discharge ports 75B. That is, in the present embodiment, the port 82B formed in the sleeve 72 functions as a communication path. Other configurations are the same as those of the above-described embodiment, and the present embodiment can provide the same effects as those of the above-described embodiment.

In this embodiment, it goes without saying that the orifice hole 62 may be formed not between the land portions 32a and 32b of the spool 32 but between the land portions 32b and 32c as shown in FIG. . Further, if the annular passage 61 is separated and blocked near the land 32b of the spool 32 so that the annular passages 37A and 37B do not communicate with each other, the orifice holes 62 are formed on both sides of the land 32b, and the respective separate passages are formed. Aisle (eg, port 82
A, 82B) can be drained to separate hydraulic outlet ports (eg, hydraulic outlet ports 75A, 75B).

(Effect) According to the present invention, a liquid passage having an orifice is formed in a spool for adjusting the supply and discharge of hydraulic pressure to and from the load side port, and a part of the liquid introduced into the manifold from the hydraulic pressure introduction port is removed. Since the liquid is returned to the hydraulic pressure discharge port through the liquid passage, there is no need to add an external cooling means as in the past, and the internal cooling can be performed by the circulating liquid circulating in the liquid passage, and stable even at high temperatures It is possible to provide a small-sized electric / hydraulic converter capable of obtaining a reduced output.

In addition, if the manifold is provided with a communication path that connects the liquid passage and the hydraulic pressure discharge port near the driving means, the driving means can be sufficiently cooled.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the electric-hydraulic converter according to the present invention, and FIG. 2 is a sectional view showing another embodiment of the electric-hydraulic converter according to the present invention. FIG. 3 is a view showing another aspect of the spool in each embodiment. 12 ... Hydraulic cylinder (hydraulic actuator), 23A, 23B
…… Hydraulic chamber, 31, 71 …… Manifold, 32 …… Spool, 33A, 33B, 73A, 73B …… Load side port, 34, 74 ……
Hydraulic inlet port, 35, 75A, 75B …… Hydraulic outlet port, 51
... Drive means, 54 holes (communication passages), 61 annular passages (liquid passages), 62 orifice holes (orifices), 63
… Communication passage, 82B …… port (communication passage).

Claims (1)

(57) [Claims] 1. A manifold having a pair of load-side ports communicating with a hydraulic chamber of a hydraulic actuator, a hydraulic pressure introduction port and a hydraulic pressure discharge port; and a manifold provided inside the manifold so as to be axially displaceable. And a pair of annular passages that are always in communication with the load-side port, respectively, and a hydraulic pressure introduction port is communicated to one of the pair of annular passages and a hydraulic pressure discharge port is communicated to the other by axial displacement. An electric / hydraulic pressure conversion device comprising: a spool capable of adjusting supply / discharge of hydraulic pressure to / from a load-side port; and a driving means for driving the spool provided inside the manifold. A communication passage that forms a liquid passage having the same and that communicates the liquid passage and the hydraulic pressure discharge port near the drive unit with the manifold. Formed, the liquid pressure discharge electrical and hydraulic conversion device is characterized in that so as to reflux the port portion of the introduced liquid through the liquid passage and the communication passage on one of the annular passage.