JPH10325437A - Rotary actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a trouble by an oil invasion by installing a magnet assembly on the upper end of a piston rod for forming a hydraulic buffer in series and penetrating a through hole bored in the axial core part of the piston rod and connecting a drive shaft to the upper end of a control unit for connecting a rotary valve to a lower end. SOLUTION: In a rotary actuator A, a magnet assembly 10 is connected in series directly to the upper end of a piston rod 1 and connected to the magnet assembly 10 in a fixed state under such state that the axial core part of a coil assembly 20 is inserted on its upper end side. Therefore, the inside of a housing is communicated with a rotary valve side, namely a through hole 1a side bored on the axial core part of the piston rod 1 and an oil invasion state is allowed, while it is intercepted on the coil assembly 20 side which is the outer part. Even if the inside of the magnet assembly 10 is in the oil invasion state, the inside of the coil assembly 20 is not in the oil invasion state and the generation of an electric trouble by the oil invasion of the rotary actuator A is not apprehended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rotary actuator as a drive source for operating a damping force adjusting section incorporated in a hydraulic shock absorber.

[0002]

2. Description of the Related Art In recent years, some hydraulic shock absorbers mounted on vehicles have been set so as to generate an optimum damping force according to the running condition of the vehicle by operating a built-in damping force adjusting unit. In this case, for example, as shown in FIG. 5, a rotary actuator A serving as a drive source for operating the damping force adjusting unit in the hydraulic shock absorber S is provided at the top of the hydraulic shock absorber S. There is.

[0003] That is, although not shown in detail, the hydraulic shock absorber S is set, for example, to generate a predetermined damping force by a damping valve disposed on a piston in a cylinder. It has a bypass flow path and a rotary valve in the flow path for controlling the flow rate of hydraulic oil in the flow path.

When the rotary valve is rotated via the control rod 2 which penetrates the through hole 1a in the axial center of the piston rod 1, the damping force generated when the hydraulic shock absorber S expands and contracts. Is set so that the height can be adjusted.

A drive shaft a of a rotary actuator A as a drive source integrally held at the upper end of the piston rod 1 is connected to the upper end of the control rod 2, and the rotary valve is driven by the rotary actuator A. Is rotated.

Therefore, in this hydraulic shock absorber S,
Although not shown, for example, the rotary actuator A can be set to be driven based on the detection results of various sensors mounted on the vehicle, so that an optimal damping force according to the running condition of the vehicle can be generated. become.

In the hydraulic shock absorber S, since the inside of the through hole 1a of the piston rod 1 into which the control rod 2 is inserted is in an oil-immersed state, oil from the inside of the through hole 1a is filled with oil. Care is taken not to cause an electrical failure in the rotary actuator A by penetrating into the rotary actuator A.

That is, a seal 3 composed of an O-ring interposed on the outer periphery of the upper end of the control rod 2 is accommodated in a portion of the shaft core at the upper end of the piston rod 1 where the diameter of the through hole 1a is increased. The seal 3 prevents oil in the through-hole 1a from entering the rotary actuator A.

As a result, since the seal 3 is set to have a predetermined interference, the control rod 2
When the rotation of the control rod 2 is reduced, there is a fear that the rotation control of the rotary valve cannot be realized as set, and In order to realize the rotation control of the rotary valve as set, the rotary actuator A must be made large or large in power consumption.

Then, looking back to the basics, since the seal 3 in this case is disposed on the movable part that moves frequently, the hydraulic shock absorber S is used for a long time, That is, when the control rod 2 is rotated frequently, mechanical deterioration such as wear is likely to be caused.

In particular, in the case of large vehicles such as buses and trucks, the running distance is generally long, so that the seal 3 is likely to be deteriorated. When this occurs, there is a problem that the hydraulic shock absorber S itself is replaced.

The present invention has been made in view of the above circumstances, and its purpose is to not only function as a predetermined drive source but also to prevent an electrical failure due to oil immersion. Accordingly, it is an object of the present invention to provide a rotary actuator which is optimal for being used as a drive source for operating a damping force adjusting section incorporated in a hydraulic shock absorber mounted on a vehicle.

[0013]

In order to achieve the above object, the structure of a rotary actuator according to the present invention is described as follows.
Basically, it is excited by a magnet assembly holding a magnet connected to a drive shaft for rotating a rotary valve for adjusting the level of a generated damping force in a hydraulic shock absorber and a coil wound corresponding to the magnet. And a coil assembly enclosing a core to be formed, the magnet assembly is fixedly connected to the shaft core of the coil assembly, and the magnet forms a magnet assembly and is connected to the hydraulic shock absorber. It is assumed that the housing is housed in a housing portion of the case body, and the inside of the housing portion is communicated with a rotary valve side to allow an oil immersion state, while being shut off to an outside coil assembly side.

More specifically, a magnet assembly is connected to an upper end of a piston rod forming a hydraulic shock absorber, and a through hole is inserted through a shaft core of the piston rod, and a rotary shaft is inserted into a lower end of the piston rod. It is assumed that the drive shaft is connected to the upper end of the control rod connecting the valve.

Further, a magnet assembly is provided so as to penetrate an outer cylinder forming a hydraulic cylinder set in a double cylinder type, and is formed between the outer cylinder and the cylinder to form a damper in the hydraulic cylinder. It is assumed that a rotary valve disposed in a flow path bypassing the valve is held in a magnet assembly.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a rotary actuator according to an embodiment of the present invention; FIG.
And a magnet assembly 10 and a coil assembly 20.

The rotary actuator A
In the illustrated embodiment, while the magnet assembly 10 is directly connected to the upper end of the piston rod,
The coil assembly 20 is disposed on the upper end side of the magnet assembly 10 such that the shaft core of the coil assembly 20 is fitted therein. In this state, the coil assembly 20 is mounted on the magnet assembly 20 by using a nut 30 from above the coil assembly 20. 10 is connected to the fixed state.

Therefore, in this embodiment, since the rotary actuator A is directly connected to the upper end of the piston rod 1 which forms the top of the hydraulic shock absorber S, FIG. In comparison with the case shown in FIG.
This is advantageous in that the arrangement of (shown by) is unnecessary.

Incidentally, the hydraulic shock absorber S in this embodiment has the same structure as the hydraulic shock absorber S shown in FIG. 5 described above.
As will be described later, the output shaft of the magnet assembly 10, that is, the drive shaft a of the rotary actuator A is connected to the control rod 2 inserted into the through hole 1a of the piston rod 1 so as to be able to rotate synchronously. .

As shown in FIG. 2, the magnet assembly 10 includes a case body 11 which constitutes the magnet assembly 10 and is connected to the piston rod 1 of the hydraulic shock absorber S, and an upper end of the case body 11. And a magnet 12 rotatably housed in a cylindrical housing part 11a.

Incidentally, this magnet assembly 1
In the case of 0, not only the case body 11 but also the magnet 12 and a spacer 13 described later are formed of a non-magnetic material.

Therefore, the housing portion 11a on the upper end side of the case body 11 is connected to a coil assembly 2 described later.
The thickness is set as thin as possible so long as it has a predetermined mechanical strength so as to allow the magnetic force from zero.

However, as described above, the housing portion 11a, that is, the upper end side of the magnet assembly 10 is disposed so as to be fitted on the shaft core portion of the coil assembly 20, so that the coil assembly 20 can be used. The outer peripheral side is reinforced, so that even if the housing portion 11a is set as thin as possible, it is sufficient.

On the other hand, the lower half-side mounting portion 11b of the case body 11 is formed in a thick cylindrical shape having a predetermined mechanical strength so as to function as a nut. The screw 11c is screwed into a screw 1b formed on the outer periphery of the upper end of the piston rod 1, whereby the case body 11 is connected to the upper end of the piston rod 1.

The magnet 12 is in the embodiment shown in the drawing, and is formed in a cylindrical shape in which four divided bodies are assembled, and the output shaft, that is, this rotary The drive shaft a of the actuator A is held.

Incidentally, in the four-piece body forming the magnet 12, the inner circumference and the outer circumference are selectively set to the N pole or the S pole, but the same magnetic pole is not adjacent to the same circumference. Are arranged in a so-called alternate state.

The spacer 13 is disposed so as to be integral with the magnet 12 and the drive shaft a, so that the magnet 12 is not displaced in the axial direction of the drive shaft a, that is, the magnet 12 will be described later. It is set so that the core 21 in the coil assembly 20 is always aimed at.

Further, the spacer 13 is rotated such that the drive shaft a rotates in synchronization with the spacer 13 at the axis of the spacer 13, that is, at a rotation angle corresponding to the rotation angle of the magnet 12. Is set to work.

In the illustrated embodiment, the spacer 13 has a lower end formed between the housing portion 11a and the mounting portion 11b in the case body 11d.
And the upper end is locked to the lower end of a cap 15 that seals the upper end of the housing portion 11a of the case body 11 under a liquid-tight structure such as welding.

The spacer 13 may be made of a non-magnetic material and may be integrated with the magnet 12.

The drive shaft a disposed on the shaft core of the spacer 13
The upper end of the mounting portion 1 in the case body 11 has a lower end penetrating through the shaft core of the bearing 14 while the upper end thereof is present in a bearing hole 15 a formed in the shaft core on the lower end side of the cap 15.
1b, that is, in the enlarged through hole 1a formed at the upper end of the piston rod 1.

The lower end of the drive shaft a is connected to the upper end of the control rod 2 through which the through hole 1a of the piston rod 1 is inserted under a deformed structure such as double-sided machining, so as to synchronize with the control rod 2. The rotation is set to be realized.

The cap 15 has a bolt 15 at its upper end.
b, and the bolt 15b allows the nut 30 to be screwed from above the coil assembly 20.

Therefore, in the magnet assembly 10 according to this embodiment formed as described above, the inside of the housing portion 12a is formed in the rotary valve side, that is, the through hole formed in the shaft core portion of the piston rod 1. While the oil immersion state is permitted by communicating with the side of the coil assembly 1a, it is shut off on the side of the coil assembly 20 which is the outside.

As a result, in this embodiment, the through hole 1 which is the shaft core at the upper end of the piston rod 1 is provided.
It is sufficient that only the sleeve 4 through which the upper end of the control rod 2 penetrates is disposed at the portion where the diameter of the seal 3 is increased, and the arrangement of the seal 3 is smaller than that of the conventional case shown in FIG. This is advantageous in that it can be omitted.

Incidentally, the purpose of this sleeve 4 is to center the upper end of the control rod 2 and has no interference as in the seal 3.
There is no danger of lowering the rotation of the control rod 2 in the through hole 1a.

Therefore, according to this embodiment, since there is no fear that the rotation of the control rod 2 is reduced by the arrangement of the seal 3, the rotation of the rotary valve connected to the control rod 2 is controlled as set. Therefore, it is advantageous in that the rotary actuator A can be made smaller and the power consumption can be reduced.

On the other hand, the coil assembly 20 has a core 21 for exciting the magnet 12 in the magnet assembly 10, and a coil 22 wound around the core 21.

The coil assembly 20 is
In order that the state in which the coil 22 is wound around the core 21 is maintained permanently, and the protruding state of the lead wire 23 (see FIG. 1) connected to the coil 22 is maintained in a permanent manner. It is molded with a resin material 24 made of a non-magnetic material.

In the illustrated embodiment, the coil assembly 20 has the magnet 12
Is divided into four parts, that is, four pieces, while the core 2
1 is composed of three cores, and one of the cores 21
When the magnet is excited by energizing the coil 22 and the tip becomes the N pole, the outer periphery closest to the coil 22 attracts the magnet 12 set to the S pole.

The number of the cores 21 can be arbitrarily set in relation to the number of the corresponding magnets 12 as long as a predetermined magnetic force is exerted.

Therefore, in the coil assembly 20 according to this embodiment formed as described above, as described above, the upper end of the magnet assembly 10 is disposed in the shaft core portion in the inserted state. Nut 3 from above
0, the coil assembly 20 is fixedly connected to the magnet assembly 10.
In the case where the coil 22 is disconnected, only the coil assembly 20 can be replaced.

FIGS. 3 and 4 show a rotary actuator A according to another embodiment of the present invention. In this embodiment, the rotary actuator A has the rotary valve 5 and the hydraulic shock absorber. It is characterized in that it is provided on the outer surface of S, and the other configuration of the rotary actuator A is basically the same as that of the embodiment shown in FIG.

Therefore, in the following description, portions having the same configuration will be denoted only by the same reference numerals in the drawings, and detailed description thereof will be omitted unless necessary.

First, the hydraulic shock absorber A is of a double-cylinder type having an outer cylinder 7 on the outer peripheral side of the cylinder 6 and defining a reservoir chamber R between the cylinder 6 and the outer cylinder 7. The actuator A is provided so as to penetrate the outer cylinder 7 from the outer peripheral side.

By the way, the rotary actuator A is
It is stated that an interposed ring 17 is screwed around the outer periphery of the magnet assembly 10 to a fixed ring 16 welded to the outer cylinder 7 so as to be fixedly disposed at a predetermined position.

Therefore, in the case of this embodiment, compared with the case of the embodiment shown in FIG.
By providing the rotary actuator A, the hydraulic shock absorber S
This is advantageous in that it is not necessary to diminish the effective length at.

In the hydraulic shock absorber A according to this embodiment, an upper piston chamber R1 and a lower piston chamber R2 defined by a piston 8 in a cylinder 6 are communicated with each other via a damping valve 8a disposed on the piston 8. While generating a predetermined damping force, the upper piston chamber R1 and the lower piston chamber R
2 is communicated with a flow path bypassing the damping valve 8a, and the generated damping force is adjusted by controlling the flow rate of hydraulic oil in the flow path by the rotary valve 5.

The flow path bypassing the damping valve 8a is:
In the illustrated embodiment, it is formed on the inner peripheral side of the pipe P disposed in the reservoir chamber R, and although not shown in detail, communicates with the upper piston chamber R1 at the upper end and the lower end. Side communicates with the lower piston chamber R2.

On the other hand, the rotary valve 5 is provided in the case body 11 of the magnet assembly 10 constituting the rotary actuator A, that is, in the mounting portion 11b of the case body 11, and in the opening end of the mounting portion 11b. The perforated stopper 51 fixed to the periphery prevents the dropout from the inside of the mounting portion 11b.

The rotary valve 5 is directly connected to a drive shaft a of the rotary actuator A so as to be able to rotate synchronously, and is radially opened in a so-called main body formed in a cylindrical shape. The main body has a port 5a for allowing communication between the inner and outer peripheral sides.

On the other hand, the mounting portion 11b has a port 11e which allows communication on the inner and outer peripheral sides, that is, communication between the rotary valve 5 side and the reservoir chamber R side, and is aimed at the port 5a. doing.

Therefore, in the rotary actuator A according to this embodiment, it is possible to select whether or not the communication with the reservoir chamber R of the flow path bypassing the damping valve 8a can be performed by rotating the rotary valve 5. That is, the level of the damping force generated when the hydraulic shock absorber S expands and contracts can be adjusted.

In addition, in the case of this embodiment, the rotary valve 5 is not built in the hydraulic shock absorber S, but is provided in an externally mounted rotary actuator A. The valve 5 can be arbitrarily selected, that is, the diameter of the port 5a formed in the rotary valve 5 can be arbitrarily selected, so that it is possible to easily provide a wide range for adjusting the damping force.

In the illustrated embodiment, the number of magnets 12 in the magnet assembly 10 constituting the rotary actuator A is larger than that in the above-described embodiment, and the rotary actuator A Assuming that a large number of cores 21 are set in the coil assembly 20 to be configured, the rotation control of the rotary valve 5 can be realized more finely.

[0056]

As described above, according to the present invention, while the magnet assembly constituting the rotary actuator allows the oil immersion state in the housing for accommodating the magnet, the housing also accommodates the rotary actuator. Since it is assumed that the coil assembly side which is configured and external is shut off, even if the inside of the magnet assembly is in an oil immersion state, the inside of the coil assembly is not in an oil immersion state. The occurrence of electrical failure is no longer a concern.

As a result, when the rotary actuator is connected to the upper end of the piston rod that constitutes the hydraulic shock absorber, the diameter of the through hole, which is the axis of the upper end of the piston rod, is increased. Need not be provided with a seal interposed at the upper end of the control rod inserted through the through-hole, and it is sufficient to provide only a sleeve through which the upper end of the control rod is inserted at this portion. Will be.

At this time, since the sleeve only centers the upper end of the control rod and does not have an interference such as a seal, not only does the rotation of the control rod in the through hole not decrease, but also the control rod does not decrease. Therefore, the rotation of the rotary valve connected to the rotary actuator can be realized as set, and the rotary actuator itself can be further reduced in size and the power consumption can be reduced.

When the rotary actuator is disposed on the outer surface of the hydraulic shock absorber, the effective length of the hydraulic shock absorber is not reduced as compared with the case where the rotary actuator is provided at the upper end of the piston rod. Needless to say, when the rotary actuator has a built-in rotary valve for controlling the flow rate of hydraulic oil in a flow path bypassing the damping valve in the hydraulic shock absorber, the control area of the rotary valve is limited. Can be set arbitrarily, and it is possible to provide a wider range of adjustment of the damping force.

As a result, according to the present invention, not only does it function as a predetermined drive source, but also it does not cause an electrical failure due to oil immersion, and the damping built into the hydraulic shock absorber S mounted on the vehicle does not occur. There is an advantage that it is optimal to be used as a drive source for operating the force adjusting unit.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a state in which a rotary actuator according to an embodiment of the present invention is connected to the top of a hydraulic shock absorber S;

FIG. 2 is a cross-sectional view of the rotary actuator indicated by a line XX in FIG.

FIG. 3 is a longitudinal sectional view partially broken away showing a state in which a rotary actuator according to another embodiment is continuously provided on the outer surface of a multiple cylinder type hydraulic shock absorber S;

FIG. 4 is a vertical sectional view of the rotary actuator indicated by a position YY in FIG. 1;

FIG. 5 is a view showing a state in which a rotary actuator as a conventional example is continuously provided on the top of a hydraulic shock absorber S, similarly to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston rod 1a Through-hole 2 Control rod 4 Sleeve 5 Rotary valve 7 Outer cylinder 8a Damping valve 10 Magnet assembly 11 Case body 11a Housing part 12 Magnet 20 Coil assembly 21 Core 22 Coil A Rotary actuator a Drive shaft P Form a flow path Pipe S hydraulic shock absorber

Claims (1)

[Claims] 1. A magnet assembly for holding a magnet connected to a drive shaft for rotating a rotary valve for adjusting a level of a generated damping force in a hydraulic shock absorber, and excited by a coil wound corresponding to the magnet. And a coil assembly enclosing the core. The magnet assembly is fixedly connected to the shaft core of the coil assembly, and the magnet forms a magnet assembly and is connected to the hydraulic shock absorber. It is housed in the housing part of the case body, and
A rotary actuator in which the interior of the housing communicates with the rotary valve to allow an oil immersion state, while the interior of the housing is shut off to the outer coil assembly.