JPH0313640Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an actuator for a hydraulic shock absorber used in a variable damping force type hydraulic shock absorber.

[Conventional technology]

Conventionally, variable damping force type hydraulic shock absorbers installed in vehicles etc. have a piston slidably provided in a cylinder, and the piston is connected to the other end of a piston rod whose one end protrudes outside the cylinder. a first damping force generating structure that constantly generates a damping force when the piston rod is displaced in at least one of extension and contraction; and an oil defined by the piston in addition to the first damping force generating structure. The chambers are communicated through a throttle channel, and the throttle channel includes a valve mechanism that opens and closes the throttle channel by rotation, and an operating rod inserted into the piston rod to rotate the valve mechanism. An actuator consisting of a rotary actuator for rotating the operating rod is provided at the tip of the piston rod of the hydraulic shock absorber.

FIG. 3 shows an actuator for a hydraulic shock absorber according to this type of prior art.

In Fig. 3, 1 is a cylinder that forms the main body of the hydraulic shock absorber, and inside the cylinder 1 is a piston, a first damping force generating mechanism that is always in an operating state, and a damping force generating mechanism that is in an operating state and a non-operating state. A second damping force generating mechanism (neither shown) is provided which is switchable between the two damping force generating mechanisms. A piston rod 2 has one end connected to a piston, and the other end of the piston rod 2 protrudes outside the cylinder 1, and its tip forms a small diameter cylindrical portion 2A. Inside the piston rod 2 is an operating rod 3 for rotating a valve mechanism constituting the second damping force generating mechanism.
is rotatably inserted through a bearing 4 and an O-ring 5.

6 is operated by rotating the operating rod 3.
7 is a casing constituting the actuator 6, and the casing 7 has a bottomed cylindrical casing body 8 with an open upper side and a central part. The inside of the casing 7 has a sealed structure. Here, the bottom part 8 of the casing body 8
A is provided with a through hole 10 located at the center and having a larger diameter on the outside, and a screw insertion hole 11 located on one side in the radial direction. Further, an annular stepped portion 12 is formed on the peripheral wall portion 8B of the casing body 8 toward the tip, and a fitting hole 13 into which a grommet 22, which will be described later, is fitted is formed below the annular stepped portion 12. The cylindrical portion 2A of the piston rod 2 is inserted into the large diameter side of the through hole 10 of the casing body 8 formed as described above, and the piston rod 2 and the bottom portion 8A of the casing body 8 are connected by a connecting means. It is attached firmly.

On the other hand, the lid body 9 is fitted into the annular stepped portion 12 of the casing body 8, and is integrally fixed to the casing body 8 by caulking the open end of the casing body 8 inward. Reference numeral 14 denotes an annular mounting member protruding from the center of the outside of the lid 9 via welding means in order to secure the actuator 6 together with the hydraulic shock absorber to a vehicle or the like.

Next, 15 indicates a rotary actuator housed in the casing 7, and the rotary actuator 15 has a rotating shaft 16A protruding from the through hole 10 into the piston rod 2 and connected to the operating rod 3. It is comprised of a transmission part 16 housed on the inner bottom 8A side of the casing 7, and a motor part 17 located above the transmission part 16 and housed in the casing 7. A screw hole 18 is bored in the bottom of the transmission section 16, and the rotary actuator 15 is inserted into the screw insertion hole 1 in the bottom 8A.
It is fixed in the casing 7 by a fixing screw 19 that is inserted into the transmission section 1 and screwed into a screw hole 18 of the transmission section 16.

20, 20 is a wire whose one end is connected to the motor part 17 by soldering parts 21, 21, and the other end is connected to a vehicle power source (both not shown) via an operating switch; 22 is a casing body The grommet 22 is fitted into the fitting hole 13 of No. 8, and the grommet 22 elastically supports each wiring 20 with respect to the casing body 8, and maintains an airtight state inside the casing 7. It's summery.

The conventional technology is configured as described above, is assembled into a vehicle etc. together with a hydraulic shock absorber, and supplies voltage to the rotary actuator 15 via the wiring 22, 22.
By driving the rotary actuator 15, the second damping force generating mechanism can be appropriately switched between an operating state and a non-operating state.

[Problem that the invention attempts to solve]

In the hydraulic shock absorber actuator, a screw insertion hole 11 is provided in the bottom 8A of the casing body 8 in order to fix the rotary actuator 15 housed in the casing 7 from the outside of the casing 7 with a fixing screw 19. However, even if a sealing member is used, it is not possible to completely prevent muddy water from entering into the casing 7 from the screw insertion hole 11, and there is a drawback that the reliability of the actuator 6 is impaired. In particular, since the hydraulic shock absorber is installed between the vehicle body and the undercarriage, muddy water and the like are likely to enter, which shortens the life of the hydraulic shock absorber.

The present invention was developed in view of the above-mentioned shortcomings of the prior art, and the present invention is a hydraulic shock absorber that enables the rotary actuator to be fixed while keeping the inside of the casing in a sealed state without using fixing screws or the like. The purpose is to provide a dexterous actuator.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention adopts a means for a hydraulic shock absorber in which the damping force generated by the hydraulic shock absorber is made variable by rotating an operating rod inserted into the piston rod. The actuator includes a casing that is fixed to the tip of the piston rod and forms a closed container with a casing body and a lid, and a rotation shaft that is movably housed in the casing and is connected to the operating rod. a rotary actuator having a stepped portion in an axially intermediate portion; wiring that is led from the rotary actuator to the outside of the casing and supplies voltage to the rotary actuator; A rotary actuator is provided between the stepped portion of the actuator and the upper side of the casing, and pushes the rotary actuator in the axial direction toward the piston rod so as to fix the rotary actuator to the bottom side of the casing. The elastic pressing member has a gap in a part of the circumferential direction, and is twisted such that the distal end side of the gap is spaced apart in the axial direction in a free state to give it springiness. It is characterized by being formed by a circular ring body.

[Effect]

With this configuration, even if the rotary actuator is accommodated in the casing, which is an airtight container, so as to be movable in the axial direction, the rotary actuator will not change from the C-shaped ring state with spring properties. It is fixed in a pressed state against the bottom side of the casing by an elastic pressing member.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 and 2. Note that the same components as those of the prior art described above are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, 31 is a casing, and the casing 31 is composed of a bottomed cylindrical casing body 32 consisting of a bottom portion 32A and a peripheral wall portion 32B, and a lid body 9 that covers the opening side of the casing body 32. ing. Unlike the prior art, no screw insertion holes are formed in the bottom 32A of the casing body 32. The rotary actuator 33 of this embodiment is housed in the casing 31 so as to be movable in the axial direction. It is composed of a transmission section 34 housed on the inner bottom 32A side of the casing 31 in a connected state, and a small diameter motor section 35 located above the transmission section 34 and housed inside the casing 31, The rotary actuator 33 has a stepped portion 33A formed at an arbitrary intermediate position in the axial direction.

36 is an elastic pressing member for fixing the rotary actuator 33 within the casing 31;
The elastic pressing member 36 has an outer diameter smaller than the inner diameter of the casing 31, a height equal to the distance from the step 33A of the rotary actuator 33 to the inner surface of the lid 9, and a part of the circumferential direction. Grommet 2
C is provided with a gap L so as not to come into contact with 2.
It has an annular ring body, and in the free length state, both tip ends 36A, 3 of the elastic pressing member 36
The 6B sides are twisted so as to be spaced apart from each other by a distance H in the axial direction, thereby imparting springiness in the axial direction.

This embodiment is constructed as described above, and its operation as an actuator for a hydraulic shock absorber is not particularly different from that of the prior art.

According to this embodiment, the rotary actuator 33 is housed within the casing 31, and the elastic pressing member 36 is inserted into the casing 31 such that the grommet 22 is positioned within the space L. rear,
The lid 9 is integrally fixed to the casing body 32 by applying the lid 9 from the outside and caulking the open end of the casing body 32 inward.
At this time, the elastic pressing member 36, which is twisted by a distance H in the axial direction, is held between the step portion 33A of the rotary actuator 33 and the lid body 9 while receiving a pressing force, so that the elastic pressing member 36 is twisted by a distance H in the axial direction. The rotary actuator 33 is fixed in a pressed state against the bottom portion 32A of the casing 32 due to the springiness of the rotary actuator 36. Moreover, since the elastic pressing member 36 is provided with a gap L, the wirings 20, 20 are connected from the gap L.
can be easily pulled out horizontally, and each wiring 2
The degree of freedom in the direction of extracting 0 can be increased.

In the above-described embodiment, the rotary actuator 33 was described as consisting of a transmission section 34 and a motor section 35, but the rotary actuator is composed only of a motor section such as a stepping motor. Good too.

[Effect of idea]

The present invention is as described in detail above, and includes a casing formed as a closed container by a casing body and a lid, a rotary actuator accommodated in the casing so as to be movable in the axial direction, and a rotary actuator having spring properties. A configuration in which the rotary actuator is pushed in the axial direction toward the piston rod side so as to fix the rotary actuator to the bottom side of the casing by an elastic pressing member made of a C-shaped ring body. Therefore, the following effects can be achieved.

The rotary actuator can not only be fixed to the bottom side of the casing by means of a ring-shaped elastic pressing member provided between the stepped portion and the upper side of the casing, but also the rotary actuator can be fixed to the bottom side of the casing. There is no need to provide screw holes through which muddy water or the like can enter, and the inside of the casing can be kept completely sealed.

During the manufacturing process, there is no need to align the screw insertion hole of the casing with the screw hole of the rotary actuator, unlike in conventional technology.
It is possible to improve the efficiency of manufacturing work.

Since the elastic pressing member is shaped like a C ring and has a space, the wiring can be easily drawn out laterally from this space, and the degree of freedom in the direction of drawing out the wiring can be increased.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
Fig. 1 is a partial sectional view showing the actuator according to the present embodiment assembled into a hydraulic shock absorber, Fig. 2 is an external perspective view of an elastic pressing member, and Fig. 3 is a conventional actuator mounted on a hydraulic shock absorber. It is a partial sectional view showing an assembled state. 2... Piston rod, 3... Operating rod, 32...
...Casing, 36...Rotary actuator, 34A...Rotating shaft, 36...Elastic pressing member.

Claims (1)

[Scope of utility model registration request] In an actuator for a hydraulic shock absorber, the damping force generated by the hydraulic shock absorber can be varied by rotating an operating rod inserted into the piston rod. a rotary actuator that is housed in the casing so as to be movable in the axial direction, has a rotating shaft connected to the operating rod, and has a stepped portion in the axially intermediate portion; Wiring that is led from the rotary actuator to the outside of the casing and supplies voltage to the rotary actuator, and is provided within the casing between the stepped portion of the rotary actuator and the upper side of the casing. , an elastic pressing member that presses the rotary actuator in the axial direction toward the piston rod so as to fix the rotary actuator to the bottom side of the casing, and the elastic pressing member presses a portion of the rotary actuator in the circumferential direction An actuator for a hydraulic shock absorber, characterized in that the actuator is formed by a C-shaped ring body which has a gap between the two sides and which is twisted so that the front end sides of the gap are spaced apart in the axial direction in a free state to provide spring properties. .