JPH0640343Y2 - Hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a variable damping force type pressure damper suitable for use as a suspension of a model automobile such as a radio control (radio control).

[Conventional technology and its problems]

It can be said that a hydraulic shock absorber used in a model car such as a radio-controlled model can be obtained by directly reducing the size of the hydraulic shock absorber used in a general car.
In the structure of the variable damping force type disclosed in Japanese Patent Laid-Open No. 57240, there are inconveniences such as difficulty in implementation and inconvenience in use.

That is, in the hydraulic shock absorber disclosed in Japanese Utility Model Publication No. 57-57240, two oil chambers in a cylinder defined by a piston communicate with each other through a bypass oil passage formed in a piston rod that carries the piston. A damping force adjusting member having a plurality of orifices having different diameters is arranged at the mouth end of the bypass oil passage so that one of these orifices selectively opposes.

Then, with the hydraulic shock absorber in the most extended state, the damping force adjusting member is applied to the fully-extending cushion in the cylinder, and the piston rod is moved while the rotation of the damping force adjusting member is blocked by the frictional resistance between the cushion and the cushion. When the rotary operation is performed, the mouth end of the bypass oil passage on the piston rod side is selectively communicated with the plurality of orifices of the damping force adjusting member by the relative rotation generated between the piston rod and the damping force adjusting member. By doing so, the damping force is changed.

Therefore, by reducing the size of the hydraulic shock absorber configured as described above and downsizing, it is possible to provide a damping force adjusting hydraulic shock absorber for a model automobile such as a radio-controlled model.

However, in the above-mentioned conventional hydraulic shock absorber, since it is necessary to rotate the piston rod or the working cylinder having the connecting bracket in adjusting the damping force, it is necessary to move the connecting bracket to the vehicle body. I have to remove the mounting pins of the
There is an inconvenience that the damping force cannot be easily adjusted in the state of being built in the vehicle body.

In addition to this, in the hydraulic shock absorber of a model car with a light weight, since the shock at the time of full extension is extremely small, it is not necessary to provide a cushion for full extension, rather this is abolished and the hydraulic shock absorber is eliminated. It is more advantageous to shorten the total length of itself, and because of this, it is difficult to obtain a large frictional resistance that blocks the rotation of the damping force adjusting member, which makes it difficult to reliably perform the damping force adjusting operation. Occurs.

This invention was created in view of the above circumstances,
The purpose is not only to reduce the size of the original structure of the hydraulic shock absorber but also to change the damping force with a simple operation without removing the hydraulic shock absorber from the vehicle body. In particular, it is to provide a hydraulic shock absorber most suitable for use as a model car such as a radio controlled car.

[Means for Solving the Problems]

In the present invention, the above-mentioned object is to attach a rod guide holder member fixed to one end of the outer cylinder and a other end to the other cylinder type hydraulic shock absorber having a reservoir chamber between the inner cylinder and the outer cylinder. The cap and the outer cylinder are configured to be rotatable relative to the inner cylinder, and a connecting bracket is provided on the bottom portion of the inner cylinder.

Then, the holder member on the outer cylinder side is provided with a notch hole and a port communicating with the notch hole, and the inner cylinder side is selectively opposed to the port on the inner cylinder side with the relative rotation of the outer cylinder with respect to the inner cylinder. This is achieved by disposing a plurality of communicating orifices and communicating the rod-side oil chamber of the inner cylinder with the reservoir chamber through one of the notch hole and the port and the selected orifice.

[Action]

That is, by adopting the above configuration, during the compression stroke of the hydraulic shock absorber, like the conventional hydraulic shock absorber,
The hydraulic oil in the head side oil chamber opens the piston check valve and flows into the rod side oil chamber.

In parallel with this, an amount of hydraulic oil equivalent to the intrusion volume of the piston rod into the rod-side oil chamber is directly supplied from the head-side oil chamber to the reservoir chamber through the orifice provided at the end of the inner cylinder on the connecting bracket side. To generate a compression side damping force by the flow resistance of the hydraulic oil flowing through this orifice.

During the expansion stroke of the hydraulic shock absorber, the hydraulic oil in the reservoir chamber is sucked into the head-side oil chamber through the orifice, and the hydraulic oil in the rod-side oil chamber is selected along with the relative rotation of the outer cylinder with respect to the inner cylinder. The extruded side damping force is generated by the flow resistance of the hydraulic oil passing through the selected orifice and pushing out into the reservoir chamber.

Moreover, the diameter of the orifice arranged in the communication passage from the rod side oil chamber to the reservoir chamber side is selected, that is, the flow resistance of the hydraulic oil passing through the orifice is determined by removing the mounting pin of the connecting bracket. Without the need to remove the hydraulic shock absorber from the vehicle body, simply by rotating the outer cylinder from the outside.

As a result, the extension side damping force can be changed easily and reliably by rotating the outer cylinder during the extension stroke of the hydraulic shock absorber.

Further, even when enabling the changing operation of the extension side damping force, a special member is not required, and the outer cylinder and the inner cylinder may be configured to be relatively rotatable, so that the hydraulic shock absorber can be downsized. Especially, it is most suitable for use as a radio control.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

As shown in FIG. 1, a hydraulic shock absorber according to an embodiment of the present invention includes an outer cylinder 1, an inner cylinder 4 arranged coaxially inside the outer cylinder 1, and an inside of the inner cylinder 4. The piston rod 2 is inserted into and removed from the piston rod 2, and the piston 3 is attached to the base end of the piston rod 2 so as to be in sliding contact with the inner peripheral wall of the inner cylinder 4.

A slide metal 13 for guiding the piston rod 2 is arranged at one end (left end in the figure) of the outer cylinder 1, and the slide metal 13 is supported by a holder member 12 which is caulked to the outer cylinder 1. .

An O-ring 11 is interposed between the outer cylinder 1 and the holder member 12, and an O-ring 14 is also interposed between the piston rod 2 and the holder member 12.

The O-ring 14 is pressed by the cap 15 which is locked to the holder member 12 by the snap ring 16.
11, 14 seals the protruding end side of the piston rod 2 of the outer cylinder 1.

On the other hand, the inner cylinder 4 includes a bottom portion 4a that closes the base end, and an O-ring 4b between the bottom portion 4a and the outer cylinder 1 is interposed between the other end (right end in the figure) of the outer cylinder 1 and The O-ring 4b is inserted inside while keeping the coaxial state, and the other end of the outer cylinder 1 is also sealed.

Further, the open end side of the inner cylinder 4 is rotatably fitted to a support portion 12a formed with respect to the holder member 12, whereby a hydraulic oil storage space is provided between the outer cylinder 1 and the inner cylinder 4. A reservoir chamber C is formed for use therein, and an air bag 41 for compensating the volume of the hydraulic oil is housed in the reservoir chamber C.

Thus, the inside of the inner cylinder 4 is partitioned by the holder member 12 in cooperation with the bottom portion 4a, and is partitioned by the piston 3 inserted into the inner cylinder 4 into the head side oil chamber A and the rod side oil chamber B. ing.

The air bag 41 prevents the mixing of the hydraulic oil and air in addition to the volume compensating action of the hydraulic oil, and enables the use as an inverted type in which the hydraulic shock absorber is attached with the piston rod 2 facing downward. .

A threaded portion 1a is formed on the outer peripheral surface of the other end of the outer cylinder 1, and a cap 17 is screwed onto the threaded portion 1a to rotatably support the bottom portion 4a of the inner cylinder 4. The outer cylinder 1 and the inner cylinder 4 can be rotated relative to each other by the cooperative action of the holder 17 and the holder member 12.

From the central part of the cap 17, a connecting bracket 4c penetrating the part and integrally formed with the bottom part 4a of the inner cylinder 4 is projected to the outside, and the other connecting bracket 21 facing the connecting bracket 4c. Is provided on the projecting end side of the piston rod 2, and the hydraulic shock absorber is attached to a model automobile or the like through these connecting brackets 4c and 21.

A cutout hole 12b and a port 12c communicating with the cutout hole 12b are formed in the support portion 12a of the holder member 12, and the port 12c is formed by the relative rotation of the outer cylinder 1 and the inner cylinder 4. Are selectively communicated with a group of orifices 4d, 4e ...

That is, in the case of this embodiment, as shown in FIG. 2, four orifices having different diameters are provided on the tip side of the inner cylinder 4.
4d, 4e, 4f and 4g are arranged side by side in the circumferential direction.

These orifices 4d to 4g are ports on the holder member 12 side that rotate together with the outer cylinder 1 when the outer cylinder 1 and the inner cylinder 4 rotate relative to each other.
The rod side oil chamber B in the inner cylinder 4 is communicated with the reservoir chamber C through the cutout hole 12b, the port 12c and one of the selected orifices 4d to 4g.

On the other hand, the body portion 31 of the piston 3 is provided with a pressure side port 31a which penetrates the body portion 31 in the axial direction and communicates the head side oil chamber A and the rod side oil chamber B with each other.
A check valve 32 is provided at the outlet of the rod side oil chamber B.

A valve stopper 34 is provided on the piston rod 2 so as to face the check valve 32.
A non-return spring 33 interposed between the valve stopper 34 and the valve stopper 34 urges the piston 3 toward the main body portion 31 side.

Further, on the side wall of the inner cylinder 4 on the bottom portion 4a side, an orifice 4h is provided penetrating the inner cylinder 4, and the head side oil chamber A in the inner cylinder 4 is directly connected to the reservoir chamber C through the orifice 4h. It is in communication.

Thus, during the compression stroke of the hydraulic shock absorber, the hydraulic oil in the head side oil chamber A opens the check valve 32 of the piston 3 and flows into the rod side oil chamber B, and in parallel with this, the rod side oil chamber A A quantity of hydraulic oil corresponding to the intrusion volume of the piston rod 2 into B flows directly from the head side oil chamber A into the reservoir chamber C through the orifice 4h provided on the side wall of the inner cylinder 4 on the bottom portion 4a side, A compression side damping force is generated by the flow resistance of the hydraulic oil passing through the orifice 4h.

Further, during the expansion stroke of the hydraulic shock absorber, the working oil in the reservoir chamber C is sucked into the head side oil chamber A through the orifice 4h provided on the side wall of the inner cylinder 4 on the bottom portion 4a side, and at the same time as the rod side. The working oil in the oil chamber B is transferred to the holder member.
Along with the relative rotation of the outer cylinder 1 with respect to the port 12c and the inner cylinder 4 from the notch hole 12b provided in 12, it is pushed out into the reservoir chamber C through one of the orifices 4d to 4g having different diameters selected, and passes through this selected orifice. The extensional damping force is generated by the flow resistance of hydraulic oil.

Moreover, the selection of the orifices 4d to 4g having different diameters, in other words, the flow resistance of the hydraulic oil passing through the orifices, is to remove the hydraulic shock absorber from the vehicle body without removing the mounting pins of the connecting brackets 4c and 21. Instead, simply rotating the outer cylinder 1 together with the holder member 12 from the outside and switching the communication of the port 12c with the orifices 4d to 4g on the inner cylinder 4 side.

As a result, the extension side damping force can be changed easily and reliably by rotating the outer cylinder 1 during the extension stroke of the hydraulic shock absorber.

In this embodiment, the detent mechanism 5 using the snap ring 51 as shown in FIG. 3 is provided between the cap 17 screwed on the outer cylinder 1 and the bottom portion 4a on the inner cylinder 4 side. It is provided.

The snap ring 51 is fitted in the groove 17a formed on the outer periphery of the cap 17, and is formed in a split ring shape as a whole, and both ends 51b thereof are formed in the raised portion 17c left when the groove 17a is formed. It is locked by abutting.

The center portion of the snap ring 51 has a bent portion 51a at the portion by being bent inward, and an opening 17b formed by penetrating the tip of the bent portion 51a from the groove 17a through the thickness of the cap 17 is formed. It contacts the outer peripheral surface of the bottom portion 4a of the inner cylinder 4 through.

On the outer peripheral surface of the bottom portion 4a, the holder member 12 described above is provided.
Orifice 4 on the inner cylinder 4 side that selectively communicates with port 12c of
Corresponding to d to 4g, concave portions 4i, 4j, 4k, 4l into which the bent portion 51a of the snap ring 51 is selectively fitted are formed.

As a result, when the outer cylinder 1 is rotated, the holder member 12 and the cap 17 rotate together, and the tip of the bent portion 51a of the snap ring 51 provided on the cap 17 is formed on the bottom portion 4a of the inner cylinder 4. The recesses 4i to 4l are selectively fitted and the outer cylinder 1 is locked at these four positions.

Moreover, since these recesses 4i to 4l are positioned corresponding to the orifices 4d to 4g on the inner cylinder 4 side as described above, the port 12c of the holder member 12 is located at the inner cylinder 4 at the above-mentioned four positions.
The orifices 4d to 4g on the side are selectively communicated with each other, whereby the extension side damping force is changed.

[Effect of device]

As described above, according to the present invention, the piston rod and the attachment pin of the connecting bracket provided at the end of the inner cylinder are not removed, that is, the hydraulic shock absorber is not removed from the mounted object, and the There is an advantage that the damping force can be changed by a simple operation of turning the cylinder.

Further, since the outer cylinder and the inner cylinder are simply configured to be relatively rotatable without requiring a special member when changing the damping force, the hydraulic shock absorber can be downsized. It can be optimized for use as a radio control.

[Brief description of drawings]

1 is a front view showing a partial cross-section of a hydraulic shock absorber according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. III in Fig. 1
It is a transverse cross-sectional view from the line III. [Explanation of Codes] 1 ... Outer cylinder, 2 ... Piston rod, 3 ... Piston section 4, Inner cylinder, 4a ... Bottom section, 4c ... Connection bracket 4d ... Orifice, 4e ... Orifice, 4f ... Orifice 4g ... Orifice, 12 ... Holder member, 12b ... Notch hole 12c ... Port, 17 ... Cap, A ... Head side oil chamber B ... Rod side oil chamber, C ... Reservoir chamber

Claims (1)

[Scope of utility model registration request] 1. A double-cylinder type hydraulic shock absorber having a reservoir chamber between an inner cylinder and an outer cylinder, wherein a rod guide holder member fixed to one end of the outer cylinder and a cap attached to the other end The outer cylinder is configured to be rotatable relative to the inner cylinder, the connecting bracket is provided on the bottom portion of the inner cylinder, and the holder member on the outer cylinder side is provided with the notch hole and the port communicating with the notch hole. On the cylinder side, a plurality of orifices that face the port and selectively communicate with the relative rotation of the outer cylinder with respect to the inner cylinder are provided, and the rod of the inner cylinder is passed through one of the notch hole, the port, and the selected orifice. A hydraulic shock absorber characterized in that the side oil chamber communicates with the reservoir chamber.