JP3446027B2 - Rotary damper - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic rotary damper that damps external vibrations by utilizing rotational movement, and more specifically, vehicle body vibrations of automobiles, motorcycles, industrial vehicles, special vehicles, or the like, or The present invention relates to safety measures for rotary dampers that dampen external vibrations of other equipment or devices.

[0002]

2. Description of the Related Art Generally, a rotary damper has two sets of hydraulic fluid chambers that alternately contract and expand by a casing having a separate block on the inner wall surface and a vane body press-fitted into a rotor shaft by a keyed connection such as serration. Flowing resistance is given to the hydraulic fluid that moves between these two sets of hydraulic fluid chambers to generate damping torque.

As a flow resistance imparting means for the above-mentioned hydraulic oil, a sealless type means for generating a damping torque while giving a flow resistance by utilizing a sliding contact gap between a casing and a vane body, or There are various types such as a sealed type in which a damping valve is arranged in a communication oil passage that connects two sets of hydraulic oil chambers to each other to generate a damping torque.

[0004]

However, in any of these types of rotary dampers, a linear external vibration is transmitted as a rotational vibration between the casing and the rotor shaft to perform a damping action. At least one of the casing and the rotor shaft is inevitably connected to the external vibrating body, that is, the wheel side or the vehicle body side in the case of a vehicle through a connecting mechanism such as a link.

In addition, in order to keep the damping torque constant (temperature compensation) irrespective of the change in hydraulic oil temperature due to the operation of the rotary damper, the vane body is made of aluminum material having a large linear expansion coefficient, and the like. Other members including the rotor shaft are generally made of an iron-based material having a smaller linear expansion coefficient.

As a result, when the temperature of the rotary damper itself rises and each component expands due to the operation of the rotary damper, the tightening margin of the press-fitted portion due to the key-shaped connection between the rotor shaft and the vane body causes a linear expansion coefficient. And the rotor shaft deviates from the vane body and may come out.

Depending on the structure, even if the bearing does not come out, the bearing is cut by the serration portion provided on the rotor shaft, resulting in a large amount of hydraulic oil leakage and deterioration in damping characteristics. As a result, the supporting strength of the rotor shaft may become insufficient, and eventually the rotor shaft may tilt without breaking and may not be repairable except for the replacement of the rotary damper.

Therefore, an object of the present invention is to provide a rotary damper capable of reliably preventing the rotor shaft from slipping in the direction of coming out of the vane body even if a thrust force is applied to the rotor shaft.

[0009]

DISCLOSURE OF THE INVENTION The above-mentioned object of the present invention is to press-fit a vane body to a rotor shaft by a key-shaped connection and store the vane body in a casing provided with a separate block, and use a bearing to form the casing and the vane body. In the rotary damper in which the rotor shaft is rotatably supported while the vane body and the separate block are partitioned as a hydraulic fluid chamber, the vane body is shifted from the vane body to one side by receiving external input or internal hydraulic fluid pressure. This is achieved by configuring the outer diameter of the support portion on the base end side of the rotor shaft that is about to come out in the opposite direction to be larger than the inner diameter of the protrusion of the key-shaped connection on the vane body side.

What is important is that the outer diameter of the support portion on the base end side of the rotor shaft is made larger than the inner diameter of the protrusion of the key-shaped coupling on the vane body side, so that the influence of external input or internal hydraulic oil pressure, etc. When the rotor shaft tries to come out from the vane body in one direction in response to this, the support portion on the base end side of the rotor shaft interferes with the side surface of the protrusion of the key-shaped connection on the vane body side.

As a result, the side surface of the protrusion of the key-shaped connection of the vane body receives the force of the rotor shaft trying to come out, and the side surface of the protrusion on the side of the vane body is prevented from coming off to prevent the rotor shaft from coming out. It will be.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In describing the embodiments of the present invention with reference to the attached drawings, a case where the present invention is applied to a sealless type rotary damper 1 will be described here.

As shown in FIGS. 1 and 2, the rotary damper 1 includes a housing 2 forming an outer shell and two main parts of a rotor 3 rotatably supported along the axis of the housing 2. It is configured.

The housing 2 is formed into a cylindrical shape by using a material having a high pressure resistance such as cast metal or iron-based sintered bond metal and having excellent sliding property, and a phase difference of 180 degrees is provided on the inner peripheral surface of the casing 4. Thus, two separate blocks 5 and 6 (of course, one or three or more) may be formed.

Both ends of the casing 4 are covered with thick bearings 7 and 8 made of a material such as cast metal or iron-based sinter-bonded metal having excellent pressure resistance and slidability. The rotor shaft 9 is slidably supported while sandwiching the casing 4 from the left and right, and is covered with a packing case 10 and an end cap 11 formed of a thin press material or the like.

Further, between the casing 4 and the bearings 7 and 8, two positioning pins 1 are used by utilizing separate blocks 5 and 6 having a large space in advance.
2 and 13 are inserted, and the positioning pins 12 and 13 secure the concentricity of the casing 4 and the bearings 7 and 8 while also controlling the shift in the rotational direction.

A seal 14 is provided on the outer periphery of the rear surface of the bearing 7, and the casing 4 is sandwiched between the bearing 7 and the other bearing 8 so as to be housed inside together with the end cap 11 from the open end of the packing case 10 and the packing case 10. By crimping the open end of the seal 14, the seal 14 keeps the space between the bearing 7 and the packing case 10 and the end cap 11 oil-tight.

In this case, the packing case 10 is fixed to the casing 4 and the bearings 7 and 8 with an adhesive, and the open end of the packing case 10 is added with the end cap 11 facing. By tightening, not only the detent but also the thrust that pushes and opens the caulked portion by the internal working pressure is also shared.

However, the packing case 10 and the casing 4 may be only the fixing means by the above-mentioned adhesive when the required damping torque is low, but when the required damping torque is high, laser welding or plug is used. The housing 2 may be integrated by being fixed by welding means such as welding.

Further, a mounting member 15 for external connection composed of a nut body or the like is fixed to the outer wall of the packing case 10 by means such as projection welding, and the mounting member 15 is used to connect the housing 2 to the outside. In the case of one of the vibrating bodies, that is, the vehicle, it is connected to the vehicle body side directly or via a link or the like.

On the other hand, the rotor 3 is rotatably supported on both sides by bearings 7 and 8 on the housing 2 side, and a rotor shaft 9 is slidably contacted with the inner wall surfaces of these bearings 7 and 8 and is keyed to the rotor shaft 9. And a vane body 17 integrally connected to each other by using a serration 16 which is one of the above.

The rotor shaft 9 is formed into a predetermined shape by plastic working such as cold forging using an iron-based material having a superior strength, and then the serrations 16 connecting the vanes 17 are sandwiched therebetween. The support portion on the base end side is provided with a vane body 17
The large-diameter portion 18 having an outer diameter larger than the inner diameter of the protrusion of the side serration 16 and the small-diameter portion 19 having a small outer diameter on the other hand are machined to finish the support portion on the tip side. .

The vane body 17 is made of an aluminum material having a larger linear expansion coefficient than the iron-based casing 4 and the bearings 7 and 8, and cooperates with the casing 4 and the bearings 7 and 8. Thus, the sliding contact gap between the rotary damper 1 and the rotary damper 1 is kept as constant as possible regardless of the temperature of the internal hydraulic oil.

In this way, the vane body 17 is pressed into the rotor shaft 9 from the small diameter portion 19 side to the position where the projection of the serration 16 contacts the side surface of the large diameter portion 18, and
The large diameter portion 18 and the small diameter portion 19 are rotatably supported by the bearings 7 and 8, so that the rotor shaft 9 is supported by the vane body 1.
7 is left to prevent the bearing 8 from shifting toward the side.

Therefore, in manufacturing the rotor shaft 9, as shown in FIG. 3, the outer peripheral surface has a large diameter portion 18 having a larger outer diameter than the protrusion of the serration 16 in the vane body 17, and a small outer diameter portion. The small-diameter portion 19 having a diameter is divided into two stages.

Then, the groove of the serration 16 is bored from the boundary between the large diameter portion 18 and the small diameter portion 19 to the middle of the large diameter portion 18, so that the rotor shaft 9 can be easily constructed. It becomes possible to do.

One end of the rotor shaft 9 penetrates the side wall of the packing case 10 and extends to the outside, and the portion projecting to the outside serves as a mounting portion 20 on the other side of the external vibrating body, that is, on the wheel side in the case of a vehicle. The rotor shaft 9 is connected directly or via a link or the like, and the protruding portion of the rotor shaft 9 is kept in an oil-tight state by an oil seal 21 provided in the packing case 10.

The other end of the rotor shaft 9 ends at a portion facing the inside of the end cap 11, and inside the rotor shaft 9, the end cap 11 is formed.
Is provided with a bottomed hollow hole 22 that communicates with the inside and extends along the axial direction.

A free piston 24 having a seal 23 on its outer peripheral surface is movably accommodated in the hollow hole 22, and the free piston 24 connects the hollow hole 22 to the inside of the end cap 11. Chamber 25,
It is partitioned into a gas chamber 26 that is compressed and expanded according to the hydraulic oil pressure of the oil storage chamber 25.

On the other hand, the vane body 17 connected to the rotor shaft 9 by the serrations 16 has vanes 27 and 28 of the same number and the same phase as the separate blocks 5 and 6 of the casing 4 on the housing 2 side provided on the outer peripheral surface. Configured.

The outer peripheral surface of the vane body 17 is in sliding contact with the front end surfaces of the separate blocks 5, 6 on the casing 4 side, and the front end surfaces of the vanes 27, 28 are in sliding contact with the inner wall surface of the casing 4. 6 and the vanes 27 and 28, the hydraulic oil chambers 29 and 30 and the hydraulic oil chamber 3 in which the interior of the rotary damper 1 alternately repeats contraction and expansion with the relative rotational movement of the housing 2 and the rotor 3.
It is divided into 1, 32.

Moreover, in addition to this, the bearings 7, 8
A slight step is provided on the inner wall surface of the vane 27, and the vanes 27, 28 are caused by the thrust force between the housing 2 and the rotor 3 to cause the bearing 7,
In order to prevent it from being strongly pressed against 8, the minute clearances (exaggerated in FIG. 1) 33 and 34 are provided between the vanes 27 and 28 at the step.

The vane 27, 28 has a hydraulic oil chamber 2
Cartridge-type check valves 35, 36, 37, 38 that open toward the 9, 30, 31, 32 side are press-fitted and fixed, respectively, and the rotary damper 1 is rotated in parallel with the check valves 36, 38. Orifice 3 for setting a damping torque ratio that gives a predetermined difference in damping torque depending on the direction
9, 40 are provided.

The check valves 35, 36, 3
Connect the vanes 2 to the inner ends of the orifices 7, 38 and the orifices 39, 40.
The oil passages 41 and 42 provided in the insides of the bearings 7 and 28 are connected to the oil passages 43 and 44 provided at the meshing portion of the serration 16 to the bearing 7
Through the oil passage 45 provided on the bearing surface of the rotor and further through the inside of the end cap 11 to the oil storage chamber 25 in the rotor shaft 9.

A similar oil passage 46 is also provided on the bearing surface of the bearing 8, but the oil passage 46 causes the bearing 8 and the oil seal 21 to leak due to the oil leaking from the contracting high-pressure hydraulic oil chamber. This is for releasing the hydraulic oil pressure trapped between the two to the low-pressure side hydraulic oil chamber that expands.

Thus, the vibration generated in the external vibrating body is
It is transmitted between the mounting member 15 on the housing 2 side of the rotary damper 1 and the mounting portion 20 of the rotor shaft 9 on the rotor 3 side directly and through a connecting mechanism such as a link.

Therefore, the housing 2 and the rotor 3 of the rotary damper 1 cause a relative rotational movement around the axis along with the vibration of the external vibrating body, so that between the separate blocks 5 and 6 and the vanes 27 and 28. The hydraulic oil chambers 29 and 31 and the hydraulic oil chambers 30 and 32 are alternately contracted and expanded.

Now, assuming that the rotary damper 1 is rotated in the direction of contracting the hydraulic oil chambers 29 and 31, the hydraulic oil chambers 29 and 31 contract and the internal hydraulic oil has a high pressure. The hydraulic oil chambers 30 and 32 are expanded so that the internal hydraulic oil has a low pressure.

As a result, the hydraulic oil chambers 29 and 3 which have a high pressure
The hydraulic oil in 1 is generated from the clearances 33, 34 between the bearings 7, 8 and the vanes 27, 28, and in addition to the vanes 27, 28 and the casing 4, the separate blocks 5, 6 and the vane body. The clearances 17 and the bearings 7 and 8 flow toward the expansion-side hydraulic oil chambers 30 and 32, which have a low pressure.

A damping torque is generated by the flow resistance of the hydraulic oil when passing through the above-mentioned clearances, and the damping torque is directly applied from the mounting member 15 of the housing 2 and the mounting portion 20 of the rotor shaft 9 to a link or the like. It acts on the external vibrating body via the coupling mechanism of and damps the vibration generated in the external vibrating body.

On the other hand, when the rotary damper 1 is rotated in the opposite direction to contract the hydraulic oil chambers 30 and 32,
The hydraulic oil in the hydraulic oil chambers 30 and 32 becomes a high pressure and flows toward the hydraulic oil chambers 29 and 31 on the expanding side while flowing in the respective clearances in the opposite directions.

Moreover, in addition to this, the hydraulic oil chambers 30, 3
2 through the orifices 39, 40 for setting the damping torque ratio depending on the rotating direction of the rotary damper 1, the vanes 27, 2
The hydraulic oil is pushed out into the oil passages 41, 42 in the tank 8, and then the check valves 35, 37 are pushed open to flow into the hydraulic oil chambers 29, 31 on the expansion side.

As a result, the flow rate of the hydraulic oil flowing through the above-mentioned clearances is reduced by the orifices 39, 40.
Therefore, the check valves 35 and 37 are pushed open to reduce the flow rate of the operating oil, and a damping torque lower than that in the previous case is generated to damp the vibration of the external vibrating body.

Further, the operating oil chambers 29, 3 are caused by the temperature drop of the operating oil sealed in the rotary damper 1 and external leakage.
When a shortage of hydraulic oil inside 0, 31, 32 occurs, the hydraulic oil in the oil storage chamber 25 is passed from the inside of the end cap 11 through the path formed by the oil passages 45, 44, 43 and the oil passages 42, 41. Check valves 35, 36, 37, 38
Is opened and is sucked into each of the hydraulic oil chambers 29, 30, 31, 32, and the shortage of the hydraulic oil is replenished by an accumulator.

On the contrary, when the hydraulic oil in the hydraulic oil chambers 29, 30, 31, 32 becomes excessive due to the rise of the hydraulic oil temperature, the hydraulic oil in the hydraulic oil chambers 30, 32 is From the damping torque ratio setting orifices 39 and 40, the above paths are passed in the opposite direction and pushed out into the oil storage chamber 25, and excess hydraulic oil is removed to the accumulator, whereby the damping action of the rotary damper 1 is improved. To compensate.

On the other hand, in the above, the reaction force due to the gas pressure of the accumulator acts on the bearing 7 side of the rotor shaft 9, that is, the end surface of the large diameter portion 18 through the working oil in the oil storage chamber 25.

In this case, the rotor shaft 9 has the vane 2
Since 7, 28 are joined by the serration 16 to the vane body 17 sandwiched by the bearings 7, 8,
The joint portion formed by the serration 16 receives the reaction force due to the gas pressure of the accumulator.

However, the rotor shaft 9 and the vane body 17 are made of different materials such as iron-based and aluminum-based materials having different linear expansion coefficients so as to give the temperature compensation function to the rotary damper 1 as described above. Since both of them are configured, as the temperature of the hydraulic oil inside increases, the coupling force by the serrations 16 decreases and the rotor shaft 9 is pushed out.

In this respect, in the present embodiment, the support portion on the base end side of the rotor shaft 9 sandwiching the serration 16 portion has an outer diameter larger than the inner diameter of the protrusion of the serration 16 on the vane body 17 side. As the large diameter portion 18 having
On the other hand, the support portion on the front end side is conversely made as a small diameter portion 19 having a small outer diameter.

As a result, when the vane body 17 is inserted into the rotor shaft 9 from the side of the small diameter portion 19 and press-fitted thereto, when the rotor shaft 9 tries to come out from the vane body 17 toward one side due to the internal hydraulic oil pressure. The large-diameter portion, which is the support portion on the base end side of the rotor shaft 9, is the vane body 17.
It will interfere with the side surface of the protrusion of the serration 16 on the side.

As a result, the side surface of the protrusion of the serration 16 of the vane body 17 receives the force of the rotor shaft 9 trying to come out, and the side surface of the protrusion of the serration 16 of the vane body 17 is prevented from coming off to allow the rotor shaft 9 to move. It will surely prevent you from getting out.

Although it is possible to assume that a pulling external force in the same direction as above is applied through the mounting portion 20 of the rotor shaft 9, it goes without saying that the external force can be dealt with in the same manner.

On the contrary, even if a pushing force is applied to the rotor shaft 9 from the mounting portion 20, the magnitude of the input in that case is an extremely small value as compared with the input by the gas pressure on the accumulator side. Because of this, it is not possible to push in the rotor shaft 9.

Therefore, the rotor shaft 9 does not shift to the oil storage chamber 25 side of the accumulator, and therefore, as a measure for preventing the rotor shaft 9 from coming off, only the portion of the rotor shaft 9 on the oil storage chamber 25 side is illustrated. It should be provided.

[0055]

As described above, according to the first aspect of the present invention, the support portion on the base end side of the rotor shaft that tends to come out from the vane body in one direction in response to an external input, an internal hydraulic oil pressure, or the like. By configuring the outer diameter of the rotor to be larger than the inner diameter of the protruding portion of the key-shaped connection on the vane body side, the force of the rotor shaft trying to come out is received by the side surface of the protruding portion of the key-shaped connection of the vane body, and It is possible to reliably prevent the rotor shaft from slipping out by using the side surface of the protrusion as a stopper.

According to the second aspect of the present invention, the outer peripheral surface of the rotor shaft into which the vane body is press-fitted by the key-shaped connection has a large diameter portion having a larger outer diameter and a smaller outer diameter than the protrusion of the key-shaped coupling. In addition to the above effect, it is divided into two stages with a small diameter part and a groove for key type coupling is formed from the boundary part between these large diameter part and small diameter part to the middle of the large diameter part. Thus, the rotor shaft originally formed by cold forging can be formed without machining such as cutting, that is, without extending the processing time.

[Brief description of drawings]

1 shows an embodiment of a rotary damper to which the present invention is applied, and is a developed vertical sectional front view taken along line AA of FIG.

FIG. 2 is a vertical sectional side view showing the relationship between the housing and the rotor.

FIG. 3 is a front view showing a rotor shaft taken out and longitudinally cut.

[Explanation of symbols]

1 rotary damper 2 housing 3 rotor 4 casing 5,6 separate block 7,8 bearing 9 rotor shaft 16-key type serration 17 vanes 18 Large diameter part of rotor shaft 19 Small diameter part of rotor shaft 24 Free piston 25 oil storage room 26 gas chamber 27,28 vanes 29, 30, 31, 32 Hydraulic oil chamber

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chihori Horiba 2-4-1, Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Mitsuhiro Tabata 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Masaharu Oba 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (56) Reference JP-A-5-26278 (JP, A) JP-A-9-310730 ( JP, A) Actual Kaihei 7-12643 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 9/14

Claims (2)

(57) [Claims] 1. A vane body is press-fitted into a rotor shaft by a key-shaped connection to be housed in a casing equipped with a separate block, and the rotor shaft is rotatable while bearings sandwiching the casing and the vane body from both sides. In a rotary damper that supports and partitions the vane body and the separate block as a hydraulic oil chamber, the base end side of the rotor shaft that tends to come out from the vane body in one direction by receiving external input or internal hydraulic oil pressure. A rotary damper, wherein an outer diameter of the support portion is larger than an inner diameter of a protrusion of the key-shaped connection on the vane body side. 2. An outer peripheral surface of a rotor shaft into which a vane body is press-fitted by a key-shaped connection is divided into two stages, a large-diameter portion having an outer diameter larger than a protrusion of the key-shaped connection and a small-diameter portion having a smaller outer diameter. 2. The rotary damper according to claim 1, wherein the rotary damper is formed separately and a key-shaped coupling groove is formed from the boundary between the large-diameter portion and the small-diameter portion to the middle of the large-diameter portion.