JPH11173360A - Hydraulic shock absorber cooling mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a damper oil from being heated and the loss of damping characteristics when a violent stroke is repeated. SOLUTION: In an inversion type strut damper 1 constituted in such a way that a lubrication oil is filled in a lubrication oil chamber S3 formed between an inner face of an outer tube 3 and an outer face of an inner tube 4, the slide of the inner tube 4 is made smooth by this lubrication oil, and a damper oil and a piston 7 are internally mounted inside the inner tube 4 to generate damping force, a cooling circulation passage 10 is connected with the lubrication oil chamber S3 to cool the lubrication oil by a cooling mechanism 2 so as to prevent the damper oil in the inner tube 4 from being heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydraulic shock absorber in which a lubricating oil chamber is defined between an outer tube and an inner tube.

[0002]

2. Description of the Related Art For example, in a strut damper of a vehicle running under severe conditions such as a race and a rally, damping characteristics are deteriorated due to a decrease in viscosity of damper oil due to heating of the damper. To prevent this problem, Japanese Patent Application Laid-Open
A hydraulic shock absorber with a cooling mechanism disclosed in JP-A-8-37572 or JP-B 64-1128 is known.
Among them, Japanese Patent Application Laid-Open No. 48-37572 discloses an oil storage chamber formed by providing an outer cylinder outside a cylinder containing oil and a piston so that the oil storage chamber can communicate with the inside of the cylinder. It is cooled by connecting to a cooler.
In Japanese Utility Model Publication No. 64-1128, a water jacket is provided on the outer periphery of a damper, and cooling water is introduced into the water jacket to cool oil in the damper.

[0003]

The problem to be solved by the present invention is disclosed in
In JP-A-37572, after the oil in the cylinder enters the oil storage chamber on the outer periphery of the cylinder, the oil in the oil storage chamber is introduced into the cooler to be cooled, so that the oil heated in the cylinder enters the storage chamber. The temperature of the cylinder tends to increase as a whole, and there is a problem in terms of the cooling effect. In addition,
In Japanese Patent No. 1128, since the water jacket is provided on the outer peripheral portion of the damper, there is a problem that the damper is large and heavy.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an inner surface of an outer tube and an outer surface of an inner tube which is slidably inserted into the outer tube and has at least a damper oil and a piston inside. In a hydraulic shock absorber that defines a lubricating oil chamber through an oil seal between the lubricating oil chamber, the lubricating oil inside is drawn out to the outside, sent to the cooling mechanism, and cooled by the cooling mechanism. A cooling circuit was sent back to the lubricating oil chamber.

[0005] That is, a damping force generating mechanism is formed at least by the damper oil and the piston in the inner tube. Under severe conditions where the piston slides repeatedly, the damper oil is heated and the damper function deteriorates. However, by cooling the lubricating oil in the lubricating oil chamber surrounding the inner tube, the damper oil in the inner tube can be effectively cooled, and the original lubricating effect can be enhanced. Here, the lubricating oil is an oil for smoothing the sliding of the inner tube, and has a high cooling effect because it is separate from the internal damper oil. Also, for example, by pressurizing the lubricating oil, it is possible to change the friction of the oil seal with respect to the inner tube and control the damping force.

Here, if the cooling mechanism is of an air-cooling type, it can be simply configured without increasing the weight. Further, an oil amount measurement unit that can visually check the oil amount of the lubricating oil may be provided in the cooling mechanism or the cooling circulation path. In this case, as the oil amount measurement unit, for example, a transparent pipe or the like that can see through the oil level in the vicinity of the cooling mechanism or the cooling circulation path is provided, and when the oil amount is small, replenishment and the like can be appropriately performed. .

[0007] A lubricating oil tank may be provided in the middle of the cooling circuit. By providing the lubricating oil tank in this manner, the total oil amount of the lubricating oil line increases, so that cooling can be performed efficiently and a situation in which lubricating oil is insufficient can be avoided. It is preferable to apply such a hydraulic shock absorber with a cooling mechanism to an inverted strut damper.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a structural example of a hydraulic shock absorber with a cooling mechanism according to the present invention, FIG. 2 is another structural example of a cooling mechanism, and FIG. 3 is a structural example in which a lubricating oil tank is provided in the middle of a cooling circuit. .

A hydraulic shock absorber with a cooling mechanism according to the present invention comprises:
As shown in FIG. 1, the lubricating oil applied to the inverted strut damper 1 is cooled by a cooling mechanism 2 in a lubricating oil chamber S3 to be described later. Deterioration can be effectively prevented.

The inverted strut damper 1 is constructed by slidably inserting an inner tube 4 from above into an outer tube 3 below, and a lower end of the outer tube 3 is connected to a wheel through a knuckle (not shown). Mounted on
The upper end of the inner tube 4 is attached to the vehicle body.

A free piston 5 is provided in an upper portion of the inner tube 4, and is separated into an upper gas chamber S1 and a lower oil chamber S2. A damper oil is sealed in the oil chamber S2, and a lower end is provided. A piston rod 6 fixed to the outer tube 3 is inserted from below, and an oil chamber S2 is further defined as an upper and lower oil chamber by a piston 7 fixed to an upper end of the piston rod 6. The upper and lower oil chambers communicate with each other through an oil hole formed in the piston 7, and a damping force generating mechanism is provided in the oil hole.

Further, between the inner surface of the outer tube 3 and the outer surface of the inner tube 4, and above and below,
An upper oil seal 8 and a lower oil seal 9 are respectively disposed adjacent to the upper and lower guide bushes g, g, and a lubricating oil chamber S is formed by the inner surface of the outer tube 3, the outer surface of the inner tube 4, the upper oil seal 8 and the lower oil seal 9.
3 is formed and the inside is filled with lubricating oil.

In the lubricating oil chamber S3, a cooling circuit 10 for circulating the lubricating oil therein and cooling it by the cooling mechanism 2 is provided.
Is connected. An oil pump 11 is provided in the middle of the cooling circuit 10.

The cooling mechanism 2 is of an air-cooling type, for example, an oil cooler in which corrugated radiating fins or the like are laminated as shown in FIG. 1 or a simple spiral winding of an oil passage tube as shown in FIG. The type is optional, such as an oil cooler with an increased heat dissipation area.

Further, in the configuration example shown in FIG.
Is provided with an oil amount measuring unit 12. This oil amount measuring unit 12
Connects the oil level measuring pipe 13 made of a transparent material to the oil passage pipe of the cooling mechanism 2 and visually checks the oil level so that the amount of lubricating oil in the lubricating oil chamber S3 can be appropriately managed. . Note that such an oil amount measurement unit 12 may be provided in the cooling circulation path 10.

The operation of the inverted strut damper 1 as described above will be described. When the compression stroke starts from the state of maximum extension shown in FIG. 1, the inner tube 4 enters the outer tube 3, and at the same time, the piston 7 The inner tube 4 slides relatively upward. With the upward movement of the piston 7, the damper oil in the upper oil chamber flows into the lower oil chamber via an oil hole provided in the piston 7, and a damping force is generated at this time. Since the damper oil is an incompressible liquid, the invading volume of the piston rod 6 during the compression stroke is absorbed by the compression of the gas chamber S1. Further, in the extension stroke, the damper oil in the lower oil chamber becomes
And flows into the upper oil chamber through the oil hole provided in the oil tank, and a damping force is generated at this time.

In the above-described compression stroke and expansion stroke, the sliding of the inner tube 4 is smoothly performed by the lubricating oil filled in the lubricating oil chamber S3. When the piston 7 slides violently, the temperature of the damper oil in the inner tube 4 rises and the damping characteristics deteriorate.

Therefore, in the present invention, the lubricating oil is circulated by the oil pump 11 of the cooling circuit 10, cooled by the cooling mechanism 2, and then returned to the lubricating oil chamber S3. For this reason, the damper oil in the inner tube 4 is cooled by the lubricating oil, thereby suppressing a problem that the damping characteristics are deteriorated. By the way, if the cooling mechanism 2 is provided at a place where air circulation is good due to traveling or the like, the cooling effect can be enhanced. Although the lubricating oil is circulated using the oil pump 11 in the embodiment, the oil pump 11
May be omitted and natural circulation may be performed based on the temperature difference.

When the lubricating oil is circulated, if the amount of lubricating oil is found to be insufficient in the oil amount measuring unit 12, the oil is supplied from the oil supply unit 14, for example.

Incidentally, by utilizing the lubricating oil in the lubricating oil chamber S3, the binding force between the upper and lower oil seals 8, 9 with respect to the inner tube 4 is changed, so that the sliding of the inner tube 4 is moderately braked. You may do it. That is, when the pressure of the lubricating oil in the lubricating oil chamber S3 is increased, the oil seal 8, which defines the lubricating oil chamber S3,
9, the lubricating oil pressure in the lubricating oil chamber S3 is changed through the pressurizing unit 15 in accordance with, for example, the vehicle speed, the steering angle, the brake operation, and the like. Let it.

FIG. 3 shows an example of a configuration in which a lubricating oil tank 16 is provided in the middle of the cooling circulation path 10. In this case, it is possible to prevent a problem that the amount of lubricating oil in the lubricating oil chamber S3 is insufficient, and to increase the total amount of oil in the lubricating oil line, thereby further improving the cooling effect.

In the illustrated example, an inverted strut damper is shown, but the hydraulic shock absorber to which the present invention is applied is not limited to this, and any hydraulic shock absorber having a lubricating oil chamber may be used. It can be applied to any type.

[0023]

According to the present invention as described above,
In a hydraulic shock absorber in which a lubricating oil chamber is defined via an oil seal between the inner surface of the outer tube and the outer surface of the inner tube, lubricating oil in the lubricating oil chamber is sent to the cooling mechanism through a cooling circuit to lubricate the cooled oil. Since the oil is sent back into the oil chamber, the damper oil can be effectively cooled even under severe conditions in which the piston slides violently and repeatedly, and the damping characteristics can be maintained well.
In addition, since cooling is performed by utilizing the lubricating oil in the existing lubricating oil chamber, the structure can be simplified without increasing the size and weight,
The cooling of the lubricating oil also improves the original lubricating performance.

Here, if the cooling mechanism is of an air-cooling type, it can be simply constructed without increasing the weight, etc., and an oil amount measuring unit for visually checking the amount of lubricating oil in the cooling mechanism or the cooling circuit. Is provided, the amount of lubricating oil can be appropriately managed. If a lubricating oil tank is provided in the middle of the cooling circuit, the total oil amount in the lubricating oil line increases, so that cooling can be performed efficiently and a situation such as a shortage of lubricating oil can be avoided. It is preferable to apply such a hydraulic shock absorber with a cooling mechanism to an inverted strut damper.

[Brief description of the drawings]

FIG. 1 is a structural example diagram of a hydraulic shock absorber with a cooling mechanism according to the present invention.

FIG. 2 is a diagram showing another example of the configuration of a cooling mechanism.

FIG. 3 is a configuration example diagram in which a lubricating oil tank is provided in the middle of a cooling circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inverted strut damper, 2 ... Cooling mechanism, 3 ... Outer tube, 4 ... Inner tube, 7 ... Piston,
8 ... upper oil seal, 9 ... lower oil seal, 10 ...
Cooling circulation path, 12: oil amount measuring section, 16: lubricating oil tank, S3: lubricating oil chamber.

Claims (5)

[Claims] A lubricating oil chamber is defined via an oil seal between an inner surface of an outer tube and an outer surface of an inner tube slidably inserted into the outer tube and having at least damper oil and a piston therein. A cooling circuit connected to the lubricating oil chamber, wherein the lubricating oil chamber draws out the internal lubricating oil to the outside, sends it to the cooling mechanism, and sends back the oil cooled by the cooling mechanism to the lubricating oil chamber. A hydraulic shock absorber with a cooling mechanism. 2. The hydraulic shock absorber with a cooling mechanism according to claim 1, wherein the cooling mechanism is air-cooled. 3. The hydraulic shock absorber with a cooling mechanism according to claim 1 or 2, wherein the cooling mechanism or the cooling circulation path is provided with an oil amount measuring unit capable of visually confirming an oil amount of lubricating oil. A hydraulic shock absorber with a cooling mechanism. 4. The hydraulic shock absorber with a cooling mechanism according to claim 1, wherein:
A hydraulic shock absorber with a cooling mechanism, wherein a lubricating oil tank is provided. 5. The hydraulic shock absorber with a cooling mechanism according to claim 1, wherein the hydraulic shock absorber is an inverted strut damper.