JPS625923Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic shock absorber with a vehicle height adjustment mechanism, and more specifically, one end of a rolling diaphragm is attached to the outer periphery of a cylinder constituting the hydraulic shock absorber, and the other end of the rolling diaphragm is attached to the outer periphery of a cylinder constituting the hydraulic shock absorber. It is assembled to the lower end opening of a cylinder fixed to the outer periphery of the piston rod that passes through an oil seal that seals the upper end opening of the cylinder and a seal cover that covers the oil seal, and the rolling diaphragm and the cylinder seal the outer periphery of the cylinder and piston rod. An air chamber is formed which is connected to an air pressure source through an air passage provided in the piston rod, and by adjusting the air pressure in the air chamber, the cylinder and the piston rod are moved up and down relative to each other to adjust the vehicle height. This article relates to a hydraulic shock absorber with a vehicle height adjustment mechanism.

In this type of hydraulic shock absorber with a vehicle height adjustment mechanism, when the air pressure in the air chamber falls below a predetermined pressure, the rolling diaphragm moves between the cylinder and the cylindrical body when the hydraulic shock absorber with a vehicle height adjustment mechanism is activated. Since there is a risk of the air getting caught and bursting in a short period of time, it is necessary to prevent the air pressure in the air chamber from falling below a predetermined value (guaranteeing the minimum pressure). By the way, in order to cope with such a demand, it is sufficient to install a valve in the airline connecting the air chamber and the air pressure source (usually an air compressor) to ensure that the air pressure is above a predetermined value. If the installation location is close to the air pressure source, there may be air leakage from the dryer, control valve, air tube, etc. in the air line leading from this valve to the air chamber, and the air pressure in the air chamber may be reduced to the lowest pressure. cannot be guaranteed.

An object of the present invention is to provide a device that can guarantee the air pressure in the air chamber to be the lowest pressure regardless of air leakage from the dryer, control valve, air tube, etc. In order to achieve such an object, in the present invention, a compressed gas of a predetermined pressure is housed in the air passage provided in the piston rod, and the air pressure from the air chamber and the air pressure source is received on the outside surface, and the piston rod is pushed by this air pressure. A gas bag was inserted, which contracts to open the air passage when the pressure is above a set value, and expands to close the air passage when the pressure is less than the set value. As a result, in this invention, the dryer,
Regardless of air leakage from the control valve, air tube, etc., the air pressure in the air chamber can be reliably guaranteed to be the lowest pressure, and bursts due to the rolling diaphragm can be prevented.

Hereinafter, the present invention will be explained based on the drawings. FIG. 1 shows an embodiment of a hydraulic shock absorber with a vehicle height adjustment mechanism according to the present invention. In this hydraulic shock absorber with a vehicle height adjustment mechanism (hereinafter sometimes simply referred to as a hydraulic shock absorber), the cylinder 10 has its lower end attached to an unsprung member of the vehicle, and both the inner and outer cylinders 1
1 and 12, and includes a first oil chamber R1 formed in the inner cylinder 11 and an annular second oil chamber R2 formed between the two cylinders 11 and 12. These oil chambers R1 and R2 can communicate with each other through a known base valve 13 provided at the bottom of the cylinder 10. The piston rod 20 has an upper end mounted on a sprung member of a vehicle, and has a known piston 21 and a piston valve 22 at its lower end. This piston rod 20 has a piston 21
is slidably inserted into the inner tube 11 of the cylinder 10, and a rod guide 14 and a rubber oil seal 1 are fixed to the upper end opening of the cylinder 10.
5 and a seal cover 16 that covers this. Further, the piston 21 divides the first oil chamber R1 into upper and lower chambers. As a result, in this hydraulic shock absorber, during the compression stroke, the hydraulic oil in the lower chamber of the first oil chamber R1 flows into the second oil chamber R2 through the base valve 13, and flows into the upper chamber of the first oil chamber R1 through the piston valve 22. and generates a damping force. Further, during the extension stroke, the hydraulic oil in the second oil chamber R2 flows into the lower chamber of the first oil chamber R1 through the base valve 13, and the hydraulic oil in the upper chamber of the first oil chamber R1 flows through the piston valve 22 into the first oil chamber R1. It flows into the lower chamber of chamber R1 and generates a damping force.

On the other hand, a rolling diaphragm 31 made of rubber and reinforced with reinforcing cloth constituting a vehicle height adjustment mechanism is fitted to the outer periphery of the outer cylinder 12 of the cylinder 10. One end of this rolling diaphragm 31 is connected to the outer cylinder 12. 12 is tightened and fixed to the outer periphery of the upper end.
Further, the other end of the rolling diaphragm 31 is folded back and extended upward, and is fastened and fixed to the lower end opening of a cylindrical body 32 that is fixed to the outer periphery of the piston rod 20 and hangs down. As a result, cylinder 1
An air chamber R3 is formed on the outer periphery of the outer cylinder 12 and the outer periphery of the piston rod 20, and an air passage 23 provided in the piston rod 20 opens into this air chamber R3. This air passage 23 is connected to an air compressor 46 via an air tube 41, an air supply/exhaust valve 42, an air tube 43, a dryer 44, and an air tube 45. In addition, the number 4 in the figure
Reference numeral 7 indicates an exhaust valve that constitutes an air pressure supply control device including the supply and exhaust valve 42, the air compressor 46, and the like. As a result, in the hydraulic shock absorber,
By adjusting the air pressure in an air chamber R3 according to the increase/decrease in the load (passenger, cargo) on the rear of the vehicle, the cylinder 10 and the piston rod 20 are moved up and down relative to each other, and the posture of the vehicle is always kept constant. For example, if the load at the rear of the vehicle is large and the vehicle height drops backwards, the vehicle height sensor senses this and activates the air pressure supply control device described above to supply air pressure into the air chamber R3. The air pressure in the air chamber R3 is automatically increased to maintain a constant posture of the vehicle.

In this hydraulic shock absorber, as shown in an enlarged view in FIG. 2, an L-shaped bent portion is formed at the bottom of the air passage 23, and a gas bag 50 is inserted in this bent portion. There is. gas bag 50
is the bag body 51 facing the bending part of the air passage 23.
and a holder 52 that supports this and is hermetically fixed to the piston rod 20, and compressed air (gas) at a predetermined pressure is sealed inside. The bag body 51 is formed by providing a rubber layer on the surface of a reinforcing cloth, and is airtightly fixed to the holder 52 at the opening thereof. It contracts as shown by the line to open the air passage 23, and when it is less than the set value it expands as shown by the solid line to close the air passage 23. The holder 52 is provided with a plug 53 for injecting (or discharging) compressed air (gas) into the gas bag 50.
is hermetically secured, so that the compressed air (gas) pressure within the gas bag 50 can be adjusted.

In the hydraulic shock absorber configured in this way, normally the bag body 51 is contracted as shown by the imaginary line and the air passage 23 is open, and the air pressure in the air chamber R3 is controlled by the supply/exhaust valve 42, It can be increased or decreased by an air pressure supply control device consisting of an air compressor 46, an exhaust valve 47, etc. By the way, in the hydraulic shock absorber with vehicle height adjustment mechanism,
Even if the air pressure in the air chamber R3 drops to a predetermined value due to air leakage from the air tube 41, supply/exhaust valve 42, air tube 43, dryer 44, air tube 45, air compressor 46, exhaust valve 47, etc., the bag body 51 expands as shown by the solid line to close the air passage 23, so the air chamber R3
The air pressure inside is maintained at a predetermined value to ensure a minimum pressure. Therefore, the cylinder 1 of the rolling diaphragm 31 when the hydraulic shock absorber is activated.
0 and the cylindrical body 32 can be prevented, and a burst due to the rolling diaphragm 31 can be prevented from occurring.

In this embodiment, the present invention is applied to a hydraulic shock absorber in which the cylinder 10 is composed of both inner and outer cylinders 11 and 12, and the upper part of the second oil chamber R2 between them is used as a gas chamber. However, it goes without saying that the present invention can also be applied to a so-called decarbon type hydraulic shock absorber in which the inside of a single cylinder is divided into a high pressure gas chamber and a hydraulic oil chamber by a free piston. That is, in the present invention, one end of a rolling diaphragm is attached to the outer periphery of the cylinder, and the other end is attached to the lower end opening of a cylindrical body fixed to the outer periphery of the piston rod. A vehicle height system in which an air chamber is formed that is connected to an air pressure source through an air passage provided in the piston rod, and by adjusting the air pressure in this air chamber, the cylinder and piston rod are moved up and down relative to each other to adjust the vehicle height. It can be applied to various types of hydraulic shock absorbers with adjustment mechanisms.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted vertical cross-sectional view showing an embodiment of a hydraulic shock absorber according to the present invention, and FIG. 2 is an enlarged cross-sectional view of the same main part. Explanation of symbols, 10...Cylinder, 11...Inner cylinder, 12...Outer cylinder, 15...Oil seal, 16
... Seal cover, 20 ... Piston rod, 2
2...Piston valve, 23...Air passage, 31
... Rolling diaphragm, 32 ... Cylindrical body, 5
0... Gas bag, 51... Bag body, 52...
…holder.

Claims (1)

[Scope of utility model registration request] One end of a rolling diaphragm is attached to the outer periphery of a cylinder constituting a hydraulic shock absorber, and the other end of the rolling diaphragm is attached to the outer periphery of a piston rod that passes through an oil seal that seals the upper end opening of the cylinder and a seal cover that covers this oil seal. The rolling diaphragm and the cylinder form an air chamber connected to an air pressure source through an air passage provided in the piston rod on the outer periphery of the cylinder and piston rod. In a hydraulic shock absorber with a vehicle height adjustment mechanism that adjusts the vehicle height by moving the cylinder and piston rod up and down relative to each other by adjusting the air pressure in the room, compressed gas at a predetermined pressure is supplied into the air passage. It is housed inside and receives the air pressure from the air chamber and the air pressure source on its outer surface, and when the pressing force due to this air pressure is above a set value, it contracts and opens the air passage, and when it is less than the set value, it expands and closes the air passage. A hydraulic shock absorber with a vehicle height adjustment mechanism featuring a gas bag.