WO1998008713A1

WO1998008713A1 - Automobile bumper impact absorbing device and control method thereof

Info

Publication number: WO1998008713A1
Application number: PCT/KR1997/000161
Authority: WO
Inventors: Heung-Jai Lee
Original assignee: Lee Heung Jai
Priority date: 1996-08-31
Filing date: 1997-08-30
Publication date: 1998-03-05

Abstract

An automobile bumper impact absorbing device, including: a bumper mounted on the front side of an automobile and supported by one or more operation rods; a driving unit on which the operation rods are slidingly installed, for supplying a driving force to automatically protrude the bumper by an automobile running speed sensing signal; a buffering unit installed on the rear side of the driving unit, for absorbing an impact applied from the bumper; first and second servo valves (54, 54') having a compressor (50) in which an oil pressure generated by means of an engine (40) or an oil pressure pump (41) is stored and having first and second solenoids (55, 55') which supplies the compressed oil pressure with an appreciate compressing force and oil quantity to the driving unit; and a speed detecting unit (60) for detecting a speed signal of the automobile to amplify a voltage by the detected speed signal, for selectively opening/closing first and second passages (56, 56') which are connected to the supply sides of the first and second servo valves (54, 54') to thereby protrude and draw the operation rods installed on the driving unit.

Description

AUTOMOBILE BUMPER IMPACT ABSORBING DEVICE AND CONTROL

METHOD THEREOF

BACKGROUND OF THE INVENTION

Field of the Invention The present invention relates to an automobile bumper impact absorbing device and control method thereof . More particularly, the present invention relates to an automobile bumper impact absorbing device and control method thereof which is capable of automatically protruding or drawing within a predetermined set range an impact absorbing bumper which is mounted on the body of an automobile in proportion to a running speed of the automobile and applying an impact absorbing force proportional to the running speed to the impact absorbing bumper upon generation of an unexpected front -end or rear-end collision, such that the damage of the automobile can be minimized and passengers can be also protected.

Discussion of Related Art

Generally, bumpers, which are mounted on various kinds of automobiles, serve to decrease an amount of impact applied from the outside by filling a reinforcing sponge or PVC (polyvinyl chloride) grill in the interior thereof. To improve such the impact absorbing function, there have been presented novel bumpers which have various types of structure and materials. However, since such the conventional bumpers are designed to absorb the impact applied from the outside on the basis of their material characteristics and structural actions, they exhibit a good buffering effect against the front -end or rear- end collision generated during a low running speed of the automobile, but fails to exhibit such good buffering effect during a high running speed of the automobile. As a result, a body as well as the bumper of the automobile are greatly damaged and the passengers are of course injured.

Specifically, at the time when an occurrence ratio of accident is drastically high as the number of vehicles and the congestions of the vehicles are gradually increased, it must be noted that a new technology for preparing unexpected front - end or rear-end collisions between vehicles should be really needed . On the other hand, as an example of conventional automobile bumper impact absorbing devices, there is disclosed Korean Patent Application Publication No. 96-8263, in which an air buffering device having a bumper which is mounted on the front and rear ends of the automobile and is operated by an air cylinder is installed. Thereby, after a driver starts the automobile, he drives the automobile in the state where the air bumper switch is operated and the bumper is protruded by a predetermined distance. Upon generation of the contact or collision of the automobile, the air cylinder of the air buffering device acts as an impact absorbing device on the automobile .

In the above conventional art, however, the driver arbitrarily manipulates the protrusion operation of the bumper, which results in inconvenience of the manipulation operation. Of course, in the case where the driver does not operate the air bumper switch carelessly, the air buffering device fails to execute the impact absorbing function.

Further, since the protrusion operation and the impact absorbing action of the bumper are all implemented by the action of the air cylinder, there occurs a problem that the impact absorbing force of the air buffering device is considerably deteriorated.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an automobile bumper impact absorbing device and control method thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art .

An object of the invention is to provide an automobile bumper impact absorbing device and control method thereof which is capable of automatically displacing a protrusion range of a bumper functioning as an impact absorbing device in proportion to a running speed of an automobile.

To accomplish this and other objects of the present invention, there is provided an automobile bumper impact absorbing device including: a bumper mounted on the front side of an automobile and supported by one or more operation rods; a driving unit on which the operation rods are sildingly installed, for supplying a driving force to automatically protrude the bumper by an automobile running speed sensing signal; a buffering unit installed on the rear side of the driving unit, for absorbing the impact applied from the bumper; first and second servo valves having a compressor in which an oil pressure generated by means of an engine or an oil pressure pump is stored and having first and second solenoids which supplies the compressed oil pressure with an appreciate compressing force and oil quantity to the driving unit; and a speed detecting unit for detecting a speed signal of the automobile to amplify a voltage by the detected speed signal, for selectively opening/closing first and second passages which are connected to the supply sides of the first and second servo valves to thereby protrude and draw the operation rods installed on the driving unit.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the drawings. In the drawings :

FIG. 1 is a side view illustrating an impact absorbing device embodied in an automobile according to an embodiment of the present invention;

FIGS. 2A and 2B are plan views illustrating the states before and after the impact absorbing device according to the embodiment of the present invention is operated; FIG. 3 is a circuit diagram illustrating the control construction of the impact absorbing device of FIG. 1;

FIG. 4 is a block diagram illustrating the control construction of the impact absorbing device of FIG. 1; FIGS. 5A and 5B are circuit diagrams illustrating an operational state of a driving unit according to another embodiment of the present invention;

FIG. 6 is a circuit diagram illustrating an operational state of a driving unit according to still another embodiment of the present invention; and

FIGS. 7A and 7B are plan views illustrating an impact absorbing device embodied according to another embodiment of the present invention and a driving unit therein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Now, the construction of an automobile bumper impact absorbing device and a control method thereof will be discussed with reference to FIGS. 1 to 3.

FIG. 1 is a side view illustrating an impact absorbing device embodied in an automobile according to an embodiment of the present invention. FIGS. 2A and 2B are plan views illustrating the states before and after the impact absorbing device according to the embodiment of the present invention is operated. In construction, a bumper 10 is installed on the front side of an automobile 100 and is supported by at least one or more operation rods 11. A driving unit is installed on the back ends of the operation rods 11 and supplies a driving force to the operation rods 11, thus automatically protruding and drawing the operation rods 11 by an automobile speed sensing signal .

The driving unit is comprised of first and second cylinders 20 and 20a which are operated by an oil pressure or an air pressure. A buffering unit is comprised of first and second air pressure cylinders 30 and 30a each installed on the rear sides of the first and second cylinders 20 and 20a and when an outside impact applied to the bumper 10 is transmitted via the operation rods 11 to the driving unit, serves to absorb the impact transmitted to the driving unit.

FIG. 3 is a circuit diagram illustrating the control construction of the impact absorbing device of FIG. 1. In construction, an oil pressure generated by means of a power source such as an engine 40 or an oil pressure pump 41 is stored in a compressor 50, and a check valve 42, which is connected to the compressor 50, serves to cut a reverse flowing of the oil pressure to thereby prevent a reverse load on the oil pressure pump 41 from being formed.

A relief valve 43 for preventing an over oil pressure from being applied, a pressure gauge 44 having a stop valve 44' which displays a pressure of an oil pressure circuit, and an electronic valve 45 having a switch 45' which prevents a pressure of the oil pressure circuit from being excessively raised are each installed on a pipe passage connected to the check valve 42. The oil pressure stored in the compressor 50 is passed through an oil amount adjusting valve 51 which adjusts an operation speed of the bumper 10 according to the running speed of the automobile 100 and is then divided through a dividing valve 52 which serves to equally supply the oil pressure to each of the first and second cylinders 20 and 20a of the driving unit. The oil pressure divided by the dividing valve 52 passes through each of passages 53 and 53' and finally flows to first and second servo valves 54 and 54' . On the other hand, a speed detecting unit 60, which serves to detect the running speed of the automobile 100, is installed on a predetermined position of the automobile 100 and inputs a detected speed signal to a control unit 61. Thereby, a voltage generated from the control unit 61 is amplified by an amplifying unit 62 and serves to magnetize first and second solenoids 55 and 55' of the first and second servo valves 54 and 54' .

The speed detecting unit 60 can detect the running speed of the automobile 100 in a well known a centrifugal, magnetic, electrical, or electronic method, and it is satisfied with a condition that the wheel of the automobile 100 is not in a racing state or speed indicated on a speed gauge is not different from a real speed of the automobile 100.

First and second passages 56 and 56', which each supply the oil pressure to the first and second cylinders 20 and 20' of the driving unit, are connected to each of the first and second servo valves 54 and 54 ' , thus making it render the operation rods 11 on which the bumper 10 is supported desirably slid. FIG. 4 is a block diagram illustrating the control construction of the impact absorbing device of FIG. 1. Referring to FIG. 4, the oil pressure generated from the engine 40 and the oil pressure pump 41 is stored in the compressor 50 and then the electronic valve 45 and the oil amount adjusting valve 5i control an appropriate oil pressure and an amount of oil and determine an oil pressure supply direction.

In the state where the oil pressure supply direction is decided, the control unit 61 and the amplifying unit 62 are controlled by the detected signal from the speed detecting unit 60, and thereby the first and second passages 56 and 56' of the first and second servo valves 54 and 54' are selectively opened/closed. By the selective opening/closing operation of the first and second servo valves 54 and 54', the oil pressure is supplied to each of the first and second cylinders 20 and 20' of the driving unit. Thereby, the bumper 10 mounted on the front end of the operation rods 11 is automatically protruded or drawn in proportion to the speed variation of the automobile 100. The outside impact applied to the bumper 10 during the running of the automobile 100 is completely absorbed by means of the buffering device installed on the rear side of the driving unit.

Hence, in the automobile bumper impact absorbing device and a control method thereof according to the present invention, the speed detecting unit 60 does not detect the running speed in the state where the automobile 100 stops and accordingly the control unit 61 does not receive any detected signal from the speed detecting unit 60. As a result, no voltage is applied to the amplifying unit 62 and then the electrical signal for magnetizing the first and second solenoids 55 and 55' of the first and second servo valves 54 and 54' is not generated. As a result, the oil pressure, which flows to each of the first and second servo valves 54 and 54' through the passages 53 and 53', is supplied via the first passages 56 to each of the first and second cylinders 20 and 20a of the driving unit, to thereby draw the operation rods 11 which are slid in the interior of the first and second cylinders 20 and 20a. As a result, the bumper 10 which is mounted on the front surface of the automobile 100 maintains a substantially adjacent state to the automobile body.

To the contrary, when the automobile 100 runs at a high running speed, the detected signal by the speed detecting unit 60 strongly magnetizes the first and second solenoids 55 and 55' of the first and second servo valves 54 and 54' . As a result, the oil pressure, which flows to each of the first and second servo valves 54 and 54' through the passages 53 and 53', is supplied via the second passages 56' to each of the first and second cylinders 20 and 20a of the driving unit, to thereby protrude the operation rods 11 which are slid in the interior of the first and second cylinders 20 and 20a. As a result, the bumper 10 which is mounted on the front surface of the automobile 100 is protruded in a forward direction. In the state where the bumper 10 is protruded in a forward direction of the automobile 100, if the front-end or rear-end collision is generated and the impact applied from the counterpart's object is transmitted to the bumper 10, the impact generated is transmitted via the operation rods 11 to each of the first and second cylinders 20 and 20a of the driving unit and is slightly buffered. Sequentially, most of the impact is finally absorbed by means of the first and second air pressure cylinders 30 and 30a of the buffering uni . Since air is compressed in the first and second air pressure cylinders 30 and 30a to maintain an appropriate pressure, at an initial step, the first and second air pressure cylinders 30 and 30a exhibit a flexible buffering effect against the impact transmitted through the bumper 10 to the driving unit, but at a final step, they exhibit a strong buffering effect against the impact. Accordingly, when the impact on the automobile 100 is applied, the running speed variation time is greatly increased. The first and second air pressure cylinders 30 and 30a surprisingly decrease the impact force to safely protect the passengers or the automobile, on the basis of a principle of the impact force that is proportional to the mass of automobile and variation quantity of a running speed but is inversely proportional to variation quantity of the time.

At the time, the buffering unit is preferably formed as a unitary body with the rear end of the driving unit in the preferred embodiment of the present invention, but may be connected by a separate passage such as an internal pressure hose with the driving unit.

Further, the driving unit is comprised of the first and second cylinders 20 and 20a in the preferred embodiment of the present invention, but may vary the number of cylinders and their installation positions in accordance with the size or structure of automobile. Meanwhile, the buffering unit may be made of a strong elastic spring.

FIGS. 5A and 5B are circuit diagrams illustrating an operational state of a driving unit according to another embodiment of the present invention. If a speed detecting unit 200 inputs a speed detecting signal to a control unit 201, the control unit 201 transmits an operation signal to a driver 202. While a position determining motor 210 constituting a driving unit is rotated forwardly or reversely, a motor gear 211 and a conveying screw gear 220 are rotated in a racing state. Then, a conveying screw 230, which is coupled on the co-axis of a connecting gear 231 inner-contacted with the conveying screw gear 220, is rotated by means of the connecting gear 231. During the rotation of the conveying screw 230, the rear end of the conveying screw 230 is supported by an impact transmitting unit 241 of a cylinder 240, whereas the front end of the conveying screw 230 is associated with a bumper connecting unit 251 of a bumper 250 which is slid according to the rotational direction of the conveying screw 230.

In more detail, if the running speed of the automobile 100 is increased and the speed detecting unit 200 drives the position determining motor 210, the conveying screw 230 is rotated forwardly. By the rotation of the conveying screw 230, the bumper connecting unit 251 and the bumper 250 are pushed outwardly and protruded from the automobile body, as shown by a solid line of FIG. 5A, to thereby ensure a buffering distance proportional to the running speed. To the contrary, if the running speed of the automobile 100 is decreased, the bumper connecting unit 251 and the bumper 250 are drawn to the automobile body, as shown by a dotted line of FIG. 5A.

If the front-end or rear-end collision accident is generated at the state where the bumper 250 is protruded, the conveying screw 230, which is installed on the co-axis of the connecting gear 231 inter-connected with the convey screw gear 220, as shown in FIG. 5B, is drawn along with the bumper 250. At the time, the impact transmitting unit 241 of the cylinder 240 is pressurized and the buffering operation is completed. FIG. 6 is a circuit diagram illustrating an operational state of a driving unit according to still another embodiment of the present invention. If a speed detecting signal of a speed detecting unit 300 is input to a control unit 301, an actuator 310 is operated according to a compared result of the speed detecting signal with a position signal of a bumper 340 which is fed back from an encoder or sensor. The actuator 310 selectively provides an air pressure supplied from an air pressure supply source 320 which is operated by an additional air pressure circuit to a driving cylinder 330, to thereby slide operation rods 331. Accordingly, the bumper 340, which is mounted on the front end of the operation rods 331, is protruded in proportion to the running speed of the automobile 100 to thereby exhibit the buffering function corresponding to the running speed. At the time, if the front -end or rear-end collision accident is generated at the state where the bumper 340 is protruded, the fluid remaining in the interior of the driving cylinder 330 is compressed to thereby execute an impact buffering function. On the other hand, FIGS. 7A and 7B are plan views illustrating an impact absorbing device embodied according to another embodiment of the present invention and a driving unit therein. A driving unit for protruding a bumper 410 in proportion to the running speed of the automobile 100 is comprised of a pair of actuators 400, which serve to protrude the bumper 410 corresponding to the running speed and provide a buffering function. The impact generated from the front -end or rear-end collision accident at the state where the bumper 410 is protruded is all absorbed by means of a buffering unit which is comprised of operation rods 421 of cylinders 420 connected to an air pressure tank 430. At the time, a rapid flow cutting valve 431 is installed on a passage connected to the air pressure tank 430 to correspond strongly with a pressure applied to the cylinders 420 and thereby prevents the pressure from being leaked.

As clearly apparent from the above, an automobile bumper impact absorbing device and a control method thereof according to the present invention which can automatically protrude a bumper which absorbs an impact generated from the front -end or rear-end collision accident of an automobile in proportion to a running speed of the automobile and can provide a buffering force corresponding to the running speed, to thereby minimize the impact caused due to the accident and to ensure a safe protection of passengers and decrement of damage of automobile body.

Further, during the automobile runs at a low speed or stops, the bumper is drawn adjacent to the automobile body and no inconvenience to the front and rear side vehicles is made, such that an additional manipulation for the protrusion or drawing of the bumper is not required.

It will be apparent to those skilled in the art that various modifications and variations can be made in an automobile bumper impact absorbing device and a control method thereof of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. An automobile bumper impact absorbing device, comprising : a bumper mounted on the front side of an automobile and supported by one or more operation rods; a driving unit on which said operation rods are sildingly installed, for supplying a driving force to automatically protrude said bumper by an automobile running speed sensing signal ; a buffering unit installed on the rear side of said driving unit, for absorbing an impact applied from said bumper; first and second servo valves having a compressor in which an oil pressure generated by means of an engine or an oil pressure pump is stored and having first and second solenoids which supplies the compressed oil pressure with an appreciate compressing force and oil quantity to said driving unit; and a speed detecting unit for detecting a speed signal of said automobile to amplify a voltage by the detected speed signal, for selectively opening/closing first and second passages which are connected to the supply sides of said first and second servo valves to thereby protrude and draw said operation rods installed on said driving unit.

2. The device as defined in claim 1, wherein said driving unit is comprised of first and second cylinders which are operated by the oil pressure or an air pressure, and said buffering unit is comprised of first and second air pressure cylinders which are each installed on the rear sides of said first and second cylinders.

3. The device as defined in claim 1, wherein said driving unit is comprised of: a position determining motor rotated forwardly or reversely by the speed signal of said speed detecting unit; a conveying screw gear outer-connected to a motor gear coupled on a co-axis of said position determining motor and being in a racing state; a conveying screw coupled on the co-axis of a connecting gear inner- contacted with said conveying screw gear and being in a racing state; and a bumper supported by an impact transmitting unit of a cylinder of said buffering unit on the rear end thereof and screw-coupled with a bumper connecting unit on the front end thereo .

4. The device as defined in claim 1, wherein said driving unit is comprised of: an actuator operated according to a compared result of a speed detecting signal with a position signal of a bumper which is fed back from an encoder or sensor, when the speed detecting signal of a speed detecting unit is input to a control unit; a driving cylinder having an operation rod which is slid, as said actuator selectively provides an air pressure supplied from an air pressure supply source to said driving cylinder; and said bumper mounted on the front end of said operation rod and protruded in proportion to a running speed of the automobile to thereby exhibit a buffering function corresponding to the running speed.

5. The device as defined in claim 1, wherein said driving unit is comprised of a pair of actuators for protruding said bumper in proportion to a running speed of the automobile, and said buffering unit is comprised of a cylinder which is connected to an air pressure tank.

6. A control method in an automobile bumper impact absorbing device having a bumper which absorbs an impact applied when a front-end or rear-end collision is generated during the running of an automobile and is mounted on an operation rod to automatically be protruded, said operation rod which is slid by a driving unit, and a buffering unit which is mounted on the rear end of said driving unit, for absorbing the impact, said method comprising the steps of: storing an oil pressure generated by means of a power source such as an engine or an oil pressure pump in a compressor and installing a check valve for cutting a reverse flowing and a reverse load of the oil pressure on a passage to said compressor; supplying the oil pressure stored in the compressor to an oil amount adjusting valve which adjusts an operation speed of said bumper according to the running speed of said automobile and to first and second servo valves having first and second solenoids which equally supply the oil pressure to each of first and second cylinders of said driving unit through a dividing valve which divides the oil pressure; installing a speed detecting unit which detects the running speed of said automobile on a predetermined position of said automobile and inputting a detected speed signal from said speed detecting unit to a control unit and an amplifying unit to thereby magnetize said first and second solenoids of said first and second servo valves; and selectively opening/closing first and second passages which are connected to said driving unit to automatically increase/decrease a protruded distance of said bumper.