JPH0522216U - Vehicle rear shock absorber - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the rear-end collision vehicle from digging in and sufficiently absorb the collision energy without sacrificing the running performance (securing the departure angle) under normal conditions. [Structure] A rear bumper 2 of a vehicle is supported so as to be movable in the front-rear direction, and a hydraulic buffer 5 for absorbing collision energy that biases the rear bumper 2 toward the rear of the vehicle and a biasing force of the hydraulic buffer 5 are resisted. An actuator 4 that variably regulates the position of the rear bumper 2 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rear-end collision damping device for a vehicle.

[0002]

[Prior Art]

 For example, in the case of a large vehicle, a spare tire placed under the floor at the rear of the vehicle body as a rear-end collision buffering means in order to absorb collision energy and prevent the rear-end collision vehicle from getting caught in the event of a rear-end collision of a succeeding vehicle (such as a passenger car). It is known to utilize (Japanese Utility Model Publication No. 62-10158).

[0003]

[Problems to be solved by the device]

 By the way, in such a conventional device, the fixed position of the spare tire has to be determined in consideration of the running performance (departure angle is secured), and therefore, in terms of preventing the collision of the rear-end collision vehicle and absorbing the collision energy, the spare tire is a spare. It is desirable to push the tires toward the rear of the vehicle as much as possible, but there is a problem that it is not always possible to obtain sufficient effects because it is not possible to do so.

[0004]

[Means for Solving the Problems]

 Therefore, this invention supports the rear bumper of the vehicle so as to be movable in the front-rear direction, and also the hydraulic buffer for absorbing collision energy that urges the rear bumper toward the rear of the vehicle and the rear bumper against the urging force of the hydraulic buffer. It is equipped with an actuator that variably regulates the position.

[0005]

[Action]

 Normally, the actuator holds the rear bumper at a specified position determined by the balance with running performance against the biasing force of the hydraulic buffer. If the rear bumper is actuated so that the rear bumper projects toward the rear of the vehicle by the urging force of the hydraulic buffer when a following vehicle is likely to collide, the hydraulic buffer will be in the most extended state, for example, and the collision energy will be sufficient. In addition to being absorbed, the rear bumper can be effectively projected to prevent the rear-end collision vehicle from getting caught. Also, when applied to a dump truck, the rear bumper can be stored inside the vehicle by operating an actuator so as not to interfere with the dumping work.

[0006]

【Example】

 1 to 4, reference numeral 1 is a pair of slide guides that support a rear bumper 2 of a truck so as to be movable in the front-rear direction of a vehicle with respect to left and right chassis frames 3, and 4 is a resisting biasing force of a hydraulic buffer 5 described later. It is an electric winch as an actuator that variably regulates the position of the rear bumper 2.

The slide guide 1 is a combination of an inner tube 6 and an outer tube 7 that can expand and contract freely, and is fixed to the left and right chassis frames 3 via brackets 8 on the outer tube 7 side. A well-known hydraulic buffer 5 that constantly biases the rear bumper 2 toward the rear of the vehicle via an inner tube 6 is housed in the center of these slide guides 1, and the rear bumper 2 is attached to the tip of the inner tube 6 via a rubber block 9. Are combined.

Here, the rear bumper 2 is composed of a steel core material 10 and an outer cover 11 made of synthetic resin, and a space 12 for fitting the rubber block 9 is formed in the core material 10. The inner tube 6 of the slide guide 1 is inserted from the rear side of the rear bumper 2 into the space 12 of the core material 10, and the rubber block 9 is fitted between the steel plates 13 and 14 on the front side and the back side so that the flange piece 15 on the outer periphery of the tube 6 is secured. It is pinched through. Reference numeral 16 denotes a guide bush interposed between the outer tube 7 and the inner tube 6.

As shown in FIG. 5, the hydraulic buffer 5 includes a piston 18 slidable in a cylinder 17, a piston rod 19 protruding from one end of the cylinder 17, an oil sump 20 provided on the outer periphery of the cylinder 17, and the like. When the piston rod 19 receives a collision force and contracts against the spring force of the return spring 21, the oil in the cylinder 17 is pushed by the piston 19 and is contracted from the chamber to the outer periphery of the cylinder 17. The collision energy is absorbed by the hydraulic resistance force flowing through the small hole 22 to the oil reservoir 20 and the expanding chamber in the cylinder 17 and passing through the small hole 22.

The electric winch 4 is arranged at the center of a cross member 23 that connects the left and right chassis frames 3 and is connected to the rear bumper 2 via a wire 24. In this case, the electric winch 4 rotates forward and backward in response to a change in the flow of current during operation, and is fixed at the stop position when not in operation.

As shown in FIG. 6, the control system of the electric winch 4 includes a laser head 25 for detecting the traveling state of the following vehicle, a vehicle speed sensor 26 for detecting the traveling state of the own vehicle, and a detection result of the following vehicle. From the CPU 27 that determines the possibility of rear-end collision and outputs an operation signal when the rear-end collision is unlikely to be avoided, and the controller 28 that controls the drive (forward / reverse rotation) of the electric winch 4 based on this operation signal. Composed.

FIG. 7 further shows a block configuration of the control system. The CPU 27 has a distance processing circuit 30 for calculating the inter-vehicle distance between the own vehicle and the following vehicle and its change rate (relative speed), the vehicle speed of the own vehicle, and An information processing circuit 31 is provided that outputs an operation signal or the like when there is a high possibility that the following vehicle will collide with another vehicle due to the distance between the following vehicle and the like. The controller 28 includes a bumper position detecting means 32 for detecting the position of the rear bumper 2 in order to accurately control the electric winch 4. Reference numeral 33 is a monitor output processing circuit for outputting a display signal of information such as the sudden approach of a following vehicle to a monitor arranged in the driver's cab, and 34 is a power supply.

FIG. 8 illustrates the control pattern of the CPU 27, that is, when the operation signal is output. In this example, the operation signal is output using the inter-vehicle distance to the following vehicle and the relative speed as parameters. In the low relative speed range (20 km / h), the electric winch is kept inactive regardless of the distance between vehicles, and in the high relative speed range (60 km / h), when the distance between vehicles approaches 50 m or less. Output an operation signal. Then, in the intermediate range of relative speed (20 to 60 km / h), the operation signal is set to be output when the inter-vehicle distance / relative speed is less than or equal to a predetermined time (3 seconds) based on human danger avoidance ability.

FIG. 9 is a flow chart for explaining the control contents. When the engine key switch of the vehicle is in a stopped state (temporarily stopped state) or at a slow speed, the relationship between the own vehicle and the following vehicle is output as the operation signal in FIG. When entering the area, the electric winch is rotated forward and the hydraulic buffer is extended to project the rear bumper from the normal position to the rear of the vehicle, and when a predetermined time (10 seconds) elapses in this state, it is determined to avoid a rear-end collision and the electric motor is driven. Rotate the winch in the reverse direction and pull the rear bumper back to the normal position to fix it (steps 51 to 59).

When the engine key switch is off (parking state), the control of the electric winch is performed for a predetermined set time (10 to 15 minutes assuming roadside parking) by the operation of the power timer. It is kept in a possible state (step 2 → 60 to 68). Note that the set time of the power supply timer may be variable.

With such a configuration, the electric winch 4 normally holds the rear bumper 2 at the specified position against the biasing force of the hydraulic buffer 5, while the following vehicle is likely to collide with the vehicle when the vehicle is temporarily stopped or parked. By driving the electric winch 4, the rear bumper 2 is pushed out toward the rear of the vehicle by the urging force of the hydraulic buffer 5, so that it is possible to effectively prevent the rear-end collision vehicle from sneaking in, and the hydraulic buffer 5 is in the most extended state, so that the collision energy is reduced. Can be fully absorbed.

In this case, since the electric winch 4 is connected to the rear bumper 2 via the wire 24, the flexibility of the wire 24 can prevent the impact at the time of a rear-end collision from being properly transmitted to the winch 4. Further, since the rubber block 9 is interposed at the joint between the rear bumper 2 and the inner tube 6 of the slide guide 1, even if an unbalanced load is applied to the rear bumper 2, the good operability of the hydraulic buffer 5 is impaired. There are few things.

Therefore, it is possible to effectively reduce the damage in the case of a rear-end collision without sacrificing the traveling performance under normal conditions (securing the departure angle).

10 to 12 show another embodiment. A pair of parallel links 70 are attached to the rear end portions of the left and right chassis frames 3, respectively, and the stays of the rear bumper 2 are connected through these links 70. 71 is swingably supported in the front-rear direction of the vehicle. The left and right stays 71 are connected to each other by a strength member 72, and are connected to the rear bumper 2 via the rubber block 9 as in the above embodiment.

One hydraulic buffer 5 is provided on each of the left and right sides, and one end is pivotally connected to the chassis frame 3 side and the other end is pivotally connected to the stay 71, respectively. In this case, each hydraulic buffer 5 is attached so as to incline in the tangential direction to the swing locus of the stay 71.

An air cylinder 4A is adopted as an actuator that variably regulates the position of the rear bumper 2, and the air cylinder 4A is fixed horizontally at the center between the left and right chassis frames 3 with the piston rod 74 facing forward of the vehicle. It The subframe 76 on the chassis frame 3 is provided with a mounting surface for the air cylinder 4A.

In the air cylinder 4 A, the wire 24 from the strength member 72 of the rear bumper 2 is connected to the tip of the piston rod 74, and the air is passed through a solenoid valve (not shown) that controls the stroke position of the piston rod 74. Piped to a pressure source. Reference numeral 75 denotes a pulley that supports the wire 24 in front of the air cylinder 4A.

According to such a configuration, the rear bumper 2 swings via the parallel link 70, so that there is also an advantage that a large energy absorption stroke of the hydraulic buffer 5 can be obtained even in a vehicle with a short rear overhang.

FIG. 13 and FIG. 14 show a main part configuration of a device and a block configuration of a control system for explaining an application example to a dump truck, and a vehicle in which the rear bumper 2 is not disturbed from a normal position during dumping work. In order to be able to store inside, a reverse gear SW77 that detects switching of the transmission to the reverse gear and a dump lever SW78 that detects the operating position of the dump lever in the cab are provided, and at least these SW77, 78 are provided. The controller 28 operates the actuator 4 in the retracting direction of the rear bumper 2 on condition that one of them is turned on. The same components as those in the embodiment (FIGS. 6 and 7) are designated by the same reference numerals.

Specifically, as shown in FIG. 15, when the reverse gear SW 77 or the dump lever SW 78 is turned on, the rear bumper 2 is retracted to the storage position by the forward movement of the actuator 4, and when the SW 77 or 78 is turned off, the rear bumper 2 is returned by the backward movement of the actuator 4. The damper 2 is returned to the original normal position (steps 81-87, 88-94). Since the control operation at the time of a collision is the same as that in FIG. 9, duplicate description will be omitted.

By carrying out such control, it is possible to secure the departure angle according to the rough road traveling at the construction site, etc., and it becomes possible to perform the vessel up operation in the state of the closest approach to the discharge place of earth and sand and the like. .. A manual SW may be provided in the driver's cab so that the rear bumper can be stowed if necessary even when the vehicle is moving forward.

[0027]

[Effect of the device]

 In short, according to the present invention, the rear bumper of the vehicle is movably supported in the front-rear direction, and the hydraulic buffer for collision energy absorption for urging the rear bumper toward the rear of the vehicle and the urging force of the hydraulic buffer are resisted. Since an actuator that variably regulates the position of the rear bumper is provided, the actuator can actuate the rear bumper to the rear of the vehicle by the urging force of the hydraulic buffer when a following vehicle is likely to collide. It is possible to prevent the rear-end collision vehicle from slipping in and absorb the collision energy without sacrificing the running performance (securing the departure angle). Further, when applied to a dump truck, the rear bumper can be stored via an actuator so as not to disturb the dump work.

[Brief description of drawings]

FIG. 1 is a plan configuration diagram of a rear bumper portion.

FIG. 2 is likewise a side view.

3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a cross-sectional view of the configuration of a hydraulic buffer.

FIG. 6 is a configuration diagram of the entire apparatus.

FIG. 7 is a block configuration diagram of a control system.

FIG. 8 is a control pattern diagram of a CPU.

FIG. 9 is a flowchart illustrating the control content at the time of a rear-end collision.

FIG. 10 is a plan configuration diagram of a rear bumper portion showing another embodiment.

FIG. 11 is likewise a side view of the rear bumper section.

12 is a sectional view taken along line CC of FIG.

FIG. 13 is a configuration diagram of a main part of an apparatus showing another embodiment.

FIG. 14 is a block diagram of a control system of the same.

FIG. 15 is a flowchart illustrating control contents during storage.

[Explanation of symbols]

 1 Slide Guide 2 Rear Bumper 3 Chassis Frame 4 Electric Winch 5 Hydraulic Buffer 9 Rubber Block 25 Laser Head 26 Vehicle Speed Sensor 27 CPU 28 Controller 77 Reverse Gear SW 78 Dump Lever SW

Claims (1)

[Scope of utility model registration request] 1. A hydraulic buffer for absorbing collision energy, which supports a rear bumper of a vehicle so as to be movable in the front-rear direction, and biases the rear bumper toward the rear of the vehicle, and a rear bumper of the rear bumper against the biasing force of the hydraulic buffer. A rear impact collision damping device for a vehicle, which is provided with an actuator that variably regulates a position.