Crashproof guard bar

[0024] According to the momentum theorem, if a particle's speed changes sharply in a very short period of time, but its position remains almost unchanged, the particle will suffer a collision. Assuming that during the collision, the mass of the objects involved in the collision does not change, and the time interval Δt is integrated by Newton's law, the change in momentum is equal to the impulse, namely:

[0025] I′=mv s ′ Momentum of the particle after collision

[0026] I=mv s Momentum of the particle before collision

[0027] P = ∫ t t ′ Fdt Impulse of mass point

[0028] I′-I=P

[0029] In the entire collision process, F is a variable and a function of time, but it can be approximately regarded as a constant value in each time interval Δt, then:

[0030] mv n -mv n-1 = F n Δt n=1, 2, 3Λ

[0031] Another way to reduce the collision force is to extend the collision time, that is, the total collision time.

[0032] Based on the above principles, such as figure 1 As shown, the anti-collision guardrail of the present invention includes a concrete guardrail foundation 1, a column 2, a beam 3, and an energy-absorbing threaded component 4. The guardrail foundation 1 is F-shaped and is placed horizontally in the roadbed, so that the foundation is firm and effective. Driving on the road; Figure 5 The structure of the guardrail foundation 1 is shown. The rear section of the guardrail foundation beam 11 on the guardrail foundation 1 is provided with a guide groove 12, and a hole 13 is formed in the guardrail foundation beam 11 at the front end of the guide groove 12 along the longitudinal direction.

[0033] From figure 2 , 3 4 It can be seen that an energy-absorbing threaded part 4 is arranged in the hole 13 on the guardrail foundation 1. The energy-absorbing threaded part 4 includes an energy-absorbing threaded sleeve 41 and an impact guide 42. The energy-absorbing threaded sleeve 41 is embedded in the foundation beam of the guardrail. 11 is provided in the hole 13 and positioned by the fixing pin 5 at one end of the energy-absorbing threaded sleeve 41. Such as image 3 , 6 As shown, one end of the inner hole of the energy-absorbing threaded sleeve 41 is provided with a trapezoidal internal thread 411, which may also be a triangular thread, a rectangular thread, a sawtooth thread or a circular thread. The other end of the energy absorbing threaded sleeve 41 is a light hole 412, and the impact guide rod 42 is sleeved in the energy absorbing threaded sleeve 41. Such as Figure 7 As shown, one end of the impact guide rod 42 is provided with a boss 421. The boss 421 is located in the light hole 412 of the energy-absorbing threaded sleeve 41, and its diameter can be equal to or smaller than the major diameter of the internal thread 411 and greater than the minor diameter of the internal thread 411 This embodiment is the same as the major diameter of the internal thread 411; in the event of a collision, the column 2 drives the impact guide rod 42 to impact and shear the internal thread 411 in the energy-absorbing sleeve 41 through the boss 421, causing it to shear Cut deformation to achieve the effect of absorbing energy and buffering. The other end of the impact guide rod 42 is provided with an external thread 422. The column 2 is arranged in the guide groove 12 and is installed on the impact guide rod 42 through a hole opened at the lower end thereof, and is fastened by a nut 6 screwed with the external thread 422.

[0034] Such as figure 1 As shown, the cross-sectional shape of the beam 3 in this embodiment is rectangular, which is arranged in front of the column 2 and is connected to the column 2; the cross-sectional shape of the beam 3 can also be circular, trapezoidal, wavy or other forms. In the present invention, the column 2 of the anti-collision guardrail is installed in the guide groove 12 of the foundation beam 11 and connected with the energy-absorbing threaded part 4 to make it a movable type, that is, it can move backward with the impact when it is impacted. distance. First, the car collides with the beam 3 to deform it, and transmits the force to the column 2. The column 2 slides in the guide groove 12 of the F-shaped guardrail foundation 1 to produce a lateral displacement, which drives the impact guide 42 to impact and shear the energy-absorbing casing. The internal thread 411 inside 41 causes it to shear deformation, absorb energy to achieve the effect of the column 2 retreating and buffering, and the column 2 can consume a certain amount of kinetic energy when it slides in the guide groove 12 by friction force. The load-carrying capacity is basically a constant, so the force that the guardrail exerts on the car during a collision is basically a constant. Since the upright column 2 moves in the guiding groove 12, the guiding ability is better than other types of guardrails. The present invention can adjust the geometrical size and pitch of the threaded section according to the actual conditions of different road sections, and further ensure that the collision mechanics characteristics of the automobile are close to the ideal collision curve. The energy-absorbing threaded component 4 shears energy, and the beam 3 and the column 2 plastic deformation absorb The combined effect of energy can extend the collision time, reduce the collision force between the car and the guardrail, and fully protect the safety of the occupants and the car. According to finite element dynamic numerical simulation experiments and theoretical calculations, the safety of cars and occupants can be protected.

[0035] The invention is a semi-rigid guardrail suitable for special-risk areas, and is particularly suitable for highway anti-collision guardrails and bridge anti-collision guardrails on cliffs.