JPS632349Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to improvements in shock absorbers for automobiles and the like.

BACKGROUND ART In automobiles, typically passenger cars, bumpers are provided at the front and rear of the vehicle body in order to absorb and alleviate the impact when the vehicle body contacts or collides with an object.

Incidentally, the impact force generated when a vehicle body collides with an object generally varies greatly depending on the relative speed between the two objects, and is weak at low speeds and strong at high speeds. Therefore, the function required of this type of shock absorber is to apply the buffering force slowly and softly when the relative speed is low.
In addition, at high speeds, it is necessary to increase the buffering force and make it hard and strong so that it can reliably absorb and alleviate the impact, and to obtain an effective and good impact buffering function according to the relative speed.

However, conventional bumpers are simply fixed to the front and rear of the vehicle.
I have yet to find a structure that adjusts the buffering force depending on the relative speed between the object and the vehicle body.

Disclosure of the invention This invention was created in view of the above points.
Depending on the relative speed between the object and the vehicle body, the buffering force can be applied slowly and softly at low speeds, and the buffering force can be increased at high speeds to ensure shock absorption and mitigation. It is an object of the present invention to provide a shock absorber for automobiles, etc., which has a simple structure and is inexpensive, which can act hard and strongly.

In order to achieve this objective, this invention connects and supports the bumper that protrudes forward of the vehicle body using regular springs and springs made of shape memory alloy, and uses sensors installed at predetermined positions on the vehicle body to detect the relative speed of objects. At the same time, this detection output is compared with the set output set by the setting device, and when the detected output exceeds the set output, the drive circuit energizes the spring made of the shape memory alloy. The structure is such that the spring pressure is heated to return it to the desired state, and the buffering force is increased by the mutual action of the spring pressure and the spring pressure of a normal spring to make it strong and hard.

According to this idea, depending on the relative speed between the obstacle and the vehicle body, when the speed is low, the buffering force is applied only by ordinary springs, and when the speed is higher than a certain level, the buffering force is applied using a shape memory alloy. The spring is heated with electricity,
This is restored to its initial state, and the buffering force is increased by the interaction between the spring pressure and the spring pressure of a normal spring, so the buffering force is applied slowly and softly at low speeds. can be made,
Furthermore, at high speeds, the shock absorbing force can be applied hard and strongly to ensure that the impact force is absorbed and alleviated. Therefore, a reliable and good shock-absorbing effect that constantly responds to changes in relative speed can be obtained. In addition, shape memory alloy springs have an extremely fast response speed when heated with electricity, and can instantly return to their initial state, so even if an object comes very close to the vehicle body, they can reliably provide a buffering effect without any problems. I can do it. Therefore, a sensor that is relatively inexpensive and easy to use, such as an ultrasonic sensor, can be used.

Furthermore, the bumper that protrudes toward the front of the vehicle body is connected and supported by regular springs and springs made of shape memory alloy, and the shock absorbing force is increased by heating the memory alloy springs with electricity, so other complicated shock absorbing mechanisms are not required. Therefore, the structure is simple and inexpensive.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the invention will be described in detail with reference to the drawings. (Hereinafter, a spring made of a shape memory alloy will be referred to as a memory alloy spring.) Figures 1 and 2 show an example of a shock absorber according to this invention, and 10 is the body of an automobile. A bumper 11 is provided on the front surface of a vehicle body 10 to protrude forward at a predetermined interval.
This bumper 11 is constructed by a pair of normal springs 12, 12 provided at a predetermined interval in the width direction of the vehicle body 10, and memory alloy springs 13, 13 provided in parallel inside the normal springs 12, 12. It is connected and supported on the front surface of 10.

The memory alloy spring 13 is heated so that it returns to its initial state and its spring pressure returns to the set pressure, and is in a state where it can be freely deformed at room temperature, and its spring pressure becomes approximately "0". It is made of a type of shape memory alloy.

A sensor 14 is attached to the front surface of the vehicle body 10, for example, at a position approximately below the center thereof, and is adapted to detect the relative speed and distance between the vehicle body and an obstacle located in front of the vehicle body while the vehicle is running. For example, an ultrasonic sensor is used as the sensor 14 due to ease of handling, but other sensors may also be used.

FIG. 2 is a block diagram showing an example of a circuit configuration for embodying this invention. In the figure, 1
5 is a calculation unit that calculates the relative speed and distance between the obstacle and the vehicle body by applying, for example, the Doppler effect. 16 is a comparator, 17 is a setter, and comparator 1 outputs a set output according to the set speed and distance set in advance.
Output to 6. Reference numeral 18 denotes a drive circuit for applying electricity to heat the memory alloy spring 13 to return it to its shape, and is comprised of a power source 19 and a switch 20 for turning it on and off.

The relative speed set by the setting device 17 is, for example,
80km/h, and the relative distance is about 5 to 10m.

In the above configuration, when an obstacle object A is located in front of the vehicle body 10 and approaches within a predetermined range, the sensor 14 detects this object A, and the relative speed between the object A and the vehicle body 10 is Detect distance. This detection output is input to the calculation section 15, where the speed and distance are calculated. The calculated relative speed and distance are output to the comparator 16 and compared with the set speed and distance set by the setting device 17, respectively. If the relative speed and distance are within the set values, no signal is output from the comparator 16, and the memory alloy springs 13, 13 are kept at room temperature. Therefore, obstacle A is bumper 1.
The impact force when colliding with or touching spring 1 is usually
It is absorbed, relaxed, and buffered only by the spring pressures 2 and 12. Therefore, the impact force is moderately and softly buffered.

On the other hand, when the relative speed and distance exceed the set speed and distance, that is, exceed 80 km/h and the distance is within 10 m, a signal is output from the comparator 16 to the drive circuit 18. . This signal turns on the switch 20, and the memory alloy springs 13, 13 are energized and heated by the power source 19. As a result, memory alloy spring 1
3 and 13 instantly return to their initial shapes, and their spring pressures return to their desired set values. Therefore, the spring pressure of the memory alloy springs 13, 13 is added to the spring pressure of the normal springs 12, 12, and the spring pressure is increased. Therefore, the impact force due to the collision with object A is applied to both springs 12, 12 and 13,
The additional spring pressure of 13 is absorbed, relaxed, and buffered, and the time for which the impact force acts, that is, the time for the impact to be absorbed by the spring, becomes longer. As a result, the buffering force acts hard and strongly on the object A, and the buffering force increases, and the impact force is reliably absorbed and alleviated by this buffering action.

Thus, according to this embodiment, when the relative speed is low, the impact force can be absorbed and relaxed only by the springs 12, 12, and the buffering force can be applied gently and softly, and When a high speed above a certain level is exceeded, the impact force is absorbed and alleviated by the mutual action of the spring pressure by the normal springs 12, 12 and the spring pressure by the memory alloy springs 13, 13, and the impact absorption time is lengthened. Increase the buffering force by
The buffering force can be applied hard and strongly, and a smooth and reliable buffering effect can be obtained at all times.

Note that the number of memory alloy springs is not limited to those shown in the embodiments, and the number can be increased as needed. In this case, if the memory alloy springs are actuated by being energized and heated in stages according to the set speed, etc., the buffering force of the springs can be changed, for example, from the normal spring to the normal spring and the first memory alloy spring. The strength can be increased stepwise or linearly, such as by using the normal spring and the first and second memory alloy springs.

Next, FIGS. 3 and 4 show other examples of the spring used in this invention. and a memory alloy spring 32, the springs 32 and 33 are stacked on top of each other and combined into one, and the pipe-shaped member 3
It is inserted and assembled from one side of 1. and,
Both ends of the spring 33 protrude from both ends of the member 31 by a predetermined length, and terminals 34 and 35 connected to the drive circuit are provided at these protruding portions. According to this, the structure becomes more compact and simpler than that in which a normal spring and a memory alloy spring are separately assembled.

FIGS. 5 and 6 show other embodiments of this invention, and the same reference numerals are used for the same parts as in the above embodiment, and the explanation thereof will be omitted.

Similarly to the above, memory alloy springs 40, 40 are arranged inside the normal springs 12, 12, and the bumper 11
is connected and supported by both springs 12, 12 and 40, 40 at a position protruding from the front surface of the vehicle body 10 at a predetermined distance.

The memory alloy spring 40 has a length A that is approximately the same length as the normal spring 12 at room temperature, and returns to its initial shape when heated with electricity.
As the length expands to B, the spring pressure returns to the set spring pressure and performs a spring action.

As shown in FIG. 7, this memory alloy spring 40 is housed in a cylinder 41 that is extendable and retractable within a length l ₁ to l ₂ and is interposed between the front surface of the vehicle body 10 and the bumper 11. 41, it is designed to extend and contract within a predetermined range toward the front of the vehicle body.

First, under normal driving conditions, as shown in FIG. 5, the bumper 11 is in a position protruding from the front of the vehicle body 10 by a distance l ₁ , and the spring pressure of the memory alloy springs 40, 40 is approximately equal to "0". Therefore, the impact force when contacting or colliding with an object is usually absorbed, relaxed, and buffered only by the spring action of the springs 12, 12.

On the other hand, when an obstacle A is located in front of the vehicle body and approaches within a predetermined range, the sensor 14 detects this object A as described above, and also detects its relative speed and approach distance. This detection output is compared with the setting output set by the setting device 17 as described above, and if it exceeds this setting output, a signal is output from the comparator 16 to the drive circuit 18, and the power supply 1
9, the memory alloy springs 40, 40 are energized and heated. As a result, the memory alloy springs 40, 40 return to their original shapes, and their lengths extend from A to B together with the cylinders 41, 41, as shown in FIG. The spring pressure will be restored. As a result, the bumper 11 protrudes from the position where it protrudes at a distance _l1 in front of the vehicle body shown in FIG. 5 to a position further forward at a distance _l2 shown by the imaginary line. At this time, the normal springs 12, 12 are separated from the bumper 11, but the spring action of the memory alloy springs 40, 40 provides a buffering effect without any problem. When the object A collides with the bumper 11, the impact force is first absorbed and relaxed by the memory alloy springs 40, 40, and then the springs 40, 40 contract in the direction of the vehicle body, and the bumper 11 is moved a distance l ₁ In other words, when the normal springs 12, 12 reach the position and are connected, the spring pressure of the normal springs 12, 12 is added to the spring pressure of the springs 40, 40, and the impact force is absorbed and alleviated by the spring action of both springs. be done. According to this, the time required to absorb and alleviate the impact force is at least 4
It is longer than the above embodiment by an amount corresponding to the forward protrusion length l ₂ −l ₁ of 0.40, and a smoother and better buffering effect can be obtained.

In this case, of course, the number of memory alloy springs can be increased as needed.

[Brief explanation of the drawing]

Fig. 1 is a plan view of essential parts of the shock absorber of the present invention, Fig. 2 is a block diagram showing an example of its circuit configuration, Fig. 3 is an exploded perspective view showing another example of the memory alloy spring used in this invention, and Fig. 3 is an exploded perspective view showing another example of the memory alloy spring used in this invention. FIG. 4 is a perspective view showing the assembled state, FIG. 5 is a plan view of main parts showing another embodiment of the shock absorber of the present invention, FIG. 6 is a block diagram showing an example of its circuit configuration, and FIG. 7 is the same. FIG. 2 is a perspective view of a memory alloy spring used in an absorber and a cylinder housing the memory alloy spring. 10...Vehicle body, 11...Bumper, 12,12
...Normal spring, 13,13,40,40...Memory alloy spring, A...Object, 14...Sensor, 17...
...Setter, 16...Comparator, 18...Drive circuit.

Claims (1)

[Scope of utility model registration request] A spring made of a normal spring material and a spring made of a shape memory alloy are interposed to connect and support a bumper protruding from the front of the vehicle body to the front surface of the vehicle body, and a front obstacle object disposed at a predetermined position on the vehicle body. A sensor that detects the relative speed and distance to the sensor, and a comparison that calculates the detected output of this sensor and the set output set by the setting device and outputs a signal when the detected output of the sensor exceeds the set output A shock absorber for an automobile or the like, comprising a comparator and a means for heating the shape memory alloy spring to return the spring to its shape based on a signal from the comparator.