Impact energy absorption mechanism

Abstract

This invention provides a highly versatile impact energy absorption mechanism that can absorb the impact energy of a colliding object regardless of its installation location. [Solution] The impact energy absorption mechanism consists of a collision receiving part 10, a disc 20, and a specific link mechanism 30. The collision receiving part 10 is movable with one degree of freedom in the collision direction of the colliding object 1. The disc 20 has a one-way clutch 21 and a handle connection point 22 for rotating the disc around a rotation axis. The specific link mechanism 30 is designed to prevent the impact on the colliding object 1 from being transmitted to the collision receiving part 10 during the collision and to prevent the impact on the colliding object 1 when it has finished stopping. One end of the specific link mechanism 30 is connected to the collision receiving part 10 so as to be axially rotatable on an axis perpendicular to the collision direction of the colliding object 1, and the other end is connected to the handle connection point 22 so as to be axially rotatable on an axis in the same direction as the rotation axis of the disc 20.

Description

Technical Field

[0001] The present invention relates to an impact energy absorption mechanism, and particularly to an impact energy absorption mechanism capable of absorbing the impact energy of a collision object.

Background Art

[0002] When a machine body contacts a contact surface, such as when a spacecraft lands, a robot walks, or a car collides, a very large impact occurs at the moment of changing from a non-contact state to a contact state. When such an extremely large instantaneous impact energy is transmitted to the machine body, it leads to problems such as component damage. Therefore, various impact energy absorption mechanisms capable of absorbing the impact energy transmitted to the machine body have been developed.

[0003] As impact energy absorption mechanisms, there are various types, such as those using springs, dampers, protectors, airbags, etc. However, those using springs, dampers, etc. generate an infinite acceleration at the time of collision due to their mass, which results in an extremely large instantaneous impact energy being transmitted to the machine body.

[0004] In order to reduce such an extremely large instantaneous impact energy, for example, there is an impact mitigation mechanism in Patent Document 1 by the same applicant as the applicant of the present application. The collision mitigation mechanism disclosed in Patent Document 1 uses a link mechanism with structural specificity. It is attached to an object to be mitigated from impact and is used to mitigate the impact when the object falls.

[0005] Furthermore, shock absorption mechanisms designed to be installed on the floor as impact absorption mechanisms for falling objects are also known (Non-Patent Document 1, Non-Patent Document 2). These are designed to be installed on the floor that receives falling objects, and they convert the mechanical energy of the falling object into the mechanical energy of a weight in the shock absorption mechanism, thereby decelerating the falling object. The weight is mounted on a link mechanism with structural uniqueness, and the velocity of the weight is zero when the falling object hits the floor, and the velocity of the falling object becomes zero when the weight hits the ground plate at the end of the impact absorption. At the moment the falling object hits the floor, there is a collision between the falling object and the floor, and at the end of the impact absorption, the weight swings and a collision occurs between the weight and the ground plate. At this time, by utilizing the structural uniqueness, the equivalent mass of the weight is made zero when it hits the floor to reduce the force acting on the falling object due to the collision, and at the end of the impact absorption, the acceleration transfer coefficient from the weight to the floor is made zero to reduce the force acting on the falling object due to the collision. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-134911 [Non-patent literature]

[0007] [Non-Patent Document 1] "Optimal Design of Impact Absorbing Floor Mechanisms by Singular Posture and Mechanical Energy Exchange," by Ryo Kihara et al., Japan Society of Mechanical Engineers Robotics and Mechatronics Conference 2023, 2A1-I19, Nagoya, June 28 - July 1, 2023. [Non-Patent Document 2] "Development of an impact-absorbing floor based on unique posture and mechanical energy exchange for non-transmission of impact force," by Ryo Kihara et al., Japan Society of Mechanical Engineers Robotics and Mechatronics Conference 2024, 2P2-O10, Utsunomiya City, May 29 - June 1, 2024. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] For example, the collision mitigation mechanism described in Patent Document 1 was capable of effectively mitigating the impact when an object falls vertically. However, because its structure is specialized for mitigating the impact of objects falling vertically, it was difficult to install it on the floor side that receives the falling object.

[0009] Furthermore, when attempting to absorb the impact of a large falling object using a shock absorption mechanism with weights, for example, as described in Non-Patent Documents 1 and 2, the collision of the swinging weights with the ground plate caused distortion of the mechanism components, preventing the maintenance of the structurally unique link structure, and sometimes resulting in slight transmission of the impact. Moreover, there was a possibility of structural component damage due to the violent collision of the weights. In addition, if a structure using the swing of weights is optimized for shock absorption against vertically falling objects, the potential energy of the weights changes when the shock absorption mechanism tilts, thus disrupting its optimality. In particular, in the case of a shock absorption mechanism combining multiple link structures, it is necessary to consider the orientation and direction of the shock absorption mechanism, maintain the standby position of each weight, and consider the swing direction of each weight, making the design complex and difficult.

[0010] In view of these circumstances, the present invention aims to provide an impact energy absorption mechanism that is highly versatile, independent of installation location, and capable of having a high-strength structure, thereby absorbing the impact energy of even large impact objects. [Means for solving the problem]

[0011] To achieve the above-mentioned objectives of the present invention, the impact energy absorption mechanism according to the present invention comprises: an impact receiving portion that is movable with one degree of freedom in the direction of impact of the impacting object upon impact; a disc having a one-way clutch that is rotatable in only one direction about a rotation axis and having a handle connection point for rotating the disc about the rotation axis; and a special link mechanism for preventing impact on the impact receiving portion upon impact with the impacting object and for preventing impact on the impacting object upon completion of stopping. Here, the specific link mechanism is configured such that one end is connected to the collision receiving part so as to be rotatable on an axis perpendicular to the collision direction of the colliding object, and the other end is connected to the handle connection point so as to be rotatable on an axis in the same direction as the rotation axis of the disk, and when the colliding object collides, the longitudinal direction of the specific link mechanism is positioned perpendicular to the collision direction of the colliding object so that the impact energy of the colliding object is not transmitted to the disk, and when the colliding object collides and the collision receiving part is moving with one degree of freedom, the specific link mechanism rotates the disk via the handle connection point, thereby converting the impact energy of the colliding object into rotational energy of the disk, and when the colliding object has finished coming to a halt, the longitudinal direction of the specific link mechanism, the handle connection point, and the rotation axis of the disk are aligned on the same line so that the rotational energy of the disk is not transmitted to the colliding object, and the disk continues to rotate for a predetermined time even after the colliding object has finished coming to a halt.

[0012] Here, the disc consists of a first disc, a second disc, and a speed change mechanism that transmits the rotation of the first disc to the second disc. The first disc has a handle connection point, and the second disc has a one-way clutch. The other end of the special link mechanism is connected to the handle connection point of the first disc. When an object collides, the longitudinal direction of the special link mechanism is positioned perpendicular to the collision direction of the object, so that the impact energy of the object is not transmitted to the first disc. When the object collides and the collision receiving part is moving with one degree of freedom, the special link mechanism rotates the first disc via the handle connection point and rotates the second disc via the speed change mechanism, thereby converting the impact energy of the object into rotational energy of the second disc. When the object has finished stopping, the longitudinal direction of the special link mechanism, the handle connection point, and the rotation axis of the first disc are aligned on the same straight line, so that the rotational energy of the first disc is not transmitted to the object, and the second disc continues to rotate for a predetermined time even after the object has finished stopping.

[0013] Furthermore, the gear shifting mechanism may be configured to allow for changes in the equivalent moment of inertia of the second disc.

[0014] Furthermore, the unique link mechanism may consist of a first link and a second link, with one end of the second link integrally fixed to the rotation axis of the disk, the other end of the second link located at the handle connection point, one end of the first link connected to the collision receiving section so as to be axially rotatable on an axis perpendicular to the collision direction of the colliding object, and the other end of the first link connected to the other end of the second link so as to be axially rotatable on an axis in the same direction as the rotation axis of the disk, and configured such that when the colliding object collides, the longitudinal direction of the first link is positioned perpendicular to the collision direction of the colliding object, and when the colliding object has finished stopping, the longitudinal direction of the first link, the longitudinal direction of the second link, and the rotation axis of the disk are aligned on the same straight line.

[0015] Furthermore, the second link may have a thickness that allows the retaining holes necessary to hold the ends of the connecting shaft and the rotating shaft of the first link to not interfere with each other, so as not to interfere with the rotating shaft of the first link.

[0016] Furthermore, it may have a holding mechanism that holds the position where the longitudinal direction of the specific link mechanism is perpendicular to the collision direction of the colliding object until the colliding object collides, and releases the holding at the time of the collision of the colliding object.

[0017] Also, the specific link mechanism may be composed of a pair of specific link mechanisms arranged symmetrically with respect to the disk surface.

[0018] Also, the impact energy absorption mechanism may have two or more pairs of the disk and the specific link mechanism.

Advantages of the Invention

[0019] The impact energy absorption mechanism of the present invention has the advantage that it has high versatility, does not depend on the installation position, and can have a high-strength structure.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a schematic front view for explaining the impact energy absorption mechanism of the present invention. [Figure 2] FIG. 2 is a schematic side view for explaining the configuration of the disk of the impact energy absorption mechanism of the present invention. [Figure 3] FIG. 3 is a schematic front view for explaining another configuration of the disk of the impact energy absorption mechanism of the present invention. [Figure 4] FIG. 4 is a schematic front view for explaining an example of the structure of the specific link mechanism of the impact energy absorption mechanism of the present invention. [Figure 5] FIG. 5 is a graph of the simulation result at the time of collision of the impact energy absorption mechanism of the present invention. [Figure 6] FIG. 6 is a schematic side sectional view for explaining an example of the second link of the impact energy absorption mechanism of the present invention. [Figure 7] FIG. 7 is a schematic side view for explaining the holding mechanism for holding the position of the specific link mechanism of the impact energy absorption mechanism of the present invention. [Figure 8]Figure 8 is a schematic side view illustrating an example of a pair of unique link mechanisms in the impact energy absorption mechanism of the present invention. [Figure 9] Figure 9 is a schematic top view illustrating an example using two pairs of disk and specific link mechanisms of the impact energy absorption mechanism of the present invention. [Modes for carrying out the invention]

[0021] The embodiments for carrying out the present invention will be described below with reference to the illustrations. The impact energy absorption mechanism of the present invention is capable of absorbing the impact energy of a colliding object. When a colliding object collides with the impact energy absorption mechanism of the present invention, it is sufficient to optimize the mechanism so as to minimize the maximum acceleration generated on the colliding object from the time of collision until the completion of stopping, and so as not to impose a large force on the colliding object. The impact energy absorption mechanism of the present invention may be placed, for example, on the floor next to a bed and used to absorb the impact energy of a person who falls from the bed. It may also be installed on the bumper of a vehicle, etc., to prevent impact energy from being imparted to colliding objects such as walls or people.

[0022] Figure 1 is a schematic front view illustrating the impact energy absorption mechanism of the present invention. Figure 1(a) shows the state at the moment of impact, Figure 1(b) shows the state during impact energy absorption, and Figure 1(c) shows the state when the impacting object has finished coming to a stop. In this specification, the state in Figure 1(a) is referred to as the starting point, and the state in Figure 1(c) is referred to as the ending point. As shown in the figure, the impact energy absorption mechanism of the present invention mainly consists of an impact receiving part 10, a disc 20, and a specific link mechanism 30. Note that the illustrated example represents only a mechanical model of the mechanism and does not show the specific structure of each part. Also, the illustrated example shows a mechanism that absorbs the impact energy of an impacting object 1 that has fallen in the vertical direction. That is, the impact direction is vertical. However, the present invention is not limited to this, and any mechanism capable of absorbing mechanical energy in the direction of impact may be configured to absorb impact energy in the horizontal direction, for example.

[0023] The collision receiving section 10 is movable with one degree of freedom in the collision direction of the collision object 1 upon impact. Specifically, the collision receiving section 10 can be a flat plate-like body such as a floor, and it is sufficient if it is movable with one degree of freedom in the vertical direction. The collision receiving section 10 has a connecting section 11 for connecting to the special link mechanism 30 described later. In the illustrated example, one end of the connecting section 11 is fixed vertically to the lower part of the flat plate-like body of the collision receiving section 10. The other end of the connecting section 11 is connected to the special link mechanism 30 via the first rotational pair 12. The first rotational pair 12 is rotatable around an axis perpendicular to the collision direction of the collision object 1. That is, if the collision direction is vertical, it is sufficient if it is rotatable around a horizontal axis. Although the illustrated example shows a connecting section 11 fixed vertically, the present invention is not limited to this, and the flat plate-like body of the collision receiving section 10 may be directly connected to the special link mechanism 30 via the first rotational pair 12. Furthermore, a linear slide mechanism 13 may be provided as appropriate so that the collision receiving part 10 is configured to move with one degree of freedom. The slider of the linear slide mechanism 13 should be fixed to the ground such as a base, and the rail should be fixed to the collision receiving part 10.

[0024] The disc 20 has a one-way clutch 21 that allows it to rotate in only one direction around the axis of rotation. The disc 20 in the illustrated example is shown to be rotatable counterclockwise. That is, it is configured so that it does not rotate clockwise due to the one-way clutch 21. The one-way clutch 21 can be any mechanism, such as a ratchet type, roller type, or cam type, as long as it allows rotation in only one direction. The axis of rotation C of the disc 20 can be fixed to the ground, such as a base, as appropriate. The disc 20 also has a handle connection point 22. The handle connection point 22 is for rotating the disc 20 around the axis of rotation C. Therefore, the handle connection point 22 can be in a direction normal to the axis of rotation C. Furthermore, since the handle connection point 22 is rotated by the impact energy of the colliding object 1, it is preferable that it be positioned above the axis of rotation C (closer to the colliding object), that is, above the halfway point of the disc 20. Furthermore, the handle connection point 22 does not need to be directly above the rotation axis C, and may be positioned further away from the first rotational pair 12 than directly above it. Moreover, although the illustrated example shows the handle connection point 22 positioned at a position shorter than the radius of the disc 20, the present invention is not limited to this, and may be positioned beyond the radius of the disc 20 by a crank or the like.

[0025] An example of the configuration of the disc 20 will be explained using Figure 2. Figure 2 is a schematic side view illustrating the configuration of the disc of the impact energy absorption mechanism of the present invention. In the figure, parts with the same reference numerals as in Figure 1 represent the same components. As shown in the figure, the disc 20 can consist of, for example, a one-way clutch 21, a handle connection point 22, and a weight portion 23. The weight portion 23 continues to rotate by receiving the rotational force from the handle connection point 22. More specifically, the one-way clutch 21 should be positioned between the part where the handle connection point 22 is located and the weight portion 23. As a result, when the handle connection point 22 is rotated, for example, counterclockwise, the weight portion 23 rotates counterclockwise around the rotation axis C via the one-way clutch 21. Even if the counterclockwise rotation of the handle connection point 22 is stopped, the weight portion 23 continues to rotate counterclockwise. The rotation of the weight section 23 stops after a predetermined time, depending on the magnitude of the rotational force at the handle connection point 22, the resistance of the rotation axis C, the resistance of the one-way clutch 21, etc.

[0026] Referring again to Figure 1, the impact energy absorption mechanism of the present invention further includes a special link mechanism 30. The special link mechanism 30 is designed to prevent impact from being applied to the impact receiving part 10 when the impact occurs on the colliding object 1, and also to prevent impact from being applied to the colliding object 1 when it has finished stopping. One end of the special link mechanism 30 is connected to the connection part 11 via the first rotational pair part 12. That is, one end of the special link mechanism 30 should be connected to the impact receiving part 10 so as to be axially rotatable on an axis perpendicular to the direction of impact of the colliding object 1. The other end of the special link mechanism 30 is connected to the handle connection point 22 via the second rotational pair part 14. The second rotational pair part 14 is axially rotatable on an axis in the same direction as the rotation axis C of the disk 20. That is, the other end of the special link mechanism 30 should be connected to the handle connection point 22 so as to be axially rotatable on an axis in the same direction as the rotation axis C of the disk 20. As shown in Figure 1(a), at the starting point, the peculiar link mechanism 30 is configured such that, at the time of impact with the object 1, its longitudinal direction is perpendicular to the direction of impact with the object 1. That is, in the illustrated example, it is positioned horizontally. As a result, the impact energy of the object 1 is not transmitted to the disk 20. This is the first peculiarity of the peculiar link mechanism 30. Therefore, only a force proportional to the mass of the impact receiving part 10 and the peculiar link mechanism 30 acts on the object 1 as an impact force due to the collision. For this reason, by reducing the mass of the impact receiving part 10 and the peculiar link mechanism 30, the force acting on the object 1 can be reduced.

[0027] Then, after passing the state at the moment of impact shown in Figure 1(a), as shown in Figure 1(b), while absorbing impact energy, the impact receiving part 10 receives impact energy from the impacting object 1 and moves with one degree of freedom. During the movement of the impact receiving part 10, the peculiar link mechanism 30 rotates the disk 20 via the handle connection point 22. As a result, the impact energy of the impacting object 1 is converted into rotational energy of the disk 20. As shown in Figure 1(c), at the endpoint, the longitudinal direction of the peculiar link mechanism 30, the handle connection point 22, and the rotation axis C of the disk 20 are aligned on the same straight line. As a result, the rotational energy of the disk 20 is not transmitted to the impacting object 1. This is the second peculiarity of the peculiar link mechanism 30. Therefore, the impacting object 1 and the impact receiving part 10 stop with zero acceleration. For this reason, no impulsive force is generated on the impacting object 1 when it stops. This corresponds to the equivalent mass of the disk 20 relative to the impacting object 1 being infinite. Furthermore, the disc 20, which is rotated by the impact energy of the colliding object 1, continues to rotate for a predetermined time even after the colliding object 1 has finished coming to a complete stop. That is, it continues to rotate until a predetermined time has elapsed, depending on the magnitude of the impact energy, the resistance of the rotation axis C, the resistance of the one-way clutch 21, etc.

[0028] The impact energy absorption mechanism of the present invention, configured in this way, converts the impact energy of the colliding object into rotational energy of the disk, thereby absorbing the impact energy of the colliding object. The amount of sinking and acceleration from the start to the end point of the collision of the colliding object can be optimized by appropriately adjusting parameters such as the length and mass of the special link mechanism 30, the position of the handle connection point 22, and the mass and rotational speed of the disk 20.

[0029] The impact energy absorption mechanism of the present invention does not employ a structure that causes distortion in the mechanical components, such as a swinging weight or collisions with a weight, so there is no risk of the uniqueness of the unique link mechanism being compromised. Furthermore, since it is not a structure that receives violent collisions with weights, there is no risk of damage to the structural components. Moreover, the impact energy absorption mechanism of the present invention does not use a mechanism such as a swinging weight, where the potential energy changes depending on the installation position, and because it uses a disc structure, the potential energy does not change depending on the installation position. Therefore, the unique link mechanism itself is independent of the installation position, making it easy to design. Thus, the impact energy absorption mechanism of the present invention is not limited to the vertical direction of installation, and can be installed horizontally, for example, to absorb horizontal impacts. Therefore, the impact energy absorption mechanism of the present invention is highly versatile and can absorb the impact energy of collisions regardless of the installation position. Furthermore, since it is a structure that converts impact energy into rotational energy, there is no part that receives violent impacts such as a swinging weight. Therefore, the collision receiving section 10 and the specific link mechanism 30 only need to be designed to withstand the impact on the collision object 1, and it is possible to make them highly strong structures to match the collision object.

[0030] Next, other configurations of the disk of the impact energy absorption mechanism of the present invention will be described using Figure 3. Figure 3 is a schematic front view illustrating other configurations of the disk of the impact energy absorption mechanism of the present invention. Figure 3(a) shows the starting state, and Figure 3(b) shows the ending state. In the figures, parts with the same reference numerals as in Figure 1 represent the same objects. The illustrated disk 20 consists of a first disk 24, a second disk 25, and a gear shift mechanism 26. The first disk 24 has a handle connection point 22. The second disk 25 is a weight portion that continues to rotate by receiving the rotational force from the handle connection point 22. The second disk 25 has a one-way clutch 21. The gear shift mechanism 26 is for transmitting the rotation of the first disk 24 to the second disk 25. In the illustrated example, the gear shift mechanism 26 consists of a first gear 26a, a second gear 26b, and a belt 26c. The first gear 26a, the second gear 26b, and the belt 26c can be, for example, a toothed belt and toothed pulley with grooves at a predetermined pitch. Alternatively, a chain and sprocket can be used. The gear ratio of the first gear 26a and the second gear 26b determines the equivalent moment of inertia applied to the second disc 25. These configurations correspond, for example, to the crank of a bicycle: the first disc 24 corresponds to the first gear 26a, the chainring to the first gear 26a, the wheel to the second disc 25, the cog to the second gear 26b, the chain to the belt 26c, and the freehub to the one-way clutch 21.

[0031] The singular link mechanism 30, with one end connected to the connection part 11 of the collision receiving part 10 via the first rotational pair part 12, has its other end connected to the handle connection point 22 of the first disc 24. Similar to the example described using Figure 1 above, the example shown in Figure 3 is also configured so that the impact energy of the collision object 1 is converted into rotational energy of the second disc 25. As shown in Figure 3(a), in the starting state, the singular link mechanism 30 is positioned horizontally to realize the first singularity. As a result, the impact energy of the collision object 1 is not transmitted to the first disc 24. On the other hand, during impact energy absorption, the singular link mechanism 30 rotates the first disc 24 via the handle connection point 22. This rotation of the first disc 24 rotates the second disc 25 via the speed change mechanism 26. As a result, the impact energy of the collision object 1 is converted into rotational energy of the second disc 25. As shown in Figure 3(b), in the final state, in order to achieve the second singularity, the longitudinal direction of the singularity link mechanism 30, the handle connection point 22, and the rotation axis C of the first disc 24 are aligned on the same straight line. With this structure, the rotational energy of the first disc 24 is not transmitted to the impact object 1. The second disc 25, which is rotated by receiving the impact energy of the impact object 1, continues to rotate for a predetermined time even after the impact object 1 has come to a complete stop, due to the one-way clutch 21.

[0032] Here, the aforementioned gear shifting mechanism 26 may be configured to change the equivalent moment of inertia of the second disc 25. For example, it could be a one-way clutch 21 with a planetary gear shifting mechanism incorporated into it, or a one-way clutch 21 with multiple types of sprockets with different numbers of teeth combined with a derailleur to change the gear ratio, or any other mechanism that can change the gear ratio. This makes it possible to optimize the impact energy absorption mechanism of the present invention according to, for example, the mass and acceleration of the colliding object 1.

[0033] Next, the specific structure of the specific link mechanism 30 will be described using Figure 4. Figure 4 is a schematic front view illustrating an example of the structure of the specific link mechanism of the impact energy absorption mechanism of the present invention. Figure 4(a) shows the starting state, and Figure 4(b) shows the ending state. In the figures, parts with the same reference numerals as in Figures 1 and 3 represent the same objects. In the illustrated example, only the area around the specific link mechanism is shown, and other parts are omitted from the illustration. Also, the disc 20 in the illustrated example is shown to consist of a first disc 24, a second disc 25, and a speed change mechanism 26. However, the present invention is not limited to this, and the disc may be as shown in Figure 1. Also, an example is shown in which the handle connection point 22 is positioned beyond the radius of the disc 20. As shown in the illustration, the specific link mechanism 30 may consist of a first link 31 and a second link 32. In the illustrated example above, the handle connection point 22 is shown to be directly provided on the first disc 24, but as shown in Figure 4, it may also be provided via the second link 32. Here, one end of the second link 32 is integrally fixed to the rotation axis C of the first disk 24. That is, one end of the second link 32 should be fixed to the rotation axis C that rotates in conjunction with the first disk 24 so that it rotates together with the first disk 24. The other end of the second link 32 is located at the handle connection point 22. That is, the second link 32 should be fixed to the rotation axis C so that the other end of the second link 32 is positioned at the handle connection point 22. On the other hand, one end of the first link 31 is connected to the connection part 11 via the first rotational pair part 12. The other end of the first link 31 is connected to the other end of the second link 32 via the second rotational pair part 14. Similar to the illustrated example described above, as shown in Figure 4(a), in the starting state, the first link 31 is positioned horizontally to realize the first uniqueness. Furthermore, as shown in Figure 4(b), in the final state, the longitudinal direction of the first link 31, the longitudinal direction of the second link 32, and the rotation axis C of the first disk 24 are arranged on the same straight line in order to realize the second singularity. Thus, the singularity link mechanism 30 may be composed of a combination of multiple links.

[0034] A simulation was conducted to examine the changes in the position of the impact receiving section 10 and the changes in the acceleration of the impacting object when an impacting object is dropped onto the impact energy absorption mechanism of the present invention using the unique link mechanism 30 shown in Figure 4. The simulation conditions were as follows: First, the impacting object 1 was assumed to weigh 60 kg and be dropped from a height of 30 cm. The dimensions of the unique link mechanism 30 were set as follows: the length L1 of the first link 31 was 149.3 mm, the horizontal length L2 from the first rotating pair 12 to the rotation axis C was 143.1 mm, and the length L3 of the second link 32 was 13.8 mm. In the impact energy absorption mechanism of the present invention, the behavior during impact absorption is mainly determined by these dimensions. The radius of the second disc 25 was set to 75 mm and its weight to 8 kg. The gear ratio of the first gear 26a and the second gear 26b when transmitting rotation from the first disc 24 to the second disc 25 using the belt 26c was set to 3:1 (the ratio of rotational speeds was 1:3). Figure 5 shows the simulation results of the impact energy absorption mechanism designed in this way during a collision. Figure 5 is a graph of the simulation results of the impact energy absorption mechanism of the present invention during a collision. Figure 5(a) shows the change in the position of the impact receiving part over time, and Figure 5(b) shows the change in the acceleration of the impacting object over time. As can be seen from the position change graph in Figure 5(a), the endpoint is reached after about 0.07 seconds, and the object stops at around -0.09m. Also, as shown in Figure 5(b), it can be seen that in the impact energy absorption mechanism of the present invention, a large impact force is not generated during the collision, the impact is suppressed, and there is no vibration, and the endpoint is reached in about 0.07 seconds. Note that two acceleration peaks can be seen, the first peak is the acceleration due to the reaction force obtained by rotating the disk, and the second peak is the acceleration due to constraint by the second singularity. These two peaks can be adjusted as appropriate by tuning the length of each link. For example, when absorbing shock with a general damper, there is a risk of generating a large impact force, bottoming out resulting in a large acceleration, or vibration during shock absorption. However, with the shock energy absorption mechanism of the present invention, there is no risk of vibration or bottoming out.

[0035] In the impact energy absorption mechanism of the present invention, when each parameter is optimized to absorb the impact energy of the colliding object 1, the distance from the disc 20 to the handle connection point 22 may become extremely short depending on the conditions. For example, in the example shown in Figure 4, the second link 32 may become extremely short. Below, using Figure 6, a structure that prevents interference between the connection axis of the first link and the rotation axis of the disc even when the second link 32 is extremely short will be described. Figure 6 is a schematic side cross-sectional view illustrating an example of the second link of the impact energy absorption mechanism of the present invention. In the figure, parts with the same reference numerals as in Figure 4 represent the same parts. As shown in the figure, the second link 32 has a structure that prevents interference between the second rotational pair part 14, which is the connection axis of the first link 31, and the rotation axis C of the disc 20 (24). Specifically, the second link 32 has a thickness that allows the holding holes necessary to hold the end of the second rotational pair part 14 and the end of the rotation axis C to be provided at a depth that does not interfere with each other. The second rotating pair 14, which is the connecting shaft of the first link 31, is positioned at the handle connection point 22. If the length of the second link 32 is short, the ends of each shaft may interfere with each other, making it impossible to hold the ends of each shaft. However, even if the diameters of each shaft are of a size that would cause interference, if the second link 32 is configured to have a thickness that allows the holding holes to be provided at a depth that does not interfere with each other, the shafts will not interfere with each other.

[0036] Next, the holding mechanism for maintaining the position of the special link mechanism of the impact energy absorption mechanism of the present invention will be described. Figure 7 is a schematic side view illustrating the holding mechanism for maintaining the position of the special link mechanism of the impact energy absorption mechanism of the present invention. Figure 7(a) shows the starting state, and Figure 7(b) shows the ending state. In the figures, parts with the same reference numerals as in Figure 1 represent the same objects. The holding mechanism 40 maintains the position in which the longitudinal direction of the special link mechanism 30 is positioned perpendicular to the collision direction of the impact object 1 until the impact object 1 collides with it. That is, for example, in the case of an impact energy absorption mechanism for absorbing impact energy from an impact object 1 falling in the vertical direction, the holding mechanism is designed to ensure that the special link mechanism 30 is held in a horizontal position in the starting state. Furthermore, the holding mechanism is configured to be released when the impact object 1 collides with it. In the illustrated example, the holding mechanism 40 is shown to consist of a lever part 41 and an elastic body 42. Also, the holding mechanism 40 is shown to consist of a pair of parts to support the two connecting parts 11 arranged at both ends of the impact receiving part 10. Furthermore, the specific link mechanism 30 is shown as consisting of a pair of left and right parts. However, the present invention is not limited to this, and may consist of a single holding mechanism or a single specific link mechanism 30. One end of the lever portion 41 should be in contact with the connecting portion 11 of the collision receiving portion 10 so as to support it. The contact position with the connecting portion 11 becomes the point of application of the lever portion 41. The other end of the lever portion 41, which is the point of force application, is connected to one end of the elastic body 42. The other end of the elastic body 42 may be fixed to, for example, the base 43 of the impact energy absorption mechanism. The fulcrum of the lever portion 41 may also be rotatably fixed to the base 43. With the holding mechanism 40 configured in this way, the collision receiving portion 10 can be held so as not to move due to the weight of the collision receiving portion 10 itself, even if the collision object 1 has not collided with it. Furthermore, at the moment of impact, the point of application of the lever portion 41 lowers, releasing contact with the connecting portion 11, and the impact energy of the colliding object 1 is converted into rotational energy of the disk 20 via the special link mechanism 30 as described above. The positioning and release of the special link mechanism 30 can be optimized by appropriately adjusting the length of the lever portion 41, the position of the pivot point, and the elastic force of the elastic body 42.

[0037] Furthermore, when designing an impact energy absorption mechanism to absorb horizontal impact energy, a holding function is not necessarily required. However, a holding function may be provided as appropriate to prevent the starting position from being disrupted by micro-vibrations, etc. Also, in the impact energy absorption mechanism of the present invention, the potential energy does not change depending on the installation position because it uses a disc structure. Therefore, the basic design of the specific link mechanism 30 itself remains unchanged regardless of whether a holding function is present or not.

[0038] Figure 8 is a schematic side view illustrating an example of a pair of peculiar link mechanisms in the impact energy absorption mechanism of the present invention. In the figure, parts with the same reference numerals as in Figure 4 represent the same components. As shown in the figure, the peculiar link mechanism 30 may consist of a pair of peculiar link mechanisms 30, 30 arranged symmetrically with respect to the disk 20. That is, as shown in the illustrated example, peculiar link mechanisms 30 may be provided on the left and right sides of the disk 20. For example, when it is assumed that a very large impact energy is applied to the collision receiving part 10, it is conceivable that one peculiar link mechanism 30 may not be sufficient to withstand it. In such cases, by using a pair of peculiar link mechanisms 30, 30, the impact energy can be dispersed and the peculiar link mechanism 30 can be configured so that no distortion occurs.

[0039] Furthermore, the impact energy absorption mechanism of the present invention may use multiple pairs of discs 20 and specific link mechanisms 30. Figure 9 is a schematic top view illustrating an example in which two pairs of discs and specific link mechanisms of the impact energy absorption mechanism of the present invention are used. In the figure, parts with the same reference numerals as in Figure 3, etc., represent the same objects. As shown in the figure, the impact energy absorption mechanism of the present invention uses two pairs of discs 20 and specific link mechanisms 30. In the illustrated example, the pairs of discs 20 and specific link mechanisms 30 are arranged at a 90-degree angle with respect to the collision receiving part 10. Note that, as in the illustrated example, if multiple specific link mechanisms 30 are used and arranged so that the rotation axes of each first rotating pair part 12 are not parallel, the collision receiving part 10 can move with one degree of freedom in the collision direction of the colliding object. That is, pairs of discs 20 and specific link mechanisms 30 should be arranged around the collision receiving part 10 so that the rotation axes of the first rotating pair parts 12 are not parallel. This arrangement makes it possible to omit the linear slide mechanism shown in the illustrated example above. Furthermore, multiple pairs of discs 20 and specificity link mechanisms 30 can be arranged so that the collision receiving section 10 becomes the center of gravity. For example, three pairs could be arranged at 120 degrees, or four pairs at 90 degrees. This configuration allows for the absorption of even greater impact energy.

[0040] In the illustrated example above, the longitudinal direction of the special link mechanism 30 and the direction of the rotation axis of the disk 20 are shown to be perpendicular, but the present invention is not necessarily limited to this. For example, depending on the arrangement of the impact energy absorption mechanism, the rotation axis of the disk and the longitudinal direction of the special link mechanism may be arranged to be parallel. In this case, the direction of the rotation axis of the disk can be changed by using a speed change mechanism that can change the rotation axis direction as appropriate, such as a bevel gear or a worm gear.

[0041] It should be noted that the impact energy absorption mechanism of the present invention is not limited to the illustrated example described above, and various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0042] 1 Colliding object 10 Collision receiver 11 Connection part 12 First rotational pair 13 Linear slide mechanism 14. Second rotational pair 20 discs 21 One-way clutch 22 Handle connection points 23 Weight section 24. First Disc 25. Second Disc 26a First gear 26b Second Gear 26cm belt 26. Transmission 30. Specificity Link Mechanism 31. Link 1 32. Second Link 40 Retention mechanism 41 Lever section 42 Elastic body 43. Base

Claims

1. An impact energy absorption mechanism that absorbs the impact energy of a colliding object, wherein the impact energy absorption mechanism is A collision receiving part that is movable with one degree of freedom in the direction of the collision of the colliding object, A disc having a one-way clutch that allows it to rotate in only one direction about a rotation axis, and having a handle connection point for rotating the disc about the rotation axis, A special link mechanism for preventing impact on the collision receiving part during collision with the colliding object and for preventing impact on the colliding object upon completion of stopping, wherein the special link mechanism is One end is connected to the collision receiving part so as to be rotatable on an axis perpendicular to the direction of collision of the colliding object. The other end is connected to a handle connection point so as to be rotatable on an axis in the same direction as the rotation axis of the disk, During a collision, the longitudinal direction of the singular link mechanism is positioned perpendicular to the collision direction of the objects, so the impact energy of the objects is not transmitted to the disk. When an object collides and the collision receiving part moves with one degree of freedom, the singular link mechanism rotates the disk via the handle connection point, thereby converting the impact energy of the object into rotational energy of the disk. When the collision object has come to a complete stop, the longitudinal direction of the unique link mechanism, the handle connection point, and the axis of rotation of the disk are aligned on the same straight line, so that the rotational energy of the disk is not transmitted to the collision object. A special link mechanism is configured such that the disc continues to rotate for a predetermined time even after the collision object has come to a complete halt, An impact energy absorption mechanism characterized by comprising the following:

2. In the impact energy absorption mechanism described in claim 1, The aforementioned disc consists of a first disc, a second disc, and a gear shift mechanism that transmits the rotation of the first disc to the second disc, wherein the first disc has a handle connection point and the second disc has a one-way clutch. The other end of the special link mechanism is connected to the handle connection point of the first disk, During the collision of the colliding objects, the longitudinal direction of the singular link mechanism is positioned perpendicular to the collision direction of the colliding objects, so that the impact energy of the colliding objects is not transmitted to the first disk. When an object collides and the collision receiving part moves with one degree of freedom, the singular link mechanism rotates the first disk via the handle connection point and rotates the second disk via the speed change mechanism, thereby converting the impact energy of the object into rotational energy of the second disk. When the collision object has come to a complete stop, the longitudinal direction of the special link mechanism, the handle connection point, and the rotation axis of the first disk are aligned on the same straight line, so that the rotational energy of the first disk is not transmitted to the collision object. The system is configured such that the second disc continues to rotate for a predetermined time even after the collision object has come to a complete halt. A shock energy absorption mechanism characterized by the following features.

3. The impact energy absorption mechanism according to claim 2, wherein the speed change mechanism is configured to change the equivalent moment of inertia of the second disk.

4. In the impact energy absorption mechanism according to claim 1, the specific link mechanism consists of a first link and a second link, One end of the second link is integrally fixed to the axis of rotation of the disk, The other end of the second link is located at the handle connection point. One end of the first link is connected to the impact receiving section so as to be rotatable on an axis perpendicular to the direction of impact of the colliding objects, and the other end of the first link is connected to the other end of the second link so as to be rotatable on an axis in the same direction as the rotation axis of the disk. During the collision of the colliding objects, the longitudinal direction of the first link is positioned perpendicular to the direction of collision of the colliding objects. The system is configured such that when the colliding object has come to a complete stop, the longitudinal direction of the first link, the longitudinal direction of the second link, and the axis of rotation of the disk are aligned on the same straight line. A shock energy absorption mechanism characterized by the following features.

5. The impact energy absorption mechanism according to claim 4, wherein the second link has a thickness that allows the holding holes necessary to hold the end of the connecting shaft and the end of the rotating shaft to not interfere with each other, so that the connecting shaft of the first link and the rotating shaft of the disk do not interfere with each other.

6. An impact energy absorption mechanism according to claim 1, further characterized in that it has a holding mechanism for maintaining a position in which the longitudinal direction of the special link mechanism is positioned perpendicular to the collision direction of the colliding object until the colliding object collides with it, and for releasing the holding when the colliding object collides with it.

7. An impact energy absorption mechanism according to claim 1, characterized in that the special link mechanism comprises a pair of special link mechanisms arranged symmetrically with respect to the disk.

8. An impact energy absorption mechanism according to any one of claims 1 to 7, characterized in that the impact energy absorption mechanism has two or more pairs of disks and specific link mechanisms.

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