JP4418314B2 - Crushing buckling stability controller for vehicle frame - Google Patents

Description

The present invention relates to a crush buckling stability control device for a vehicle frame for crushing the frame.

  2. Description of the Related Art Conventionally, a vehicle body frame is required to be crushed in the longitudinal direction while suppressing bending deformation in order to efficiently absorb collision energy due to a collision. As such a technology, for example, a power unit such as an engine or a transfer disposed in the center of a vehicle and a side frame that supports the left and right sides of the power unit are connected by a special bracket, and the side frame is connected by the special bracket. There is a technique for canceling the bending moment applied to the surface (see Patent Document 1). In addition, as another technology, by forming two elongated holes in a predetermined position of the side frame so as to have a square shape, a bending moment is intentionally generated at the predetermined position at the time of collision. There is a technique for canceling a bending moment applied to a side frame at the time of collision by a bending moment caused by a hole (see Patent Document 2).

JP 2000-168624 A (paragraph 0019, FIG. 1) Japanese Patent Laid-Open No. 10-129521 (paragraph 0019, FIG. 1)

  However, in the conventional technology, the longer the frame length, the more difficult it is to crush the entire frame only by crushing buckling. The reason for this is that in the conventional technology, it is necessary to predict the location of the bending moment at the time of collision and provide a bracket or hole at that location, but in a long frame, there is a disturbance in a location other than the location where the bracket is provided. This is because a bending moment due to the above is easily generated locally, and the frame is broken therefrom. And when such a crease | fold occurred, there existed a possibility that the absorption efficiency of the collision energy of the whole flame | frame might worsen.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle frame collapse / buckling stability control device that can collapse and buckle the frame while suppressing bending deformation even when the frame is long.

The vehicle frame collapse buckling stability control device according to claim 1 of the present invention that solves the above-described problems is a vehicle frame that controls deformation of a frame composed of a plurality of side frames disposed on the left and right sides of the vehicle. A collapsible buckling stability control device, comprising: a joint mechanism that rotatably couples the adjacent side frames; and an impact load applied to the adjacent side frames or a deformation or strain of the side frames at the time of a collision. Detection means for detecting , brake means for restricting rotation of the adjacent side frame around the joint mechanism, and bending applied to the side frame based on an impact load, deformation or strain detection signal detected by the detection means and control means for calculating a moment, when the bending moment calculated by the control unit becomes equal to or greater than the predetermined value, the control And canceling means for canceling the restriction of rotation around the joint mechanism according to the brake means by a signal from the stage, to one of said plurality of side frame by a signal from said control means, in the direction substantially perpendicular to the longitudinal direction A crushing buckling promoting means for applying a lateral force to crush and buckle .
Here, “lateral force” refers to a force applied in a direction substantially orthogonal to the longitudinal direction of the frame. Strictly speaking, this lateral force is a force that faces in a direction other than the longitudinal direction of the frame, but in order to favorably promote crushing buckling, the lateral force is preferably directed in a direction perpendicular to the longitudinal direction of the frame.

  According to the first aspect of the present invention, when the bending moment applied to the frame becomes equal to or greater than a predetermined value, the releasing means releases the joint mechanism in a locked state and releases the bending moment. That is, even when a bending moment is locally applied to an arbitrary portion of the frame, the bending moment is released by making the joint mechanism free.

A second aspect of the present invention is the vehicle frame collapse buckling stability control apparatus according to the first aspect, wherein the release means is operated when a bending moment calculated by the control means is equal to or greater than a predetermined value. In accordance with a signal from, the restriction of the rotation around the joint mechanism by the brake means is set to a free state, and the crush buckling promoting means is operated to crush the side frame .
According to the second aspect of the present invention, when the bending moment calculated by the control unit becomes equal to or greater than a predetermined value, the signal from the release unit frees the restriction of the rotation around the joint mechanism by the brake unit, The crushing buckling promoting means operates to crush and buckle the side frame.

A third aspect of the present invention is the vehicle frame collapse / buckling stability control apparatus according to the first or second aspect, wherein the detection means includes a strain cage and a piezoelectric element, and the side frame includes It consists of a fixed sensing sheet.
According to the invention described in claim 3, when the load is applied to the side frame, the detection means can detect the load with the sensing sheet.

A fourth aspect of the present invention is the vehicle frame collapse / buckling stability control device according to any one of the first to third aspects, wherein the joint mechanism extends in the longitudinal direction of the vehicle. A first hinge provided on one of the adjacent side frames, a second hinge provided on the other of the side frames, and a connecting shaft that rotatably connects the first hinge and the second hinge. The brake means normally applies a brake to the connecting shaft to restrict rotation, and when the bending moment calculated by the control means exceeds a predetermined value, from the release means The brake is released according to the signal to allow rotation of the connecting shaft.
According to the fourth aspect of the present invention, the brake means makes the rotation impossible by applying a brake to the connecting shaft and restricting the rotation. When the bending moment calculated by the control means becomes a predetermined value or more, the brake means releases the brake by a signal from the release means to allow the connecting shaft to turn and to turn.

  According to the first aspect of the present invention, even when a bending moment is locally applied to an arbitrary portion of the frame, the bending moment is released by making the joint mechanism free, so that the frame is long. Even in this case, the frame can be crushed and buckled while suppressing bending deformation.

  According to the second aspect of the present invention, since the crushing buckling can be started from the portion where the lateral force is applied by the accelerating means, the frame can be crushed from the desired location.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a plan view showing a rear frame provided with a collapsed buckling stability controller according to the present embodiment, and FIG. 2 is a partially enlarged view showing details of the collapsed buckling stability controller of FIG. It is. 3 is a partially broken perspective view showing details of the joint mechanism of FIG. 2, and FIG. 4 is a block diagram showing the control device of FIG.

  As shown in FIG. 1, the rear frame RF disposed at the lower rear portion of the vehicle M extends to the front and rear of the vehicle M, and is disposed on the left and right side frames SF, SF, and these side frames. It is mainly composed of three cross members CM, CM, and CM that connect SF and SF. Each side frame SF is divided at a predetermined location, and includes a crushing buckling stability control device 1.

As shown in FIG. 2, the crushing buckling stability control device 1 includes a joint mechanism 2 that rotatably connects a side frame SF divided into two, an impact load applied to the side frame SF, or a deformation of the side frame. Alternatively , it mainly includes a sensing sheet (detection means) 3 for detecting strain and an electromagnetic brake mechanism (brake means) 4 for restricting the rotation of the joint mechanism 2. Further, the collapsed buckling stability control device 1 includes a buckling device ( collapsed buckling promoting means) 5 that accelerates the collapsed buckling of the side frame SF by applying a lateral force to the side frame SF, and the sensing sheet 3. Is provided with a control device (release means) 6 for controlling the electromagnetic brake mechanism 4 and the buckling device 5 on the basis of the signal from.

  As shown in detail in FIG. 3, the joint mechanism 2 mainly includes a first hinge 21, a second hinge 22, a connecting shaft 23, and a spacer 24. The first hinge 21 is joined to one frame SF1 (hereinafter referred to as “front frame SF1”) of the divided side frames SF, and is opposite to the front frame SF1 from the joint plate portion 21a. The two flange portions 21b and 21c extending to the side are formed in a substantially F-shaped cross section. In addition, hole portions 21d and 21d through which the connecting shaft 23 is inserted are formed in the flange portions 21b and 21c. The flange portions 21b and 21c and the connecting shaft 23 are coupled to each other so as not to rotate, for example, by providing a key groove or the like in the holes 21d and 21d.

  Similar to the first hinge 21, the second hinge 22 is configured by a joining plate portion 22a and two flange portions 22b and 22c to have a substantially F-shaped cross section, and the connecting shaft 23 is inserted through the two flange portions 22b and 22c. Holes 22d and 22d to be formed are formed. In addition, these hole parts 22d and 22d are supporting the connection shaft 23 rotatably. The first hinge 21 and the second hinge 22 having a substantially F-shaped cross section are overlapped with each other in a state where the first hinge 21 is turned upside down with respect to the second hinge 22, and the overlapping portion (the flange portion 21b). The ring-shaped spacer 24 is disposed between the flange portion 22c and the flange portion 21c and the flange portion 22b.

  As shown in FIG. 2, the sensing sheet 3 is a long sheet that is bonded to the corner portion of the side frame SF along the vehicle front-rear direction, and an optical fiber, a strain gauge, and a piezoelectric element (not shown) are provided therein. It is prepared for. The sensing sheet 3 detects deformation, deformation speed and deformation acceleration of the side frame SF with an optical fiber, measures deformation signs from an elastic region to a plastic region with a strain gauge, and further detects an impact load with a piezoelectric element. is doing.

  The electromagnetic brake mechanism 4 is a so-called planetary gear head having a plurality of gears therein. As shown in FIG. 3, the rotating shaft 41 is non-rotatably coupled to the connecting shaft 23 that is coaxial, and the main body 42. Is fixed to the flange portion 22 c of the second hinge 22 via the support base 43. The connecting shaft 23 is also rotatable with respect to the support base 43. The electromagnetic brake mechanism 4 fixes the main body 42 and the connecting shaft 23 in a state in which relative rotation is impossible in a normal state based on a control signal from the control device 6 (see FIG. 2). When a predetermined moment is applied to the frame SF, it operates so as to allow relative rotation between the main body 42 and the connecting shaft 23. In other words, the electromagnetic brake mechanism 4 restricts the rotation of the connecting shaft 23 by constantly applying a brake to the connecting shaft 23, and the brake (control of the joint mechanism 2) when a predetermined moment is applied to the side frame SF. Is released.

  In the present embodiment, the electromagnetic brake mechanism 4 and the connecting shaft 23 are arranged coaxially. However, the present invention is not limited to this, for example, by providing a gear between the electromagnetic brake mechanism 4 and the connecting shaft 23. The two may be arranged offset. However, in the case of being coaxial as in the present embodiment, the structure can be reduced in size and the torque transmission is improved, so that the structure as in the present embodiment is desirable.

  As shown in FIG. 2, the buckling device 5 includes a coiled spring member 51 made of a shape memory alloy, a pair of abutting members 52 and 52 attached to both ends of the spring member 51, and the spring member 51. And an electric heater 53 for heating the spring member 51, and a power supply unit (not shown) for supplying electric power to the electric heater 53. The buckling device 5 is disposed in the front frame SF1 disposed on the front side of the vehicle M and in the rear frame SF2 disposed on the rear side, and the abutting members 52, 52 thereof. Has a structure that is joined from the inside to two opposing surfaces of the hollow side frame SF (front frame SF1, rear frame SF2). The buckling device 5 has a structure in which, when the power supply unit is turned on and the electric heater 53 is activated, the spring member 51 extends to apply an outward force (lateral force) to the two surfaces. It has become.

  In the following description, for convenience of explanation, the buckling device 5 disposed in the front frame SF1 is also referred to as a front device 5A, and the buckling device 5 disposed in the rear frame SF2 is referred to as a rear device 5B. Say. In the present embodiment, the spring member 51 is heated by the electric heater 53. However, for example, the spring member may be heated and extended by supplying current directly to the spring member 51. Further, the spring member 51 is not limited to a coil-like one as in the present embodiment, and for example, may have a shape obtained by bending a plate, or may be changed as appropriate.

  As shown in FIG. 4, the control device 6 includes a collision determination unit 61, a crush determination unit 62, a device activation unit 63, a moment calculation unit 64, a moment determination unit 65, and an electromagnetic brake control unit 66. It is configured. The collision determination unit 61 determines whether or not the vehicle M collides based on a signal output from a radar RD that is disposed at the rear of the vehicle M and detects a rear collision of the vehicle M. If it is determined, a signal indicating that a collision occurs is output to the device activation unit 63.

  The crush determination unit 62 determines the progress of the crushing buckling in the vicinity of the buckling device 5 based on the signal output from the sensing sheet 3. When the crushing determination unit 62 determines that the crushing buckling is still in progress, the crushing determination unit 62 outputs a signal indicating that the crushing buckling is in progress to the moment determination unit 65 and determines that the crushing buckling has ended. In this case, a signal indicating completion is output to the device activation unit 63.

  Upon receiving the signal output from the collision determination unit 61, the device activation unit 63 outputs an ON signal for activating a power supply unit (not shown) of the rear device 5B (see FIG. 2) to the rear device 5B. . When the device activation unit 63 receives the signal output from the collapse determination unit 62, the device activation unit 63 outputs an ON signal for activating a power supply unit (not shown) of the front device 5A (see FIG. 2) to the front device 5A. Yes.

  The moment calculation unit 64 calculates a bending moment applied to the front frame SF1 and the rear frame SF2 based on the signal output from the sensing sheet 3, and outputs a signal indicating the calculated value to the moment determination unit 65. Yes. Upon receiving the signal output from the collapse determining unit 62, the moment determining unit 65 receives the bending moment indicated by the signal output from the moment calculating unit 64 and the bending collapse moment stored in advance in a storage device (not shown). The value is compared with (bending moment when the side frame SF is folded).

  The moment determination unit 65 performs electromagnetic brake control on a signal that causes the electromagnetic brake mechanism 4 to be in a fixed state so that the connecting shaft 23 and the main body 42 cannot be rotated relative to each other when the bending moment is smaller than the bending collapse moment. When the bending moment is equal to or greater than the bending collapse moment, a signal is output to the electromagnetic brake control unit 66 so that the electromagnetic brake mechanism 4 is free and the connecting shaft 23 and the main body 42 can rotate relative to each other. ing. The electromagnetic brake control unit 66 performs control to switch the electromagnetic brake mechanism 4 between a fixed state and a free state based on a signal from the moment determination unit 65.

Next, the operation of the control device 6 will be described with reference to FIGS. Here, FIG. 5 to be referred to is a flowchart showing the operation of the control device.
As shown in FIG. 5, first, when the radar RD that monitors the collision of the vehicle M outputs a signal (step S1), the collision determination unit 61 determines whether the vehicle M collides based on the signal (step S1). Step S2). When it is determined in step S2 that the vehicle M does not collide (NO), the buckling device 5 is maintained in the non-operating state, and the electromagnetic brake mechanism 4 is maintained in the operating state (step S3). Is kept high.
Note that, during normal traveling, the electromagnetic brake mechanism 4 is maintained in operation.

  If it is determined in step S2 that the vehicle M has collided (YES), the rear device 5B is activated by the device activation unit 63, and a lateral force is applied to the rear frame SF2 by the spring member 51 (step S4). ). Next, it is determined whether or not the collapse buckling of the rear frame SF2 has been completed by the collapse determination unit 62 (step S5).

  If it is determined in step S5 that the collapse buckling has not yet been completed, i.e., is in progress (NO), the bending moment currently applied to the rear frame SF2 by the moment determination unit 65 is set in advance. It is determined whether or not the bending collapse moment (predetermined value) is exceeded (step S6).

  If it is determined in step S6 that the bending moment is smaller than the bending collapse moment (NO), the electromagnetic brake mechanism 4 is fixed by the electromagnetic brake control unit 66 (step S7), and the process returns to step S5. If it is determined in step S6 that the bending moment is greater than or equal to the bending collapse moment (YES), the electromagnetic brake mechanism 4 is brought into a free state by the electromagnetic brake control unit 66 (step S8), and the process returns to step S5. .

  If it is determined in step S5 that the collapse buckling has ended (YES), the device starter 63 starts the front device 5A, and the spring member 51 applies a lateral force to the front frame SF1 (step S9). ). By controlling the buckling device 5 and the electromagnetic brake mechanism 4 in this way, the side frames SF are crushed and buckled in order from the rear side.

  The above description relates to the case where a collision load is applied from the rear frame SF2. However, when the collision load is applied from the front frame SF1, the control order of the front device 5A and the rear device 5B is reversed. Similarly, the entire side frame SF can be crushed and buckled in the same manner.

  Next, the crushing method of the side frame SF by the crushing buckling stability control apparatus 1 will be described based on the simulation result shown in FIG. In the simulation shown in FIG. 6, the deformation when a collision load is applied from the front frame SF1 will be described as a representative.

  As shown in FIG. 6A, when a collision load is applied from the front end of the front frame SF1, a lateral force is generated in the vicinity of the front device 5A by turning on the front device 5A. The crook begins. At this time, when a bending moment greater than the bending collapse moment is applied to the front frame SF1 or the rear frame SF2, the bending moment is released by making the electromagnetic brake mechanism 4 free. And while this buckling is progressing, the electromagnetic brake mechanism 4 is repeatedly switched between the free state and the fixed state, thereby preventing the folding from the intermediate portion of the front frame SF1 or the intermediate portion of the rear frame SF2. As shown in FIGS. 6B and 6C, the crushing buckling of the front frame SF1 is favorably performed.

  Then, after the collapse buckling of the front frame SF1 is completed, as shown in FIG. 6 (d), the rear device 5B is turned on to generate a lateral force in the vicinity of the rear device 5B. Start crushing buckling from the part. Also at this time, as described above, the electromagnetic brake mechanism 4 is operated, and the collapse buckling proceeds without the bending moment being equal to or greater than the bending collapse moment. As shown in FIG. SF2 will also be satisfactorily buckled.

Finally, experimental results comparing the structure of the present embodiment with a conventional integrated side frame will be described.
As shown in FIG. 7, in a conventional integrated side frame, a large compressive load is applied to the side frame at the start of the side frame collapse buckling (deformation start), and thereafter, a smaller compressive load continues. However, in the structure of the present embodiment, a compression load having substantially the same size as the conventional one can be obtained at the first deformation stage, and a compression value that dramatically increases when deformed to a predetermined deformation amount. It can be seen that a load is applied to the side frame SF. Therefore, the structure of this embodiment can be satisfactorily collapsed by a remarkably high compressive load as compared with the conventional structure.

  Moreover, as shown in FIG. 8, it turns out that the energy absorption amount of side frame SF in this embodiment is improving about 40% compared with the energy absorption amount of the conventional side frame. Therefore, the side frame SF in the present embodiment can absorb the collision load better than the conventional side frame.

According to the above, the following effects can be obtained in the present embodiment.
Even when a bending moment is locally applied to any part of the side frame SF, the bending moment makes the electromagnetic brake mechanism 4 free, that is, makes the joint mechanism 2 free (in a rotatable state). Therefore, even if the side frame SF is long, the side frame SF can be buckled and collapsed while suppressing bending deformation. Moreover, since the buckling buckling can be started from the portion where the lateral force is applied by the buckling device 5, the side frame SF can be buckled buckling from a desired location.

As mentioned above, this invention is implemented in various forms, without being limited to the said embodiment.
In the present embodiment, the buckling device 5 is disposed on the rear end side of the front frame SF1 and the rear end side of the rear frame SF2. However, the present invention is not limited to this, and the installation location of the buckling device 5 is arbitrary. Can be set. For example, as shown in FIG. 9A, when the buckling device 5 is disposed on the front end side of the rear frame SF2, as shown in FIGS. 9B and 9C, the rear frame SF2 Crush buckling can be started from the front end side. Further, as shown in FIG. 10A, when the buckling device 5 is disposed in the middle part of the rear frame SF2, as shown in FIGS. 10B and 10C, the rear frame SF2 Crush buckling can be started from the middle part.

In the present embodiment, the side frame SF is divided into two, but the present invention is not limited to this, and the side frame SF may be divided into any number. In this case, it is necessary to appropriately provide the joint mechanism 2 and the electromagnetic brake mechanism 4 as in the present embodiment between the divided side frames according to the number of the divided portions.
In this embodiment, the lateral force is generated by heating the spring member 51 of the shape memory alloy. However, the present invention is not limited to this, and mechanically by, for example, pressing the frame with a screw motor or a piston. Lateral force may be generated.

The rotation direction of the joint mechanism 2 can be arbitrarily set according to the shape of the frame. That is, the connecting shaft 23 that is the rotation center of the joint mechanism 2 may be disposed along the left-right direction of the vehicle M, or may be disposed along the vertical direction.
Further, in the present embodiment, the present invention is applied to the side frame SF constituting the rear frame RF. However, the present invention is applied to, for example, a front side frame disposed on the left and right in front of the vehicle, a side sill disposed on the lower portion of the door, and the like. The present invention may be applied to a cross member extending in the left-right direction of the vehicle.

It is a top view which shows the rear frame in which the crushing buckling stability control apparatus which concerns on this embodiment is provided. It is the elements on larger scale which show the detail of the crushing buckling stable control apparatus of FIG. It is a partially broken perspective view which shows the detail of the joint mechanism of FIG. It is a block diagram which shows the control apparatus of FIG. It is a flowchart which shows operation | movement of a control apparatus. (A) is the figure which shows the state which the crushing buckling of the front side frame started, (b) is the figure which shows the state which the crushing buckling of the front side frame has progressed, (c) is the crushing buckling of the front side frame completed FIG. 6D is a diagram showing a state in which crushing buckling of the rear frame has started, and FIG. 5E is a diagram showing a state in which crushing buckling of the rear frame has been completed. It is a graph which shows the relationship between a compressive load and a deformation amount. It is a graph which shows the relationship between energy absorption amount and deformation amount. It is a figure which shows the deformation | transformation of the back side frame when providing a buckling device in the front end side of a back side frame, (a) is a figure which shows the state which the crushing buckling started, (b) is a state where crushing buckling progresses The figure which shows the state which is doing, (c) is a figure which shows the state which the crushing buckling was complete | finished. It is a figure which shows the deformation | transformation of a back side frame when providing a buckling device in the intermediate part of a back side frame, (a) is a figure which shows the state which the crushing buckling started, (b) is a state where crushing buckling progresses The figure which shows the state which is doing, (c) is a figure which shows the state which the crushing buckling was complete | finished.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crushing buckling stable control apparatus 2 Joint mechanism 3 Sensing sheet 4 Electromagnetic brake mechanism 5 Buckling device 5A Front side device 5B Rear side device 6 Control apparatus M Vehicle RF Rear frame SF Side frame SF1 Front side frame SF2 Rear side frame

Claims (4)

A vehicle frame crush buckling stability control device for controlling deformation of a frame composed of a plurality of side frames disposed on the left and right sides of a vehicle,
A joint mechanism for rotatably connecting the plurality of adjacent side frames ;
Detecting means for detecting an impact load applied to the adjacent side frame or a deformation or strain of the side frame at the time of a collision ;
Brake means for restricting rotation of the adjacent side frame around the joint mechanism;
Control means for calculating a bending moment applied to the side frame based on a detection signal of impact load, deformation or strain detected by the detection means;
A release means for releasing the restriction of the rotation around the joint mechanism by the brake means by a signal from the control means when the bending moment calculated by the control means exceeds a predetermined value;
Crush buckling promoting means for applying a lateral force in a direction substantially perpendicular to the longitudinal direction to one of the plurality of side frames by a signal from the control means to crush and buckle;
A crush buckling stability control device for a vehicle frame, comprising: The vehicle frame collapse stability control apparatus according to claim 1,
When the bending moment calculated by the control means becomes a predetermined value or more, a signal from the release means makes the restriction of rotation around the joint mechanism by the brake means free, and the crushing seat An apparatus for controlling a stable buckling buckling of a vehicle frame, wherein a buckling promoting means is operated to collapse the side frame . A crush buckling stability control device for a vehicle frame according to claim 1 or 2,
The vehicle frame collapse buckling stability control device, wherein the detection means comprises a sensing sheet having a strain cage and a piezoelectric element and fixed to the side frame. A vehicle buckling stability control device for a vehicle frame according to any one of claims 1 to 3,
The joint mechanism includes a first hinge provided on one of the adjacent side frames extending in the front-rear direction of the vehicle, a second hinge provided on the other of the side frames, the first hinge, and the first hinge. A connecting shaft that rotatably connects the two hinges,
The brake means restricts the rotation by applying a brake to the connecting shaft in a normal state, and when the bending moment calculated by the control means exceeds a predetermined value, the brake means A crushing buckling stability control device for a vehicle frame, which is released to allow rotation of the connecting shaft.

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