JP4192710B2 - Shock absorber - Google Patents

Description

  The present invention relates to an impact absorbing device for a steering column mounted on a vehicle, and more particularly to an impact absorbing device for effectively absorbing energy of the collision at the time of a secondary collision with a steering wheel, for example.

For the purpose of protecting the driver in the event of a vehicle collision, an impact absorbing device is provided on the steering column and its mounting portion. The shock absorbing device absorbs the energy of the shock applied to the steering wheel or the like by moving the column in a state of being dragged or a part of the column (hereinafter, sometimes referred to as “column moving portion”). For the above purpose, it is desired that the impact absorbing device has a function capable of effectively absorbing the impact. As a technique aiming at effective impact energy absorption, for example, there is a technique described in Patent Document 1 below. The shock absorbing device described in Patent Document 1 assumes a driver's secondary collision with the steering wheel, and has a function of changing the amount of shock absorption depending on whether or not the driver is wearing a seat belt. Yes. Assuming that the impact received when the driver collides with the steering wheel may vary depending on whether the seat belt is worn or not, it is assumed that the impact will increase when the seat belt is not worn, and the impact energy is absorbed. The amount is changed over the entire moving stroke of the column moving unit.
JP 2002-3612381 A

  In the technique described in Patent Document 1, since the energy absorption amount is not changed based on the impact actually applied to the steering column, it is not certain whether or not the effective shock absorption is actually performed. . In other words, assuming a secondary collision of the driver, the impact applied to the steering column by various factors such as the magnitude of the impact of the collision of the vehicle and the physique (weight) of the vehicle as well as whether or not the seat belt is worn Since the size of the shock absorber can change, an impact absorbing device that cannot change the amount of energy absorption based on the parameters related to the actual impact magnitude is insufficient from the viewpoint of efficient impact absorption. Think. Accordingly, in view of the above circumstances, the present invention has an object to obtain an impact absorbing device capable of efficiently absorbing an impact by operating based on a parameter related to the magnitude of an actual impact applied to a steering column. To do.

The shock absorbing device of the present invention is
An impact absorbing device for absorbing impact energy applied to a steering column to which a steering wheel is attached when a driver collides with the steering wheel,
In the case where the steering column has a structure in which only a part of the steering column on the side of the steering wheel is allowed to move during the collision, a part of the steering column is allowed to move as a whole. When the entire structure is defined as a column moving portion, the shock absorbing device allows the column moving portion to move in a state of being dragged, thereby allowing the steering column to move to the steering column. It absorbs the applied impact energy,
The shock absorbing device is
And a deforming member that engages the deforming member while moving relative to the deforming member at a speed corresponding to an actual moving speed of the column moving unit when the column moving unit moves. A drag generating device that generates the drag due to the deformation resistance of the deformable member by forcing the deformation of the deformable member with the movement of the deformable member;
By changing the engagement relationship between the deformation member and the deformation forcing member by an acting force that varies depending on the relative movement speed between the deformation member and the deformation forcing member, the deformation resistance of the deformation member is increased. Depending on the actual moving speed of the column moving unit, thereby increasing the amount of absorption of the impact energy when the actual moving speed of the column moving unit is large compared to when it is small. and a shock energy absorbing amount changing mechanism,
In the first aspect of the present invention,
The deformation member is a plate-like member, and the plate-like member has a groove extending in a moving direction thereof;
The deformation forcing member is a roller that is pressed against the plate-like member to deform the plate-like member, and the roller has a protrusion that bites into the groove at a certain rotational position,
The impact energy absorption amount changing mechanism is
When the relative movement speed between the plate-like member and the roller increases beyond a threshold value, rotation as the acting force acting on the roller due to friction between the plate-like member and the roller By allowing the roller to rotate to the certain rotational position by force and causing the protrusion to bite into the groove, the deformation resistance of the plate-like member can be changed between the plate-like member and the roller. It is configured to increase the amount of absorption of the impact energy when the actual moving speed of the column moving unit is larger than a set threshold speed, by changing so as to increase ,
In the second aspect of the present invention,
The deformable member is a plate-shaped member,
The deformation compulsory member is a roller that is pressed against the plate-like member to deform the plate-like member, and the roller has an eccentric shape in the axial cross-sectional shape, so that the eccentricity having a large radius is obtained. Has a convex part
The impact energy absorption amount changing mechanism is
When the relative movement speed between the plate-like member and the roller increases beyond a threshold value, rotation as the acting force acting on the roller due to friction between the plate-like member and the roller By allowing the eccentric convex portion of the roller to rotate to a rotational position where it engages with the plate-like member by force, and increasing the amount of deformation of the plate-like member, the plate-like member and roller Is changed so that the deformation resistance of the plate-like member is increased, so that the impact energy is absorbed when the actual moving speed of the column moving part is larger than a set threshold speed. It is characterized by being configured to increase the amount.

  If the column moving part is allowed to move and absorbs an impact as in the present shock absorbing device, the moving speed of the column moving part increases as the impact applied to the steering column increases. Therefore, the moving speed of the column moving unit is an appropriate parameter indicating the magnitude of impact received by the steering column. In the present shock absorbing device, the amount of shock energy absorbed can be changed depending on the moving speed of the column moving portion, which is an appropriate parameter, so that the shock can be absorbed according to the magnitude of the actual shock. Detailed description will be given in the section (1) of [Aspect of the Invention] later.

  According to the impact absorbing device of the present invention, it is possible to absorb impact energy according to the magnitude of the actual impact, so that efficient impact absorption is possible. Therefore, for example, in the event of a secondary collision of the driver with the steering wheel, the impact received by the driver can be effectively mitigated, and appropriate protection of the driver can be achieved in the event of a vehicle collision.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”, a concept including the present invention) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the invention, and is not intended to limit the combination of the constituent elements constituting the invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the descriptions accompanying the respective sections, descriptions of the embodiments, drawings, etc., and as long as the interpretation is followed, other components are added to the modes of the respective sections. In addition, the aspect in which the constituent elements are deleted from the aspect of each item can also be an aspect of the claimable invention.

In each of the following terms, (1), (2), (6), (7), (8), (9), (10), (11) and (12) ) Is a common configuration of claims 1 and 2, and a configuration in which a specific configuration of the shock absorbing device of the first embodiment described later is added to the common configuration is claimed. Item 1 to which the specific structure of the impact absorbing device of the third embodiment described later is added corresponds to item 2 respectively.

(1) An impact absorbing device that absorbs impact energy applied to the steering column by allowing a column moving portion that is one of the steering column and a part thereof to move in a state of receiving a drag force. ,
An impact absorbing device comprising: an impact energy absorption amount changing mechanism that changes an absorption amount of impact energy depending on a moving speed of the column moving portion.

  The impact absorbing device described in this section absorbs the impact applied to the steering wheel by allowing the column moving portion to move. For example, when a driver's collision with a steering wheel is considered, the driver receives a large impact when the kinetic energy of the driver is large, and the shock applied to the steering column increases. At this time, since the column moving unit is moved by the kinetic energy of the driver, the moving speed of the column moving unit increases when the kinetic energy of the driver is large. Therefore, the moving speed of the column moving unit is an appropriate parameter indicating the magnitude of impact received by the steering column. In the present shock absorbing device, the amount of shock energy absorbed can be changed depending on the moving speed of the column moving portion, which is an appropriate parameter, so that shock absorbing according to the actual shock magnitude is possible. For example, assuming that the driver collides with the steering wheel, steering column, etc. due to a vehicle collision, the collision energy can be absorbed according to the magnitude of the impact at that time. Can effectively relieve the impact received. This makes it possible to effectively protect the driver in the event of a vehicle collision.

  The basic configuration excluding the shock energy absorption amount changing mechanism of the shock absorbing device described in this section is not particularly limited, and may be in accordance with the configuration of a shock absorbing device that is already generally used. In general, a steering column is supported and fixed to the vehicle body, specifically, for example, a reinforcement (reinforcing member) of an instrument panel (instrument panel). When an impact is applied, the steering column is released. It has a structure. When the fixation is released, the movement of the steering column is allowed. For example, there are two methods for the movement. One of them is a method in which a part of the steering column functions as a column moving part and the movement of the part is allowed, for example, the steering column is composed of two parts, and only the part on the side where the steering wheel is attached. The system is such that the movement is allowed after the fixation is released, and the other is the system in which the entire steering column is used as a column moving portion, and the movement is released with the entire fixation being released. The impact absorbing device of this aspect can be employed in any of these methods. Regardless of which system is used, the shock absorbing device may be a component of the steering column itself, or a component of a mounting mechanism between the column moving portion and the vehicle body that is a part of the steering column. Also good.

  The “moving speed of the column moving part” in this section means, for example, the relative speed with the vehicle body, or the relative speed with other fixed parts when a part of the steering column is the column moving part. To do. The moving speed on which the energy absorption amount is changed may be the moving range in which the column moving unit moves, that is, the moving speed in the entire moving stroke, or the moving speed at a specific position of the moving stroke. It may be. For example, when considering a secondary collision with the steering wheel, the movement speed at a relatively early time after the start of movement, that is, the movement speed at a position relatively close to the movement start end in the movement stroke is applied to the steering column. In view of this point, an aspect in which the energy absorption amount is changed depending on the moving speed at the initial position of movement is an effective aspect.

  “Drag” in this section means a force that prevents or suppresses the movement of the column moving portion, and can be expressed as a load, specifically, an energy absorption load. Various forces such as friction force generated in two sliding members, force for elastic deformation, plastic deformation of a member, inertial force, magnetic force, electromagnetic force, etc. or some of them combined It can be caused by force, and the drag referred to in this section may be caused by any of them. The “impact energy absorption amount” to be changed may be the total amount of impact energy absorbed as the column moving unit moves. For example, it is possible to make the movement stroke variable according to the movement speed. However, since the movement stroke of the column moving part cannot be sufficiently long due to restrictions on the structure of the vehicle, the shock absorbing device described in this section absorbs energy per unit moving distance of the column moving part. It is desirable that the amount be changed.

  The “impact energy absorption amount changing mechanism”, which is a characteristic part of the impact absorbing device described in this section, is not particularly limited in specific means. For example, it is possible to adopt an aspect by an electric means such as detecting the moving speed of the column moving unit and starting some actuator by electronic control to change the energy absorption amount based on a signal related to the detected speed. In other words, pure mechanical means, in other words, various aspects such as an aspect based on a mechanical principle alone can be used. In view of the advantage that the change mechanism can be simplified and reduced in cost, an aspect in which only mechanical means is employed as in an aspect exemplified later is desirable.

  (2) The impact according to (1), wherein the impact energy absorption amount changing mechanism increases the amount of absorption of the impact energy when the moving speed of the column moving portion is large compared to when the column moving portion is small. Absorber.

  When the impact applied to the steering column is large, the moving speed of the column moving unit increases. On the other hand, the range in which the column moving part is movable for absorbing shock, that is, the moving stroke is often set to a certain length due to restrictions such as the structure of the vehicle and the mounting structure of the steering column. In this case, in order to effectively absorb the impact within the moving stroke, it is desirable to increase the energy absorption amount per unit moving distance of the column moving unit when the moving speed is high. According to the aspect described in this section, an impact absorbing device that can meet the demand is realized. More specifically, taking a secondary collision with the driver's steering wheel as an example, if the impact applied is large, it will not be able to absorb sufficient impact energy within the travel stroke and will be given to the driver at the end of the travel stroke. Can effectively prevent and alleviate the impact (so-called impact caused by the bottom), and when the applied impact is small, it is possible to absorb the impact gently over a long movement stroke region.

  (3) The impact energy absorption amount changing mechanism changes the absorption amount of the impact energy depending on whether the moving speed of the column moving unit is large or small across a set threshold speed (1 ) Or the shock absorbing device according to item (2).

  When changing the amount of energy absorption according to the moving speed of the column moving unit, it is possible to change the amount of absorption continuously according to the moving speed, and so that it becomes a discrete value, That is, it can be changed in stages. The mode described in this section is a mode in which the energy absorption amount is changed stepwise according to the moving speed of the column moving unit. Specifically, in this aspect, for example, when the moving speed is greater than a certain threshold value, the energy absorption amount is relatively large, and when the moving speed is less than the threshold value, the energy absorption amount is relatively small. A mode having an impact energy absorption amount changing mechanism is included. This aspect can be roughly changed, and a practical shock absorbing device having a relatively simple configuration can be realized.

  (4) The shock energy absorption amount changing mechanism according to any one of (1) to (3), wherein the shock energy absorption amount is changed without depending on electrical means. Shock absorber.

  For example, using a speed sensor or the like, the moving speed of the column moving unit is detected, the speed is transmitted as a signal to a control device mainly composed of a computer, and the control device controls and drives some actuator based on the signal. It is also possible to change the energy absorption amount by means. However, when such an electrical means is used, the possibility that the impact energy absorption amount changing mechanism malfunctions or does not operate due to the impact of a vehicle collision or the like cannot be denied. In addition, since the change mechanism requires a control device, an actuator, and the like, the configuration is complicated, and the cost of the shock absorbing device itself increases. According to the aspect described in this section, the above-described problem in the case where the electric means is employed can be solved, and an impact absorbing device having advantages such as being relatively simple in terms of configuration and being inexpensive in terms of cost is realized.

  (5) The impact energy absorption amount changing mechanism is configured such that the impact energy absorption amount is changed by an acting force acting on itself which changes depending on a moving speed of the column moving portion. The impact absorbing device according to any one of items (1) to (4).

  The aspect described in this section can also be positioned as one aspect that does not employ electrical means. In other words, this is a mode in which a so-called purely mechanical shock energy absorption amount changing mechanism using a mechanical means in a narrow sense using a mechanical principle is employed. In other words, for example, the amount of impact energy absorbed is changed by changing the magnitude of the force acting in the mechanism, the transmission state of the force, etc., by changing the moving speed of the column moving unit. According to the aspect described in this section, since it is a mechanical mechanism, the reliability is high, and when the electric means is not adopted, the above-described advantages can be enjoyed.

  (6) The impact absorbing device includes a drag generating device that generates the drag with the movement of the column moving unit, and the drag generating device serves as the impact energy absorption amount changing mechanism to move the column moving unit. The impact absorbing device according to any one of (1) to (5), further including a moving speed-dependent drag changing mechanism that changes the magnitude of the drag depending on speed.

  When absorbing the impact energy by moving the column moving part in a state of being dragged, for example, to reduce the impact applied to the driver who collides with the steering wheel or the like, the amount of energy absorbed by the impact is changed. Sometimes, it can be performed by changing the movable length of the column moving unit, and can also be performed by changing the magnitude of the drag. However, the movable length of the column moving part, that is, the moving stroke cannot be sufficiently long due to the structure of the vehicle, etc. In that case, the magnitude of the generated drag is changed. It is desirable to change the magnitude of the energy absorption load of the shock absorber. The embodiment described in this section meets that need. The aspect described in this section includes an aspect in which, for example, the generated drag is increased when the column moving unit has a high moving speed, and the generated drag is decreased when the moving speed is low.

  (7) The drag generator includes a deformable member that deforms as the column moving unit moves, and generates the drag due to the deformation resistance of the deformable member. Shock absorber.

  As a means for generating a drag force accompanying the movement of the column moving part, for example, a means for utilizing a force required for deformation of any member, a means for utilizing a frictional force, a means for utilizing a magnetic force or an electromagnetic force, or an inertial force is utilized. Various means such as means can be employed. Of these, the aspect described in this section employs a means for utilizing the force required for deformation of the member. For example, the reaction force of the force required for the deformation, that is, the resistance force accompanying the deformation or the force Includes those that make at least part of the potency that occurs. The deformation includes elastic deformation and plastic deformation. For example, a structure in which a spring and a damper are combined can be used as the main deformation. However, since such a structure is relatively complicated, it is desirable to use plastic deformation. Although the specific mode using plastic deformation is not particularly limited, for example, it is possible to use a force that bends and deforms a band-like or plate-like member (for example, an energy absorbing plate). Moreover, such a device becomes a drag generating device having a relatively simple structure. Note that the term “deformation resistance” in this section has a broad meaning such as difficulty of deformation. When other forces such as frictional force are applied not only with deformation stress but also with deformation, it is attributed to that force. It also means that it also includes a resistance.

  (8) The impact absorbing device according to (7), wherein the moving speed-dependent drag changing mechanism changes the magnitude of the drag by changing the magnitude of the deformation resistance.

  The aspect described in this section is an aspect in which the drag resistance is changed by changing the deformation resistance according to the moving speed of the column moving unit in the aspect including the drag generation device using the deformation resistance of the deformable member. It is. The specific means for changing the deformation resistance is not particularly limited. For example, the degree of deformation, the amount of deformation, or the like is changed, or when another force such as a frictional force is generated along with the deformation, the force is changed. It can be set as the mode which is. According to this aspect, the energy absorption amount can be easily changed.

  (9) The drag generator includes a deformation compulsory member that forces the deformation of the deformation member as the column moving portion moves while engaging with the deformation member, and is caused by the deformation resistance due to the force of the deformation. The impact absorbing device according to item (7) or (8), which generates a drag force.

  The “deformation compulsory member” referred to in this section is a member that forcibly deforms, for example, by being pressed against or pressed against the deformable member. In the drag generator in this section, for example, when the deformation forcing member is engaged by contacting the deformation member, the deformation moving member is provided on one of the column moving portion and the vehicle body, and the deformation forcing member is provided on the other of them. In such a case, the above-described drag can be generated due to the action / reaction force acting between the two engaging portions. Note that the number of deformation forcing members is not necessarily one for each deformation member, and a plurality of deformation forcing members may be engaged. In that case, it is also possible to treat one of them as the main deformation compulsory member and the other as an auxiliary deformation compulsory member.

  (10) The impact according to (9), wherein the moving speed-based drag changing mechanism changes the magnitude of the drag by changing an engagement relationship between the deformable member and the deformable compulsory member. Absorber.

  “Changing the engagement relationship” in this section means the engagement position, engagement area, engagement strength, the number of engagement points, the presence / absence of engagement, etc. between the deformable member and the deformable member. It means changing any one or more of the various states related to the combination. A mode in which the magnitude of the generated drag force is changed by changing the engagement relationship according to the moving speed of the column moving unit is included in the mode described in this section.

  (11) The deformation member and the deformation compulsory member are engaged with each other while relatively moving at a speed corresponding to the moving speed of the column moving portion, and the moving speed-dependent drag changing mechanism is connected to the deforming member. The impact absorbing device according to item (10), wherein the engagement relationship between the deformation member and the deformation forcing member is changed according to a relative movement speed with respect to the deformation forcing member.

  When both the deformation member and the deformation compulsory member move relative to each other according to the movement of the column moving unit, the relative moving speed of the both is not the moving speed of the column moving unit, as in the aspect described in this section. Even if it relies on and changes the engagement relationship between them, it is possible to change the amount of absorption of impact energy depending on the moving speed of the column moving portion. The “relative movement speed” referred to in this section does not mean only the relative movement speed of the entire deformation member and the entire deformation forcing member, but the deformation forcing member and the deformation forcing member of the deformation member are engaged. It is a concept that includes the relative movement speed between the parts that engage with each other, and the relative movement speed between the deformation member and the deformation compulsory member.

  (12) The deformation member and the deformation forcing member are applied by an acting force acting on the movement speed-dependent drag changing mechanism that changes depending on a relative movement speed between the deformation member and the deformation forcing member. The shock absorbing device according to item (11), wherein the engagement relationship is changed.

  The aspect described in this section is a sub-concept aspect of the above-described aspect, that is, an aspect in which the amount of absorption of impact energy is changed by an acting force that changes depending on the moving speed of the column moving unit and acts on itself. It can be considered as an aspect of the subordinate concept. In the mode described in this section, for example, a mode in which the engagement relation is changed according to the relative movement speed between the deformable member and the deformable compulsory member by mechanical means instead of electrical means. Is included.

(13) The deformable member has a shape obtained by bending a band-shaped member in a generally U shape, and one end portion of the deformable member extends in a direction substantially parallel to the moving direction of the column moving portion. The position is fixed to one of the moving part and the vehicle body, and the other end is arranged in a free state where the position is not fixed,
The drag generating device has a pressing member whose position is fixed to the other of the column moving portion and the vehicle body as the deformation compulsory member, and the pressing member has a U-shaped bent of the deforming member on the outer peripheral surface. Any one of the items (9) to (12), wherein the drag is generated by pressing and deforming the deformable member with the movement of the column moving portion in a state of being engaged with the inner surface of the portion. The shock absorber described in 1.

  The mode described in this section is a mode in which specific limitations relating to the combination of the deformable member and the deformable member are added. The drag generator of the aspect described in this section utilizes a deformable member called a so-called impact absorbing plate, and is a drag generator that is currently employed in widely used shock absorbers. The drag generator will be described in detail in the following [Example], but the embodiment described in this section is an improved embodiment of the shock absorber that has been put to practical use so that it can absorb the shock efficiently. According to this aspect, a practical shock absorbing device is realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition to the following examples, the present invention is implemented in various modes including various modes modified and improved based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. be able to.

<First embodiment>
1 is a side view of a steering column to which an impact absorbing device as a first embodiment of the present invention is applied, FIG. 2 is a plan view of the steering column, and FIG. 3 is a side sectional view of the steering column. Are shown respectively. In these drawings, the right end is the steering wheel side and the left side is the wheel side, and this steering column is attached to the vehicle in an inclined state. The left end portion of the steering column is located obliquely below and forward of the vehicle. In this embodiment, to simplify the description, unless otherwise specified, the right side in the figure is the upper side, the right side direction is the upper side, the left side in the figure is the lower side, and the left side direction is the lower side. The same applies to the examples).

  The steering column 5 is roughly divided into a shaft portion and a tube portion that supports the shaft portion in a state where the shaft portion is inserted. The shaft portion is located on the upper shaft 10 located on the steering wheel side and on the wheel side. The lower shaft 12 is configured to be included. The upper shaft 10 is formed in a pipe shape and the lower shaft 12 is formed in a rod shape, and the upper portion of the lower shaft 12 is inserted into the lower portion of the upper shaft 10. Splines that mesh with each other are formed on the lower inner peripheral surface 14 of the upper shaft 10 and the upper outer peripheral surface 16 of the lower shaft, and the upper shaft 10 and the lower shaft 12 can be moved relative to each other in the axial direction and cannot be rotated relative to each other. Connected in a normal state. Further, the tube portion includes an upper tube 18 and a lower tube 20 that are located on the steering wheel side. The upper tube 18 and the lower tube 20 are both pipe-shaped, and the upper portion of the lower tube 20 is inserted into the lower portion of the upper tube 18. A pipe-shaped liner 22 is provided on the lower inner surface of the upper tube 18, and the lower tube 20 is inserted into the upper tube 18 without rattling through the liner 22. The inner peripheral surface of the liner 22 that comes into contact with the outer peripheral surface of the lower tube 20 has been subjected to anti-friction treatment, which facilitates relative movement in the axial direction between the upper tube 18 and the lower tube 20. Further, radial bearings 24 and 26 are respectively provided at the upper end portion of the upper tube 18 and the lower end portion of the lower tube 20, and the upper tube 18 and the lower tube 20 are respectively connected to the upper shaft via the radial bearings 24 and 26. Each of 10 and the lower shaft 12 is rotatably supported in the middle part thereof. With such a structure, the steering column 5 can be expanded and contracted.

  The steering column 5 is attached to the vehicle body at each of the upper tube 18 and the lower tube 20. More specifically, a supported member 30 is fixedly provided at the lower end portion of the lower tube 20, and a support shaft (illustrated) fixedly provided on the vehicle body in a shaft insertion hole 32 of the supported member 30. The lower tube 20, that is, the steering column 5 is attached so as to be swingable about its support shaft. The upper tube 18 is attached to the vehicle body, more specifically to the reinforcement of the instrument panel, via the supported member 34. A member to be held 36 is fixedly provided on the upper tube 18, and this member to be held 36 is held by a holding member 38 having a channel shape (U-shape) that is a constituent part of the supported member 34. At the same time, the supported plate 40, which is another component of the supported member 34, is fixed to the vehicle body, whereby the upper tube 18 is attached to the vehicle body. More specifically, referring to FIG. 4, the reinforcement is provided with a support member 42, and the supported plate 40 is formed by two ends formed at the ends of the cuts 44 provided therein. The attachment pin 48 is inserted into the attachment hole 46 (which is wider than the other part and formed as a substantially circular hole), and depending on the head of the attachment pin 48 and the support member 42, respectively. It is fixed by being pinched. An intervening plate 50 is sandwiched between the supported plate 40 and the support member 42. The interposition plate 50 has an insertion hole 52 through which the mounting pin 48 is inserted, and an annular protrusion 54 that protrudes downward in the drawing so as to extend the insertion hole 52. The outer diameter of the mounting pin 48 is smaller than the width of the notch 44, but the annular protrusion 54 is fitted in the mounting hole 46, so that the mounting pin 48 moves along the notch 44. As a result, the axial movement of the upper tube 18 is restricted.

  The steering column 5 has a tilt mechanism and a telescopic mechanism. Although detailed description is omitted, each of the holding member 38 and the held member 36 has elongated holes 56 and 58 that intersect each other, and the shaft member 60 is inserted into these elongated holes 56 and 58. Has been. As a result, the steering column 5 can be swung around the support shaft by the length of the long hole 56 provided in the holding member 38, and by the length of the long hole 58 provided in the held member 36, It can be stretched. FIG. 1 shows a lock lever 62 of a tilt mechanism and a telescopic mechanism. When the lock lever 62 is pushed up (the position indicated by a solid line in the drawing), the held member 36 is strongly held by the holding member 38, and the steering The swinging position and the expansion / contraction position of the column 5 are fixed. The position is adjusted by releasing the lock lever 62 by pushing down the lock lever 62 (the position of the two-dot chain line in the figure).

  When an impact is applied to a steering wheel (not shown) attached to the steering column 5 due to a secondary collision of the driver, the above-described fixing of the upper tube 18 to the vehicle body is released. The intervening plate 50 is made of a material such as a resin that is relatively brittle and generates a small frictional force. When the impact is applied, the annular protrusion 54 is broken, and the supporting member 42 and the supported member are separated. Relative movement with respect to 34, specifically, relative movement in the direction in which the mounting pin 48 is guided by the notch 44 is enabled. Thereby, the movement in the state with which the upper tube 18 and the upper shaft 10 were united is permitted. That is, in the present steering column 5, a part located at the upper part of the steering column 5 is a column moving portion, and when an impact is applied, the upper tube 18 and the upper shaft 10 (hereinafter referred to as “column” in this embodiment). However, the movement of the steering column 5 in the axial direction is permitted. The end point of the moving range of the column moving part is defined by the upper end of the lower shaft 12 coming into contact with the inner surface part where the inner diameter of the upper shaft 10 is small. Even when in the telescopic position, a sufficient movement stroke for absorbing the impact is secured.

  Further, the steering column 5 includes a drag generating device 70, and with the movement of the upper tube 18 and the upper shaft 10, a drag in a direction to prevent the movement is generated. The drag generating device 70 is a device that mainly generates a drag due to the deformation resistance of the deformable member. The shock absorbing device 71 of the present embodiment includes a drag generating device 70 and a mechanism that allows the column moving portion to move in the axial direction. 5 shows an enlarged view of the portion of the drag generating device 70 in FIG. 1, FIG. 6 shows an enlarged view of that portion in FIG. 3, and FIG. 4 shows a perspective view of that portion.

  The drag generating device 70 includes a shock absorbing plate 72 (hereinafter, may be abbreviated as “EA plate 72”) as a deforming member, and a pressing roller 74 as a deforming forcing member forcing deformation of the EA plate 72. (Which is the main deformation compulsory member). The pressing roller 74 is a pressing member that includes a thick tubular roller portion 76 and a shaft portion 78 that is inserted through the roller portion 76. The roller portion 76 and the shaft portion 78 are not relatively rotatable with respect to each other and have a shaft. Relative movement is impossible in the direction. The pressing roller 74 has a pair of shaft support members 80 and 82 provided at the lower end of the supported member 34 (the left portion in FIG. 1 and the like). It is supported so that it can rotate through. The EA plate 72 is made of a band-shaped metal bent in a U-shape, and is bent at a substantially right angle and fixed to the support member 42, and the other end is in a free state. It is said that. The two straight portions connected by the bent portion of the EA plate 72 are parallel to each other, and the EA plate 72 is disposed so that the extending direction of these portions is parallel to the column moving direction. The outer periphery of the pressing roller 74 is engaged with the inside of the U-shaped bent portion of the EA plate 72. Further, the supported member 34 is provided with square holes 86, and on both sides of the square holes 86, there are provided regulating members 88 formed by bending in a U-shape. 88 prevents the EA plate 72 from expanding the U-shape. That is, the restricting member 88 functions as an auxiliary deformation compelling member.

  In addition, a break pin 90 and a locked member 92 are fixedly provided at one end of the shaft portion 78 of the pressing roller 74. When the rotational force of the pressing roller 74 is weak, the breaking pin 90 contacts the pin contact member 94 provided on the bearing member 80 and prevents the pressing roller 74 from rotating. When the rotational force of the pressing roller 74 increases beyond a certain threshold value, the breaking pin 90 breaks (may be bent). When the breaking pin 90 is broken, the pressing roller 74 rotates to a position (position indicated by a broken line in FIG. 6) where the locked member 92 contacts the locking member 96 provided on the bearing member 80, that is, approximately. A rotation of 45 ° is allowed.

  When the column moving part is released and the column moving part moves downward (leftward in FIG. 1, in the direction of the white arrow in FIG. 6), the pressing roller 74 attempts to push down the EA plate 72. Accordingly, the EA plate 72 is deformed while the free end portion is moved while the shape of the U-shaped portion is substantially maintained. When the impact received by the steering column 5 is relatively small, the column moving unit moves at a relatively slow speed. In this case, the breaking pin 90 is not broken and the pressing roller 74 is prevented from rotating, and the EA plate 72 is deformed while sliding on the outer peripheral surface of the roller portion 76. The roller portion 76 of the pressing roller 74 is formed of a hard resin and the friction generated between the pressing roller 74 and the EA plate 72 is relatively small. Therefore, a force necessary to bend and spread the EA plate 72 is increased. In general, it is comparable to the deformation resistance of the EA plate 72. Then, the drag generator 70 generates a drag according to the deformation resistance. In other words, the generated drag is a reaction force caused by the movement of the column moving portion, and is an energy absorption load. The drag due to such a mechanism, that is, the drag due to the deformation resistance of the EA plate 72 is basically constant regardless of the moving speed of the column moving portion. That is, as long as the deformation resistance of the EA plate 72 does not change, the generated drag is basically constant.

  However, when the impact received by the steering column 5 is large, the moving speed of the column moving unit is increased. In this case, sudden deformation of the EA plate 72 is forced instantaneously. In that case, due to the inertia of the drag generator, a phenomenon in which the deformation speed does not follow, etc., the reaction force accompanying the pressing down of the EA plate 72 of the pressing roller 74 becomes strong for a short time. Accordingly, the force for rotating the pressing roller 74 due to the frictional force generated between the roller portion 76 and the EA plate 72 is also increased in a short time. Then, the breaking pin 90 is broken and the pressing roller 74 is rotated. As shown in FIG. 7, the roller portion 76 of the pressing roller 74 has two protrusions 98 having a substantially short cylindrical shape, and each of the protrusions 98 is formed on one surface of the EA plate 72. Corresponding to these, two grooves 100 are formed. These protrusions 98 are made of relatively hard metal or the like, and the width of the groove 100 is slightly narrower than the outer diameter of the protrusion 98. When the pressing roller 74 rotates, each of the two protrusions 98 is rotated. Bite into each of the two grooves 100. In this state, the deformation resistance of the EA plate 72 includes the force required for bending and spreading, the force by which the protrusion 98 pushes the groove 100, the frictional force generated between the contact surfaces of the protrusion 98 and the groove 100, and the like. This is comparable to the force applied, and is larger than when the pressing roller 74 is not rotated. That is, the magnitude of the deformation resistance is changed by changing the engagement relationship between the EA plate 72 that is a deformable member and the pressing roller 74 that is a deformable member, thereby generating the drag generator 70. The drag is also changed in the direction of increasing. In addition, once the pressing roller 74 rotates, the increased drag is maintained.

FIG. 8 is a schematic graph showing the magnitude of the drag σ generated with respect to the moving speed v of the column moving portion, specifically, the maximum moving speed in a relatively short time after the impact is applied. become. As can be seen from this graph, the speed at which the pressing roller 74 starts to start rotating as threshold velocity v _0, and the threshold speed v ₀ as a boundary, the moving speed v is greater drag sigma _H when large occurs, move When the speed v is small, a small drag σ _L is generated. That is, the drag generator 70 has a moving speed-based drag changing mechanism that changes the magnitude of the drag depending on the moving speed of the column moving unit. In addition, since the amount of shock energy absorbed is the product of the column moving distance and the drag, the shock absorbing device 71 including the drag generating device 70 depends on the moving speed of the column moving portion to change the impact energy. It is provided with a shock energy absorption amount changing mechanism for changing the absorption amount. In other words, the EA plate 72, which is a deformable member, has a bent portion that moves relative to the pressing roller 74, which is a deformable member. That is, since both engage with each other at a speed corresponding to the movement speed of the column moving portion, the movement speed-based drag changing mechanism included in the drag generating device 70 corresponds to the relative movement speed. Thus, the engagement relationship between the deformation member and the deformation compulsory member is changed. Further, the engagement relationship is changed by the rotational force acting on the pressing roller 74, that is, the force acting depending on the relative moving speed, and this collision energy absorption amount changing mechanism is electrically Regardless of the means, the structure is such that the amount of shock energy absorbed is changed by the acting force acting on itself.

<Second embodiment>
In this embodiment, the drag generator in the above embodiment is replaced with a different drag generator. The other parts in the steering column are the same as in the above embodiment, so the description thereof will be omitted, and only the part relating to the drag generator will be described. FIG. 9 shows a drag generator that constitutes the shock absorber of this embodiment. FIG. 9A is a cross-sectional view similar to FIG. 6, and FIG. 9B is a view of the centrifugal clutch that constitutes the drag generator as viewed from the back side in FIG. 9A. The following will be described with reference to this figure.

  In the drag generator 110, a pressing roller 114 (a pressing member) is rotatably supported by a pair of bearing members 112 (one is not shown) provided at the lower end of the supported member 34. Is the main deformation compulsory member. As in the previous embodiment, the pressing roller 114 is a roller portion 116 and a shaft portion 118 that are integrated, and is supported by a pair of bearing members 112 in the shaft portion 118. In the present embodiment, the roller portion 116 is made of metal, and generates a relatively large frictional force with the EA plate 72 (the surface of the present embodiment has no groove formed on the surface). Yes. Both ends of the shaft 118 protrude from the bearing member 112, and a centrifugal clutch 120 is provided at one end thereof. The centrifugal clutch 120 includes a ratchet plate 124 having ratchet teeth 122 formed on the outer periphery thereof, and a rotating disk 126 positioned inside the ratchet teeth. A shaft hole through which the shaft portion 118 is inserted is provided at the center of the ratchet plate 124, and the protruding portion of the shaft portion 118 is inserted into the shaft hole via a sliding bearing bush so that the ratchet plate 124 has a shaft portion. 118 is supported so as to be relatively rotatable. The rotating disk 126 is fixed to the shaft portion 118 on the outer side in the axial direction of the ratchet plate 124, and can rotate integrally with the pressing roller 114. A rotating plate (not shown) having the same external shape as the ratchet plate 124 and not formed with ratchet teeth is provided on the protruding portion on both sides of the shaft portion 118 where the centrifugal clutch 120 is not provided. Similar to the plate 124, it is supported so as to be rotatable relative to the shaft portion 118. The ratchet plate 124 and the rotating plate have a portion in which a part of the outer periphery protrudes in the radial direction, and these protruding portions are connected by a connecting rod 128.

  In the vicinity of the inside of each bearing member 112 between the pair of bearing members 112, a pair of curved swing levers 130 (one is not shown) are provided. Specifically, a pair of swing levers 130 are rotatably supported by swing shafts 132 supported at both ends by each of the bearing members 112. An intermediate portion of each of the pair of swing levers 130 is connected by a roller shaft 134 that is parallel to the swing shaft 132, and the pair of swing levers 130 maintain the same relative positional relationship while maintaining the same relative positional relationship. It swings around 132. An auxiliary roller 136 having an outer diameter smaller than that of the pressing roller 114 is rotatably supported on the roller shaft 134. The auxiliary roller 136 is positioned between the EA plate 72 and the upper tube 18, and can swing against the outer surface of the EA plate 72 at a position close to the U-shaped bent portion by swinging the swing lever 130. ing. The end of each of the pair of swing levers 130 opposite to the end supported by the swing shaft 132 is adapted to engage with the connecting rod 128 described above. The curvature of the swing lever 130 is a means for avoiding interference with the EA plate 72 and the pressing roller 114. Further, between the pair of bearing members 112, there are provided restriction rods 138 that are supported at both ends of each of them, and the restriction rods 138 are in contact with the inner surface of the EA plate 72. Has been. The auxiliary roller 136 abuts the EA plate 72 between the pressing roller 114 and the regulating rod 138 from the opposite side when the swing lever 130 swings, and sandwiches the EA plate 72 therebetween. . That is, the pressing roller 114 and the regulation rod 138 also have a function as an auxiliary deformation compulsory member.

  The centrifugal clutch 120 has an engaging claw 140 provided on the outer periphery of the rotating disk 126 so as to be able to swing, and the rotation of the rotating disk 126, that is, the rotation speed of the pressing roller 114 is greater than a certain value. In addition, the engaging claw 140 swings when the generated centrifugal force overcomes the urging force of the tension spring 142 that is the urging member, and the tip thereof moves outward in the radial direction, thereby causing the ratchet teeth 122 of the ratchet plate 124 to move. It will be in the state engaged with. As a result, the rotating disk 126 and the ratchet plate 124 rotate integrally, the swing lever 130 swings, the auxiliary roller 136 contacts the EA plate 72, and sandwiches the EA plate 72 as described above. The EA plate 72 is bent as shown by a two-dot chain line in the drawing. In this state, the EA plate 72 is in a state of tightly binding the pressing roller 114, and the rotation of the pressing roller 114 is restricted. The EA plate 72 is located between the outer peripheral surface of the roller portion 116 of the pressing roller 114. It is deformed while receiving the frictional force generated in the. That is, when the centrifugal clutch 120 is operated, the engagement state between the pressing roller 114 and the EA plate 72 is changed, so that the deformation resistance of the EA plate 72 increases, and the drag generated thereby increases. is there. In addition, the movement of each member when the centrifugal clutch 120 works is indicated by white arrows in the figure.

If the column moving part moves with its fixation being released due to a secondary collision of the driver with the steering wheel or the like, the EA plate 72 is deformed, and the drag generator 110 generates a drag. In this embodiment, the pressing roller 114 rotates as the EA plate 72 moves. When the impact received by the steering column 5 is small, the moving speed of the column moving portion is slow, the rotation of the pressing roller 114 is slow, and the centrifugal clutch 120 does not work. In that case, since the EA plate 72 is deformed with the rotation of the pressing roller 114, only a relatively small drag is generated. However, when the impact received by the steering column 5 is large, the moving speed of the column moving portion is high and the rotational speed of the pressing roller 114 is also increased. Drag is generated. As in the previous embodiment, as shown in FIG. 8, when the moving speed of the column moving unit exceeds a certain threshold speed v ₀ , the generated drag increases. That is, the drag generator 110 also has a moving speed-based drag changing mechanism that changes the magnitude of the drag depending on the moving speed of the column moving unit, as in the previous embodiment. The shock absorbing device 150 of this embodiment configured to include the drag generating device 110 includes an impact energy absorption amount changing mechanism that changes the amount of absorbed shock energy depending on the moving speed of the column moving unit. -ing

  Also in the present embodiment, the EA plate 72 that is a deformable member has a U-shaped bent portion that moves relative to the pressing roller 114 that is a deformable member. That is, since both engage with each other at a speed corresponding to the movement speed of the column moving unit, the movement speed-based drag changing mechanism of the drag generator 110 is in accordance with the relative movement speed. Thus, the engagement relationship between the deformation member and the deformation compulsory member is changed. Further, the engagement relationship is changed depending on the centrifugal force acting on the rotating disk 126 of the centrifugal clutch 120 that rotates integrally with the pressing roller 114, that is, between the deformable member and the deformable member. The collision energy absorption amount changing mechanism is changed by the force acting depending on the relative movement speed. The structure is such that the absorption amount of impact energy is changed by force.

<Modification of Second Embodiment>
A modification of the impact absorbing device of the second embodiment will be described. In this modification, the drag generator in the second embodiment is replaced with a different drag generator. FIG. 10 shows a drag generator that constitutes the shock absorbing device of this modification. FIG. 10A is a cross-sectional view similar to FIG. 6, and FIG. 10B is a view of the centrifugal force stopper constituting the drag generator as viewed from the back side in FIG. 10A. The following description will be given with reference to these drawings.

  The drag generator 230 is similar to that of the second embodiment, and includes a first bearing member 232 and a second bearing member (not shown) that are two bearing members provided at the lower end of the supported member 34. A pressing roller 234 (which is a pressing member) that is rotatably supported by the main body is used as a main deformation forcing member. As with the second embodiment, the pressing roller 232 is a roller part 236 and a shaft part 238 integrated with each other, and both ends of the shaft part 238 are provided with the first bearing member 232 and the second bearing member 232. Each of the bearing members is rotatably supported. The roller portion 236 is made of metal, and a plurality of small protrusions 240 are formed on the outer peripheral surface over the entire circumference. The pressing roller 234 is engaged with the EA plate 72 in a state where the protrusion 24 is in contact.

  As can be seen from FIG. 10 (b), at the end of the shaft portion 238 supported by the first bearing member 232, a rotating disk 126 similar to that of the second embodiment rotates relative to the shaft portion 238. The rotating disk 126 and the pressing roller 234 are integrally rotated. The first bearing member 232 is formed with ratchet teeth 122 similar to the ratchet plate 124 in the second embodiment. That is, the first bearing member 232 is like the ratchet plate 124 and the bearing member 112 of the second embodiment integrated. The rotating disk 126 is provided with an engaging claw 140 and a tension spring 142 similar to those in the second embodiment. When the rotation speed of the pressing roller 234 is greater than a certain value, the engaging claw 140 swings when the generated centrifugal force overcomes the urging force of the tension spring 142 that is the urging member, and the tip thereof is in the radial direction. It moves outward and engages with the ratchet teeth 122. When engaged with the ratchet teeth 122, the rotation of the pressing roller 234 is prohibited. A centrifugal force stopper 242 that stops the rotation of the pressing roller 234 using a centrifugal force is configured including the first bearing member 232, the rotating disk 126, the engaging claw 140, and the tension spring 142. In other words, the centrifugal force stopper 242 has a function for locking the pressing roller 234. In FIG. 10A, a part of the first bearing member 232 is drawn so as to be located above the lower end portion of the supported member 34 (right direction in the figure). This is because the member 34 has a cut and is attached to the supported member 34 so that the first bearing member 232 fits into the cut. Further, the second bearing member (not shown) is not provided with a centrifugal force stopper, and the second bearing member only has a function of rotatably supporting the shaft portion 238 of the pressing roller 234.

  If the column moving part is moved after its fixation is released due to a secondary collision of the driver with the steering wheel or the like, the EA plate 72 is deformed as in the case of the second embodiment, and the drag force is reduced. The generator 230 generates drag. Also in this modification, the pressing roller 234 rotates with the EA plate 72 and the movement. When the impact received by the steering column 5 is small, the moving speed of the column moving portion is slow, the rotation of the pressing roller 234 is slow, and the centrifugal stopper 242 does not work. In this case, since the EA plate 72 is deformed with the rotation of the pressing roller 234, only a relatively small drag is generated. However, when the impact received by the steering column 5 is large, the moving speed of the column moving portion is high, and the rotational speed of the pressing roller 234 is also increased. Therefore, the centrifugal force stopper 242 works and the rotation of the pressing roller 234 is stopped. . In this case, since the protrusion 240 of the pressing roller 234 is engaged with the EA plate 72, a large force is required for the EA plate 72 to rub on the surface of the pressing roller 234. Therefore, the deformation resistance of the EA plate 72 is increased, and the effect generating device 230 generates a large drag force.

  That is, also in this modified example, the engagement state between the two according to the moving speed of the column moving portion, that is, according to the relative moving speed between the EA plate 72 that is the deforming member and the pressing roller 234 that is the deforming forcing member. Is changed, and the drag generated is increased. The relationship between the column moving speed and the magnitude of the generated drag is as shown in FIG. 8 as in the second embodiment. That is, the drag generator 230 also includes a moving speed-based drag changing mechanism that changes the magnitude of the drag depending on the moving speed of the column moving unit, and includes the drag generator 230. The shock absorbing device 250 according to this modification includes a shock energy absorption amount changing mechanism that changes the amount of shock energy absorbed depending on the moving speed of the column moving unit.

<Third embodiment>
A steering column to which the impact absorbing device of this embodiment is applied is shown in FIG. The steering column 155 shown in this figure includes a steering shaft 160 (hereinafter sometimes simply referred to as “shaft 160”) and a steering tube 162 (hereinafter simply referred to as “shaft 160”) that holds the shaft 160 rotatably and immovably in the axial direction. Tube 162 ”in some cases). The steering column 155 is different from the previous embodiment in that a part of the steering column 155 is not movable with respect to other parts, but the entire steering column 155 is a column moving portion, and the impact is applied. When it is received, it can be moved as a whole. The right side of the steering column 155 in the figure is the upper part, a steering wheel (not shown) is attached to the upper end of the shaft 160, and the lower end of the shaft 160 is connected to a member on the wheel side.

  The tube 162 is attached to the vehicle body at a lower end portion and an intermediate portion in the axial direction. A mounting bracket 164 is provided on the reinforcement of the vehicle body, specifically the instrument panel, and an intermediate portion is mounted on the mounting bracket 164. A mounted member 166 (indicated by a two-dot chain line in the drawing) is fixedly provided on the tube 162, and a mounting shaft 168 is inserted into a hole provided in the mounted member 166. The mounting shaft 168 is hooked on the mounting bracket 164, so that the intermediate portion is fixed to the vehicle body. When an impact is applied to the steering column 155 due to a driver's secondary collision or the like, the latching of the intermediate portion is easily released. In this steering column 155, the tilt mechanism is incorporated in the mounted member 166, but the description thereof is omitted because it is not related to the present invention.

  A lower portion of the steering column 155 is attached to the vehicle body via an impact absorbing device 170. FIG. 12 shows the shock absorbing device 170 in an enlarged manner. The impact absorbing device is configured with a substantially U-shaped channel-type member 172 as a base material. The channel type member 172 is fixed to the tube 162 at the tips of the two flanges 174 (parts parallel to each other standing on the tube 162). Each of the two flanges 174 is formed with an oblong hole 176 having a generally oblong elliptical shape. By inserting a support shaft 178 fixed to the vehicle body into the oblong hole 176, the steering column 155 is inserted. Is supported by the vehicle body. On the outer periphery of the support shaft 178, a collar 180 made of a relatively soft material such as resin and having good sliding characteristics and having an outer diameter substantially equal to the width of the long hole is fitted. It is engaged with the slot through. The elongated hole 176 is formed in a constricted shape having a narrow portion by forming a protruding portion 182 from which a part of the flange 174 that defines the elongated hole 176 protrudes. The lower portion of the steering column 155 is attached at a position where the support shaft 178 is located below the projecting portion 182 (left side in the drawing), and the support shaft 178 is prevented from moving in the long hole 176 in a normal state. ing. When an impact is applied to the steering column 155, a part of the collar 180 is deformed, and the support shaft 178 moves over the protrusion 182 and moves in the long hole 176. Thus, the steering column 155 moves relative to the vehicle body while being guided in a direction in which the elongated hole 176 extends (a direction slightly inclined with respect to the axial direction of the steering column 155). The stroke of this relative movement is determined by the length of the long hole 176, and the end of the movement stroke is a position where the support shaft 178 (specifically, the outer periphery of the collar 180) contacts the upper end of the long hole.

  The channel type member 172 is provided with an EA plate 190 as a deformation member. The EA plate 190 is a metal band-shaped member that has a shape in which one straight portion is bent into a long U shape and the other short straight portion is further bent inward. Various rod-shaped members are fixedly disposed between the two flanges 174 of the channel type member 172 so as to connect the two flanges 174. One end of the EA plate 190 is fixed to two fixing rods 192 located on the left side of the elongated hole 176 in the figure of the rod-shaped member, and the longer extending end is a free end. It is arranged in the state. Note that the support shaft 178 passes through a space surrounded by the EA plate 190. The other rod-shaped members abut on the EA plate 190 and function as restricting rods 194, 196, 198, 200 that restrict the EA plate 190 from being freely deformed.

  Further, between each of the two flanges 174, there is provided a roller shaft 202 that is rotatably supported at both ends of each flange 174. The roller shaft 202 has an eccentric shape in an axial straight section. The roller 204 is supported in a state in which it cannot rotate relative to the roller shaft 202. One end portion on the near side of the roller shaft 202 discharges outward from the flange 174, and a collar 206 is fixedly provided on the protruding portion. The collar 206 has a breaking pin 208 and a locked member 210 protruding in a direction perpendicular to the axial direction. The breaking pin 208 is in contact with a pin contact member 212 that is fixedly provided on the outer surface of the flange 174, and prevents the roller shaft 202 from rotating. When the roller shaft 202 is rotated with a large force, the roller is broken until the breaking pin 208 is broken and the locked member 210 is locked to a locking member 214 fixed to the outer surface of the flange 174. The rotation of the shaft 202 is allowed (the white arrow in FIG. 12B). In the state where the fracture pin 208 is in contact with the pin contact member 212, the eccentric convex portion 216 of the eccentric roller 204 is not engaged with the EA plate 190 (the state indicated by the solid line in FIG. 12A). When the breaking pin 208 is broken and the rotation of the roller shaft 202 is allowed, the roller shaft 202 is rotated approximately 90 ° (the white arrow in FIG. 12A), and the eccentric convex portion 216 of the eccentric roller 204 is A state of engagement with the EA plate 190 (a state indicated by a two-dot chain line) is established.

  When an impact is applied to the steering column 155 and the steering column 155 moves, the support shaft 178 functions as a pressing member and abuts the outer peripheral surface of the collar 180 on the inner side of the U-shaped bent portion of the EA plate 190. After contact, the EA plate 190 is moved while being deformed. Drag is generated due to the deformation resistance accompanying the deformation of the EA plate 190. The deformation resistance is generated by bending and spreading the EA plate 190 at the U-shaped bent portion of the EA plate 190 with which the support shaft 178 is engaged. Further, in the present shock absorbing device 170, deformation resistance is also generated by the deformation of the EA plate 190 at the portion engaged with the restriction rods 196, 198 and the eccentric roller 204. Specifically, as the steering column 155 moves, the above-mentioned portion of the EA plate moves relative to the restriction rods 196 and 198 and the eccentric roller 204, and as the relative movement moves, the portion of the EA plate 190 bends. It is caused by being spread.

As described above, when the impact received by the steering column 155 is small, the moving speed of the steering column 155 is low, and the relative moving speed of the EA plate 190 is also low. In this case, the force to rotate the eccentric roller 204 is small, the roller shaft 202 does not rotate, and the state where the eccentric convex portion 216 does not engage with the EA plate is maintained. However, when the impact received by the steering column 155 is large, the moving speed of the steering column 155 increases and the relative moving speed of the EA plate 190 also increases. In this case, as in the case of the previous embodiment, the EA plate 190 is instantly forced to be deformed, and the rotational force of the roller shaft 202 is short in a short time because the deformation speed does not follow. There is an increase. As a result, the breaking pin 208 is broken and the eccentric roller 204 is rotated. In the state where the eccentric roller 204 is rotated, the deformation amount of the EA plate 190 in the portion where the eccentric roller 204 is engaged increases, and the deformation resistance also increases. Therefore, the magnitude of the drag that is changed in accordance with the change in the deformation resistance is generated when the moving speed of the steering column 155 exceeds a certain threshold speed v ₀ as shown in FIG. It will be changed to increase the drag.

  Due to the structure as described above, the shock absorbing device 170 has a drag generating device 218. The drag generating device 218 is an EA plate 190 as a deforming member and a main deforming forcing member that forces deformation of the EA plate 190. The support shaft 178, the eccentric roller 204 as an auxiliary deformation compulsory member, and the restriction rods 196, 198, 200 are included. The drag generating device 218 has a moving speed-based drag changing mechanism that changes the magnitude of the drag depending on the moving speed of the steering column 155, whereby the shock absorbing device 170 is In addition, an impact energy absorption amount changing mechanism that changes the absorption amount of impact energy depending on the moving speed of the steering column 155 is provided.

  Also in this embodiment, the EA plate 190 that is a deforming member and the eccentric roller 204 that is one of the deforming forcing members are engaged with each other while relatively moving, and the relative moving speed is determined by the movement of the steering column 155. The speed depends on the speed. And the movement speed dependence drag change mechanism which this drag generator 218 has changes the engagement relationship between a deformation member and a deformation compulsion member by rotating eccentric roller 204 according to those relative movement speeds. It has been done. The engagement relationship is changed depending on the force that acts on the roller shaft 202 to rotate the roller shaft 202, that is, changes depending on the relative moving speed between the deformation member and the deformation compulsory member. Therefore, the collision energy absorption amount changing mechanism is also changed by the acting force acting on itself, regardless of the electric means, as in the previous embodiment. The structure is such that the amount of absorption is changed.

It is a side view which shows the steering column to which the impact-absorbing device of 1st Example was applied. It is a top view of the steering column shown in FIG. It is side surface sectional drawing of the steering column shown in FIG. FIG. 2 is a perspective view showing an upper tube mounting structure and an impact absorbing device in the steering column shown in FIG. 1. FIG. 2 is an enlarged view of a portion where a drag generator is shown in FIG. 1. FIG. 4 is an enlarged view of a portion where a drag generator is shown in FIG. 3. It is a perspective view which shows the relationship between the groove | channel provided in the impact-absorbing plate which a drag generator has, and the protrusion provided in the pressing roller which deform | transforms an impact-absorbing plate, and it bites into the groove | channel. It is a figure which shows typically the relationship between the magnitude | size of the drag which the drag generator with which the shock absorber of 1st Example is provided, and the moving speed of a column moving part. It is a figure which shows the efficacy generator with which the impact-absorbing device of 2nd Example is provided. It is a figure which shows the efficacy generator with which the impact-absorbing device of the modification of 2nd Example is provided. It is side surface partial sectional drawing which shows the steering column to which the impact-absorbing device of 3rd Example was applied. It is a figure which expands and shows the impact-absorbing device of 3rd Example.

Explanation of symbols

5: Steering column 10: Upper shaft 12: Lower shaft 18: Upper tube 20: Lower tube 34: Supported member 42: Support member 70: Drag generator 71: Shock absorber 72: Shock absorber plate (EA plate) (deformation) 74): Pressing roller (deformation forcing member) 88: Restriction member 90: Breaking pin 98: Protrusion 100: Groove 110: Drag generator 114: Pressing roller (deformation forcing member) 120: Centrifugal clutch 130: Swing lever 136 : Auxiliary roller 138: Restriction rod 150: Shock absorber 155: Steering column 160: Steering shaft 162: Steering tube 170: Shock absorber 172: Channel type member 176: Long hole 178: Support shaft 190: Shock absorber plate (EA plate) ) (Deformation member) 1 4,196,198,200: Restriction rod 202: Roller shaft 204: Eccentric roller (deformation forcing member) 208: Breaking pin 216: Eccentric protrusion 218: Drag generation device 230: Drag generation device 234: Pressing roller (deformation forcing member) 240: Projection 242: Centrifugal force stopper 250: Shock absorber

Claims (2)

An impact absorbing device for absorbing impact energy applied to a steering column to which a steering wheel is attached when a driver collides with the steering wheel,
In the case where the steering column has a structure in which only a part of the steering column on the side of the steering wheel is allowed to move during the collision, a part of the steering column is allowed to move as a whole. When the entire structure is defined as a column moving portion, the shock absorbing device allows the column moving portion to move in a state of being dragged, thereby allowing the steering column to move to the steering column. It absorbs the applied impact energy,
The shock absorbing device is
And a deforming member that engages the deforming member while moving relative to the deforming member at a speed corresponding to an actual moving speed of the column moving unit when the column moving unit moves. A drag generating device that generates the drag due to the deformation resistance of the deformable member by forcing the deformation of the deformable member with the movement of the deformable member;
By changing the engagement relationship between the deformation member and the deformation forcing member by an acting force that varies depending on the relative movement speed between the deformation member and the deformation forcing member, the deformation resistance of the deformation member is increased. Depending on the actual moving speed of the column moving unit, thereby increasing the amount of absorption of the impact energy when the actual moving speed of the column moving unit is large compared to when it is small. and a shock energy absorbing amount changing mechanism,
The deformation member is a plate-like member, and the plate-like member has a groove extending in a moving direction thereof;
The deformation forcing member is a roller that is pressed against the plate-like member to deform the plate-like member, and the roller has a protrusion that bites into the groove at a certain rotational position,
The impact energy absorption amount changing mechanism is
When the relative movement speed between the plate-like member and the roller increases beyond a threshold value, rotation as the acting force acting on the roller due to friction between the plate-like member and the roller By allowing the roller to rotate to the certain rotational position by force and causing the protrusion to bite into the groove, the deformation resistance of the plate-like member can be changed between the plate-like member and the roller. The impact is configured to increase so that the amount of absorption of the impact energy is increased when the actual moving speed of the column moving unit is larger than a set threshold speed. Absorber. An impact absorbing device for absorbing impact energy applied to a steering column to which a steering wheel is attached when a driver collides with the steering wheel,
In the case where the steering column has a structure in which only a part of the steering column on the steering wheel side is allowed to move during the collision, a part of the steering column is allowed to move in the whole of the steering column. When the entire structure is defined as a column moving part, the shock absorbing device allows the column moving part to move in a state of receiving a drag, thereby allowing the steering column to move to the steering column. It absorbs the applied impact energy,
The shock absorbing device is
And a deforming member that engages the deforming member while moving relative to the deforming member at a speed corresponding to an actual moving speed of the column moving unit when the column moving unit moves. A drag generating device that generates the drag due to the deformation resistance of the deformable member by forcing the deformation of the deformable member with the movement of the deformable member;
By changing the engagement relationship between the deformation member and the deformation forcing member by an acting force that varies depending on the relative movement speed between the deformation member and the deformation forcing member, the deformation resistance of the deformation member is increased. Depending on the actual moving speed of the column moving unit, thereby increasing the amount of absorption of the impact energy when the actual moving speed of the column moving unit is large compared to when it is small. and a shock energy absorbing amount changing mechanism,
The deformable member is a plate-shaped member,
The deformation compulsory member is a roller that is pressed against the plate-like member to deform the plate-like member, and the roller has an eccentric shape in the axial cross-sectional shape, so that the eccentricity having a large radius is obtained. Has a convex part
The impact energy absorption amount changing mechanism is
When the relative movement speed between the plate-like member and the roller increases beyond a threshold value, rotation as the acting force acting on the roller due to friction between the plate-like member and the roller By allowing the eccentric convex portion of the roller to rotate to a rotational position where it engages with the plate-like member by force, and increasing the amount of deformation of the plate-like member, the plate-like member and roller Is changed so that the deformation resistance of the plate-like member is increased, so that the impact energy is absorbed when the actual moving speed of the column moving part is larger than a set threshold speed. An impact absorbing device configured to increase the amount .

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