JP4524899B2 - Shock absorbing steering column device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an impact absorption type steering column device having a variable operating load type collision energy absorbing means, and more particularly to a technique for realizing simplification of the structure of an electromagnetic actuator.
[0002]
[Prior art]
When an automobile collides with another automobile or a building, the driver may make a secondary collision with the steering wheel due to inertia. In recent passenger cars and the like, in order to prevent the driver from being damaged in such a case, an impact absorption type steering shaft and an impact absorption type steering column device are widely adopted. The shock absorption type steering column device is one in which the steering column falls off together with the steering shaft when the driver has a secondary collision, and usually moves forward with the steering shaft, and at that time, the collision energy is absorbed.
[0003]
The collision energy absorption method includes a mesh type that compressively buckles and deforms the mesh part formed in a part of the steering column, and an inner periphery of the outer column by a metal ball interposed between the outer column and the inner column. A ball type or the like in which a plastic groove is formed on the surface or the outer peripheral surface of the inner column is conventionally known, but in recent years, an ironing type described in JP-A-7-329796 has been widely adopted. The ironing-type collision energy absorbing mechanism is, for example, a steel rod that is fixed to one end of an energy absorbing member made of a strip-shaped steel plate on a vehicle body side bracket and fitted into a bent portion formed on the energy absorbing member on the steering column side. An ironing means is provided, and the energy absorbing member is ironed and deformed by the ironing means when the steering column moves forward.
[0004]
[Problems to be solved by the invention]
By the way, in the shock absorbing type steering column apparatus provided with the ironing type collision energy absorbing mechanism described above, the collision energy absorbing means is activated and the steering column moves forward when a predetermined operating load is applied. As a result, the following problems occurred. Usually, the operating load of the collision energy absorbing means is set based on the kinetic energy when a standard weight driver makes a secondary collision with the steering wheel at a predetermined speed. However, when the driver is a small woman or the like, the kinetic energy is naturally reduced. Not done. As a result, the collision energy is not absorbed at all because the steering column (that is, the steering wheel) does not move forward, and the shock absorption type steering column device cannot perform the intended function. There was a big shock.
[0005]
Therefore, German Patent DE195542491C1 and International Publication No. WO98 / 22325 describe an impact absorption type steering column device that switches a collapse load according to driving conditions as a device for solving this problem. Yes. In these devices, the electronic control means that detects various operation information switches the operation mode of the energy absorption means, and an electromagnetic actuator is used as a switching drive source. An electromagnetic actuator moves a working iron core (plunger) from one position (hereinafter, first position) to the other position (hereinafter, second position) by attracting magnetic force with an electromagnet (solenoid). When the current is not energized, the plunger is held in the first position by the urging force of the return spring.
[0006]
By the way, in the electromagnetic actuator mentioned above, several problems have arisen as described below on account of using a return spring for holding the plunger. For example, when the plunger is held at the second position for a long time, the solenoid continues to be energized, so that the power consumption increases and the solenoid suction performance may gradually deteriorate due to the heat generated by the coil. In addition, the spring force of the return spring is required to be strong enough to prevent the movement (malfunction) of the plunger due to acceleration / deceleration and vibration during driving, but this requires a large solenoid with a large magnetic attractive force. Larger equipment is inevitable. Also, if the solenoid is de-energized while holding the plunger in the second position, the plunger returns to the first position due to the spring force of the return spring, so that the current supply at the time of the collision is stopped. In order to avoid this, it is desirable to provide a fail-safe standby power supply or an electric circuit. However, the system becomes complicated and the cost of the apparatus greatly increases.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an impact absorption type steering column device having a variable operating load type collision energy absorbing means that realizes simplification of the structure of an electromagnetic actuator.
[0007]
[Means for Solving the Problems]
Therefore, in the invention of claim 1, in order to solve the above problem, a collision energy absorbing means for absorbing a secondary collision energy of the occupant at the time of a vehicle collision,
An energy absorption amount adjusting means for changing the amount of absorption of the secondary collision energy by the collision energy absorbing means, and an impact absorption type steering column device comprising:
The energy absorption amount adjusting means uses an electromagnetic actuator as a drive source, and the electromagnetic actuator operates under a first operating condition and a second operating condition that are different from each other in the plunger and the secondary collision energy, thereby causing the plunger to be in a first predetermined condition. A first electromagnet and a second electromagnet moved to a position or a second predetermined position,
The plunger is attracted and held by the permanent magnet at the first predetermined position or the second predetermined position;
The energy absorption amount adjusting means is characterized in that the amount of absorption of the secondary collision energy is changed when the plunger takes the first predetermined position and when the plunger takes the second predetermined position. To do.
[0009]
According to a second aspect of the present invention, in the shock absorbing steering column device according to the first aspect, the collision energy absorbing means is provided between the steering column and the vehicle body side bracket, and the movement of the steering column is performed. It comprises first and second squeezing means for plastically deforming an energy absorbing member made of a metal plate or metal wire, and the energy absorption amount adjusting means is configured such that when the plunger assumes the second predetermined position, Deactivate the ironing means .
[0010]
In the invention of claim 2 , for example, when the driver's weight is large, the operating load is increased by increasing the amount of plastic deformation of the energy absorbing member, while when the driver's weight is small, the energy absorbing member of the energy absorbing member is increased. By reducing the amount of plastic deformation, the operating load is reduced, so that the steering column is properly advanced.
[0011]
According to a third aspect of the present invention, in the shock absorption type steering column apparatus of the second aspect, the first and second ironing means are each a metal rod or a metal ball, and the energy absorption amount adjusting means is the first energy absorption amount adjusting means . Also proposed is one in which at least one of the plastic deformation portion and the plastic deformation amount of the energy absorbing member by the second ironing means is changed.
[0012]
In the invention of claim 3 , for example, four steel bars are used as the first and second ironing means of the energy absorbing member, and when the driver's weight is large, all four steel bars are used. When the person's weight is small, the two steel bars are moved to the retracted position, and the ironing depth of the two steel bars with respect to the energy absorbing member is increased or decreased.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a passenger compartment side portion of a tilt steering apparatus to which the present invention is applied. Reference numeral 1 in the figure denotes an impact absorbing steering column apparatus. The shock absorbing steering column device 1 is mounted on the vehicle body side member 3 at two locations, upper and lower, and an upper steering shaft (hereinafter simply referred to as a steering shaft) 9 is rotatably supported by bearings 5 and 7. . A steering wheel 11 is attached to the upper end of the steering shaft 9, and a lower steering shaft 15 is connected to the lower end via a universal joint 13. In the figure, 17 is a column cover that covers the upper portion of the steering column 1, and 19 is a dashboard that partitions the vehicle compartment and the engine compartment.
[0014]
In this steering apparatus, when the driver rotates the steering wheel 11, the rotational force is transmitted to a steering gear (not shown) via the steering shaft 9 and the lower steering shaft 15. The steering gear incorporates a rack and pinion mechanism or the like that converts rotational input into linear motion, and steering is performed by changing the steering angle of the wheel via a tie rod or the like. In addition to the rack and pinion type, various types of steering gears such as a ball screw type and a worm roller type are known.
[0015]
FIG. 2 is a side view showing the shock absorbing steering column device according to the embodiment, FIG. 3 is a plan view (viewed in the direction of arrow A in FIG. 2) showing the device, and FIG. 5 is an enlarged BB sectional view, FIG. 5 is an enlarged CC sectional view in FIG. 2, and FIG. 6 is an enlarged DD sectional view in FIG. As shown in these drawings, the steering column 21 has a steel plate upper distance bracket (hereinafter abbreviated as “upper bracket”) 25 welded to a substantially central portion of a steel tube column tube 23, and a front portion ( This is manufactured by welding a lower distance bracket (hereinafter abbreviated as a lower bracket) 27 made of a steel plate to the left in FIGS.
[0016]
The upper bracket 25 is held by a tilt bracket 31 of a steel plate welded structure fixed to the vehicle body side member 3, and is clamped and fixed with a predetermined fastening force by a tilt bolt 33 and a nut 35 penetrating the tilt bracket 31. Has been. The upper bracket 25 is formed with a substantially U-shaped notch 37 that opens rearward, and the tilt bolt 33 is fitted on the front end side of the notch 37. 4 and 6, the members denoted by reference numerals 41 and 43 are known tilt cams, and are used for fixing the steering column 21 at a predetermined angle. A member denoted by reference numeral 45 is a tilt lever that rotationally drives the tilt cam 41, and a member denoted by reference numeral 47 is a thrust bearing interposed between the head of the tilt bolt 33 and the tilt lever 45.
[0017]
On the other hand, the lower bracket 27 is sandwiched by a cast pivot bracket 51 fixed to the vehicle body side member 3, and is fixed by a pivot bolt 53 and a nut 55 that penetrate the pivot bracket 51. The pivot bracket 51 is formed with a substantially U-shaped notch 57 that opens forward, and the pivot bolt 53 is inserted into the rear end side of the notch 57. The steering column 21 is swingable about the pivot bolt 53, and by operating the tilt lever 45, the driver can adjust the vertical position of the steering wheel 11 within a predetermined range.
[0018]
In the case of the present embodiment, the collision energy absorbing means includes an energy absorbing plate 61 held by the tilt bolt 33 and a variable ironing device 63 fixed to the steering column 21. The energy absorbing plate 61 is a substantially U-shaped steel plate opened forward, and the tilt bolt 33 penetrates the vicinity of the rear end portion.
[0019]
On the other hand, the variable ironing device 63 is welded to the column tube 23 as shown in FIGS. 6 and 7 (cross-sectional view taken along line EE in FIG. 6) and FIG. 8 (cross-sectional view taken along line FF in FIG. 6). A base plate 65 of a pressed steel plate product, a housing 67 bolted to the base plate 65, a slide block 69 slidably held in the housing 67, and an ECU (electronic control unit) 70 held in the housing 67. And an electromagnetic actuator (hereinafter referred to as a solenoid) 71 that is driven and controlled. In addition to the seat position sensor 73, the ECU 70 is connected to at least one sensor such as a weight sensor 74, a vehicle speed sensor 75, an occupant position sensor 76, a seat belt wearing sensor 77, and the like.
[0020]
The solenoid 71 includes a yoke 81 of a steel plate press-formed product, a plunger (movable iron core) 83 slidably held in the yoke 81, and a first and a first disposed in the front-rear manner so as to surround the plunger 83. Two coils 85, 87, a permanent magnet 89 interposed between the coils 85, 87, and first and second fixed iron cores 91, 93 fixed to the front and rear inner end surfaces of the yoke 81. It is configured. The plunger 83 has a rod portion 95 formed at the tip thereof screwed and connected to the slide block 69, and moves forward and backward integrally with the slide block 69. The first fixed iron core 91 is formed with a through hole 97 through which the rod portion 95 is inserted. In FIG. 6, members indicated by 98 and 99 are cushioning materials attached to the slide block 69, and suppress the collision noise of the slide block 69 with the housing 67 and the solenoid 71.
[0021]
The housing 67 holds a pair of left and right guide plates 101 and 103 adjacent to both side surfaces of the slide block 69, and the energy absorbing plate 61 described above is located between the guide plates 101 and 103 and the slide block 69. Is inserted. Both guide plates 101, 103 have U-shaped recesses 105, 107 inside the substantially central part and the rear part, respectively, and before and after the U-shaped recesses 105, 107 are formed on the energy absorbing plate 61. U-shaped bent portions 109 and 111 are inserted.
[0022]
In the energy absorbing plate 61, a fixed ironing pin 113 is fitted into the front U-shaped bent portion 109, while a moving ironing pin 115 is fitted into the rear U-shaped bent portion 111. The housing 67 is formed with a pair of left and right elongated holes 121 and 123 for holding the moving-side squeezing pin 115, and the moving-side squeezing pin 115 can move in the left and right directions by a predetermined amount. Yes.
[0023]
Hereinafter, the operation of the first embodiment will be described.
When the vehicle starts traveling, the ECU 70 repeatedly calculates the target operating load of the collision energy absorbing means at a predetermined control interval based on the detection signals of the various sensors 73 to 77 described above. For example, when the driver's weight is relatively large, or when the driver's weight is relatively small and the vehicle speed is high, the kinetic energy of the driver at the time of collision increases, so the target operating load also increases. Then, the ECU 70 outputs an exciting current to the second coil 87 of the solenoid 71 for a predetermined time, and as shown in FIG. 9, the plunger 83 is attracted magnetically backward.
[0024]
As a result, the slide block 69 connected to the plunger 83 also moves rearward, and its rear side surface is located inside the moving side ironing pin 115, thereby restricting the movement of the moving side ironing pin 115 to the inside. . At this time, the plunger 83 abuts against the end surface of the second fixed iron core 93. However, since the second fixed iron core 93 is connected to the permanent magnet 89 via the yoke 81, the plunger 83 has a predetermined attraction force. 2 The magnetic iron is attracted to the fixed iron core 93. Although it is unavoidable that the slide block 69 is subjected to vibration during vehicle travel or impact during a collision, the suction force of the plunger 83 to the second fixed iron core 93 is sufficiently large. There is no prepared movement.
[0025]
In this state, when the vehicle collides with another vehicle or an obstacle on the road, the driver has a secondary collision with the steering wheel 11 due to inertia, and FIGS. 10 and 11 (viewed in the direction of arrow G in FIG. 10) due to the impact. As shown in FIG. 4, the upper bracket 25 is detached forward from the tilt bracket 31, while the lower bracket 27 is detached forward from the pivot bracket 51, and the steering column 21 is dropped and starts moving forward. Then, as the steering column 21 moves forward, as shown in FIG. 12, the variable ironing device 63 on the steering column 21 side moves forward with respect to the energy absorbing plate 61 held on the tilt bolt 33 on the vehicle body member 3 side. To do.
[0026]
Then, in the energy absorbing plate 61, the front U-shaped bent portion 109 fitted between the U-shaped concave portion 105 and the fixed ironing pin 113 and the U-shaped concave portion 107 and the moving-side ironing pin 115 are fitted. The rear U-shaped bent portion 111 is moved forward. As a result, the energy absorbing plate 61 is squeezed around the squeezing pins 113 and 115 in four places on the left and right sides, and a relatively large collision energy is absorbed. FIG. 13 is a graph showing the relationship between the moving stroke of the steering column 21 and the operating load, and the solid line in the figure shows the test result at this time (at the time of a large operating load).
[0027]
On the other hand, when the driver is a small woman or the like having a relatively small weight, the kinetic energy of the driver at the time of the collision is relatively small, so the target operating load calculated by the ECU 70 is also small. Then, the ECU 70 outputs an exciting current to the first coil 85 of the solenoid 71 for a predetermined time, and as shown in FIG.
[0028]
As a result, the slide block 69 connected to the plunger 83 is also moved forward, and the rear side surface thereof is retracted from the inside of the moving side ironing pin 115, and the moving side ironing pin 115 freely moves in the long holes 121 and 123. It becomes possible to move to. At this time, the plunger 83 abuts on the end face of the first fixed iron core 91, but the first fixed iron core 91 is also connected to the permanent magnet 89 via the yoke 81 in the same manner as the second fixed iron core 93. The plunger 83 is magnetically attracted to the first fixed iron core 91 with a predetermined attracting force.
[0029]
In this state, when the automobile collides with another automobile or an obstacle on the road, the steering column 21 drops and moves forward by the same process as described above, and the variable ironing device 63 moves forward with respect to the energy absorbing plate 61. . However, in this case, since the moving ironing pin 115 is not restrained by the slide block 69, the rear U-shaped bent portion 111 of the energy absorbing plate 61 advances from the U-shaped concave portion 107 as shown in FIG. 15. When moving, the moving-side squeezing pin 115 is pressed inward to move, and then disappears.
[0030]
As a result, the energy absorbing plate 61 is squeezed only by the two fixed-side squeezing pins 113 on the left and right sides, and the amount of absorbed collision energy is reduced, and even if the driver is a small woman or the like, the steering column 21 Thus, the forward movement of the vehicle is carried out smoothly, and a large impact is not applied to the chest and head of the driver. The broken line in FIG. 13 shows the test result at this time (at the time of a small operating load), and it can be seen that the small operating load is significantly smaller than the large operating load.
[0031]
Although description of specific embodiment is finished above, the aspect of the present invention is not limited to the above embodiment. For example, in the above embodiment, a steel plate is used as the energy absorbing member and a pin is used as the ironing member. However, a steel wire or the like may be used as the energy absorbing member, or a steel ball or the like may be used as the ironing member. Good. Moreover, in the said embodiment, although the structure which connects a 1st, 2nd fixed iron core to a single permanent magnet via a yoke was taken, the two permanent magnets which hold | maintain a plunger in the front-back position respectively are used. You may do it. In contrast to the above embodiment, the energy absorbing plate may be fixed to the steering column side, and the variable ironing device may be fixed to the vehicle body side. In addition, the specific configuration of the steering column device and the energy absorption amount adjusting means and the material and shape of the ironing means can be changed as appropriate without departing from the gist of the present invention.
[0032]
【The invention's effect】
As described above, according to the shock absorbing steering column device of the present invention, the collision energy absorbing means for absorbing the secondary collision energy of the occupant at the time of the vehicle collision, and the secondary collision by the collision energy absorbing means. An impact absorption type steering column device having energy absorption amount adjusting means for changing energy absorption amount, wherein the energy absorption amount adjustment means uses an electromagnetic actuator as a drive source, and a plunger of the electromagnetic actuator is a permanent magnet Because the electromagnetic actuator is attracted and held at a predetermined position, it is possible to energize the electromagnetic actuator only when the plunger is driven, preventing coil heat generation and reducing power consumption. The plunger will not move inadvertently due to internal vibration or impact at the time of collision. It can be simplified and cost of the structure pulling or failsafe mechanism, and the like becomes unnecessary.
[Brief description of the drawings]
FIG. 1 is a side view showing a compartment side portion of a steering device according to an embodiment.
FIG. 2 is a side view showing the shock absorbing steering column device according to the embodiment.
FIG. 3 is a plan view showing the apparatus (as viewed in the direction of arrow A in FIG. 2).
4 is an enlarged cross-sectional view along BB in FIG. 2;
FIG. 5 is an enlarged cross-sectional view taken along the line CC in FIG. 2;
6 is an enlarged DD cross-sectional view in FIG. 2. FIG.
7 is a cross-sectional view taken along line EE in FIG.
8 is a cross-sectional view taken along line FF in FIG.
FIG. 9 is an explanatory diagram showing the operation of the embodiment.
FIG. 10 is a side view showing a state where a steering column is dropped.
11 is a view on arrow G in FIG.
FIG. 12 is an explanatory diagram showing the operation of the embodiment.
FIG. 13 is a graph showing the relationship between the amount of movement of the steering column and the operating load.
FIG. 14 is an explanatory diagram showing the operation of the embodiment.
FIG. 15 is an explanatory diagram showing the operation of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Shock absorption type steering column apparatus 3 ... Body side member 9 Upper steering shaft 11 Steering wheel 21 Steering column 23 Column tube 25 Upper distance bracket 27 Lower distance bracket 31 Tilt bracket 33 Tilt bolt 51 Pivot bracket 53 Pivot bolt 61 Energy absorbing plate 63 Variable ironing device 67 Housing 69 Slide block 70 ECU
71 ... Electromagnetic actuator 81 ... York 83 ... Plunger 85 ... First coil 87 ... Second coil 89 ... Permanent magnet 91 ... First fixed iron core 93 ... Second fixed iron core 95 ... Rod Numerals 101 and 103 Guide plates 105 and 107 U-shaped concave portions 109 and 111 U-shaped bent portions 113 Fixed ironing pins 115 Moving ironing pins 121 and 123 Long holes

Claims (3)

A collision energy absorbing means for absorbing the secondary collision energy of the occupant during a vehicle collision;
An energy absorption amount adjusting means for changing the amount of absorption of the secondary collision energy by the collision energy absorbing means, and an impact absorption type steering column device comprising:
The energy absorption amount adjusting means uses an electromagnetic actuator as a drive source, and the electromagnetic actuator operates under a first operating condition and a second operating condition that are different from each other in the plunger and the secondary collision energy, thereby causing the plunger to be in a first predetermined condition. A first electromagnet and a second electromagnet moved to a position or a second predetermined position,
The plunger is attracted and held by the permanent magnet at the first predetermined position or the second predetermined position;
The energy absorption amount adjusting means is configured to change the absorption amount of the secondary collision energy between when the plunger takes the first predetermined position and when the plunger takes the second predetermined position. Steering column device. The collision energy absorbing means is provided between the steering column and the vehicle body side bracket, and first and second plastically deforms an energy absorbing member made of a metal plate or a metal wire as the steering column moves. Consisting of means of squeezing,
2. The shock absorbing steering column apparatus according to claim 1 , wherein the energy absorption amount adjusting means deactivates the second ironing means when the plunger assumes the second predetermined position. 3. The first and second ironing means are each a metal rod or a metal ball, and the energy absorption amount adjusting means changes at least one of a plastic deformation portion and a plastic deformation amount of the energy absorbing member by the ironing means. The shock-absorbing steering column device according to claim 2 , wherein:

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