JP2002120734A - Shock absorbing steering column device - Google Patents

Abstract

[PROBLEMS] To provide an impact-absorbing steering column device having a variable operating load-type collision energy absorbing means that realizes a simplified structure of an electromagnetic actuator and the like. SOLUTION: A solenoid 71 includes a yoke 81 formed of a steel sheet press-formed product, a plunger (movable iron core) 83 slidably held in the yoke 81 back and forth, and a coil 85 arranged so as to surround the plunger 83. And a permanent magnet 89 arranged in front of the coil 85 and a fixed iron core 91 caulked and fixed to the rear inner end face of the yoke 81. The plunger 83 has a distal end engaged with and connected to the slide block 69, and a return spring 93 interposed between the solenoid 71 and the slide block 69.
It is in the extended state by the urging force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact-absorbing steering column apparatus having a variable-load-type collision energy absorbing means, and more particularly to a technique for simplifying the structure of an electromagnetic actuator.

[0002]

2. Description of the Related Art When an automobile collides with another automobile, a building, or the like, the driver sometimes makes a secondary collision with the steering wheel due to inertia. In recent years, shock absorbing steering shafts and shock absorbing steering column devices have been widely used in passenger cars and the like in order to prevent the driver from being injured in such a case. In a shock absorbing type steering column device, when a driver makes a secondary collision, the steering column falls off together with the steering shaft. Usually, the steering column advances along with the steering shaft, and at that time, collision energy is absorbed.

[0003] As a method of absorbing collision energy, a mesh type for compressing and buckling a mesh formed on a part of the steering column or a metal ball interposed between the outer column and the inner column is used. A ball type or the like in which a plastic groove is formed on the inner peripheral surface or the outer peripheral surface of the inner column has been conventionally known.
The ironing method described in Japanese Patent No. 9796 is widely adopted. The ironing type collision energy absorbing mechanism is, for example,
One end of the energy absorbing member made of a band-shaped steel plate is fixed to the vehicle body side bracket, and ironing means such as a steel rod that fits into a bent portion formed on the energy absorbing member is provided on the steering column side. When moving, the energy absorbing member is deformed by the ironing means by the ironing means.

[0004]

By the way, in the above-described shock absorbing type steering column apparatus provided with the ironing type collision energy absorbing mechanism, when a predetermined operating load is applied, the collision energy absorbing means is operated to operate the steering column. Has advanced, but this has caused the following problems. Normally, the operating load of the collision energy absorbing means is set based on the kinetic energy when a driver having a standard weight collides 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. Therefore, even if such a driver collides with the steering wheel at the same speed, the ironing deformation of the energy absorbing member due to the ironing means may occur. Not done. As a result, since the steering column (i.e., the steering wheel) does not move forward, no collision energy is absorbed, the shock absorbing steering column device cannot perform its intended operation, and the driver cannot move the chest or head. Received a great shock.

[0005] Accordingly, German Patent DE1954291C
No. 1, International Publication No. WO98 / 22325, and the like, as a device for solving this problem, an impact-absorbing steering column device that switches a collapse load in accordance with operating conditions is described. In these devices, an electronic control unit that detects various kinds of operation information switches the operation mode of the energy absorbing unit, and an electromagnetic actuator is used as a drive source for switching. The electromagnetic actuator attracts a magnetic force by an electromagnet (solenoid) to move an operating iron core (plunger) to one position (hereinafter, a first position).
To the other position (hereinafter, a second position). When the solenoid is not energized, the plunger is held at the first position by the urging force of the return spring.

However, in the above-described electromagnetic actuator, there are some problems as described below, because only the return spring is used to hold the plunger. For example, when the plunger is held at the second position for a long time, the power is continuously supplied to the solenoid, so that the power consumption is increased, and the heat generated by the coil may gradually deteriorate the suction performance of the solenoid. Further, if the power supply to the solenoid is cut off while the plunger is held at the second position, the plunger returns to the first position due to the spring force of the return spring. In order to avoid this, it is desirable to provide a fail-safe backup power supply or an electric circuit. However, in this case, the system becomes complicated and the device cost increases significantly. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an impact absorbing steering column device having a variable operating load type collision energy absorbing means that realizes a simplified structure of an electromagnetic actuator.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a collision energy absorbing means for absorbing a secondary collision energy of an occupant at the time of a vehicle collision, and the collision energy absorbing means are provided. An energy absorbing amount adjusting means for changing the amount of absorption of the secondary collision energy by the impact absorbing steering column device,
The energy absorbing amount adjusting means uses an electromagnetic actuator as a drive source, and a plunger of the electromagnetic actuator is biased and held by a return spring at a first position, and is attracted and held by a permanent magnet at a second position. Suggest something.

According to the present invention, for example, when a current in a predetermined direction is supplied to a coil in the electromagnetic actuator, the plunger moves from the first position to the second position by the action of the magnetic field formed by the coil, and then the permanent magnet Adsorbed by
Will be retained. Also, when a reverse current is supplied to the coil, the reverse magnetic field formed by the coil cancels the magnetic field of the permanent magnet, and the plunger biased by the return spring moves from the second position to the first position. I do.

According to a second aspect of the present invention, in the shock absorbing type steering column device of the first aspect, the collision energy absorbing means is provided between the steering column and the vehicle body side bracket, and An energy absorbing member made of a metal plate or a metal wire is plastically deformed by ironing means as it moves.

According to the present invention, for example, when the weight of the driver is large, the working load is increased by increasing the amount of plastic deformation of the energy absorbing member. The working load is reduced by reducing the amount of plastic deformation so that the steering column is properly advanced.

According to a third aspect of the present invention, in the shock absorbing type steering column device of the first or second aspect, the ironing means is a metal rod or a metal ball, and the energy absorption amount adjusting means is provided by the ironing means. An energy absorbing member that changes at least one of a plastic deformation portion and a plastic deformation amount of the energy absorbing member is proposed.

According to the present invention, for example, four steel rods are used as ironing means for the energy absorbing member, and all four steel rods are used when the driver's weight is large, while when the driver's weight is small. In (2), the two steel rods are moved to the retracted position, and the ironing depth of the two steel rods with respect to the energy absorbing member is increased or decreased.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a passenger compartment side portion of a tilt steering device to which the present invention is applied, and reference numeral 1 in the figure denotes an impact absorbing steering column device. The shock absorbing type steering column device 1 is mounted on the vehicle body side member 3 at two upper and lower positions.
Thereby, an upper steering shaft (hereinafter, simply referred to as a steering shaft) 9 is rotatably supported.
A steering wheel 11 is attached to an upper end of the steering shaft 9, and a lower steering shaft 15 is connected to a lower end of the steering shaft 9 via a universal joint 13. In the figure, reference numeral 17 denotes a column cover that covers the upper portion of the steering column 1, and 19 denotes a dashboard that partitions a vehicle room and an engine room.

In this steering device, 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 has a built-in rack-and-pinion mechanism that converts a rotational input into a linear motion, and the steering is performed by changing the steering angle of the wheel via a tie rod or the like. Various types of steering gears such as a ball screw type and a worm roller type are known in addition to the rack and pinion type.

FIG. 2 is a side view showing the shock absorbing type steering column device according to the embodiment, FIG. 3 is a plan view showing the device (viewed in the direction of arrow A in FIG. 2), and FIG. 2 is an enlarged sectional view taken along the line BB in FIG. 2, and FIG.
FIG. 6 is a sectional view, and FIG. 6 is an enlarged sectional view taken along the line DD in FIG. As shown in these figures, the steering column 2
Reference numeral 1 denotes a steel tube upper distance bracket (hereinafter abbreviated as an upper bracket) 25 which is welded to a substantially central portion of a steel tube column tube 23 and welded to the front portion (left side in FIGS. 2 and 3). This is also manufactured by welding a lower distance bracket (hereinafter abbreviated as a lower bracket) 27 made of a steel plate.

The upper bracket 25 is provided on the vehicle body side member 3.
Is fixed to a tilt bracket 31 of a steel plate welded structure product fixed to the tilt bracket 31, and is clamped and fixed with a predetermined fastening force by a tilt bolt 33 and a nut 35 penetrating the tilt bracket 31. A substantially U-shaped notch 37 is formed in the upper bracket 25 and opens rearward. The tilt bolt 33 is inserted into the front end of the notch 37. 4 and 6, reference members 41 and 43 are known tilt cams, which are used to fix the steering column 21 at a predetermined angle. Further, a member indicated by reference numeral 45 is a tilt lever for driving the tilt cam 41 to rotate, and a member indicated by reference numeral 47 is a thrust bearing interposed between the head of the tilt bolt 33 and the tilt lever 45.

On the other hand, the lower bracket 27 is sandwiched by a pivot bracket 51 of a cast product fixed to the vehicle body side member 3, and is fixed by a pivot bolt 53 and a nut 55 penetrating through the pivot bracket 51.
A substantially U-shaped notch 57 that opens forward is formed in the pivot bracket 51, and the pivot bolt 53 is fitted to the rear end side of the notch 57. The steering column 21 can swing about a pivot bolt 53, and the driver can adjust the vertical position of the steering wheel 11 within a predetermined range by operating the tilt lever 45.

In the case of this embodiment, the collision energy absorbing means comprises 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 near the rear end.

On the other hand, the variable ironing device 63 is shown in FIGS.
As shown in FIG. 6 (a sectional view taken along the line EE in FIG. 6) and FIG. 8 (a sectional view taken along the line FF in FIG. 6), the base plate 65 of the steel plate press-formed product welded to the column tube 23 and the base plate 65 Bolt-tightened housing 67 and slide block 6 slidably held in housing 67
9 and an electromagnetic actuator (hereinafter, referred to as an actuator) held by a housing 67 and driven and controlled by an ECU (electronic control device) 70.
(Referred to as a solenoid) 71 and the like. In addition, E
In addition to the seat position sensor 73, at least one sensor such as a weight sensor 74, a vehicle speed sensor 75, an occupant position sensor 76, and a seat belt wearing sensor 77 is connected to the CU 70.

The solenoid 71 includes a yoke 81 formed of a steel sheet press-formed product, a plunger (movable iron core) 83 slidably held in the yoke 81, and a coil 85 arranged so as to surround the plunger 83. , A permanent magnet 89 disposed in front of the coil 85, and a fixed iron core 91 caulked and fixed to the rear inner end surface of the yoke 81. The tip of the plunger 83 is the slide block 6.
9 and is extended by the urging force of a return spring 93 interposed between the solenoid 71 and the slide block 69. In FIG. 6, 98, 9
A member indicated by 9 is a shock-absorbing material attached to the slide block 69, and suppresses a collision sound between the slide block 69 and the housing 67 or the solenoid 71.

The housing 67 has a slide block 6
9, a pair of left and right guide plates 10
The energy absorbing plate 61 is inserted between the guide plates 101 and 103 and the slide block 69. Each of the guide plates 101 and 103 has U-shaped recesses 105 and 107 inside a substantially central portion and a rear portion, respectively.
The front and rear U-shaped bent portions 109 and 111 formed in FIG.

A fixed ironing pin 113 is fitted into the front U-shaped bent portion 109 of the energy absorbing plate 61, while a movable ironing pin 115 is fitted into the rear U-shaped bent portion 111. The moving side ironing pin 1 is provided on the housing 67.
A pair of left and right long holes 121 and 123 for holding the hole 15 are formed, and a moving-side ironing pin 115 is movable in the long holes 121 and 123 by a predetermined amount in the left and right direction.

The operation of the first embodiment will be described below. When the vehicle starts running, the ECU 70 repeatedly calculates the target operating load of the collision energy absorbing means at predetermined control intervals based on the detection signals of the various sensors 73 to 77 described above. For example, when the weight of the driver is relatively large, or when the vehicle speed is high even if the weight of the driver is relatively small, the kinetic energy of the driver at the time of the collision becomes large, so that the target working load also becomes large. Then E
The CU 70 outputs an exciting current in a predetermined direction to the coil 85 of the solenoid 71 for a very short time, and forms a magnetic field in the same direction as the magnetic field formed by the fixed iron core 91 (that is, the permanent magnet 89). Thereby, the magnetic field generated by the coil 85 and the magnetic field generated by the permanent magnet 89 are combined, and the magnetic force acting on the plunger 83 becomes larger than the urging force of the return spring 93,
As shown in FIG. 9, the plunger 83 is moved backward.

Then, 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 moving-side ironing pin 115 from moving inward. become. At this time, the plunger 83 abuts against the end face of the fixed iron core 91, but since the fixed iron core 91 is connected to the permanent magnet 89 via the yoke 81, the plunger 83 is brought into contact with the fixed iron core 91 with a predetermined attractive force. It will be magnetically attracted. It is inevitable that the slide block 69 is subjected to vibration during vehicle running or a shock at the time of a collision. However, since the plunger 83 is sufficiently attracted to the fixed iron core 91, the slide block 69 is inadvertently moved. Does not occur.

If the vehicle collides with another vehicle or an obstacle on the road in this state, the driver collides with the steering wheel 11 due to inertia, and the impact causes the vehicle to collide with the steering wheel 11 in FIG.
As shown in FIGS. 0 and 11 (viewed in the direction of arrow G in FIG. 10), the upper bracket 25 separates forward from the tilt bracket 31 while the lower bracket 27 separates forward from the pivot bracket 51, and the steering column 21 Drop off and begin to move forward. And the steering column 21
With the advance of the vehicle body, as shown in FIG.
The variable ironing device 63 on the steering column 21 moves forward with respect to the energy absorbing plate 61 held by the tilt bolt 33 on the side.

Then, in the energy absorbing plate 61,
A front U-shaped bent portion 109 fitted between the U-shaped concave portion 105 and the fixed ironing pin 113; a rear U-shaped bent portion 111 fitted between the U-shaped concave portion 107 and the movable ironing pin 115; Will move forward. As a result, the energy absorbing plate 61 has two ironing pins 113, 1 at the four right and left locations.
15, and a relatively large collision energy absorption is realized. FIG. 13 is a graph showing the relationship between the moving stroke of the steering column 21 and the working load, and the solid line in FIG. 13 shows the test result at this time (at a large working load).

On the other hand, when the driver is a small woman with a relatively small weight, the kinetic energy of the driver at the time of collision becomes relatively small, so that the target operating load calculated by the ECU 70 also becomes small. Then, the ECU 70 outputs an exciting current in a direction opposite to the front direction to the coil 83 of the solenoid 71 for a very short time, and forms a magnetic field in a direction opposite to the magnetic field formed by the permanent magnet 89. As a result, the magnetic field generated by the coil 83 and the magnetic field generated by the permanent magnet 89 cancel each other, and the urging force of the return spring 93 becomes larger than the magnetic force acting on the plunger 83. As shown in FIG.
3 is moved forward. Then, the slide block 69 connected to the plunger 83 also moves forward, and its rear side surface is retracted from the inside of the moving-side ironing pin 115, so that the moving-side ironing pin 115 is elongated.
23 can be freely moved.

In this state, if the vehicle collides with another vehicle or an obstacle on the road, the steering column 21 falls off and moves forward by the same process as described above, and the variable ironing device 63 moves with respect to the energy absorbing plate 61. Moves forward. However, in this case, the moving side ironing pin 115
Is not restrained by the slide block 69,
As shown in FIG. 15, the rear U-shaped bent portion 111 of the energy absorbing plate 61 pushes the moving-side ironing pin 115 inward when moving forward and away from the U-shaped recess 107, and then disappears. I do.

As a result, the energy absorbing plate 61 is squeezed only by the two fixed pins 113 on the left and right sides.
Even if the driver is a small woman or the like, the steering column 21 is smoothly advanced, and a large impact is not applied to the driver's chest or head. The dashed line in FIG. 13 shows the test result at this time (at a small operating load),
It can be seen that the small working load is significantly smaller than the large working load.

The description of the specific embodiment has been completed.
The aspects of the present invention are 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. Further, contrary 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, the material and the shape of the ironing means, and the like can be appropriately changed without departing from the gist of the present invention.

[0031]

As described above, according to the shock absorbing steering column apparatus of the present invention, the collision energy absorbing means for absorbing the secondary collision energy of the occupant at the time of a vehicle collision, and the collision energy absorbing means And an energy absorbing amount adjusting means for changing the amount of absorption of the secondary collision energy by the electromagnetic actuator, wherein the energy absorbing amount adjusting means uses an electromagnetic actuator as a drive source and the electromagnetic actuator Since the plunger is biased and held by the return spring at the first position, and is attracted and held by the permanent magnet at the second position, the energization to the electromagnetic actuator can be performed only when the plunger is driven. Enables prevention of coil heat generation and reduction of power consumption, and also stops current supply in the event of a collision, etc. Also, since the plunger is held in the original position by the permanent magnet or return spring, it is not necessary to provide a standby power supply and an electric circuit for the fail-safe, also decreases system cost with a system configuration is simplified.

[Brief description of the drawings]

FIG. 1 is a side view showing a vehicle 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 (a view in the direction of arrow A in FIG. 2) showing the device.

FIG. 4 is an enlarged sectional view taken along the line BB in FIG. 2;

FIG. 5 is an enlarged sectional view taken along the line CC in FIG. 2;

FIG. 6 is an enlarged sectional view taken along the line DD in FIG. 2;

FIG. 7 is a sectional view taken along the line EE in FIG. 6;

FIG. 8 is a sectional view taken along line FF in FIG. 6;

FIG. 9 is an explanatory diagram showing the operation of the embodiment.

FIG. 10 is a side view showing a state where the steering column is dropped.

11 is a view as viewed in the direction of the arrow G in FIG. 10;

FIG. 12 is an explanatory diagram showing the operation of the embodiment.

FIG. 13 is a graph showing a relationship between a moving amount of a steering column and an operation 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]

 1 Shock-absorbing steering column device 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 ‥ {Yoke 83} Plunger 85} Coil 89> Permanent magnet 91> Fixed iron core 93> Return spring 101, 103 {Guide plate 105, 107} U-shaped recess 109, 111 {U-shaped bending Part 1 3 ‥‥ the fixed drawing pins 115 ‥‥ movable drawing pins 121 and 123 ‥‥ slot

Claims (3)

[Claims] A collision energy absorbing means for absorbing a secondary collision energy of an occupant during a vehicle collision; and an energy absorption amount adjusting means for changing an absorption amount of the secondary collision energy by the collision energy absorbing means. A shock absorbing steering column device, wherein the energy absorbing amount adjusting means uses an electromagnetic actuator as a drive source, and a plunger of the electromagnetic actuator is urged and held at a first position by a return spring. An impact-absorbing steering column device which is attracted and held by a permanent magnet at two positions. 2. The system according to claim 1, wherein said collision energy absorbing means is provided between said steering column and said vehicle body side bracket, and irons an energy absorbing member made of a metal plate or a metal wire as the steering column moves. The shock-absorbing steering column device according to claim 1, wherein the steering column device is plastically deformed by: 3. The ironing means is a metal rod or a metal ball, and the energy absorbing 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 1, wherein: