JP2006290167A - Electric steering lock device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric steering lock device capable of being miniaturized at low cost. <P>SOLUTION: The electric steering lock device 1 is provided with a cam member 5 rotated by driving of a motor unit; a lock shaft 8 having a cam following surface 10 abutted on a cam surface 6 of the cam member 5 and transferred between a lock position for suppressing the rotation of a steering shaft 16 and a lock release position for allowing the rotation of the steering shaft 16; and an urging member 11 for urging the cam following surface 10 of the lock shaft 8 to the cam surface 6 of the cam member 5. The urging member 11 is constituted by a first urging member 12 for applying the urging force to the lock shaft 8 over the whole range from the locked position of the lock shaft 8 to the unlocked position; and a second urging member 13 for applying the urging force to the lock shaft 8 in a range of from a position prior to the unlocked position of the lock shaft 8 to the unlocked position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric steering lock device that locks rotation of a steering shaft of an automobile.

  A conventional electric steering lock device of this type is disclosed in Patent Document 1.

  As shown in FIG. 10, the electric steering lock device 100 includes a rotating shaft 102 that is rotated by driving a motor 101, and is fixed to the rotating shaft 102, and is selectively integrated with the rotating shaft 102 in an unlocking direction and a locking direction. A locking position for locking the rotation of the steering shaft 104 following the cam surface 105a of the cam member 103, and a cam follower surface 105a that contacts the cam surface 103a of the cam member 103. A lock member 105 that shifts between a lock release position that allows rotation of the shaft 104, a return spring 106 that presses the cam follower surface 105 a of the lock member 105 against the cam surface 103 a of the cam member 103, and a lock member 105. And a steering lock prevention mechanism 107 that is held in the unlocked position. .

  The steering lock prevention mechanism 107 is locked from a locking position of the locking lever 109, which is slidably supported with the rotation support pin 108 as a fulcrum, a spring 110 that biases the locking lever 109 toward the holding position, and the lock member 105. The cam member 103 that holds the locking lever 109 on the standby position side against the spring force of the spring 110 is provided in a position slightly before the release position. The cam member 103 also serves as a movement restriction for the locking lever 109.

  In the above configuration, when the vehicle is parked, the lock member 105 is positioned at the lock position, and the steering shaft 104 is locked. Thereby, the vehicle theft during parking can be prevented.

When driving a parked vehicle, a driver or the like presses a steering lock / unlock button (not shown). Then, the drive of the motor 101 causes the cam member 103 to rotate in the unlocking direction, and the lock member 105 follows the cam member 103 against the spring force of the return spring 106 and moves to the unlock position (state in FIG. 10). ). Thereby, rotation of the steering shaft 104 becomes free. When the locking member 105 moves to the unlocking position, the locking lever 109 that has not received interference from the cam member 103 is moved to the holding position by the spring force of the spring 110, and the tip of the locking lever 109 is fitted to the locking member 105. Fit into the mating recess 105b. Therefore, even if a strong impact force is applied to the cam member 103 and a rotation moment in the locking direction is applied to the cam member 103, the rotation of the cam member 103 is blocked by the locking lever 109, so that the lock member 105 moves to the lock position. do not do. As a result, the steering shaft 104 is not locked while the vehicle is running.
JP 2005-14755 A

  However, in the conventional electric steering lock device 100, the steering lock prevention mechanism 107 is configured by the locking lever 109, the spring 110, etc., so there is a part cost and assembly cost, and the electric steering lock device 100 is expensive. Since the steering lock prevention mechanism 107 takes up space, there is a problem that the electric steering lock device 100 is enlarged.

  Therefore, the present invention can reliably prevent the steering shaft from being locked during traveling of the vehicle without adding a special mechanism for preventing the lock member from moving to the lock position due to malfunction, and at a low cost. And it aims at providing the electric steering lock device which can be reduced in size.

  The invention according to claim 1, which achieves the above object, has a cam member that rotates in an unlocking direction and a locking direction by driving of a driving source, and a cam follow-up surface that abuts against a cam surface formed on the cam member, A lock member that shifts between a lock position that prevents rotation of the shaft and a lock release position that allows rotation of the steering shaft; and a biasing member that biases and holds the cam following surface against the cam surface. In the electric steering lock device, the spring constant of the biasing member is set so that a spring constant when the lock member is held at the lock position is smaller than a spring constant when the lock member is held at the unlock position. It is characterized by that.

  According to a second aspect of the present invention, in the electric steering lock device according to the first aspect, the urging member causes the urging force to act on the lock member over the entire range from the lock position to the lock release position of the lock member. The first urging member and a second urging member that causes the urging force to act on the lock member at the unlocking position of the lock member.

  According to a third aspect of the present invention, in the electric steering lock device according to the second aspect, the first urging member and the second urging member are both wound springs.

  According to a fourth aspect of the present invention, in the electric steering lock device according to the second aspect, the first urging member is a winding spring, and the second urging member is a leaf spring.

  According to the first aspect of the present invention, since the urging force of the urging member acts on the lock member in the entire movement range, the lock member is reliably moved following the cam member. And since the locking member located in the unlocking position is biased by a strong biasing force against the cam surface of the cam member, even if a strong impact force that rotates the cam member in the locking direction and the unlocking direction is applied. Since the sliding frictional force between the cam follower surface of the lock member and the cam surface of the cam member is strong, the cam member does not rotate and the lock member does not shift to the lock position. Then, in order to prevent the lock member from moving to the lock position due to the impact, the configuration of the biasing member may be simply changed to have a desired spring characteristic. As described above, the steering shaft can be reliably prevented from being locked while the vehicle is running, and the steering lock device can be reduced in cost and size.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, a desired urging force can be applied by a simple spring combination structure.

  According to invention of Claim 3, in addition to the effect of invention of Claim 2, it can comprise using the same kind of spring. For example, since the first urging member and the second urging member can be easily connected, the locking structure on one end side of both springs can be simplified.

  According to invention of Claim 4, in addition to the effect of invention of Claim 2, it can comprise using a spring of a different kind. And even if it installs that one end as a free end, since a leaf spring hardly shakes by vibration etc., reliable operation | movement can be ensured.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 show an embodiment of the present invention, FIG. 1 is a front view of an electric steering lock device, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 2 is a cross-sectional view taken along line BB in FIG. 2, FIG. 4 is a cross-sectional view taken along line BB in FIG. 2 when the lock member is located at the unlocked position, and FIG. FIG. 5B is a front view of the urging member and the cam member when the locking member is located at the locking position, and FIG. 5C is the urging member and the cam when the locking member is located at the unlocking position. It is a front view of a member.

  As shown in FIGS. 1 to 4, the electric steering lock device 1 includes a frame 2 and a cover 3 that covers the frame 2, and is a drive source on the frame 2 that is covered with the cover 3. The motor unit 4 is fixed. The motor unit 4 incorporates a speed reduction mechanism, and a cam member 5 is fixed to a rotating shaft (not shown) protruding from the unit case.

  The cam member 5 is selectively rotated in the unlocking direction R1 and vice versa by the rotation of the rotating shaft. The outer peripheral surface of the cam member 5 is formed as a cam surface 6. The cam surface 6 is set so that the distance from the rotation center O gradually changes with the change of the rotation angle.

  As shown in detail in FIGS. 3 and 4, the frame 2 is formed with a slide hole 7 penetrating in the vertical direction, and a lock shaft 8 as a lock member is movably disposed in the slide hole 7. Yes. A hanger portion 9 is fixed to the upper end of the lock shaft 8. The lower surface of the hanger portion 9 is formed as a cam follower surface 10, and the cam follower surface 10 is in contact with the cam surface 6 of the cam member 5. A biasing member 11 is installed on the upper surface of the hanger portion 9. The lock shaft 8 is biased toward the lock position by the spring force of the biasing member 11 and the cam follower surface 10 of the lock shaft 8 is biased to the cam surface 6 of the cam member 5.

  An engaging portion 15 is provided at the lower end of the lock shaft 8. The lock shaft 8 moves following the cam surface 6 of the cam member 5 and shifts between the lock position in FIG. 3 and the lock release position in FIG. 4. In the locked position, the engaging portion 15 engages with the steering shaft 16 and prevents the steering shaft 16 from rotating. In the unlocked position, the engaging portion 15 is separated from the steering shaft 16 and allows the steering shaft 16 to rotate.

  As shown in FIGS. 5A to 5C, the urging member 11 is a long spring having a long natural length, a first urging member 12 having a small winding diameter, and a short spring having a natural length. And it is comprised from the 2nd biasing member 13 with a large winding diameter. The first urging member 12 and the second urging member 13 are formed of the same spring material and are connected at both upper ends. This connected upper end portion is locked to a locking protrusion 14 a formed on the spring locking portion 14. The lower end of the first urging member is supported by being disposed in the spring receiving recess 9 a of the hanger portion 9. The lower end of the second urging member is a free end. Therefore, the urging force F1 of the first urging member 12 acts on the urging member 11 over the entire range from the lock position of the lock shaft 8 to the lock release position, and the urging member 11 is locked from before the lock release position of the lock shaft 8. The urging force F2 of the second urging member 13 acts in the range up to the release position. Due to the configuration of the urging member 11, the urging member 11 is in the unlocked position of the lock shaft 8 compared to the urging force (F 1) acting from the locked position of the lock shaft 8 to the front of the unlocked position. The applied urging force (F1 + F2) is set to increase.

  In the above configuration, when the vehicle is parked, the lock shaft 8 is positioned at the lock position shown in FIG. 3, and the rotation of the steering shaft 16 is locked. This prevents the vehicle from being stolen.

  Next, when the driver depresses a steering lock switch (not shown) to drive the vehicle, the motor unit 4 is driven and the cam member 5 rotates in the unlocking direction R1. The rotation of the cam member 5 causes the lock shaft 8 to follow and move against the urging force of the first urging member 12 from the lock position to just before the lock release position. When the lock shaft 8 comes to a position just before the unlocking position, the lock shaft 8 moves following the urging forces of both the first urging member 12 and the second urging member 13. That is, since the urging force of the urging member 11 acts on the lock shaft 8 in the entire movement range, the lock shaft 8 moves reliably following the cam member 5 and finally reaches the unlocked position in FIG. Moving. Thereby, the rotation of the steering shaft 16 is allowed.

  Since the lock shaft 8 located at the unlocking position is urged by the strong urging force (F1 + F2) obtained by adding the first urging force F1 and the second urging force F2 to the cam surface 6 of the cam member 5, the cam member 5 Even when a strong impact force is applied to rotate in the locking direction R2 and the unlocking direction R1, the sliding frictional force between the cam follower surface 10 of the lock shaft 8 and the cam surface 6 of the cam member 5 is strong. The member 5 does not rotate and the lock shaft 8 does not shift to the locked position. In order to prevent the lock shaft 8 from moving to the lock position due to an impact, the configuration of the urging member 11 may be simply changed to have a desired spring characteristic. As described above, the steering shaft 16 can be reliably prevented from being locked while the vehicle is running, and the steering lock device 1 can be reduced in cost and size.

  In this embodiment, the urging member 11 is applied at the first urging member 12 that applies the urging force over the entire range from the lock position of the lock shaft 8 to the lock release position, and at the lock release position of the lock shaft 8. Since it comprised from the 2nd urging | biasing member 13 which applies urging | biasing force, a desired urging | biasing force can be made to act by the combination structure of a simple spring.

  In this embodiment, since both the first urging member 12 and the second urging member 13 are wound springs, they can be configured using the same type of spring. And if the 1st biasing member 12 and the 2nd biasing member 13 are integrally formed like this embodiment, it will conventionally hold | maintain by press-fitting a spring in the outer periphery of a column-shaped latching protrusion. The structure used when holding the winding spring can be applied, and both the winding springs 12 and 13 can be held without complicating the structure.

  Next, the form which applied the leaf | plate spring as another aspect of an urging | biasing member is shown. FIG. 6A is a front view of the urging member and the cam member when the locking member is located at the locking position, and FIG. 6B is a front view of the urging member and the cam member when the locking member is located at the unlocking position. FIG. 7A is a front view of the second urging member, and FIG. 7B is a front view of the second urging member.

  As shown in FIGS. 6 (a), 6 (b) and 7 (a), 7 (b), the biasing member 20 according to another aspect has a second biasing member 21 as compared with the embodiment described above. The difference is that it is formed by a leaf spring. The second urging member 21 includes a main body 22 made of a spring material formed in an annular shape, and three arcuate urging portions 23 formed along the outer peripheral edge of the main body 22. The urging portion 23 is a flexible cantilever-like leaf spring, and is set so that the urging force is applied in the range from the position before the unlocking position to the unlocking position, as in the above embodiment. Has been.

  Since other configurations are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  Even when the biasing member 20 of this different aspect is used, the same operation and effect as in the above embodiment can be obtained. And since the 1st biasing member 12 is a winding spring and the 2nd biasing member 21 is a leaf | plate spring, the biasing member 20 can be comprised using a different kind of spring. Further, even if the second urging member 21 which is a leaf spring is installed with one end thereof as a free end, the second urging member 21 hardly sways due to vibration or the like, so that a reliable operation can be ensured.

  8 and 9 show another embodiment of the cam member, FIG. 8 is a front view of the cam member, and FIG. 9 is a characteristic diagram of the stroke amount with respect to the rotation angle of the cam member.

  As shown in FIG. 8, the cam surface 6 of the cam member 5 is a region in which the lock shaft 8 is shifted from the front of the unlocking position to the unlocking position (at a rotation angle of 230 as compared with that used conventionally). In the range of degrees to 270 degrees), the stroke amount with respect to the rotation angle is set to be small and resists the urging force of the reinforced urging members 11 and 20. In FIG. 8 and FIG. 9, the difference is clarified by showing the cam surface and stroke amount of the cam member conventionally used by a broken line.

  According to the cam member 5 of the present embodiment, since the rotational torque of the cam member 5 when moving the lock shaft 8 from the position before the lock release position to the lock release position can be reduced, the movement is smooth as compared with the above embodiment. Can be secured.

  As another aspect of the cam member, the rotation center O of the cam member 5 and the position of the center of gravity are configured to coincide with each other. With this configuration, even if an external force such as impact or vibration is applied to the cam member 5, the cam member 5 is caused by the impact, vibration or the like on the cam member because the center of rotation O and the center of gravity position coincide with each other. Self-moment of inertia does not occur. Therefore, in a state where the lock shaft 8 is located at the unlock position, the cam member 5 does not rotate due to the self-moment of inertia and the lock shaft 8 does not move to the lock position. Therefore, it is possible to more reliably prevent the steering shaft from being locked while the vehicle is running.

  In addition, in the said embodiment and another aspect, although the structure of the urging | biasing member was demonstrated, compared with the urging | biasing force which acts from before the lock position of the lock shaft 8 to the lock release position of the present invention, Any configuration can be used as long as the biasing force acting at the unlocking position of the lock shaft 8 can be increased.

1 is a front view of an electric steering lock device according to an embodiment of the present invention. FIG. 2 shows an embodiment of the present invention and is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 shows the embodiment of the present invention, and is a cross-sectional view taken along line BB in FIG. 2 when the lock member is located at the lock position. FIG. 3 shows the embodiment of the present invention, and is a cross-sectional view taken along line BB in FIG. 2 when the lock member is located at the unlock position. 1 shows an embodiment of the present invention, (a) is a front view of a natural-length biasing member, (b) is a front view of a biasing member and a cam member when the lock member is positioned at a lock position, and (c). FIG. 6 is a front view of an urging member and a cam member when the lock member is located at the unlock position. Fig. 2 shows another embodiment of the urging member, (a) is a front view of the urging member and the cam member when the lock member is located at the lock position, and (b) is an urging when the lock member is located at the lock release position. It is a front view of a member and a cam member. The other aspect of a biasing member is shown, (a) is a top view of a 2nd biasing member, (b) is a front view of a 2nd biasing member. It is a front view of a cam member. It is a characteristic line figure of stroke quantity to a rotation angle of a cam member. It is a block diagram of the electric steering lock device of a prior art example.

Explanation of symbols

1 Electric steering lock device 4 Motor unit (drive source)
5 Cam member 6 Cam surface 8 Lock shaft (lock member)
DESCRIPTION OF SYMBOLS 10 Cam follow-up surface 11 Biasing member 12 1st biasing member 13 2nd biasing member 16 Steering shaft 20 Biasing member 21 2nd biasing member 30 Cam member 31 Cam surface R1 Unlocking direction R2 Locking direction

Claims (4)

A lock member that has a cam member that rotates in a unlocking direction and a locking direction by driving of a drive source, a cam follower surface that abuts against a cam surface formed on the cam member, and prevents the steering shaft from rotating, and the steering shaft In an electric steering lock device comprising: a lock member that shifts between a lock release position that allows rotation of the cam follower; and a biasing member that biases and holds the cam follower surface to the cam surface.
The spring constant of the biasing member is set so that a spring constant when the lock member is held at the lock position is smaller than a spring constant when the lock member is held at the unlock position. Electric steering lock device. In the electric steering lock device according to claim 1,
The biasing member is a first biasing member that applies a biasing force to the lock member over the entire range from the lock position to the lock release position of the lock member;
An electric steering lock device comprising: a second urging member that causes an urging force to act on the lock member at an unlock position of the lock member. The electric steering lock device according to claim 2,
The first steering member and the second biasing member are both wound springs. The electric steering lock device according to claim 2,
The first biasing member is a winding spring;
The electric steering lock device, wherein the second urging member is a leaf spring.

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