JP5257395B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator used in an automobile safety device, and more particularly, to an actuator used for an operation such as lifting a hood panel when receiving a pedestrian as an object to be protected.

  In the conventional actuator of this type, there is one that lifts the hood panel, and the actuator is configured as a piston cylinder type that uses a gas generated when the gas generator is operated as a drive source (for example, see Patent Document 1). In this actuator, the piston rod is slidable in the cylinder, and the hood panel as a receiving material for receiving the pedestrian as the object to be protected extends from the piston portion and protrudes out of the cylinder. And a support rod portion that supports the rod so as to move up to the receiving position. In this actuator, during operation, the piston rod lifts the hood panel supported by the support rod portion while moving the piston portion forward through the cylinder to the top dead center. And after the piston rod moves forward to the top dead center, the backward movement is restricted by the lock mechanism, and when the hood panel receives the pedestrian, the support rod is bent and plasticized so that the kinetic energy of the pedestrian can be absorbed. It was deformed.

  The actuator locking mechanism is arranged on the side surface of the piston receiving groove, the locking ring which can be expanded in diameter, stored in the receiving groove of the piston part, the locking step provided on the inner peripheral surface side of the cylinder, and And a tapered taper regulating surface. During operation of this locking mechanism, when the piston part moves forward to the top dead center, the locking ring expands in diameter, and then when the piston part moves backward to the locked position, the locking ring moves toward the backward movement side. The part is brought into contact with the locking regulation surface of the latching step part, and the backward movement is regulated, and the outer circumferential side of the outer circumferential surface side is regulated so that the further diameter expansion state is regulated. Further, the inner diameter side of the forward movement side in the inner peripheral side portion is brought into contact with the taper regulating surface of the piston portion, and the reduced diameter state is also regulated. The piston portion locked between the locking step portion and the taper regulating surface of the piston portion, and the taper regulating surface contacting the inner side surface of the locking ring on the forward movement side is also locked, and the piston The backward movement of the rod was to be restricted.

JP 2009-262853 A

  However, in the conventional actuator, when the forward movement speed of the piston rod at the time of operation is large, even if the piston portion stops at the top dead center, the locking ring strongly moves forward by receiving the inertial force of the forward movement, The piston is locked in a state before it is fitted between the edge on the forward movement side of the taper regulating surface of the piston portion and the outer circumferential regulating surface of the locking step portion of the cylinder and before moving backward to the lock position. There was a fear of being. Since such a locked state is not a position restriction at an appropriate lock position, the support rod is tilted, or when the support rod portion is subsequently plastically deformed, it is retracted to a proper lock position. Or, the plastic deformation of the support rod portion is terminated at that position, and it becomes difficult to ensure a stable plastic deformation state of the support rod portion.

  The present invention solves the above-described problems, and an object of the present invention is to provide an actuator that can stably lock the piston portion at a predetermined lock position and restrict the backward movement of the piston rod.

The actuator according to the present invention is a piston-cylinder type used in an automobile safety device,
The piston rod
A piston portion slidable in the cylinder, and a support rod portion that extends from the piston portion and protrudes out of the cylinder, and supports the receiving material for receiving the object to be protected so as to be movable to the position for receiving the protection object. As well as configured,
During operation, after the piston is moved forward in the cylinder to the top dead center, the backward movement is restricted by the lock mechanism so that the kinetic energy of the protected object received by the receiving material can be absorbed by the support rod. As a configuration for bending plastic deformation,
Lock mechanism
An annular locking ring that is housed in the housing groove of the piston portion so that the diameter can be increased, and is made of an elastically deformable wire having a circular cross section;
A locking restricting surface that is disposed at a position where the piston portion is locked on the inner peripheral surface side of the cylinder and abuts on a portion of the locking ring on the backward movement side, and a forward movement side of the piston rod from the outer peripheral edge of the locking restriction surface A locking step portion having an outer peripheral restriction surface that can be brought into contact with the outer peripheral surface of the expanded locking ring when the piston portion is locked.
Located on the side of the piston rod in the forward movement side of the piston rod in the storage groove of the piston part, it is tapered outwardly toward the forward movement side, and when the piston part is locked, the forward movement side at the inner peripheral part of the locking ring A taper regulating surface that abuts on the inner side surface of the shaft and cooperates with the locking regulating surface and the outer circumferential regulating surface of the locking step portion that contacts the locking ring, and regulates the backward movement of the piston portion;
An actuator comprising:
Cylinder
Protruding the support rod of the piston rod, provided with a tip wall that defines the arrangement position at the top dead center of the piston part,
It is arranged on the front wall part side in the locking step part, extends inward from the outer peripheral restriction surface, and with respect to the forward movement side portion of the locking ring together with the taper restriction surface of the piston part at the time of arrangement to the top dead center And a ceiling restricting surface that abuts.

  In the actuator according to the present invention, when the piston portion of the piston rod moves forward to the top dead center regulated by the tip end wall portion of the cylinder during operation, the locking ring housed in the housing groove of the piston portion is engaged. The diameter is expanded from the storage groove so as to come into contact with the outer peripheral regulating surface of the stop portion. At that time, even if the locking ring increases the inertial force that moves forward and further moves forward, it comes into contact with the ceiling regulating surface arranged on the tip wall side of the locking step portion, and stops moving forward. Is done. In other words, the locking ring brings the forward movement side portion of the piston rod into contact with the ceiling regulating surface extending inward from the outer circumferential regulating surface of the locking step portion, so that the outer circumferential surface including the taper regulating surface in the piston portion. It is prevented that it fits only between the side and the outer periphery regulating surface in the locking step portion of the cylinder. Since the locking ring abuts against the taper regulating surface of the piston portion together with the ceiling regulating surface, the taper regulating surface engages the locking ring during the backward movement from the top dead center position to the lock position of the piston portion. It can be pushed to the locking regulation surface side of the stop portion.

  Therefore, when the piston part moves backward to the lock position after being arranged at the top dead center, the locking ring is smoothly fitted without being fitted between the outer peripheral surface side of the piston part and the outer peripheral regulating surface of the locking step part. Then, it moves backward until it comes into contact with the latching restriction surface of the latching step portion, and then comes into contact with the latching regulation surface to restrict the backward movement. Further, the locking ring is brought into contact with the outer periphery regulating surface of the locking step portion so that the outer diameter side is further restricted in diameter, and the inner side surface on the forward movement side in the inner circumferential side portion is , Abutting on the taper regulating surface of the piston portion, the reduced diameter state is also regulated, so that the locking ring is stable at the locking position between the locking step portion of the cylinder and the taper regulating surface of the piston portion. Accordingly, the piston portion that is locked and the taper restricting surface is in contact with the inner surface on the forward movement side of the locking ring is also locked at the lock position, and the backward movement of the piston rod is restricted.

  Then, if the actuator is locked by restricting the backward movement of the piston rod and the receiving material receives the object to be protected, the support rod portion protruding from the cylinder in the piston rod is bent and plastically deformed in a stable state, Without variation, the kinetic energy of the object to be protected can be accurately absorbed in a predetermined amount.

  Therefore, the actuator according to the present invention can stably regulate the backward movement of the piston rod by locking the piston portion at a predetermined lock position.

  And in the actuator which concerns on this invention, it is desirable to form a ceiling control surface in the taper shape expanded in diameter to the backward movement side of a piston rod. With this configuration, when the locking ring comes into contact with the ceiling regulating surface at the top dead center of the piston portion, the locking ring can move to the taper regulating surface side of the piston portion while sliding on the ceiling regulating surface. The locking ring can come into contact with both the ceiling regulating surface and the taper regulating surface. Therefore, when the piston part moves backward to the subsequent lock position, the taper restriction surface can smoothly press the engagement ring so as to contact the engagement restriction surface of the engagement step part. Further, the piston portion can be locked at the lock position more stably.

  When the ceiling regulating surface is tapered, the taper regulating surface of the piston portion and the ceiling regulating surface at the time of placement at the top dead center are arranged such that the edge on the forward movement side of the piston rod extends in the axial direction of the cylinder. It is desirable to configure so that they substantially coincide with each other. In such a configuration, when the piston portion is disposed at the top dead center and the locking ring advances due to inertia, the locking ring enters the portion where the taper regulating surface and the ceiling regulating surface are mutually narrowed, Since it is stably brought into contact with the planar portion away from the edges of both the taper regulating surface and the ceiling regulating surface, it is further fitted between the outer circumferential surface of the piston part and the outer circumferential regulating surface. Can be prevented.

In this case, the taper regulating surface and the ceiling regulating surface are configured to have the same angle for expanding the diameter, and
The locking restriction surface of the locking step portion is set in a state in which the locking ring can be locked, and the width dimension from the inner edge to the outer circumferential restriction surface is set to be less than ½ of the diameter dimension in the circular cross section of the locking ring. It is desirable.

  In such a configuration, the width dimension of the locking restricting surface is less than the radial dimension of the circular cross section of the locking ring, and the locking ring has a portion larger than the radial dimension of the circular cross section over the entire circumference of the cylinder. Therefore, it is arranged inside the locking regulation surface. Further, the taper regulating surface and the ceiling regulating surface are made to have the same angle for expanding the diameter. Therefore, when the piston part is arranged at the top dead center and the locking ring moves forward due to inertia, the locking ring is arranged so that the center of the circular cross section is arranged between the taper regulating surface and the ceiling regulating surface. The taper restricting surface and the ceiling restricting surface can be contacted evenly and more stably, and can be prevented from being fitted between the outer peripheral surface of the piston portion and the outer peripheral restricting surface more stably. In addition, smooth movement to the subsequent lock position can be ensured.

  Furthermore, if the ceiling regulating surface is formed in a tapered shape that expands toward the backward movement side, the tip wall portion side of the cylinder is reduced in diameter by a pipe portion made of a cylindrical metal pipe material and the pipe portion. Thus, when it comprises and comprises the head part fixed by the inner peripheral side of a pipe part, it can manufacture simply. In this case, for example, the pipe portion is configured by providing a small-diameter portion that slides the piston portion, and a large-diameter portion that is expanded in diameter and extends in a cylindrical shape on the tip wall portion side of the small-diameter portion, and is locked. The latching restricting surface of the step portion is constituted by a step portion between the small diameter portion and the large diameter portion. The head portion has an insertion hole through which the support rod portion of the piston rod is inserted, and the ceiling restriction surface and the outer periphery restriction surface of the locking step portion are extended from the inner periphery of the insertion hole, It is configured on the inner peripheral surface side. In such a configuration, when the outer peripheral restriction surface and the ceiling restriction surface are cut along with the drilling of the insertion hole at the time of manufacturing the head portion, the ceiling restriction surface is arranged orthogonally from the outer peripheral restriction surface. However, even if the width of the cylinder in the direction perpendicular to the axis is narrowed, the cutting tool can be easily arranged on the inner peripheral surface side of the head portion, and processing can be performed easily. The cylinder having the above structure can be manufactured by simply caulking and fixing after preparing a pipe portion and a head portion made of a pipe material without cutting the whole including the tip wall portion side. Thus, it can be manufactured with reduced manufacturing steps and costs.

1 is a perspective view of a vehicle on which a flip-up device (hood jump-up device) in which an actuator according to an embodiment of the present invention is used is mounted. It is a partial enlarged plan view of the vehicle carrying the flip-up device of the embodiment. It is a schematic longitudinal cross-sectional view along the front-back direction which shows the flip-up apparatus of embodiment, and the hinge part of a vehicle, and respond | corresponds to the III-III site | part of FIG. It is a schematic longitudinal cross-sectional view which shows the time of the action | operation of the flip-up apparatus of embodiment. It is a schematic longitudinal cross-sectional view of the actuator of embodiment, and shows the time before an operation | movement and the time of an operation completion. It is a general | schematic expanded longitudinal cross-sectional view which shows the front-end | tip wall part vicinity before the action | operation of the actuator of embodiment. In the actuator of an embodiment, it is an expansion outline partial longitudinal section showing the state of the piston part explaining operation of a lock mechanism in order. In the actuator of an embodiment, it is an expansion outline fragmentary longitudinal cross-sectional view explaining a locking state to a locking step of a locking ring of a locking mechanism in order. It is the top view and perspective view of a locking ring used for the actuator of an embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A vehicle safety device in which the actuator 21 of the embodiment is used is a hood flip-up device (hereinafter abbreviated as “bounce-up device”) U. As shown in FIGS. 1 and 2, the flip-up device U is disposed near the left edge 10 d and the right edge 10 e on the rear end 10 c side of the hood panel 10 in the vehicle V. And a receiving seat 16 disposed on the lower surface of the rear end 10c of the hood panel 10. 3 and 4, during the operation, the flip-up device U causes the actuator 21 to raise the piston rod 50, and the receiving seat 16 is interposed so that the rear end 10c of the hood panel 10 is flipped up. Will be raised.

  In the present specification, unless otherwise specified, the front and rear and up and down directions respectively correspond to the front and rear and up and down directions of the vehicle V (see FIG. 1), and the left and right directions are from the front side of the vehicle V to the rear side. It matches with the left and right direction when looking at the side.

  In the case of the embodiment, the front bumper 5 of the vehicle V is provided with a sensor 6 capable of detecting or predicting a collision with a pedestrian as shown in FIG. When an operating circuit (not shown) that is input detects or predicts a collision between the vehicle V and a pedestrian based on a signal from the sensor 6, a gas generator 35 as a drive source in the actuator 21 of the flip-up device U. (See FIG. 5).

  Further, as shown in FIGS. 1 and 2, the hood panel 10 is disposed so as to cover the upper part of the engine room ER in the vehicle V, and is a hinge disposed in the vicinity of the rear end 10 c on both sides in the left-right direction. By the part 11, it is connected with respect to the body 1 side of the vehicle V so that opening and closing is possible by front opening. As shown in FIG. 3, the hood panel 10 is made of a sheet metal made of an aluminum alloy or the like, and includes an outer panel 10 a on the upper surface side and an inner panel 10 b that is positioned on the lower surface side and has higher strength than the outer panel 10 a. ing. The food panel 10 is configured to be plastically deformable so that it can absorb the kinetic energy of the pedestrian when receiving the pedestrian. And in embodiment, when the vehicle V and the pedestrian collide, the actuator 21 is operated, and as shown in FIG. 4, between the rear end 10c of the raised hood panel 10 and the engine room ER, Since the deformation space S can be formed, the amount of plastic deformation during bending plastic deformation can be increased.

  The hinge portion 11 is disposed on the left edge 10d and the right edge 10e on the rear end 10c side of the hood panel 10 (see FIG. 1), and is attached to the hood ridge rein hose 2 on the body 1 side, respectively. The hinge base 12 is fixed to the hood panel 10 and the hinge arm 14 is fixed to the hood panel 10 (see FIGS. 2 and 3). As shown in FIG. 3, each hinge arm 14 is configured as a shape in which a sheet metal angle member is bent in a substantially semicircular arc shape so as to protrude downward, and a base end 14 a on the hinge base 12 side is supported. The shaft 13 is pivotally connected to the hinge base 12. Each hinge arm 14 includes a connecting plate portion 15 extending from the tip 14b so as to extend substantially in the front-rear direction on the side of the tip 14b that is separated from the base end 14a. It is connected to the lower surface side of 10c using welding or the like.

  In the case of the embodiment, the connecting plate portion 15 uses the lower surface on the front side as the contact portion 15a of the tip (upper end) 50a (the head 61 of the support rod portion 60) of the piston rod 50 when ascending. That is, the front side of the connecting plate portion 15 serves as a receiving seat 16 for the upper end 50a of the piston rod 50, and the lower surface of the receiving seat 16 serves as a receiving surface 16a for the upper end 50a (see FIGS. 3 and 4).

  The support shafts 13 are arranged so that their axial directions are along the left-right direction of the vehicle V. When the hood panel 10 is opened, as shown by the two-dot chain line from the solid line in FIG. 3, the front end 10 f of the hood panel 10 along with the distal end 14 b side of each hinge arm 14 with the left and right support shafts 13 as the rotation center. If the side (refer FIG. 1) is raised by front opening, the food panel 10 can be opened by front opening.

  Further, a notch recess 14c is formed in the vicinity of the tip 14b of the hinge arm 14 so that the lower edge is notched in a substantially circular shape. The area around the notch recess 14c is the operation of the actuator 21. At this time, when the piston rod 50 pushes up the rear end 10c of the hood panel 10, the rear end 10c of the hood panel 10 can be raised as a plastic deformation portion 14d that plastically deforms (see FIG. 4). On the front end 10f side of the hood panel 10, a latch mechanism for locking a hood lock striker (not shown) disposed at the front end 10f is provided for normal closing, and the rear end 10c of the hood panel 10 is raised. Even at this time, the front end 10f of the hood panel 10 cannot be detached from the body 1 side by a latch mechanism for locking a hood lock striker (not shown).

  Further, as shown in FIGS. 2 and 3, a cowl 7 comprising a highly rigid cowl panel 7a on the body 1 side and a synthetic resin cowl louver 7b above the cowl panel 7a is provided behind the hood panel 10. Arranged. The cowl louver 7b is disposed so that the rear end side is connected to the lower portion 3a side of the front windshield 3. Further, as shown in FIGS. 1 and 2, front pillars 4 and 4 are disposed on the left and right sides of the front windshield 3.

  As shown in FIG. 3, the actuator 21 of the embodiment is held by a mounting bracket 18 having a U-shaped cross section that is bolted to a mounting flange 2 b connected to the hood ridge reinhose 2, and the hood panel 10. On the rear end 10c side, it is disposed below each hinge portion 11 below the left edge 10d and the right edge 10e. As shown in FIG. 5, each actuator 21 includes a cylinder 22 that is mounted and fixed so that its axial direction is along the vertical direction, and a gas generator 35 that causes a gas as a working fluid to flow into the cylinder 22. And a piston rod 50 disposed so as to protrude upward from the cylinder 22, and a lock mechanism R for preventing the piston rod 50 from moving backward (downward movement) after forward movement (after upward movement). It is configured.

  As shown in FIGS. 6 and 7, the locking mechanism R is provided on the side of the locking ring 71, the taper regulating surface 56 of the storage groove 53 provided in the piston portion 51 of the piston rod 50, and the tip wall portion 26 side of the cylinder 22. It is composed of a locking restricting surface 31 and an outer periphery restricting surface 32 of the stop portion 30.

  As shown in FIG. 5, the cylinder 22 includes a cylindrical main body portion 23 that slides the piston portion 51 of the piston rod 50, a distal end wall portion 26 that closes the upper end side of the main body portion 23, and a lower end side of the main body portion 23. And a former end wall portion 34 for closing. The main body portion 23 has a sliding hole 24 having a circular opening corresponding to the outer shape of the piston portion 51 extending in the vertical direction. When the actuator 21 is operated, the piston portion 51 has an inner periphery of the sliding hole 24. The surface 24a is slid to rise (forward movement).

  The cylinder 22 includes a pipe portion 38 made of a steel pipe material, a head portion 47 that forms the distal end wall portion 26, and a gas generator 35 that forms the base end wall portion 34. . Further, the pipe portion 38 includes a cylindrical small-diameter portion 39 that slides the piston portion 51, and large-diameter portions 40 and 43 that expand from both ends of the small-diameter portion 39 and extend in a substantially cylindrical shape. Yes. The head portion 47 is formed in an insertion hole 27, a ceiling regulating surface 28, an outer circumference regulating surface 32, and the like, which will be described later, and is then disposed in the large diameter portion 40, so that the large diameter portion 40 is reduced in diameter. Is fixed to the large-diameter portion 40 by plastic deformation. After the gas generator 35 constituting the base end wall portion 34 is disposed in the large diameter portion 43, the large diameter portion 43 is formed by caulking and crimping the caulking portions 44, 45 and the like so as to reduce the diameter. The cylinder 22 is formed in a fixed manner. Since the piston rod 50 is inserted into the head portion 47 and assembled before the head portion 47 is disposed in the large diameter portion 40, the actuator 21 is formed at the same time as the cylinder 22 is formed. It becomes. In addition, the member shown with the codes | symbols 36 and 48 shown in FIG. 5 is packing.

  As shown in FIGS. 5 to 7, in the cylinder 22, the engagement is recessed in the vicinity of the distal end wall portion 26 of the main body portion 23 by expanding the diameter from the inner peripheral surface 24 a of the main body portion 23 for sliding the piston portion 51. A step portion 30 is formed over the entire circumference of the cylinder 22 in the circumferential direction. As described above, the latching step portion 30 is a portion where the latching restricting surface 31 and the outer periphery restricting surface 32 constituting the lock mechanism R are disposed, and defines the lock position UP of the piston portion 51. To do. That is, when the piston rod 50 is retracted after being disposed at the top dead center UT when the piston rod 50 is moved up (during forward movement), the engagement step 71 is interposed between the piston 51 and the piston 51. It is the position which regulates the backward movement of. If the piston portion 51 is locked at this position and the backward movement of the piston rod 50 is restricted, the position becomes the pedestrian receiving position RP (see FIG. 4) between the piston rod 50 and the hood panel 10. If the support rod portion 60 undergoes bending plastic deformation at that position, a stable deformation state can be secured.

  As shown in FIGS. 6 to 8, the locking regulation surface 31 is a surface that is substantially orthogonal to the axial direction CD of the main body portion 23 along the forward / backward direction of the forward movement or backward movement of the piston rod 50. When the lowering (retreating movement) is restricted, the locking ring 71 is disposed so as to come into contact with the retreating movement side portion (retreating side surface / retreating side surface) 73. The outer peripheral restriction surface 32 extends from the outer peripheral edge of the locking restriction surface 31 to the forward movement side (upward) of the piston rod 50 along the axial direction CD of the main body 23, and at the time of restricting the backward movement of the locking ring 71, It arrange | positions so that it may contact | abut to the outer peripheral surface 72 of the locking ring 71 expanded in diameter.

  Further, as shown in FIG. 8, the locking regulating surface 31 has a width dimension CB along the direction perpendicular to the axis of the main body 23 from the inner edge 31 a on the inner circumferential surface 24 a side of the main body 23 to the outer circumferential regulating surface 32. Setting is made so that the inner peripheral side portion 74 of the locking ring 71 in a state where the surface 72 is in contact with the outer peripheral regulating surface 32 protrudes from the inner peripheral surface 24a of the main body portion 23 toward the axial center CO side of the main body portion 23. It is arranged. Further, the width dimension CB of the locking restriction surface 31 is 1 / diameter of the diameter dimension D (see FIG. 9) in the circular cross section of the locking ring 71 in a state where the locking restriction surface 31 can lock the locking ring 71. It is set as less than 2. In the case of the embodiment, the diameter dimension D of the locking ring 71 is 1.5φ, and the width dimension CB of the locking regulating surface 31 is 0.7 mm.

  Further, the front end wall portion 26 of the cylinder 22 is provided with an insertion hole 27 at the center thereof through which the piston portion 51 of the piston rod 50 cannot be inserted and the support rod portion 60 of the piston rod 50 can be inserted.

  A ceiling regulating surface 28 extending inward from the outer circumferential regulating surface 32 to a position coinciding with the inner circumferential surface 24 a of the main body 23 is provided on the distal end wall 26 side of the locking step portion 30 in the circumferential direction of the cylinder 22. It is formed over the entire circumference. The ceiling regulating surface 28 is, together with the taper regulating surface 56 of the piston portion 51 at the time of being arranged at the top dead center UT, more specifically, the forward movement side portion 76 of the locking ring 71. 77 abuts.

  In the case of the embodiment, the ceiling regulating surface 28 is formed in a tapered shape that expands in diameter toward the backward movement side of the piston rod 50. Further, the ceiling regulating surface 28 is formed so that the taper regulating surface 56 of the piston portion 51 and the edges 28a, 56a on the forward movement side of the piston rod 50 are aligned with each other along the axial direction CD of the cylinder 22 when being arranged at the top dead center UT. Are configured to match. Furthermore, in the embodiment, the ceiling regulating surface 28 is configured with the taper regulating surface 56 so that the angle θ for expanding the diameter is equal to 45 °.

  A micro gas generator is used for the gas generator 35 constituting the base end wall portion 34 on the lower end side of the main body 23, and a lead wire connector for inputting an electric signal from a control circuit (not shown) to the lower end surface. Is connected. And when the gas generator 35 inputs the electric signal from the control circuit which is not shown in figure, the built-in gunpowder will be burned, combustion gas will be generated, and the working gas (combustion gas) G will be made into working fluid. In other words, the piston portion 51 in the cylinder 22 is supplied to the bottom surface (lower surface) 51b side.

  As shown in FIG. 5, the piston rod 50 includes a piston part 51 disposed in the cylinder 22 and a support rod part 60 extending upward from the piston part 51. The piston portion 51 has a substantially cylindrical shape that is slidable with an engagement ring 71 and an O-ring 68 interposed between the inner peripheral surface 24 a of the sliding hole 24 in the main body portion 23 of the cylinder 22. On the outer peripheral surface 51a of the piston portion 51, a fitting groove 52 for fitting the O-ring 68 is formed in the vicinity of the bottom surface 51b side, and a storage groove in which the locking ring 71 can be stored in the vicinity of the ceiling surface 51c side. 53 is formed.

  The storage groove 53 is formed in a concave shape that allows the piston rod 50 to move forward (rise) while the locking ring 71 is stored. As shown in FIGS. 7 and 8, the storage groove 53 is disposed at the bottom of the storage groove 53, and has an inner peripheral surface (bottom surface) 54 along the axial direction PD of the piston rod 50, and the retraction movement side of the piston rod 50. As a surface (a side surface on the backward movement side), a backward side surface (a surface on the backward side) 55 extending from the lower edge 54a of the inner peripheral surface 54 so as to be orthogonal to the axial direction PD of the piston rod 50, and the forward movement side of the piston rod 50 As the surface, a taper regulating surface 56 that is tapered outwardly from the upper edge 54b of the inner peripheral surface 54 toward the forward movement side is configured.

  In the case of the embodiment, the outer diameter BD of the outer peripheral surface 51a excluding the locking ring 71 and the O-ring 68 of the piston portion 51 is the inner diameter CI of the inner peripheral surface 24a of the main body 23 of the cylinder 22 (the embodiment). In this case, 13.8φ is slightly smaller than 14.2φ).

  The taper regulating surface 56 is in a state where the diameter of the piston rod 50 is increased after the forward movement, and the taper regulating surface 56 is in contact with the locking regulating surface 31 and the outer circumferential regulating surface 32 of the locking step portion 30. The ring 71 is disposed so as to come into contact with the inner side surface 75 on the forward movement side in the inner circumferential side portion 74 of the ring 71. Such a configuration in which the taper regulating surface 56 can come into contact with the inner surface 75 of the locking ring 71 is that the locking step portion 30 of the cylinder 22 is locked to the diameter D of the circular cross section of the locking ring 71. The width dimension CB of the restriction surface 31, the outer diameter dimension BD of the piston portion 51, and the depth dimension (width dimension of the receding side surface 55) PB of the storage groove 53 are adjusted and set.

  Further, as described above, the arrangement position of the storage groove 53 is such that the piston rod 50 rises with the operation of the actuator 21, and the ceiling surface 51 c of the piston portion 51 is interposed between the C ring 66 and the cylinder 22. When disposed at the top dead center UT that contacts the lower surface 26a of the tip wall portion 26, the edge 56a of the taper regulating surface 56 is aligned with the edge 28a of the ceiling regulating surface 28 along the axial direction PD of the piston rod 50. It is configured.

  As shown in FIG. 5, the support rod portion 60 is disposed by being screwed into the round bar-shaped shaft portion 62 disposed along the axial direction (vertical direction) CD of the cylinder 22 and the upper end side of the shaft portion 62. And a columnar head portion 61 having an outer diameter larger than that of the shaft portion 62. When the piston rod 50 moves upward, the head 61 comes into contact with the receiving surface 16a of the receiving seat 16 provided on the hood panel 10 side and pushes up the rear end 10c of the hood panel 10 upward.

  Moreover, the support rod part 60 is comprised with metal parts, such as steel, with the piston part 51. FIG. When the support rod portion 60 is locked to the lock mechanism R after reaching the top dead center UT, the rear end 10c of the hood panel 10 is pushed up (the pedestrian receiving position RP on the hood panel 10). 4) Ascending (upwardly moving) to UP, and thereafter, a portion of the shaft portion 62 in the vicinity of the insertion hole 27 protruding from the tip wall portion 26 is configured as a bending point 63 so that bending plastic deformation is possible. .

  Further, a concave groove 64 for fitting the C ring 66 is formed in the vicinity of the head 61 of the support rod portion 60. The C-ring 66 fitted in the concave groove 64 abuts on the lower surface 26a of the tip wall portion 26 so as to prevent the piston rod 50 of the actuator 21 from protruding before operation. That is, the C-ring 66 abuts against the lower surface 26a of the tip wall portion 26 in a state of being fitted in the concave groove 64 before the operation of the actuator 21, so that the piston rod 50 is prevented from jumping out from the cylinder 22. . When the actuator 21 is operated, the C-ring 66 is deformed so as to expand in diameter with the forward movement of the piston rod 50 and is disengaged from the concave groove 64 to smoothly move the piston rod 50 forward. . In addition, an O-ring 69 pressed against the head 61 and the tip wall portion 26 is fitted to the shaft portion 62 in the vicinity of the head portion 61 in order to ensure the sealing performance in the cylinder 22 before the actuator 21 is operated. It has been.

  As shown in FIG. 9, the locking ring 71 constituting the locking mechanism R is formed by bending a wire made of spring steel having a circular cross section into an annular shape, and part of the end surface of the ring shape A gap 71a that can be reduced in diameter is provided. As shown in FIGS. 7 and 8, the locking ring 71 is stored in the storage groove 53 with a reduced diameter when the piston portion 51 is disposed in the cylinder 22. When the locking ring 71 expands in diameter and enters the locking step portion 30 from the storage groove 53, the locking ring 71 straddles the locking restriction surface 31 and the taper restriction surface 56 of the locking step portion 30, and at the time of locking. The dimensions are set so as to contact the outer periphery regulating surface 32.

  In the case of the embodiment, the outer diameter RD of the locking ring 71 in a state where the diameter is not reduced is 15.5φ, and the inner diameter RI is 12.5φ. Further, the inner diameter ID of the outer peripheral regulating surface 32 of the locking step portion 30 is 15.6φ, and includes the inner peripheral surface 26b near the insertion hole 27 of the ceiling wall portion 26, and the inner peripheral surface of the main body portion 23 of the cylinder 22. The inner diameter CI of 24a is 14.2φ (see FIGS. 8 and 6). Therefore, if the locking ring 71 is housed in the body portion 23 of the cylinder 22 together with the piston rod 50 in a state of being housed in the housing groove 53 of the piston portion 51, it slides on the inner peripheral surface 24 a of the body portion 23. If the diameter is reduced to the inner diameter CI of the inner peripheral surface 24a of the main body portion 23 of the cylinder 22 and is arranged at the position of the locking step portion 30, the entire outer peripheral surface 72 is included. Although the circumference cannot be brought into contact with the outer circumferential restriction surface 32 evenly (the outer diameter RD of the locking ring 71 in a state where the diameter is not reduced is 0.1 mm, smaller than the inner diameter dimension ID of the outer circumferential restriction surface 32), In the arrangement at the lock position UP, the diameter of the outer peripheral surface 72 is increased by the contact of the taper restricting surface 56, and the outer peripheral restricting surface 32 is pressed.

  In the flip-up device U of the embodiment, the gas generator 35 in the actuator 21 is activated when an operation circuit (not shown) detects or predicts a collision with the pedestrian of the vehicle V by a signal from the sensor 6. When the working gas generated from the gas generator 35 flows into the cylinder 22, the internal pressure in the cylinder 22 increases as shown in FIGS. 5A and 5B, and the piston in the cylinder 22 of the piston rod 50 increases. The part 51 receives the pressure and rises together with the support rod part 60 of the piston rod 50. 3 and 4, the support rod portion 60 presses the head portion 61 against the receiving surface 16a of the seat 16 to raise the rear end 10c of the hood panel 10, and the piston portion 51 is connected to the ceiling surface. 51c is made to contact | abut to the front-end | tip wall part 26 of the cylinder 22 through the C ring 66, and the piston rod 50 is arrange | positioned at the top dead center UT. After that, when the piston rod 50 moves backward and is placed at the lock position UP (see B in FIG. 5), the lock mechanism R is activated and the lowering (reverse movement) of the piston rod 50 is restricted and locked. It will be.

  At that time, in the actuator 21 of the embodiment, the piston portion 51 of the piston rod 50 reaches the position of the top dead center UT regulated by the tip wall portion 26 of the cylinder 22 as shown in FIGS. When moving forward, the engagement ring 71 accommodated in the accommodation groove 53 of the piston portion 51 is expanded in diameter from the accommodation groove 53 so as to come into contact with the outer peripheral regulation surface 32 of the engagement step portion 30. At this time, even if the locking ring 71 increases the inertial force to move forward and further move forward, as shown in FIG. 7B and FIG. 8B, the tip wall portion in the locking step 30 Abutting on the ceiling regulating surface 28 arranged on the 26th side, the forward movement is stopped. That is, the locking ring 71 causes the portion 76 on the forward movement movement side of the piston rod 50 to abut on the ceiling regulating surface 28 extending inward from the outer circumferential regulating surface 32 of the locking step portion 30. The fitting is prevented only between the outer peripheral surface 51 a side including the taper regulating surface 56 and the outer circumferential regulating surface 32 in the locking step portion 30 of the cylinder 22. Since the locking ring 71 contacts the taper regulating surface 56 of the piston portion 51 together with the ceiling regulating surface 28, the taper regulating surface is retracted from the top dead center UT position of the piston portion 51 to the lock position UP. 56 can push the locking ring 71 toward the locking regulation surface 31 of the locking step 30.

  Therefore, when the piston portion 51 moves backward to the lock position UP after being disposed at the top dead center UT, the locking ring 71 is connected to the outer peripheral surface 51a side of the piston portion 51 and the outer peripheral restriction surface 32 of the locking step portion 30. 7 and 8, smoothly retracts until it comes into contact with the locking regulation surface 31 of the locking step portion 30, and then comes into contact with the locking regulation surface 31. Backward movement is restricted. Further, the locking ring 71 is brought into contact with the outer peripheral regulating surface 32 of the locking step portion 30 so that the outer diameter surface 72 side is further restricted in diameter expansion state, and is moved forward in the inner peripheral side portion 74. The inner side surface 75 on the side is brought into contact with the taper regulating surface 56 of the piston portion 51 and the reduced diameter state is also regulated. As a result, the locking ring 71 is connected to the locking step portion 30 of the cylinder 22 and the piston portion 51. The piston portion 51 that is stably locked at the locking position UP with the taper regulating surface 56 and that causes the taper regulating surface 56 to abut against the inner side surface 75 of the locking ring 71 on the forward movement side is also provided. The piston rod 50 is locked at the lock position UP, and the backward movement of the piston rod 50 is restricted.

  If the actuator 21 is locked by restricting the backward movement of the piston rod 50 and the hood panel 10 receives the load F (see FIG. 4) of the pedestrian moving obliquely rearward and downward from above, the hood panel 10 Is deformed plastically, and the head 61 of the upper end 50a is brought into contact with the receiving surface 16a of the hood panel 10 as the lower surface (receiving surface) 16a of the rear end 10c of the hood panel 10 descends when the pedestrian receives it. As shown by the two-dot chain line in FIG. 4, the support rod portion 60 is also bent and plastically deformed in a stable state so that the upper head 61 side is bent backward from the bending point 63. The kinetic energy of the pedestrian can be accurately absorbed by a predetermined amount without variation.

  Therefore, the actuator 21 of the embodiment can stably lock the piston portion 51 at the predetermined lock position UP and restrict the backward movement of the piston rod 50.

  And in the actuator 21 of embodiment, as shown to FIG.7, 8, the ceiling control surface 28 is formed in the taper shape which diameter-expands to the backward movement side of the piston rod 50. As shown in FIG. Therefore, when the locking ring 71 comes into contact with the ceiling regulating surface 28 at the top dead center UT of the piston portion 51, it can move to the taper regulating surface 56 side of the piston portion 51 while sliding on the ceiling regulating surface 28. The locking ring 71 can reliably contact both the ceiling regulating surface 28 and the taper regulating surface 56. Therefore, in the embodiment, when the piston portion 51 moves backward to the subsequent lock position UP, the taper restricting surface 56 smoothly contacts the retaining ring 71 with the retaining restricting surface 31 of the retaining step portion 30. The piston portion 51 can be pressed so as to be in contact with each other, and the piston portion 51 can be locked more stably at the lock position UP.

  If this point is not taken into account, the ceiling regulating surface 28 may be provided in a direction orthogonal to the axial direction CD of the cylinder 22.

  In the case of the embodiment, the ceiling regulating surface 28 is tapered, and the taper regulating surface 56 of the piston portion 51 and the ceiling regulating surface 28 at the time of arrangement at the top dead center UT advance the piston rod 50. The moving-side edges 56 a and 28 a are configured to coincide with each other along the axial direction CD of the cylinder 22. Therefore, in the embodiment, when the piston portion 51 is disposed at the top dead center UT and the locking ring 71 moves forward due to inertia, the locking ring 71 narrows between the taper regulating surface 56 and the ceiling regulating surface 28. The piston portion is further brought into contact with the planar portions 56b and 28b apart from the edges 56a and 28a of both the taper regulating surface 56 and the ceiling regulating surface 28 while entering the portion. The situation where the outer peripheral surface 51a of 51 and the outer peripheral regulating surface 32 are fitted together can be prevented.

  Furthermore, in the case of the embodiment, the locking restriction surface 31 of the locking step portion 30 is connected to the locking ring 71 by setting the angle θ at which the taper restricting surface 56 and the ceiling restricting surface 28 are expanded to 45 °. As a state that can be locked, the width dimension CB from the inner edge 31 a to the outer periphery regulating surface 32 is set to be less than ½ of the diameter dimension D in the circular cross section of the locking ring 71.

  Therefore, in the embodiment, the width dimension CB of the locking restriction surface 31 is less than the radial dimension of the circular cross section of the locking ring 71, and the locking ring 71 has a radius of the circular cross section over the entire circumference of the cylinder 22. A part larger than the dimension is arranged on the inner side than the locking regulation surface 31. Then, the taper regulating surface 56 and the ceiling regulating surface 28 make the angle θ for expanding the diameter equal to each other. Therefore, when the piston portion 51 is disposed at the top dead center UT and the locking ring 71 moves forward due to inertia, the locking ring 71 moves the center WO (see B in FIG. 8) of the circular cross section to the taper regulating surface 56. And the ceiling regulating surface 28, the taper regulating surface 56 and the ceiling regulating surface 28 are easily and evenly contacted, and the outer periphery of the piston portion 51 is more stable. It is possible to prevent a situation where the surface 51a and the outer peripheral regulating surface 32 are fitted to each other, and to ensure smooth movement to the lock position UP thereafter. Note that the width dimension CB at which the locking regulating surface 31 of the locking step 30 can lock the locking ring 71 is 1 / of the diameter dimension D of the locking ring 71 in consideration of a stable locking state. It is desirable to ensure 6 or more.

  Further, in the embodiment, the end wall 26 side of the cylinder 22 is caulked so as to reduce the diameter of the pipe portion 38 made of a cylindrical metal pipe material and the inner diameter side of the pipe portion 38. And a head portion 47 fixed to the head. The pipe portion 38 includes a small diameter portion 39 that slides the piston portion 51 and a large diameter portion 40 that is expanded in diameter and extends in a cylindrical shape on the distal wall 26 side of the small diameter portion 39. The locking regulation surface 31 of the locking step portion 30 is constituted by a stepped portion 38 a between the small diameter portion 39 and the large diameter portion 40. Further, the head portion 47 is provided with an insertion hole 27 through which the support rod portion 60 of the piston rod 50 is inserted, and the ceiling restriction surface 28 and the outer peripheral restriction surface 32 of the locking step portion 30 are formed from the inner peripheral edge of the insertion hole 27. The head portion 47 is configured to extend on the inner peripheral surface 47a side. In such a configuration, the ceiling regulating surface 28 is orthogonal to the outer circumferential regulating surface 32 when the outer circumferential regulating surface 32 and the ceiling regulating surface 28 are cut along with the drilling of the insertion hole 27 at the time of manufacturing the head portion 47. Even if the width of the cylinder 22 in the direction perpendicular to the axis (corresponding to the width CB of the locking restricting surface 31) is narrowed, the head is widened. It is easy to place a cutting tool on the inner peripheral surface 47a side of the portion 47, and processing can be performed easily. And in the cylinder 22 of the configuration of the embodiment, the entire portion including the tip wall portion 26 side is not subjected to cutting or the like, and the pipe portion 38 and the head portion 47 made of a pipe material, and further, in the embodiment, the gas generator 35. Can be manufactured simply by caulking and fixing, and can be manufactured with reduced manufacturing steps and costs.

  In the actuator 21 of the embodiment, the case where the forward movement is increased and the backward movement is decreased is shown. However, the operation direction is not limited to this. For example, the main direction is the horizontal operation direction. The actuator of the present invention may be used, and the automobile safety device in which the actuator of the present invention is used may be other than the flip-up device U that raises the hood panel 10. For example, the present invention may be applied to an actuator of a knee protection device as an automobile safety device that receives a knee of a driver or a passenger in a passenger seat with a knee panel.

  Furthermore, in the actuator 21 of the embodiment, the case where the gas generator 35 that ignites and generates gas when the operation signal is input is arranged inside the cylinder 22 is shown. However, as the drive source for moving the piston rod 50, Alternatively, the piston rod 50 may be raised by using water, oil, air, or the like as a working fluid and utilizing the water pressure, hydraulic pressure, air pressure, or the like.

  Furthermore, as a drive source for moving the piston rod forward, it is possible to use a suction force of a solenoid, a biasing force (restoring force) of a compressed spring, or the like. For example, when using the suction force of a solenoid, the movable iron core is disposed in the cylinder as a piston rod, and the piston rod is moved forward by energizing the excitation coil disposed around the movable iron core in the cylinder. be able to. Also, when using a spring, the piston rod is connected to the free end of the compressed coil spring, and the tip of the piston rod or compression coil spring is locked with a stopper composed of a solenoid or the like so as to be retractable. If the stopper is retracted so as to release the lock, the piston rod moves forward by the urging force restored by the compression coil spring.

10 (Receiving material) Food panel,
21 ... Actuator,
22 ... Cylinder,
26 ... the tip wall,
27 ... insertion hole,
28 ... ceiling regulation surface,
30 ... locking step,
31 ... locking regulation surface,
32 ... outer peripheral regulating surface,
38 ... pipe part,
39: Small diameter part,
40 ... large diameter part,
47. Head part,
50 ... Piston rod,
51. Piston part,
53. Storage groove,
56 ... Taper regulating surface,
60 ... support rod part,
71 ... locking ring,
R: Lock mechanism,
V ... Vehicle,
U ... (Automotive safety device) Hood jumping device.

Claims (5)

As a piston-cylinder type used in automobile safety devices,
The piston rod
A piston portion slidable in the cylinder, and a support rod portion that extends from the piston portion and protrudes out of the cylinder, and supports a receiving material for receiving the object to be protected so as to be movable to a position for receiving the object to be protected; And configured with
In operation, after the piston portion is moved forward in the cylinder to the top dead center, the backward movement is restricted by the lock mechanism, and the kinetic energy of the protected object received by the receiving material is received by the support rod portion. As a configuration that can be absorbed and plastically deformed,
The locking mechanism is
An annular locking ring that is housed in the housing groove of the piston portion so as to be able to expand in diameter, and is made of an elastically deformable wire having a circular cross section;
A locking restricting surface that is disposed at a lock position of the piston portion on the inner peripheral surface side of the cylinder and abuts against a portion of the locking ring on the backward movement side, and an outer peripheral edge of the locking restricting surface from the piston A locking step portion having an outer circumferential regulation surface that extends to the forward movement side of the rod and that can be brought into contact with the outer circumferential surface of the locking ring that has been enlarged in diameter when the piston portion is locked;
It is arranged on the side of the piston rod in the forward movement side of the piston rod in the storage groove, and is tapered outwardly toward the forward movement side, and when the piston portion is locked, the inner peripheral side portion of the locking ring In contact with the inner side surface on the forward movement side of the inner ring, and cooperates with the locking regulating surface and the outer circumferential regulating surface of the locking step portion contacting the locking ring to regulate the backward movement of the piston portion. A taper regulating surface;
An actuator comprising:
The cylinder is
Protruding the support rod of the piston rod, provided with a tip wall portion that defines the arrangement position at the top dead center of the piston portion,
The locking ring is disposed on the front end wall side of the locking step portion, extends inward from the outer peripheral regulating surface, and advances the locking ring together with the taper regulating surface of the piston portion when arranged at the top dead center. An actuator comprising a ceiling regulating surface that abuts against a moving side portion.   2. The actuator according to claim 1, wherein the ceiling regulating surface is formed in a tapered shape whose diameter is increased toward the backward movement side of the piston rod.   The taper restricting surface of the piston portion and the ceiling restricting surface at the time of arrangement at the top dead center so that the edge on the forward movement side of the piston rod is substantially aligned along the axial direction of the cylinder. The actuator according to claim 2, wherein the actuator is configured. The taper restricting surface and the ceiling restricting surface are configured to have the same angle for expanding the diameter, and
In the state where the locking regulation surface of the locking step portion can lock the locking ring, the width dimension from the inner edge to the outer circumferential regulation surface is set to 1 / diameter of the diameter dimension in the circular cross section of the locking ring. The actuator according to claim 3, wherein the actuator is set to be less than two. A pipe portion formed of a cylindrical metal pipe material on the tip wall portion side of the cylinder; and a head portion fixed by crimping the pipe portion so as to reduce the diameter of the pipe portion. Configured with
The pipe portion includes a small-diameter portion that slides the piston portion, and a large-diameter portion that is expanded in diameter and extends in a cylindrical shape on the tip wall portion side of the small-diameter portion. The locking regulation surface of the stop portion is composed of a step portion between the small diameter portion and the large diameter portion,
The head portion includes an insertion hole through which the support rod portion of the piston rod is inserted, and the ceiling restriction surface and the outer peripheral restriction surface of the locking step portion are extended from an inner peripheral edge of the insertion hole. The actuator according to any one of claims 2 to 4, wherein the actuator is configured on an inner peripheral surface side of the head portion.

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