JP5644727B2 - 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.

Conventionally, as an actuator used in an automobile safety device, an operation gas generated from a gas generator is caused to flow into a cylindrical cylinder so that a piston portion of a piston rod disposed in the cylinder moves forward ( There has been a piston-cylinder type in which the support rod portion extending from the piston portion is protruded from the tip wall portion of the cylinder by ascending and moving (see, for example, Patent Document 1). In this conventional actuator, the support rod portion includes a shaft portion that can be inserted through the tip wall portion of the cylinder, a head portion that is formed so as to bulge from the shaft portion to the axis orthogonal direction side on the tip end side of the shaft portion, The O-ring is disposed on the outer peripheral surface side of the head. The O-ring is configured to be interposed between the head and a cover portion extending from the cylinder so as to cover the outer peripheral side of the head in order to ensure airtightness in the cylinder. It is the structure which moves forward together with a part and a contact state with a cover part is cancelled | released.
JP 2004-330912 A

  However, in the conventional actuator, in order to attach the O-ring to the head, it is necessary to form a groove on the outer peripheral surface of the head. Therefore, there has been a problem that a process of forming a groove is required and the process of creating the actuator becomes complicated.

  The present invention solves the above-described problems, and an object thereof is to provide an actuator that can simplify the process of creating the actuator and can be surely sealed.

In piston cylinder type actuators used in automotive safety devices,
The actuator is formed of a cylindrical cylinder (22), a piston part (41) disposed in the cylinder (22), and a support rod part (49) connected to the piston part (41).
The cylinder (22) includes a cylindrical main body (23) and a cap (27) inserted and fixed to the upper end of the cylinder.
The main body (23) is disposed above the sliding portion (24) and the cylindrical sliding portion (24) for sliding the piston portion (41), and the inner diameter dimension is larger than the inner diameter dimension of the sliding section. It consists of a cylindrical large diameter part (25) with a diameter,
The cap (27) has a substantially cylindrical shape, penetrates in the vertical direction, and has a through hole (27c) through which the piston portion is inserted, and a concave portion (27a) formed in a substantially central portion in the vertical direction of the outer peripheral surface.
The cylinder body (23) is formed with a convex portion (23a) corresponding to the concave portion (27a) of the cap,
The support rod part (49) is installed in a round bar-like shaft part (53) arranged along the axial direction of the cylinder and screwed into the upper end side of the shaft part (53), and is slightly smaller than the inner diameter dimension of the cylinder. And a cylindrical head (50) having a small size,
A seal disposing portion (57) is formed on the outer peripheral side surface of the head (50), and the seal disposing portion (57) includes an outer peripheral side surface of the head (50) and an upper end portion of the cap (27). An O-ring (29) is provided for tightly sealing the inner peripheral side surface of the upper end of the cylinder (22);
The seal arrangement portion (57) includes a step portion (57a) formed by cutting out the outer periphery of the head portion (50) of the support rod portion (49).
The actuator is characterized in that the head (50) of the support rod portion (49) has a tapered shape continuously from the lower portion of the stepped portion (57a) toward the cylinder center.

According to the above configuration, the outer peripheral side surface of the columnar head in which the O-ring that seals the inside of the cylinder is slightly smaller than the inner diameter of the cylinder that is screwed into the upper end side of the shaft portion of the support rod. It is installed in the seal arrangement part provided in the. The O-ring installed in the seal arrangement portion is installed between the outer peripheral side surface of the head, the upper end portion of the cap, and the inner peripheral side surface of the upper end portion of the cylinder. It is possible to seal by filling the gap, and rain water or the like can be prevented from entering the cylinder. Further, since the seal disposing portion is provided at the stepped portion formed by cutting out the outer peripheral side surface of the head portion of the support rod, the O-ring can be easily installed at a predetermined position and can be easily attached. Furthermore, the head of the support rod is screwed to the tip of the shaft, and has a tapered shape starting from the bottom of the seal disposition where the O-ring is attached. However, it is possible to secure the height of the threaded portion of the shaft portion, and the head is firmly attached.

  According to the actuator of the present invention, the seal disposition portion is formed on the outer surface of the head portion of the support rod portion, and the seal disposition portion includes the outer surface of the head portion, the upper end portion of the cap, and the upper end portion of the cylinder. By installing an O-ring that seals closely to the inner surface of the cylinder, the actuator can be waterproofed even if it is exposed to rain or rain water during car washing, and rust prevention inside the cylinder can be achieved. Further, since the O-ring is installed in the seal arrangement portion, it is not necessary to create a groove on the outer peripheral side surface of the head of the support rod portion, and the actuator can be manufactured easily.

  Embodiments of the present invention will be described below with reference to the drawings. In the present specification, unless otherwise specified, the front-rear and up-down directions coincide with the front-rear and up-down directions of the vehicle V (see FIG. 1), and the left-right direction extends from the front side to the rear side of the vehicle V. It matches the left and right direction when viewed.

  A hood flip-up device (hereinafter abbreviated as “bounce-up device”) U in which the actuator 21 of the embodiment is used is a left edge on the rear end 10c side of the hood panel 10 in the vehicle V, as shown in FIGS. 10d and the right edge 10e. The actuator 21 and the receiving seat 16 disposed on the lower surface of the rear end 10c of the hood panel 10 are provided. 3 and 4, during the operation, the flip-up device U causes the actuator 21 to raise the piston rod 40 and interpose the receiving seat 16, so that the rear end 10c of the hood panel 10 is flipped up. Will be raised.

  As shown in FIG. 1, a sensor 6 capable of detecting or predicting a collision with a pedestrian is disposed on the front bumper 5 of the vehicle V, and a signal from the sensor 6 is input. When a non-operating circuit detects or predicts a collision between the vehicle V and a pedestrian based on a signal from the sensor 6, a fluid (gas) generator 36 (see FIG. 5) is activated.

  As shown in FIGS. 1 and 2, the hood panel 10 is disposed so as to cover the upper portion 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. The hood panel 10 is made of sheet metal made of aluminum (aluminum alloy) or the like, and as shown in FIG. 3, an outer panel 10a on the upper surface side, an inner panel 10b that is positioned on the lower surface side and has higher strength than the outer panel 10a, It is composed of The food panel 10 is configured to be elastically deformed when the kinetic energy accompanying the interference with the pedestrian is small and to be plastically deformable when the kinetic energy is large so that the pedestrian can absorb the kinetic energy of the pedestrian. Has been. 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 elasticity and plastic deformation amount of the hood panel 10 during 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 FIG. 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.

  And in the case of embodiment, the connection board part 15 makes the lower surface of the front part side the contact part 15a of the upper end 40a (head 50 of the support rod part 49) of the piston rod 40 at the time of a raise. That is, the front side of the connecting plate portion 15 serves as a receiving seat 16 for the upper end 40a of the piston rod 40, and the lower surface of the receiving seat 16 serves as a receiving surface 16a for the upper end 40a (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 40 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). When the rear end 10c of the hood panel 10 is raised, the front end 10f side of the hood panel 10 is moved to the body 1 side by a latch mechanism that engages a hood lock striker (not shown) disposed at the front end 10f for normal closing. There will be no departure.

  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.

  The cowl louver 7b includes an actuator cover 8 that covers the upper side of the actuator 21, and the actuator cover 8 is integrally formed with other general portions of the cowl louver 7b. The actuator cover 8 is disposed above the left and right actuators 21 and is opened in the area surrounded by the cylindrical sleeve portion 8a by being pushed by the head 50 of the support rod portion 49 of the actuator 21 during operation. 8b is arranged. The cowl louver 7b is formed by providing portions with different flexibility, and includes a hard portion 7c and a soft portion 7d having more flexibility than the hard portion 7c. The vicinity of the sleeve portion 8a including the door portion 8b of the actuator cover 8 is configured.

  As shown in FIG. 3, the actuator 21 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 liner hose 2, and the rear end of the hood panel 10. It is disposed below each hinge portion 11 below the left edge 10d and the right edge 10e on the 10c side. As shown in FIGS. 5A and 5B, 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 as a working fluid in the cylinder 22. Gas generator 36, piston rod 40 disposed so as to protrude upward from cylinder 22, and lock mechanism R for preventing downward movement of piston rod 40 after the upward movement. ing. The lock mechanism R is formed on the cylinder 22 side so as to engage a lock pin 45 housed in a piston portion 41 described later in the piston rod 40 and a lower surface side of the lock pin 45 protruding after the piston portion 41 moves upward. The locking surface 26 is made up of.

  As shown in FIG. 5, the cylinder 22 includes a cylindrical main body 23, and a cap 27 is inserted into and fixed to the upper end portion. The main body 23 includes a cylindrical sliding portion 24 that slides the piston portion 41 of the piston rod 40 with respect to the inner peripheral surface 24a during the upward movement, and the inner side of the upper end side of the main body 23 that is above the sliding portion 24. A cylindrical shape that is disposed on the peripheral surface above the sliding portion 24 and is formed at the protruding position of the lock pin 45 after the piston portion 41 is moved upward, and has an inner diameter dimension larger than the inner diameter dimension of the sliding section 24. The large-diameter portion 25 is configured. And the level | step difference surface from the sliding part 24 in this large diameter part 25 latches the lower part side (downward movement side) of the protruding lock pin 45, and controls the downward movement of the piston part 41 (piston rod 40). The locking surface 26 is configured (see FIG. 5B).

  As shown in FIG. 5, the lower end side portion 32 of the main body 23 has a substantially disc-shaped lower end wall portion 33 disposed so as to close the lower end side of the main body 23, and upward from the outer peripheral edge of the lower end wall portion 33. And a substantially cylindrical peripheral wall portion 34 having a larger diameter than the extending sliding portion 24. An insertion hole through which the connector of the gas generator 36 can be inserted is formed in the lower end wall portion 33. The peripheral wall portion 34 has the gas generator 36 attached to the main body 23 such that the inner peripheral surface thereof is an uneven surface substantially corresponding to the unevenness of the outer peripheral surface of the gas generator 36. (See Fig. 5 (a))

  A micro gas generator is used as the gas generator 36 as a fluid generator for the working fluid, and a lead wire for inputting an electric signal from a control circuit (not shown) is connected to the lower end surface of the gas generator 36. The connector that has been removed is arranged (see FIG. 5). When an electric signal from a control circuit (not shown) is input via a lead wire, the gas generator 36 burns the built-in explosive to generate the combustion gas G, and generates the working gas (combustion gas) G. The working fluid is supplied to the lower surface 41 a side of the piston portion 41 in the cylinder 22. (See FIG. 5 (b))

  As shown in FIGS. 5A and 5B, the cap 27 inserted and fixed to the upper end side of the main body 23 has a substantially cylindrical shape, and a concave portion 27a is formed at a substantially central portion in the vertical direction of the outer peripheral surface. Is formed. The main body 23 of the cylinder 22 has a convex portion 23a corresponding to the concave portion 27a, and the cap 27 is fixed to the main body 23 by engaging the concave portion 27a and the convex portion 23a. The substantially cylindrical cap 27 is formed with an insertion hole 27c that penetrates in the vertical direction and allows the piston rod 40 to pass therethrough. A support step portion 27e is formed at the upper end portion of the insertion hole 27c. The support step portion 27e provided at the upper end of the cap 27 has a tapered shape in which the upper peripheral length is longer than the lower peripheral length toward the insertion hole 27c, and the height of the head of the support rod described later is sufficient. Can be secured.

The support rod portion 49 has a round rod-like shaft portion 53 disposed along the axial direction (vertical direction) of the cylinder 22 and is disposed on the upper end side of the shaft portion 53 and has a larger outer diameter than the shaft portion 53. A substantially cylindrical head portion 50 having a diameter, and a seal disposing portion 57 is formed on the outer surface of the head portion 50. The seal disposing portion 57 is a notched stepped portion 57a. The O-ring 29 is disposed on the stepped portion 57a. As a result, the O-ring 29 comes into contact with the outer side surface of the head 50, the upper end portion of the cap 27, and the inner side surface of the upper end portion of the cylinder 22, and can be sealed. (See FIGS. 5 (a) and 5 (b)) The head 50 is screwed to the tip of the shaft 53, and the seal disposing portion 57 starts from below the stepped portion 57a as the O-ring mounting position. It becomes possible to secure the height of the threaded portion of the shaft portion while securing the mounting height of the O-ring 29, and the mounting of the head 50 is strong. Has been. When the piston rod 40 moves forward (up), the head 50 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. . The support rod portion 49 is made of a metal material such as steel that enables the plastic portion of the shaft portion 53 to be bent and plastically deformed. In the embodiment, the support rod portion 49 is integrally formed with the piston portion 41. .

The shaft portion 53 of the support rod portion 49 includes a straight portion 54 having a constant outer diameter between the head portion 50 and the piston portion 41. The straight portion 54 is set to have an outer diameter D2 smaller than an outer diameter Dh of the head 50. Further, the outer diameter dimension D2 of the straight portion 54 is set to be slightly smaller than the inner diameter dimension D1 of the insertion hole 27c.
The head 50 has a size larger than the inner diameter of the cylinder so that the piston rod 40 does not move in the backward direction with respect to the forward movement direction (upward direction in FIG. 5) when the actuator 21 is operated.

In the actuator 21 of the embodiment, first, in a normal state, the support step portion 27e supports the head portion 50, and the cylinder rod 40 is held so as to suppress movement in the backward (upward) movement direction. The protrusion on the inner peripheral surface of the substantially E-shaped ring member as a regulating member (not shown) engages with the engaging portion of the cylinder rod, and the cylinder rod 40 moves in the forward direction of the forward (upward) movement direction. Is suppressed. For this reason, rattling of the cylinder rod 40 in the cylinder 22 can be effectively prevented by vibrations of the automobile during traveling or the like, and generation of abnormal noise can be suppressed. Further, since the inside of the cylinder 21 is sealed with an O-ring 27 and has a waterproof structure, the air inside the cylinder 21 repeatedly expands and contracts due to fluctuations in the outside air temperature, and the cylinder rod 40 moves forward and backward. However, as described above, the movement of the cylinder rod 40 is effectively suppressed, and the deterioration of the sealing performance in the cylinder 22 can be effectively suppressed.

1 is a perspective view of a vehicle equipped with a hood flip-up device in which an actuator according to an embodiment of the present invention is used. It is a partial enlarged plan view of the vehicle carrying the hood flip-up device of the embodiment. It is a schematic longitudinal cross-sectional view along the front-back direction which shows the hood flip-up apparatus and vehicle hinge part of embodiment, and respond | corresponds to the III-III site | part of FIG. It is a schematic sectional drawing which shows the time of the action | operation of the hood flip-up apparatus of embodiment. It is a schematic longitudinal cross-sectional view of the actuator of embodiment, and shows the normal time and the time of completion | finish of operation | movement.

10: Hood panel 11: Hinge part 16: Receiving seat 22: Cylinder 23: Main body 24: Sliding part 25: Large diameter part 26: Locking surface 27: Cap 27a: Recessed part 27c: Insertion hole 27e: Support step part (holding) means)
29: O-ring 32: Lower end side portion 33: Lower end wall portion 34: Peripheral wall portion 36: Fluid (gas) generator 40: Piston rod 41: Piston portion 45: Lock pin 49: Support rod 50: Head portion 54: Straight portion G: Working gas (combustion gas)
R: Lock mechanism S: Deformation space U: Hood lift mechanism

Claims (1)

In piston cylinder type actuators used in automotive safety devices,
The actuator is formed of a cylindrical cylinder (22), a piston part (41) disposed in the cylinder (22), and a support rod part (49) connected to the piston part (41).
The cylinder (22) includes a cylindrical main body (23) and a cap (27) inserted and fixed to the upper end of the cylinder.
The main body (23) is disposed above the sliding portion (24) and the cylindrical sliding portion (24) for sliding the piston portion (41), and the inner diameter dimension is larger than the inner diameter dimension of the sliding section. It consists of a cylindrical large diameter part (25) with a diameter,
The cap (27) has a substantially cylindrical shape, penetrates in the vertical direction, and has a through hole (27c) through which the piston portion is inserted, and a concave portion (27a) formed in a substantially central portion in the vertical direction of the outer peripheral surface.
The cylinder body (23) is formed with a convex portion (23a) corresponding to the concave portion (27a) of the cap,
The support rod part (49) is installed in a round bar-like shaft part (53) arranged along the axial direction of the cylinder and screwed into the upper end side of the shaft part (53), and is slightly smaller than the inner diameter dimension of the cylinder. And a cylindrical head (50) having a small size,
A seal disposing portion (57) is formed on the outer peripheral side surface of the head (50), and the seal disposing portion (57) includes an outer peripheral side surface of the head (50) and an upper end portion of the cap (27). An O-ring (29) is provided for tightly sealing the inner peripheral side surface of the upper end of the cylinder (22);
The seal arrangement portion (57) includes a step portion (57a) formed by cutting out the outer periphery of the head portion (50) of the support rod portion (49).
The actuator is characterized in that the head (50) of the support rod portion (49) has a tapered shape continuously from the lower portion of the stepped portion (57a) toward the cylinder center.

Images