Pawl Structure in a Door Locking Device for a Vehicle

The present invention relates to a pawl structure in which a pawl is engaged with a latch in a door locking device for a vehicle to prevent the latch from being rotated or released.

In general, a door for a vehicle is opened and closed by engaging a striker fixed onto a vehicle body side with a latch disposed in a locking device on the door side. The latch is prevented from being rotated by engaging it with a pawl pivotally supported and biased in a direction in which the pawl is engaged with the latch.

As shown in FIG. 1, in such a conventional pawl structure, the pawl is integrally formed by cutting work with a base shaft 10, a link connecting portion 11, a claw portion 12, and a bearing portion 13. Japanese Laid-Open Patent No. 58-11277 discloses another pawl structure in which a raw material punch-molded from a metallic flat panel is formed by pressing work in the respective shapes of the base shaft, the link connecting portion, the claw portion, etc.

However, in the pawl structure shown in FIG. 1, it is necessary to perform machining works in some processes, thereby increasing the manufacturing cost. Further, it is difficult to make the pawl structure compact by the requirements of the mechanical strength and durability. Further, since the entire structure is integrally formed by a metallic material, the weight of the structure cannot be reduced and is limited, and a high hitting sound peculiar to the metal is generated when the pawl contacts the latch.

In the pawl structrue in which a material after punching is molded by pressing work, it is necessary to perform the pressing work at some stages, and further to prepare various kinds of dies for pressing the material to form the respective shapes of the base shaft, the link connecting portion, the claw portion, etc., thereby increasing the manufacturing cost. Further, similar to the structure mentioned above, the structure is integrally made of a metallic material so that a hitting sound is generated when the pawl contacts the latch.

To overcome the problems mentioned above, an object of the present invention is to provide a pawl structure in a door locking device for a vehicle in which the structure is made compact and light and the manufacturing cost is reduced and a hitting sound of a pawl is reduced.

With the above object in view, the present invention resides in a pawl structure in a door locking device for a vehicle in which latch means is rotatably supported, said structure comprising claw means engaged with the latch means to prevent the latch means from being rotated, said claw means including a claw portion and a resin portion engaged with the latch means and made of resin and covering at least a portion of the claw portion; and base shaft means connected to the claw means and pivotally connected to the door locking device, said base shaft means having a base shaft portion substantially perpendicular to the claw portion of the claw means, and a resin portion made of resin and covering at least a portion of the base shaft portion.

The present invention will be more apparent from the following description of the preferred embodiments thereof in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view showing a conventional pawl structure;

FIG. 2 is a front view of a door locking device to which the present invention is applied;

FIG. 3 is a perspective view of a pawl structure in the door locking device of FIG. 2 in accordance with the present invention;

FIGS. 4A to 4C are respectively front, plan and rear views of the pawl structure of the present invention;

FIGS. 5A and 5B are respectively front and plan views showing a core material of the pawl structure of the present invention;

FIG. 6 is a longitudinally cross-sectional view taken along line X--X of FIG. 4A; and

FIG. 7 is a longitudinally cross-sectional view taken along line Y--Y of FIG. 4B.

The preferred embodiments of the present invention will now be described with reference to the drawings.

FIG. 2 shows a front portion of a door locking device on a latch side thereof in which a pawl structure of the present invention is used. A latch 1 is rotatably attached to a box-shaped body 2 made of synthetic resin and fixed to an unillustrated base plate, around a shaft 3 as a center. The latch 1 is biased by an unillustrated spring in the clockwise direction at any time.

A pawl structure 4 is rotatably supported by the body 2, and a rear end of the pawl structure 4 extends through the base plate and is then connected to an unillustrated open lever on the rear side.

A claw 5 of the pawl structure 4 is engaged with left and right leg pieces 1a and 1b of the latch 1. When the claw 5 is engaged with the left leg piece 1a, the device is in a full latch state, and when the claw 5 is engaged with the right leg piece 1b, the device is in a half latch state.

A spring 6 is engaged with the pawl structure 4 to bias the pawl structure 4 in the counterclockwise direction.

A guide groove 2a is transversally formed in an intermediate portion of the body 2 to receive an unillustrated striker fixed onto a vehicle body side. A door can be opened and closed by disengaging and engaging the striker inserted into the guide groove 2a with the latch 1.

The construction of the pawl structure 4 will next be described in detail.

As shown in FIGS. 3 and 4A to 4C, the pawl structure 4 comprises a base shaft 7 on which a material R made of synthetic resin is molded, and the claw 5 having an engaging end 5a approximately projecting from a front end of the base shaft 7 in the diametrical direction and engaged with the leg pieces 1a and 1b of the latch 1, and partially molded by a material R made of synthetic resin. The pawl structure 4 further comprises a bearing portion 8 disposed adjacent to the claw 5 and molded by a material R made of synthetic resin, and a link connecting portion 9 approximately in the shape of a square pole formed at the rear end of the base shaft 7 and engaged with an unillustrated open lever.

As shown in FIGS. 5A and 5B, the pawl structure 4 comprises a metallic core material 4a which is approximately in the shape of a cross in plane and is integral with a plate-shaped base shaft portion 7a, a claw portion 5c, a bearing portion 8a and the link connecting portion 9. Main portions of the core material 4a are molded by a material made of synthetic resin to form the base shaft 7, the bearing portion 8 and the claw 5.

An expanded portion 4b is disposed on the lower surface of the core material 4a to increase the mechanical strength thereof such that a central portion of the expanded portion 4b is expanded approximately in the shape of a cross in the longitudinal direction. Further, recessed grooves 4c in the shape of a cross are disposed on the upper surface of the core material 4a to increase the joining force of the synthetic resin material at the molding time, and are approximately face-symmetrically formed with respect to each other along predetermined lengths.

As shown in FIGS. 3, 6 and 7, the lower surface of the claw 5 engaged with the spring 6 is entirely molded by synthetic resin having a predetermined thickness. A downward projection 5b is integrally formed at the right end of the claw 5, and is engaged with the spring 6 and is provided with the engaging end 5a engagable with the latch 1.

The end surface of the engaging end 5a is formed in the shape of a circular arc to easily engage and disengage this end surface from both leg pieces 1a and 1b of the latch 1.

A cross-shaped material 5d made of synthetic resin is molded on the opposite surface of the downward projection 5b in slide contact with the latch 1 along the recessed grooves 4c formed in the core material 4a, and has a height slightly higher than the height of the core material 4a, as shown in FIGS. 3 and 6. The cross-shaped material 5d is connected to the circumferential end surface of the projection 5b, i.e., the engaging end 5a.

Accordingly, the latch 1 and the claw 5 contact each other through the material made of synthetic resin, thereby preventing the core material 4a from directly contacting the latch 1.

As a result, a metallic sound generated between the latch 1 and the claw 5 by the opening and closing operations of a door is reduced, and the frictional resistance therebetween is also reduced so that the door is easily opened and closed, and the latch 1 is easily engaged and disengaged with the claw 5.

The material made of synthetic resin and used for a molded material is preferably selected from a hard nylon material, for example, but may be selected from another resin having excellent wear resistance characteristics and mechanical strength and small frictional coefficient.

The core material 4a can be formed by punching a flat panel by a press, etc. in one process so that the number of processing operations is greatly reduced.

It is not necessary to accurately process the core material 4a so that the generating rate of defective product is reduced and the yield is improved.

Further, since the base shaft 7 and the bearing portion 8 are molded by a material made of synthetic resin so that the frictional resistance thereof is reduced and the pawl structure 4 is smoothly rotated.

In the embodiment mentioned above, the core material 4a is partially molded by synthetic resin with a portion thereof left exposed, but may be entirely molded with only the link connecting portion 9 left so that the metallic portion is covered, which is advantageous to prevent the metallic portion from being rusty and minimizes the treatment for preventing the core material 4a from being rusty.

As mentioned above, in accordance with a pawl structure of the present invention, the following effects can be obtained.

(1) The core material as a base material of the pawl structure is integrally formed by punching work, and only the molding processing by synthetic resin is next performed with respect to the core material so that the pawl structure is cheaply manufactured in comparison with the conventional pawl structure.

(2) The core material can be formed so as to minimize the size thereof in consideration of the mechanical strength, etc., and the base shaft, etc. are molded by resin so that the pawl structure is made compact and light, thereby making a door locking device compact and light.

(3) The claw portion engaged with the latch is molded by resin so that a hitting sound generated when the latch and the claw portion are engaged and disengaged from each other is reduced, and the frictional resistance thereof is also reduced when the latch and the claw portion are engaged and disengaged from each other, thereby facilitating the engaging and disengaging operations.