JP3361549B2 - Cam device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam device applied to a swing drive mechanism such as an automobile wiper device. 2. Description of the Related Art Conventionally, a crank mechanism has been frequently used in a drive device for swinging a wiper of an automobile. [0003] However, since the crank arm constituting the crank mechanism is relatively long and the operating range of the crank arm is large, a large installation space is required. In view of this point, the applicant has previously proposed a wiper driving device using a cam device using an end face groove cam. That is, this cam device comprises an end groove cam provided in a housing and driven to rotate in one direction, and a contact member which swings by engaging with a loop-shaped cam groove of the end groove cam. And a single output shaft that is integrally connected to the contact via a lever, is rotatably supported by the housing, and outputs a reciprocating rotational motion at a fixed angle. [0006] However, since the cam groove is one in the above-mentioned existing proposal, in order to secure a large wiper swing range, the diameter of the end face groove cam is proportionally increased. Inevitably increases the size of the housing and, consequently, the size of the entire wiper device. In view of the foregoing, the present invention provides a cam device which can provide a large swing angle output by a relatively small end face groove cam and can effectively meet the demand for a compact wiper device or the like. The purpose is to do. In order to achieve the above object, the present invention provides an end face groove cam provided in a housing and driven to rotate in one direction, and a center of rotation of the end face groove cam. A pair of independent loop-shaped inner cam grooves and outer cam grooves formed so as to have different diameters around the circumference, and a pair of inner contact elements and an outer pair that swing by engaging with the inner cam grooves and the outer cam grooves, respectively. A contact, and one output shaft that is integrally connected to the inner contact and the outer contact via a common lever, is rotatably supported by the housing, and outputs a reciprocating rotational motion at a fixed angle. , The cam groove and the contact,
At least one of the inner side and the outer side is set to the always engaged state, and the side in the non-engaged state is provided with a margin for the contact to escape in a direction to increase the swing angle of the output shaft. It is characterized by the following. According to the above construction, the cam grooves of the end face groove cam are formed as two inner and outer grooves, and the respective contacts are engaged with each other, and while one of the cam grooves is in the engaged state. In addition, since the other contact is set so as to escape from the cam groove in a direction to increase the swing angle of the output shaft, it is possible to realize an integrated configuration in which the area of the cam surface of the end face groove cam is effectively used. Therefore, the pair of cam mechanisms are housed in one configuration, and the swing angle of the output shaft can be increased without the need to particularly increase the diameter of the end face groove cam. An embodiment of the present invention will be described below with reference to the drawings. The cam device according to the present embodiment is applied to, for example, a wiper swinging device of an automobile, and FIG. 1 shows a side structure, and FIGS. 2 to 5 show a front sectional structure and operation. As shown in FIGS. 1 and 2, in this embodiment, a disk-shaped end face groove cam 3 is rotatably supported via a bearing 2 in a combined rectangular housing 1.
A gear device 4 as a drive mechanism is connected to one side surface of the end face groove cam 3. The gear device 4 comprises an input shaft 5 rotatably supported by the housing 1 and a worm gear 7 integral with the end face groove cam 3 meshing with a worm 6 formed at the tip of the input shaft 5. The rotation from a motor shaft (not shown) is applied to the end face groove cam 3 via the input shaft 5 and the gear device 4.
And the end face groove cam 3 is driven to rotate in one direction. On the other side face of the end face groove cam 3, a pair of independent loop-shaped inner cam grooves 8 and outer cam grooves 9 are formed with different diameters around the center of rotation A thereof. An inner contact 10 and an outer contact 11 engage with the inner cam groove 8 and the outer cam groove 9, respectively, so as to swing. These inner contacts 10
And the outer contact 11 are integrally connected via a common V-shaped lever 13 to an output shaft 12 rotatably supported by the housing 1, whereby the output shaft 12 is
It is configured to output a reciprocating rotation at a constant angle θ. In this embodiment, each of the cam grooves 8, 9 and each of the contacts 10, 11 are always set in an engaged state on one of the inner side and the outer side, and the outer contact 1
A margin is set to escape in a direction in which the swing angle of the output shaft 12 is increased when 1 is in the disengaged state. That is, each cam groove 8, 9 and each contact 1
0 and 11 are the outer cam grooves 9 in a certain area C shown in FIG.
And the outer contact 11 are engaged with each other, and the inner cam groove 8 and the inner contact 10 are engaged with each other in another area D. As shown in FIG. 2, a part of the outer cam groove 9 opens on the outer peripheral surface of the end face groove cam 3 via an opening 14, and the opening 14 is formed in a space 15 formed on the inner surface of the housing 1. It is designed to communicate during rotation. This space 15
Has a size that allows the outer contact 11 to be inserted, and when the opening 14 and the space 15 match during rotation of the end face groove cam 3, the outer contact 11 separates the opening 14 from the outer cam groove 9. It is possible to move to the space section 15 through the space. FIGS. 2 to 5 show the behavior when the end face groove cam 3 rotates in the counterclockwise direction (the direction of arrow a) at every 90 degrees. When the end face groove cam 3 rotates in the direction a in the state of FIG. 2, the lever 13 and the output shaft 12 rotate in the direction b due to the engagement between the outer cam groove 9 and the outer contact 11. FIG. 2 shows a state in which a quarter turn is made. After that, when the outer contact 11 is further rotated, the outer contact 11 escapes to the space 15 as shown in FIG.
Is switched to engagement with the inner contact 10. At this time, the swing angle of the output shaft 12 is increased by the escape of the outer contact 11 into the space 15. Thereafter, the lever 13 and the output shaft 12
The rotation is changed to the rotation in the 'direction, and the state shown in FIG.
State. According to this embodiment, while the inner cam groove 8 of the end face groove cam 3 and the inner contact 10 are engaged, the direction in which the outer contact 11 increases the swing angle of the output shaft 12 is increased. Since it is set in a state of escaping from the outer cam groove 9, it is possible to obtain an integrated configuration that effectively utilizes the area of the cam surface of the end face groove cam 3. Accordingly, the pair of cam mechanisms are housed in one structure, and the swing angle of the output shaft 12 can be increased without the need to particularly increase the diameter of the end face groove cam, and the wiper can be made larger. It is possible to effectively meet the demand for compact devices and the like. Although the outer contact 11 escapes in the above embodiment, the inner contact 10 may escape in some cases. As described above, according to the present invention, the cam grooves of the end face groove cams are formed as two inner and outer grooves, and the contacts are engaged with each other. Since the other contact is set so as to escape from the cam groove in a direction to enlarge the swing angle of the output shaft while in the engaged state, a large swing angle output is obtained by the relatively small end face groove cam. It is possible to increase the swing angle of the output shaft without having to increase the diameter of the end face groove cam, and to achieve excellent effects such as being able to effectively meet the demand for compact wiper devices and the like. Is done.

[Brief description of the drawings] FIG. 1 is a side sectional view showing one embodiment of the present invention. FIG. 2 is a front sectional view of the embodiment. FIG. 3 is a view showing a state rotated by １ ／ of FIG. 2; FIG. 4 is a view showing a state in which a half rotation has been made from FIG. 2; FIG. 5 is a view showing a state rotated by 3/4 from FIG. 2; [Explanation of symbols] 1 Housing 3 End groove cam 8 Inner cam groove 9 Outer cam groove 10 Inside contact 11 Outer contact 12 Output shaft 13 lever

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 25/00-25/08 B60S 1/22

Claims (1)

(57) [Claim 1] An end face groove cam provided in a housing and driven to rotate in one direction, and the end face groove cam is formed to have a different diameter around a rotation center thereof. A pair of independent loop-shaped inner and outer cam grooves; a pair of inner and outer contacts which respectively engage and swing with the inner and outer cam grooves; and the inner and outer contacts. A single output shaft that is integrally connected to the contact via a common lever, is rotatably supported by the housing, and outputs a reciprocating rotational motion at a fixed angle, and the cam groove and the contact are On the other hand, either the inner side or the outer side is always set to the engaged state, and the non-engaged side has a margin for the contact to escape in a direction to increase the swing angle of the output shaft. A cam device.