JPH0483952A - Movement switching mechanism - Google Patents

Abstract

PURPOSE:To provide a movement switching mechanism to simplify structure and reduce the number of parts by changing an eccentric amount of the reciprocating part of a cam for an eccentric and a non-eccentric state, and causing the cam part to change a slope making contact with a second follower part along with a change in an eccentric amount. CONSTITUTION:When a rotary body 1 is rotated counterclockwise, only a rotary cam part 22 is brought into a state to be eccentric from a shaft 40 and a reciprocating cam part 21 is forced into a state to be concentric to the shaft 40. Therefore, the reciprocating part 21 is solely rotated within a first follower part 31 of a cam follower 3. A rotary cam part 22 bringing a second follower part 32 into contact with a slope 24 causes the cam follower 3 to perform reciprocating rotational movement responding to inclination in an axial direction of the slope 24. When the rotary body 1 is rotated clockwise, the reciprocating camp part 21 is also brought into a state to be eccentric from the shaft 40. Since a slope 25 of the rotary cam part 22 makes contact with the cam follower 3, the cam follower 3 performs reciprocating linear movement in a axial direction of an output shaft 30 and simultaneously performs reciprocating rotational movement responding to inclination in an axial direction of the slope 25.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a motion switching mechanism that converts rotational motion about an axis into reciprocating linear motion in the axial direction or reciprocating rotational motion about the axis.

[Conventional technology]

Conventionally, when converting rotational motion into multiple types of other motion, a mechanism is formed that combines multiple motion conversion mechanisms that convert rotational motion into each motion, and a clutch is used to switch between them. Ta.

[Problem to be solved by the invention]

In this case, each motion conversion mechanism is combined with a clutch, resulting in a very complex structure. The present invention has been made in view of these points, and its object is to have a simple structure. The object of the present invention is to provide a motion switching mechanism with a small number of parts.

[Means to solve the problem]

Therefore, the present invention includes an eccentric rotating body that is rotationally driven;
A cam arranged on the outer periphery of the rotating body that rotates integrally with the rotating body and changes the amount of eccentricity with respect to the center of rotation according to the rotational direction of the rotating body, and a reciprocating cam part for reciprocating linear motion of the cam engages. a cam follower comprising a first follower part and a twenty-seventh follower part that engages with a rotary cam part for reciprocating rotational drive in which the outer circumferential surface of the cam is an inclined surface inclined in the axial direction, The reciprocating cam part of the cam changes the eccentricity between an eccentric state and a non-eccentric state, and the rotating cam part has two inclined surfaces with different axial inclinations to change the eccentricity. It is characterized in that the inclined surface in contact with the second follower section changes with the change. [Operation] According to the present invention, when the rotating direction of the rotating body is one direction,
The cam follower performs only a reciprocating rotational motion, and when the rotating direction of the rotating body is set to the other direction, the cam follower performs a compound motion of a reciprocating linear motion and a reciprocating rotational motion. [Embodiment] The present invention will be described in detail below based on the illustrated embodiment. The zero-rotating body 1, which is composed of three members: a rotating body 1, a cam 2, and a cam follower 3, has a shaft portion 11 and a face. As shown in FIG. 2, the face gear 10 is provided with a shaft hole 12 through which a shaft 40, both ends of which are supported by the housing 4, passes through, and the face gear 10 is concentric with this shaft hole 12. In contrast, the shaft portion 11 is eccentric by an amount indicated by e1 in the figure. An engagement groove 13 extending approximately half the circumference is cut into the outer peripheral edge of one end of the shaft portion 11 . The cam 2 is provided with a through hole 20 passing through the cam 2, and one end thereof has a reciprocating cam portion 21 which is eccentric by e2 with respect to the through hole 20, and the other end thereof has a reciprocating cam portion 21 which is eccentric in the direction of eccentricity of the reciprocating cam portion 21. The rotary cam portion 22 is eccentric by a distance e with respect to the through hole 20 in the direction, and a protrusion 23 is provided on the opening edge of one end of the through hole 20, and the rotary cam portion 22 is As is clear from FIG. 4, the outer peripheral surface has an inclined surface 24 whose axial direction is inclined by an angle θ1, and an inclined surface 24 whose axial direction is inclined by an angle θ1.
An inclined surface 25 inclined by 2 is formed. The cam follower 3 has one end of an output shaft 30 fixed to it, and has a first follower part 31 whose upper and lower inner peripheral edges contact the outer peripheral surface of the reciprocating cam part 21 of the cam 2, and a tilted cam part 22 of the cam 2. It is provided with a second follower part 32 whose inner surfaces on both sides are in contact with the length of the surface 24 or the inclined surface 25. A pinion 51 fixed to the output shaft 50 of the motor 5
The rotating body 1 with which the face gear 10 is engaged has a shaft portion 11 fitted into a through hole 20 of the cam 2 so as to freely rotate, and a shaft portion 11 of the cam 2 is fitted into an engagement groove 13 formed in the shaft portion 11. The cam follower 3 in which the protrusion 23 is positioned and the output shaft 30 is supported by a thrust bearing 43 provided in the housing 4 so that it can freely slide in the axial direction and freely rotate around the axis is the same as described above. The first follower part 31 is brought into contact with the reciprocating cam part 21 and the second follower part 32 is brought into contact with the rotating cam part 22. Here, the eccentricity e1 of the shaft portion 11 in the rotating body l
and the eccentricity e2 in the reciprocating cam portion 21 of the cam 2 are set to be equal in value, and the eccentricity e in the rotary cam portion 22 is set to a value different from the above-mentioned eccentricity e l + 62. , and as shown in Figure 3(a),
When the protrusion 23 of the cam 2 engages one end of the engagement groove 13 extending approximately half the circumference of the rotating body 1, the eccentric direction of the rotating body 1 and the eccentric direction of the reciprocating cam portion 21 become opposite to each other, and the shaft 40 The eccentricity of the reciprocating cam part 21 relative to the shaft 40 is O, that is, the eccentricity of the rotating cam part 22 relative to the shaft 40 is set to e, -e3 so that the reciprocating cam part 21 is concentric with the shaft 40.
As shown in Figure 4(b),
Conversely, when the protrusion 23 engages with the other end of the engagement groove 13 in the rotary body 1, the eccentric direction of the rotary body 1 and the eccentric direction of the reciprocating cam portion 21 match, and the reciprocating cam portion 2 with respect to 11140
The eccentricity of the rotary cam portion 22 with respect to the shaft 40 is set to be e, +e2=2eI, and the eccentricity of the rotary cam portion 22 with respect to the shaft 40 is set to be 26+e3. Which end of the engagement groove 13 the protrusion 23 engages with depends on
Since it is determined by the rotation direction of the rotating body 1, now,
The rotating body 1 is rotated counterclockwise as shown by the arrow in Fig. 3(a).
When the cuff follower 3 is rotated, only the rotating cam portion 22 is eccentric with respect to the shaft 40 as described above, and the reciprocating cam portion 21 is concentric with the shaft 40. As shown in FIG. Although the reciprocating cam portion 21 simply rotates within the first follower portion 31 of The cuff follower 3 is caused to perform a reciprocating rotational movement within a range corresponding to the axial direction inclination θ. When the rotating body 1 is rotated in the clockwise direction indicated by the arrow in FIG. 3(b), the reciprocating cam portion 21 also becomes eccentric with respect to the shaft 40, as shown in FIG. Since the inclined surface 25 of the rotating cam portion 22 contacts the cuff follower 3, as the cam 2 rotates, the cuff follower 3 performs a reciprocating linear movement in the axial direction of the output shaft 3, and at the same time, the axial inclination of the inclined surface 25 is reduced. A reciprocating rotational movement is performed within a range corresponding to θ2. Note that since the axial inclination θ2 of the inclined surface 25 is larger than the axial inclination θI of the inclined surface 24, the reciprocating movement in the latter case is The range of rotational movement is larger. When each eccentric direction is set as shown in FIG. 6, the cuff follower 3 performs a reciprocating linear motion and a reciprocating rotational motion with a small range, as shown in FIG.
As shown in FIG. 8, it is possible to have the cuff follower 3 and the output shaft 30 perform a reciprocating rotation movement over a large range without involving reciprocating linear movement. .

【Effect of the invention】

As described above, although the present invention can be configured with a small number of parts, consisting of only the rotating body, the cam, and the cam follower, when the rotating direction of the rotating body is in one direction, the cam follower performs only reciprocating rotational movement. When the rotating direction of the rotating body is set to the other direction, the cam follower performs a compound movement of reciprocating linear motion and reciprocating rotational motion, and at this time, the range of the reciprocating rotational motion is such that the rotational direction of the rotating body is in one direction. It is something that is different from a certain time.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are an exploded perspective view of one embodiment of the present invention and a perspective view showing the back side of the cuff follower, Figure 2 is a vertical sectional view of the same as above, and Figures 3 (a) and (b) are the same as above. 4(aHb) is a front view of the rotating body and cam of the above, and FIG.
6(a) and 6(b) are front views of the rotating body and cam in another embodiment; FIG. 7(a) (b) is a horizontal cross-sectional view and a vertical cross-sectional view when the same rotating body rotates in one direction,
FIGS. 8(a) and 8(b) are a horizontal sectional view and a vertical sectional view when the above rotating body rotates in the other direction, where 1 is the rotating body, 2
3 is a cam, 3 is a cam follower, 21 is a reciprocating cam portion, 22 is a rotating cam portion, 31 is a first follower portion, and 32 is a second follower portion. Figure 2 Agent Patent Attorney Ishi 1) Long 7th 3rd (a) (b) (a) (b) 3] 1...Rotating body 2...Cam 3...Cam follower 21...Reciprocating cam part 22... Rotating cam part 31... First follower part 32... Second follower part 4 Figure 5 Figure 6 (a) (b) 22 / Figure 7 Figure 8

Claims (1)

[Claims] (1) An eccentric rotating body that is rotationally driven; a cam that is arranged around the outer periphery of this rotating body and rotates integrally with the rotating body, and that changes the amount of eccentricity with respect to the center of rotation according to the rotational direction of the rotating body; A first follower part that engages with a reciprocating cam part for reciprocating linear motion in the cam, and a first follower part that engages with a rotary cam part for reciprocating rotation drive in which the outer peripheral surface of the cam is an inclined surface inclined in the axial direction. The reciprocating cam part of the cam changes the eccentricity between an eccentric state and a non-eccentric state, and the rotating cam part changes the eccentricity in the axial direction. A motion switching mechanism comprising two inclined surfaces having different inclinations and changing the inclined surface in contact with the second follower portion as the amount of eccentricity changes.