JP3512662B2 - Rotary shaft rotating device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary shaft rotating device for rotating a rotary shaft used in a press machine or the like for press-forming a metal plate with a cam mechanism.

[0002]

2. Description of the Related Art As a shaft rotation driving means for rotating a lower rotary shaft (rotary cam) installed in a lower die of a press machine for bringing an end portion of a metal plate close to bending, etc. There is a drive cam installed on the upper mold. A conventional structure of a rotary shaft rotating device using such a drive cam will be described with reference to FIGS.

The rotary shaft 1 shown in FIG. 3 is installed rotatably around a horizontal shaft center P in a lower die of a press machine (not shown). A drive cam 11 for rotating the rotary shaft 1 at a constant angle is fixed to an upper die for vertically driving a press machine (not shown). The rotary shaft 1 is a round shaft, and a flat notched sliding surface 3 is formed by cutting out a part of the outer circumference 2 in the chord direction.
Have. The drive cam 11 moves up and down in the vertical direction orthogonal to the axis P of the rotary shaft 1 and rotates the rotary shaft 1 at a constant angle by utilizing the notched sliding surface 3 when moving downward. The drive cam 11 includes a vertical and flat sliding side surface 12, which is one side surface, and an inclined cam surface 13 at the lower end of the sliding side surface 12.
The rotary cam 1 is rotated by the wedge cam having the following structure as shown in FIGS.

The rotary shaft 1 shown in FIG. 3 (A) is in a state in which the rotary shaft 1 is stationary at a fixed position and starts to rotate, and the shaft center P on the notch sliding surface 3 is shown.
Assuming that the position of the center line orthogonal to the perpendicular line from is the point a and both ends of the notch sliding surface 3 located on both sides of the point a are the points b and c, the rotary shaft 1 has a fixed position where the point b is almost right next to it. In c
It is stationary at a fixed position in which the notch sliding surface 3 is inclined so that the point is located almost directly above the fixed position. In the drive cam 11 with respect to the rotary shaft 1, the midpoint of the downward inclined cam surface 13 is right above the stationary point b of the rotary shaft 1, and the vertical sliding side surface 12 is a of the rotary shaft 1. Stand by above the rotary shaft 1 so as to be right above the midpoint slightly closer to the point b than the point. When the drive cam 11 is moved downward from the standby position, the fixed point near the tip of the inclined cam surface 13 comes into contact with the point b of the stationary rotary shaft 1 as shown in FIG.

When the drive cam 11 shown in FIG. 3 (A) moves further downward, the inclined cam surface 13 pushes down the point b, and the point b slides on the inclined cam surface 13 to move the axis P of the rotary shaft 1. The rotation around the center begins. When the rotary shaft 1 slightly rotates, the notched sliding surface 3 of the rotary shaft 1 and the inclined cam surface 13 of the drive cam 11 come into surface contact with each other as shown in FIG. 3 (B).
At this time, the inclined cam surface 13 and the sliding side surface 1 of the drive cam 11
Assuming that the boundary edge with 2 is the point t, and the fixed position of the inclined cam surface 13 that contacts this point is the point d, the notch sliding surface 13
Point d is at a fixed position closer to point b than point a. As a result, when the drive cam 11 is moved further downward, the point t pushes down the notch sliding surface 3, and the rotary shaft 1 is further rotated by the rotational moment given to the rotary shaft 1 at this time. By this rotation, the point t slides on the notch sliding surface 3, and the inclined cam surface 13 except the point t moves away from the notch sliding surface 3.

As shown in FIG. 3C, the rotary shaft 1 continues to rotate due to the further forward movement of the drive cam 11, and the notch sliding surface 3 is parallel to the sliding side surface 12 of the driving cam 11. When it becomes vertical, the point t approaches or coincides with the point a, and no rotational force is applied to the rotary shaft 1 in the subsequent forward movement of the drive cam 11, and the rotation of the rotary shaft 1 at a constant angle is completed here. .

Drive cam 11 shown in FIGS. 3 (A) to 3 (C)
In the press machine, for example, the forward movement is performed together with the lowering drive of the upper die, and the driving cam 11 performs positioning and holding of a work such as a metal plate which is pressed by rotation of the rotary shaft 1 which rotates at a constant angle. Then, when only the drive cam 11 moves further downward from the rotary shaft rotation end state of FIG. 3C, the sliding side surface 12 slides along the notch sliding surface 3. As shown in FIG. 3D, when the drive cam 11 descends to the bottom dead center, the press die installed in the lower die of the press, for example, which interlocks with the lowering operation, press-forms the work into a predetermined shape. After that, the drive cam 11 returns (raises) from the bottom dead center to a position just above, and from (C) to (B) of FIG.
In the order of (A), the rotary shaft 1 rotates in the opposite direction by a constant angle, the drive cam 11 returns to the original top dead center position, and stands by for the next press operation.

[0008]

Problems to be Solved by the Invention FIGS. 3 (A) to 3 (B)
Until then, the rotary shaft 1 starts to rotate smoothly due to a sufficiently large rotational moment given to the rotary shaft 1 by the forward power of the drive cam 11. However, FIG.
After the state of (B), the rotation of the rotary shaft may not proceed smoothly in some cases. The reason will be described below with reference to FIG.

FIG. 4 shows the notched sliding surface 3 of the rotary shaft 1 which has started to rotate and the inclined cam surface 13 of the drive cam 11 in the course of forward movement.
Shows the state of surface contact. When the drive cam 11 continues to move forward from this state, the point t of the drive cam 11 presses the notch sliding surface 3 to give a rotary moment to the rotary shaft 1. Let Fa be the force exerted perpendicularly to the notch sliding surface 3 at the point t, and Fb be the force exerted in the direction parallel to the notch sliding surface 3 at the point t. Do d
The resultant force Fc of Fa and Fb acts on the point. In this case, there is a relationship of Fb = Fa × (friction coefficient of the notch sliding surface 3). The larger the distance L1 from the point d to the point a and the further the resultant force Fc applied to the point d from the axis P of the rotary shaft 1, the larger the rotational moment applied to the rotary shaft 1, and the rotation of the rotary shaft 1. Becomes smooth, but when the resultant force Fc approaches the axis P,
The rotation of the rotary shaft 1 from the state of FIG. 3 (B) may not be performed smoothly.

Therefore, the notch sliding surface 3 of the rotary shaft 1 is formed of a member having a small friction coefficient so that the resultant force Fc is further away from the shaft center P, but the effect is limited even by such improvement measures. Target.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary shaft rotating device for smoothly rotating a rotary shaft at a constant angle by a drive cam that linearly moves.

[0012]

The present invention achieves the above object by modifying the shape of the rotary shaft side. That is, the present invention includes a rotary shaft rotatably installed around a shaft center at a fixed position, and a drive cam that reciprocates linearly in a fixed direction orthogonal to the shaft center of the rotary shaft.
In a rotary shaft rotating device for rotating the rotary shaft at a constant angle by moving the drive cam forward to directly contact the rotary shaft, the rotary shaft has a shape notched in a chord direction at a part of its outer periphery, the cutout surface facing the sliding side is flat on one side surface of the driving cam, slidable <br/> Suridodanmen the sliding side surface of the drive cam and projecting at one end portion of the notch surface The drive cam has an inclined cam surface at the tip of its sliding side surface, and the inclined cam surface is outside the sliding step surface of the rotary shaft before rotation due to the forward movement of the drive cam. the rotary shaft to press the edge, the Suridodanmen inner stage edge driving cam <br/> sliding stage surface when rotated to a predetermined angle to surface contact with the inclined cam surface of the drive cam At a fixed position on the inclined cam surface that is separated from the boundary edge between the inclined cam surface and the sliding side surface of the The sliding step surface is formed so that the sliding cam surface is in sliding contact with the inner step edge of the sliding step surface by the forward power of the drive cam after the sliding step surface and the inclined cam surface are in surface contact. rotary shaft presses the inner stage edge, at rotation end <br/> state of constant angle to the sliding stage surface Ru parallel to name the sliding side of the drive cam, the sliding side surface of the drive cam sliding It is characterized in that the drive cam can move forward while slidingly contacting the moving step surface.

Further, according to the present invention, a sliding member, which is a separate member having a friction coefficient smaller than that of the shaft member forming the cutout surface, is fixed on the cutout surface of the rotary shaft. It is characterized in that a sliding step is formed.

[0014]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

The rotary shaft rotating device shown in the embodiment of FIG. 1 is applied to the rotary shaft rotating device of FIG.
The same or corresponding parts as in FIG. 3 are designated by the same reference numerals to avoid duplication of description. 1 is different from that of FIG. 3 in that a flat cutout surface 5 is formed on a part of an outer circumference 2 of a rotary shaft 1 and a sliding step surface 6 is formed by projecting at one end of the cutout surface 5. Is formed, and the inclined cam surface 13 of the drive cam 11 similar to that in FIG. 3 is brought into contact with the sliding step surface 6 to rotate the rotary shaft 1 at a constant angle. Further, in the device shown in FIG. 1, a sliding member 7 having a rectangular cross section is fixed to one end of the cutout surface 5 of the rotary shaft 1, and the outer surface of the sliding member 7 is used as a sliding step surface 6. Is. The sliding member 7 is, for example, a metal block, a resin block, or the like having a friction coefficient smaller than that of the shaft member forming the cutout surface 5 of the rotary shaft 1.

The cutout surface 5 of the rotary shaft 1 has a shape in which a part of the outer circumference 2 of the rotary shaft 1 is cut out in the chordal direction, and is sufficiently separated from the center line parallel to the axis P of the cutout surface 5. A sliding step surface 6 is formed on one end in parallel with the axis P. When the rotary shaft 1 in FIG. 1 is rotated by the same constant angle as in FIG. 3 by the forward movement of the drive cam 11 similar to that in FIG. 3, the sliding step surface 6
3 is set to be the same as the height position from the axis P of the cutout sliding surface 3 of FIG. 3, and the step edge e on the outer side of the sliding step surface 6 is the cut point of FIG. It becomes the position of point b of the notched sliding surface 3. The step edge f on the inner side of the sliding step surface 6 is separated from the boundary edge t of the inclined cam surface 13 when the sliding step surface 6 and the inclined cam surface 13 are in surface contact with each other as described in FIG. Set to come in position.

1A to 1D, the constant angle rotation operation of the rotary shaft 1 by the drive cam 11 will be described. Figure 1 (A)
The rotary shaft 1 is stationary at a fixed position and starts to rotate. At this time, the midpoint of the inclined cam surface 13 of the drive cam 11 is located immediately above the outer step edge e of the sliding step surface 6, and the drive cam 1
1, the vertical sliding side surface 12 is the inner step edge f of the sliding step surface 6.
It is located a little outward from. This rotary shaft 1
When the drive cam 11 standing by immediately above is moved downwards, a fixed point near the tip of the slanted cam surface 13 becomes an outer step edge e of the sliding step surface 6 as shown in FIG. Abut.

When the drive cam 11 shown in FIG. 1 (A) moves further downward, the inclined cam surface 13 pushes down the step edge e to start rotation about the axis P of the rotary shaft 1. When the rotary shaft 1 slightly rotates, the sliding step surface 6 of the rotary shaft 1 and the inclined cam surface 13 of the drive cam 11 come into surface contact with each other as shown in FIGS. 1 (B) and 2. At this time, the fixed portion of the inclined cam surface 13 that contacts the inner step edge f of the sliding step surface 6 is s.
If it is a point, the s point is located away from the t point, and
The distance L2 from the point s to the straight line passing through the axis P orthogonal to the extension line of the inclined cam surface 13 is larger than the distance L1 in FIG. 4 by the distance between the points s and t. As a result, when the drive cam 11 is moved further downward, the point s pushes down the inner step edge f of the sliding step surface 6, and the rotary shaft 1 is further rotated by the rotational moment given to the rotary shaft 1 at this time. . By this rotation, the s point or the step edge f slides along the inclined cam surface 13, and the sliding step surface 6 separates from the inclined cam surface 13 except for the step edge f.

As shown in FIG. 1C, when the rotary shaft 1 continues to rotate due to the further forward movement of the driving cam 11, the sliding step surface 6 becomes parallel to the sliding side surface 12 of the driving cam 11. , The point t of the drive cam 11 comes into contact with the vertical sliding step surface 6, and when the drive cam 11 moves forward thereafter, no rotational force is applied to the rotary shaft 1 and the rotary shaft 1 rotates at a constant angle. Ends. In addition, from the rotary shaft rotation end state of FIG. 1 (C), only the drive cam 11 moves further downward, and as shown in FIG. 1 (D), the drive cam 11 descends to the bottom dead center before driving. Cam 1
The rise of 1 is started. As the drive cam 11 rises, the rotary shaft 1 rotates in the opposite direction by a constant angle in the order of (C) to (B) and (A) of FIG. 1, and the drive cam 11 returns to the original standby position.

Rotary shaft 1 shown in FIGS. 1 (A) to 1 (B)
The rotation is performed smoothly as in FIG. Figure 1
The rotation of the rotary shaft 1 from (B) to (C) is also smoothly performed for the following reason. That is, the vertical force on the sliding step surface 6 at the point t of the drive cam 11 from the time point when the notch surface 5 of the rotary shaft 1 that started to rotate and the inclined cam surface 13 of the drive cam 11 in the course of forward movement make surface contact. If Fx is the force in the direction parallel to the sliding step surface 6 at point t, then Fy = F
There is a relationship of xx (friction coefficient of sliding step surface 6), and the resultant force Fz of Fx and Fy acts on the inner step edge f of the sliding step surface 6. Since the inner step edge f of the sliding step surface 6 is separated from the axis P of the rotary shaft 1 by the distance L2 (> L1), the resultant force Fz is sufficiently far from the axis P of the rotary shaft 1. . As a result, from the state of FIG.
The rotational moment applied to the rotary shaft 1 also increases when the gear moves forward, and the rotary shaft 1 rotates smoothly.

Such a rotary shaft 1 from FIG. 1 (B)
The rotation becomes smoother by setting the friction coefficient of the sliding step surface 6 to be small and reducing the force Fy in the parallel direction. Although the sliding step surface 6 is formed of the rotary shaft member forming the cutout surface 5 and the sliding member 7 which is a separate member, the sliding step surface 6 is cut out if a sufficiently small friction coefficient is obtained in practical use. It is also possible to form the same rotary shaft member as the surface 5.

[0022]

According to the present invention, the inclined cam surface of the drive cam is pressed against the sliding step surface formed by projecting at one end of the notch surface formed on a part of the outer periphery of the rotary shaft to slide. After the inclined cam surface comes into surface contact with the step surface, the inner edge of the sliding step surface is pushed at the midpoint of the inclined cam surface to rotate the rotary shaft to a constant angle. The rotation moment given to can be set large,
Since the constant angle rotation of the rotary shaft over all angles can always be smoothly performed, it is possible to provide the rotary shaft rotation device that makes the press operation of the press machine smooth.

Further, by fixing another sliding member having a smaller friction coefficient than the shaft member to the notch surface of the rotary shaft and forming the sliding step surface by this sliding member, the sliding step surface It is possible to make the rotation of the rotary shaft smoother by setting the friction coefficient to a sufficiently small value.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a rotary cam and a drive cam during each operation according to an embodiment of the present invention, in which (A) starts rotary shaft rotation, (B) immediately after rotary shaft rotation, and (C) shows FIG. 6D is a cross-sectional view after the rotation of the rotary shaft is completed when the rotation of the rotary shaft is completed.

FIG. 2 is an enlarged view for explaining a mechanical relationship between a rotary shaft and a drive cam in FIG. 1 (C).

3A and 3B are cross-sectional views of a main part of the rotary shaft rotating device, which is a prerequisite technique of the present invention, during each operation of the rotary shaft and the drive cam, in which FIG. , (C) are cross-sectional views after the rotary shaft has finished rotating, and (D) are cross-sectional views after the rotary shaft has finished rotating.

FIG. 4 is an enlarged view for explaining the mechanical relationship between the rotary shaft and the drive cam in FIG. 3 (C).

[Explanation of symbols]

1 rotary shaft 2 outer circumference 5 Notch surface 6 Sliding step 7 Sliding member 11 Drive cam 12 Sliding side 13 Inclined cam surface e Outside step edge f Inner step edge t border edge

Claims (2)

(57) [Claims] 1. A rotary shaft that is rotatably installed around a shaft center at a fixed position, and a drive cam that reciprocates linearly in a fixed direction orthogonal to the shaft center of the rotary shaft. A rotary shaft rotating device for rotating the rotary shaft at a constant angle by moving the rotary shaft directly into contact with the rotary shaft, wherein the rotary shaft has a shape notched in a chord direction in a part of its outer circumference.
Shaped like a flat side surface of the drive cam , facing the sliding side surface.
The drive cam has a notched surface and a sliding step surface that projects at one end of the notched surface and is slidable on the sliding side surface of the drive cam, and the drive cam is inclined at the tip of the sliding side surface. The cam surface has a cam surface, and the forward movement of the drive cam causes the inclined cam surface to press a step edge outside the sliding step surface of the rotary shaft before rotation to move the rotary shaft, and the sliding step surface causes the driving cam to move. Makes surface contact with the inclined cam surface of
While rotating to a predetermined angle, the step edge inside the sliding step surface is in a fixed position on the inclined cam surface that is separated from the boundary edge between the inclined cam surface of the drive cam and the sliding side surface by a predetermined length. The sliding step surface is formed so that the inclined cam surface is in sliding contact with the inner step edge of the sliding step surface by the forward power of the drive cam after the sliding step surface and the inclined cam surface are in surface contact with each other. rotary shaft presses the inner stepped edge, at rotation end condition of a constant angle to the sliding stage surface Ru parallel to name the sliding side of the drive cam, the sliding step surface sliding side surface of the drive cam and the slide A rotary shaft rotating device in which a drive cam can move forward while being in contact with the rotary shaft rotating device. 2. A sliding member, which is a separate member having a friction coefficient smaller than that of a shaft member forming the cutout surface, is fixed on the cutout surface of the rotary shaft and slid by the sliding member. The rotary shaft rotating device according to claim 1, wherein a stepped surface is formed.