JP2000179653A - Plate cam mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stable-acting plate cam mechanism by eliminating fluctuating resistance to cam rotating force caused by the change of spring restraining force when a cam is displaced. SOLUTION: This plate cam mechanism is provided with a plate cam 1 in which cam distance (between symmetric faces of the cam) passing the center of a camshaft to be a basic structural component is equal in all directions; a rocking lever (or a linear moving lever) driven by the plate cam 1; a roller 5 fitted to the rocking lever (or linear moving lever) and brought into contact with the cam face; a roller 15 arranged in an exactly opposite position to the roller 5 with the camshaft as the center; a restraining arm passing the center of the camshaft to support the roller 5 and roller 15; and components related to the structural component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate cam mechanism, a kind of cam mechanism, which is a mechanical element capable of programming a series of operations of a mechanical device.

[0002]

2. Description of the Related Art A plate cam is a kind of a cam mechanism, which is lightweight, simple, and inexpensive. The swing lever (or direct acting lever) that transmits the driving force due to the cam rotation to the relevant parts is restrained on the cam surface by a spring, and the change in the restraining force when the cam stroke is displaced is a resistance to the cam rotating force and is smooth. It was a factor that hindered the rotation. In addition, an esoteric spring design for obtaining an appropriate binding force was required. Hereinafter, a conventional plate cam mechanism will be described.

FIG. 3 is a side view of a conventional swing lever type plate cam mechanism. Reference numeral 1 denotes a plate cam shown in FIG. 4 which rotates about a shaft 2. Reference numeral 3 denotes a swinging lever which is controlled by the plate cam 1 to perform a swinging movement about the shaft 4, and 5 is fixed to the swinging lever 3. A swing lever roller, which is fitted coaxially with the swing lever roller shaft 17 and contacts the cam surface of the plate cam 1 to transmit the displacement of the plate cam 1 to the swing lever 3, and 6 is attached to the tip of the swing lever 3 and swings. A roller for transmitting the movement of the moving lever 3 to the follower 7; a follower 7 for performing a terminal operation of the mechanism by the roller 6; a constraint spring 8 for restricting the swing lever 3 to the cam surface of the plate cam 1; 1 is a drive motor for rotating 1, 10 is a drive pulley attached to the rotating shaft of the drive motor 9, 11 is a drive belt for transmitting the rotation of the drive motor 9 to the camshaft 2, 12 is a driven pulley attached to the camshaft 2, 13 is the linear motion of follower 7 Shows the guide.

The operation of the plate cam mechanism configured as described above will be described below. First, at the start of operation, the drive motor 9 rotates in the direction of the arrow, the rotation is transmitted to the camshaft 2 by the drive belt 11, and the plate cam 1 rotates in the same direction. Since the cam surface gradually displaces with the rotation of the plate cam 1, the swing lever roller 5 is pushed to the left and swings about the shaft 4 together with the swing lever 3 to terminate the operation (indicated by a chain line). Position shown). If the plate cam 1 continues to rotate, the swing lever 3 returns to the right in the reverse direction with the displacement of the cam stroke, and returns to the starting point position again. This series of rotation and swinging operations is repeated to obtain the linear motion of the follower 7. The restraining spring 8 is held at the operation start position by a spring force given by calculation. When the swing lever 3 moves in accordance with the rotation of the plate cam 1, the movable end A of the restraining spring 8 moves to the left, and the restraining force gradually increases. Then, it becomes maximum at the position rotated by 180 degrees, gradually decreases and returns to the starting point.

Here, the plate cam 1 has a contour as shown in FIG. A point C is a base for displacement and is a rotation start position in the figure. Point B is the top and 18 from point C
It is in a position rotated by 0 degrees. The timing chart is as shown in FIG. 5, and the displacement amount is (DE). Further, a feature of the plate cam 1 is that the distance F between the cam surfaces at diametrically opposite positions about the axis is the same in any direction.

[0006]

However, in the above-mentioned conventional configuration, the change in the spring restraining force accompanying the rotation of the plate cam 1 becomes a resistance to the rotational force of the plate cam 1, and hinders the smooth movement of the cam mechanism. Was a factor. It also required an esoteric spring design.

The present invention solves the above-mentioned conventional problems. A plate cam mechanism capable of restraining a swinging lever (or a linearly moving lever) to a cam without using a spring and achieving a smooth operation is provided. The purpose is to provide.

[0008]

In order to achieve this object, a plate cam mechanism according to the present invention comprises a plate cam, a rocking lever (or a linear motion lever) whose operation is controlled by a cam surface of the plate cam, It is configured to include two rollers disposed at diametrically opposite positions with respect to the cam shaft and in contact with the plate cam surface, and a restraining arm passing through the center of the cam shaft and supporting the two rollers.

With this configuration, the conventional spring restraining force accompanying the cam displacement disappears, so that the operation of the cam mechanism can always be kept stable and the esoteric spring design can be eliminated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a plate cam mechanism according to an embodiment of the present invention. 1 is a plate cam similar to the plate cam shown in FIG. Reference numeral 3 denotes an oscillating lever which performs oscillating motion about the shaft 4. Reference numeral 17 denotes an oscillating lever roller shaft fixed on the center line of the oscillating lever 3. Reference numeral 5 denotes a oscillating lever roller shaft 17. The swing lever roller contacts the cam surface of the cam 1. Here, the drive motor 9 for driving the cam mechanism, the drive pulley belt 11, and the driven pulley 1
Since the configuration of No. 2 is completely equivalent to the conventional example, for convenience of explanation,
It is omitted in FIG. 14 is a cam shaft roller fitted coaxially with the cam shaft 2, 15 is fixed on the center line of the restraining arm 16, is located at a position directly opposite to the swing lever roller 5 about the cam shaft 2, and comes into contact with the cam surface. One end of the restraining arm roller 16 is fitted coaxially with the swinging lever roller shaft 17 so as to be swingable, and a slot 18 at the center is formed.
Is shown on the cam shaft roller 14.
Reference numeral 18 denotes an elongate hole for slidably supporting the cam shaft roller 14, which serves as a fulcrum when the restraining arm 16 swings with the left and right movements due to the cam displacement. Here, the longitudinal center line of the elongated hole 18 provided at the center of the restraining arm 16 matches the longitudinal center line of the restraining arm 16 and further matches the center of the cam shaft roller 14. The width C of the long hole is given by (the diameter of the cam shaft roller 14) + (the minimum size of the clearance fit), and the length of the long hole is determined when the restraining arm 16 moves left and right with the cam displacement. The dimensions are slightly longer than the start and end points.

The operation will be described below. First, as shown in FIG. 4, the contour of the plate cam 1 is such that the cam surface distances at diametrically opposite positions about the cam axis are the same in any direction. Therefore, the center distance L between the swing lever roller 5 and the restraining arm roller 15 is always constant at {F + roller diameter}. The center line of the restraining arm 16 is arranged so as to coincide with the line connecting the swing lever roller 5, the restraining arm roller 15 and the center of the cam shaft 2, and is always in this state at any position in the displacement of the plate cam 1. To maintain.

Accordingly, when the operation of the plate cam mechanism is started by driving the motor, the plate cam 1 rotates in the direction of the arrow. As the plate cam 1 rotates, the cam surface is gradually displaced, and the swing lever 3 is pushed to the left and swings around the shaft 4 to reach the operation end portion indicated by the chain line. At this time, since the restraining arm 16 has one end connected to the swing lever 3 by the swing lever roller shaft 17, as the swing lever 3 moves to the left, the cam shaft roller 14 is elongated by the elongated hole 18.
Are simultaneously moved to the left together with the restraining arm roller 15 while slidingly supporting them. Here, since the swing lever roller 5 swings around the swing lever shaft 4,
When the swing lever 3 reaches the vertical position G shown in FIG. 2, the vertical height is shifted by H from the start point and the end point. This displacement causes the restraining arm 16 to swing with the cam shaft roller 14 as a fulcrum. However, the oscillating movement of the restraining arm 16 naturally occurs with the rotation of the cam, and there is no particular significance in the performance of the plate cam mechanism. As described above, the restraining arm 16 moves left and right while swinging, and follows the displacement of the cam to restrain the swing lever 3 to the plate cam 1. When the plate cam 1 continues to rotate, the swing lever 3 and the restraining arm 16 return to the right and return to the starting point according to the displacement of the cam stroke. This series of operations is repeated to obtain the linear motion of the follower 7.

Although the plate cam mechanism of the present invention controls the operation of the swing lever, the same principle applies when the operation of the linear lever is controlled.

When the cam surface or the roller surface wears due to aging in this plate cam mechanism, rattling occurs. This is at the same level as a groove cam which is a kind of cam mechanism. There is no practical problem.

[0016]

As described above, according to the present invention, since the conventional structure for eliminating the change in the spring restraining force accompanying the rotation of the plate cam is eliminated, the resistance to the rotational force of the plate cam becomes extremely small, and the smoothness is obtained. It is possible to obtain the movement and to solve the conventional esoteric spring design, which is very useful practically.

[Brief description of the drawings]

FIG. 1 is a side view of a plate cam mechanism according to an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1 with the swing arm in a vertical position.

FIG. 3 is a side view of a conventional plate cam mechanism.

FIG. 4 is a plan view showing the shape of a plate cam used in the embodiment of FIG. 1 and the conventional example of FIG. 3;

FIG. 5 is a time chart of the plate cam shown in FIG. 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plate cam 2 cam shaft 3 swing lever 4 swing lever shaft 5 swing lever roller 6 follower drive roller 7 follower 8 restraining spring 9 drive motor 10 drive pulley 11 drive belt 12 follower pulley 13 follower slide guide 14 cam Shaft roller 15 Restraining roller 16 Restraining arm 17 Swing lever roller shaft 18 Long hole for supporting point provided on restraining arm

Claims (2)

[Claims] 1. A plate cam, a swinging lever (or a linear motion lever) whose operation is controlled by the cam surface of the plate cam, and two diametrically opposite positions which are arranged diametrically about a cam shaft and contact the plate cam surface. Through two rollers and the center of the camshaft,
A plate cam mechanism having a restraining arm for supporting the two rollers. 2. The plate cam mechanism according to claim 1, wherein a plate cam having the same cam diameter in all directions between cam diameters passing between the centers of the camshafts (between cam surfaces at diametrically opposite positions) is used.