JPH01199055A - Oscillation generating device - Google Patents

Abstract

PURPOSE:To set the property of an oscillating shaft such as oscillation angle to any desired value by providing a cam mounted fast on a rotational drive shaft with a surface consisting of No.1 and No.2 cam faces, and forming these No.1 and No.2 cam faces alternately in the cam rotating direction. CONSTITUTION:Each of the cams 5a, 5b mounted fast on a pair of rotational drive shafts 4a, 4b is equipped with a No.1 cam face C1 for guiding cam followers 3a, 3b in the direction moving apart from a rotational drive shaft 4 and No.2 cam face C2 to guide them in the direction of approaching, and they are formed alternately in the rotational direction of the cam 5. When the rotational drive shafts 4a, 4b are rotated in the opposite directions, one of the cam followers 3a, 3b moves in the direction of separating while the other in the direction of approaching, and an oscillating shaft oscillates at the rate of two bothways per turn of the cams 5a, 5b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a vibration generating device, and particularly to a vibration generating device suitable for use in a vibration testing machine or the like.

[Conventional technology]

Conventionally, as an example of a vibration generating device, one using a crank mechanism has been proposed.

A swing generating device using this crank mechanism has one end of the connecting rod rotatably attached to the crankshaft at a position radially apart from its rotation center, and the other end of the connecting rod attached to the swing shaft. It has a structure in which it is rotatably attached at a position spaced apart in the radial direction from the center of swing.

The rotational motion of the crankshaft is converted into reciprocating motion of the connecting rod, and the reciprocating motion of the connecting rod is further converted into the rocking motion of the swing shaft.

[Problems to be Solved by the Invention] By the way, in the swing generator having the above-mentioned configuration, by changing the length of the connecting rod, it is possible to change the swing angle of the swing shaft and the accompanying angular velocity and angular acceleration. The adjustment range is limited to the extent that changes can be made, and the change patterns of these angular velocities and angular accelerations can only be -like.
It is desired to have a configuration that allows these change patterns to be changed as appropriate.

The present invention aims to solve these problems.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the rocking generating device according to the present invention includes a rocking shaft and a rocking shaft that is spaced from the rocking center in the rocking radial direction. a cam follower provided along the cam follower, a rotation drive shaft provided along the swing axis, and a cam that is integrally attached to the rotation drive shaft and rotated in a plane parallel to the movement plane of the cam follower, The cam surfaces formed on the outer circumference of the cam include at least a pair of first cam surfaces that guide the cam follower in a direction away from the rotational drive shaft, and a first cam surface that guides the cam follower in a direction that approaches the rotational drive shaft. It is characterized in that it consists of at least a pair of second cam surfaces, and these first cam surfaces and second cam surfaces are formed alternately in the rotational direction of the cam.

[Operation] According to the present invention, the profile of the first and second cam surfaces of the cam is changed or each of these cam surfaces is increased, and the moving speed of the cam follower guided thereby, or the cam 1 By changing the number of reciprocations of the swing axis relative to rotation, it is possible to arbitrarily set angular velocity and angular acceleration patterns.

[Example] Hereinafter, a first example of the present invention will be described based on FIGS. 1 and 2.

In the figure, reference numeral 1 indicates a vibration generating device according to this embodiment,
A swinging shaft 2, and a pair of cam followers 3 (3I, 3b) provided on the swinging shaft 2 at a distance from the swinging center O1 in the swinging radial direction and at a predetermined angle σ in the swinging force direction. and,
A pair of rotary drive shafts 4 (41, 4b) are provided along the length direction of the swing shaft 2 on both sides of the swing shaft 2 and the cam follower 3 (3!, 3b), and these A pair of cams 5 (5*, Sb) are attached to the rotary drive shaft 4 (4i, 4b) and rotated in a plane parallel to the movement plane of the cam followers 3 (31, 3b) (7). , the cam surface C formed on the outer periphery of each of the mm 5 (sx-sb) is directed in a direction that separates the cam follower 3 (3!, 3b) from each rotational drive shaft 4 (4!, 4b). A pair of guiding first cam surfaces C8 and the cam follower 3 (
31, 3b) in a direction approaching the rotational drive shaft 4 (41, 4b), and the first cam surface C1 and the second cam surface C1 is formed alternately in the rotational direction of the cam 5 (5!・sb). Here, each cam 5!・
The rotation drive shafts 4s and 4b of the sb are located at the centers of gravity of the cams 5g to 5b, and therefore the cams S1 and sb rotate stably along their respective surfaces.

Next, to explain these details, the swing shaft 2 is swingably attached to a substrate (path shown in the figure);
As shown in FIG. 1, a disk 6 is integrally and concentrically attached to the end thereof, and the disk 3b) is attached thereto.

These cam followers 3 (3a, 3b) are connected to the disk 6
It is composed of rolling elements rotatably supported by.

Each of the rotation drive shafts 4 (41, 4b) is disposed near the disk 7 in parallel to the swing shaft 2, and is rotatably supported by the substrate. These rotary drive shafts 4 (41, 4b) are connected in opposite directions (in the illustrated example, one rotary drive shaft 4a is clockwise and the other rotary drive shaft 4b is counterclockwise). ) A drive mechanism (path shown) for synchronous rotation is connected.

As shown in FIG. 1, each of the cams 5 (5!・sb) attached to the rotational drive shaft 4 (4hata・4b) has a top portion at two locations spaced at a predetermined pitch in the rotation direction. T is formed, and a bottom part B is formed in the middle part of these top parts T.

The top portion T and the bottom portion B are continuous by a gentle curve, and in this embodiment, the outer peripheral edge thereof is further forward than the top portion T in the rotational direction of the cam 5 (Sl/sb). said first cam surface CI, and
The rear side in the rotational direction is the second cam surface C3.

Therefore, the cam follower 3 (3!・3b) that is brought into sliding contact with this cam surface C alternately moves on the first cam surface C0 and the second cam surface C3 as the cam 5 (51・sb) rotates. The rotary drive shaft 4 (re-4b)
), the height difference between the top portion T and the bottom portion B is taken as the stroke, and the cam 5 (5a, sb) can make two reciprocations per rotation.

On the other hand, the shape of the cam surface C of the one cam 5 is the same as that of the one cam follower 3! and the center of one rotational drive shaft 41 0. When the distance from

LI-A+Mx S i n (2θ) however, A; Reference circle of cam S1, M: Distance between top part T and bottom part B and reference circle θ; Angle around rotational drive shaft 4a; are shown respectively.

The shape of the other cam 5b is determined by rotating the cam 5M once while holding one cam follower 3a in contact with the cam surface C of the one cam 51, and the trajectory of the other cam follower 3b at this time and the one Rotation drive shaft 4! and the rotational position of the other rotary drive shaft 4b that is being rotated synchronously.

Furthermore, the one cam follower 3! center and swing axis 2
The distance L2 from the pivot center O1 of the pivot shaft 2 is the pivot center O1 of the pivot shaft 2.
1 and the center of one rotational drive shaft 4 & 0! and the distance L3 between the center of the cam follower 3a and the rotational drive shaft 4! Center of 0. The relationship between the distance and the distance is set to satisfy the following equation.

L, + L2) L.

Next, the operation of this embodiment will be explained.

First, when the re-rotation drive shafts 4 are rotated at a constant speed in opposite directions (one rotation drive shaft 4a clockwise and the other counterclockwise) from the position shown in FIG. The cam follower 3M is moved in the direction away from the rotary drive shaft 41 by the first cam surface CI of one of the cams 5, and this movement is caused by the cam follower 31 moving away from the top portion T of the cam S&.
This will continue until the end.

On the other hand, the cam follower 3b that is in contact with the other cam 5b is caused by the second cam 5b being rotated in the opposite direction in synchronization with the one cam Ss. The other rotary drive shaft 4 is rotated by the cam surface C8.
This movement continues until the cam follower 3b reaches the bottom portion B of the other cam sb.

By this operation, the swing shaft 2 is caused to swing from the maximum clockwise swing position to the maximum counterclockwise swing position in FIG. 1.

When both cams 5 continue to rotate further, the first cam surface C0 of the other cam sb moves the other cam follower 3b in the direction of separating it from the other rotational drive shaft 4b, contrary to the above. and one cam follower 3 is guided in a direction approaching one rotation drive shaft 4a by the second cam surface C2 for one cam 5, thereby causing the swing shaft 2 to swing clockwise. be moved.

From then on, the swing shaft 2 rotates at a rate of 2 reciprocations per rotation of both cams 5.
is shaken.

During such a rocking operation, the rocking of the rocking shaft 2 is determined by the shape of the cam surface C of the cam 5, that is, the profile, so by changing the profile of the cam 5, various rocking movements can be performed. A dynamic pattern can be obtained.

On the other hand, one cam 5m (5b) swings the swing shaft 2 only in one direction, and at this time, the other cam Sb (5m) is in contact with the cam follower 3b (31), and this cam follower 3
Since it is used to guide the
Large angular acceleration can be obtained.

When such a rocking operation is viewed as the rocking angle, angular velocity, and angular acceleration of the rocking shaft 2 relative to the rotation angle of the cam 5, it becomes as shown in FIG. 2.

In FIG. 2, curve a represents the swing angle, curve A represents the angular velocity, and curve C represents the angular acceleration.

In the embodiment described above, the same effect can be obtained even if both rotational drive shafts 48 and the cam 5 rotate in the same direction.

Examples of the shape of the cam 5 having a pair of first cam surfaces and a pair of second cam surfaces include those shown in FIGS. 3 to 5.

The shape of each of these cams 5 is determined by the following equation.

(Regarding Figure 3) Y=aX''+bX+C (Regarding Figure 4) Y=-!l!-(a''-Xl/1 (Regarding Figure 5) On the other hand, Figure 6 shows the second An example is shown, and the top part T
are formed at three locations at regular intervals, and the first cam surface C1 and the second cam surface C8 are each provided at three locations.

With this configuration, as shown by curve C in FIG. 7, a large angular acceleration can be obtained even though the cam 5 is rotated at the same rotation as the cam 5 shown in FIG. .

Furthermore, FIGS. 8 and 9 show a third embodiment of the present invention, in which the top portion T is further increased to four locations, and the first
The cam surface CI and the second cam surface C2 are each provided at four locations.

When this cam 5 is used, as shown by curve C in FIG. 9, an angular acceleration of the same magnitude as curve C in FIG. 7 is generated, but in the case of this embodiment, an additional 200 rpm is generated.
The angular acceleration of the above-mentioned magnitude is obtained at a rotation speed lower than m.

Therefore, the top portion T, the first cam surface CI and the second cam surface
As the cam surface C3 increases, a large angular acceleration can be obtained in the low rotation range. Alternatively, by appropriately setting the number of the top portions T, etc., it is possible to change the rotational speed while ensuring the desired angular acceleration, and for example, use while avoiding the resonance point.

Note that the shapes and dimensions of each component shown in each of the above embodiments are merely examples, and can be variously changed based on design requirements and the like.

[Effects of the Invention] As explained above, the vibration generating device according to the present invention has the following effects:
a swing shaft, a cam follower provided on the swing shaft at a distance from the center of swing in the swing radius direction, a rotary drive shaft provided along the swing shaft, and a cam follower integrated with the rotary drive shaft. a cam attached to the cam follower and rotated in a plane parallel to the movement plane of the cam follower, and a cam surface formed on the outer circumference of the cam at least guides the cam follower in a direction away from the rotational drive shaft. It consists of a pair of first cam surfaces and at least a pair of second cam surfaces that guide the cam follower in a direction approaching the rotational drive shaft, and these first cam surfaces and second cam surfaces , are formed alternately in the direction of rotation of the cam, and by changing the shape of the cam surface of this cam,
The moving speed of the cam follower, that is, the swing angle, angular velocity, and angular acceleration of the swing shaft, can be arbitrarily set, and the characteristics can be easily set according to the purpose of use. play.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a front view schematically showing the main parts, FIG. 2 is a characteristic curve diagram, and FIGS. 3 to 5 are: FIGS. 6 and 7 are plan views showing modified examples of the cam shown in the first embodiment, and FIGS. 6 and 7 respectively show the second embodiment of the present invention. FIG.
The figure is similar to FIG. 2, FIGS. 8 and 9 show a third embodiment of the present invention, FIG. 8 is similar to FIG. 1, and FIG. 9 is similar to FIG. 2. It is. DESCRIPTION OF SYMBOLS 1... Swing generator, 2... Swing shaft, 3... Cam follower, 4... Rotation drive shaft, 5... Cam, C...
- Cam surface, CI...first cam surface, C8...second cam surface. Applicant: Mitsuba Electric Manufacturing Co., Ltd. Figure 1 Figure 2 Cam rotation *angle Figure 7 f) Inlet Rotating Pool Figure 8 Figure 9

Claims (1)

[Claims] a swing shaft, a cam follower provided on the swing shaft at a distance from the center of swing in the swing radius direction, a rotary drive shaft provided along the swing shaft, and a cam follower integrated with the rotary drive shaft. a cam attached to the cam follower and rotated in a plane parallel to the movement plane of the cam follower, and a cam surface formed on the outer circumference of the cam at least guides the cam follower in a direction away from the rotational drive shaft. It consists of a pair of first cam surfaces and at least a pair of second cam surfaces that guide the cam follower in a direction approaching the rotational drive shaft, and these first cam surfaces and second cam surfaces , a vibration generating device characterized by being formed alternately in the rotational direction of the cam.