JPS6237273B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical feed device such as a transfer device for transporting a workpiece in a machine tool or an industrial machine.

The present invention provides a non-uniform motion mechanism, and the reason why the non-uniform motion mechanism is adopted in a transfer device, etc. is that it can cope with the increase in speed of transfer devices, etc. as productivity improves. This is the reason.

In other words, in a uniform motion mechanism, a sudden change in acceleration occurs when starting and stopping, and vibrations and shocks are applied to the transported object. The non-uniform motion mechanism of the present invention eliminates the adverse effects at the time of starting and stopping in the uniform motion mechanism,
Moreover, the time required for the process of the transfer device etc. can be shortened.

The object of the present invention relates to a mechanism that converts constant-speed rotational drive into non-uniform reciprocating linear motion. That is, the object of the present invention is to provide a new type of device that combines a crank mechanism and a slider mechanism to give a movable platform reciprocating linear motion with smooth starting and stopping.

In the past, there have been inventions related to this type of non-uniform motion mechanism, but they have had various drawbacks.

For example, in a conventional device using a slider-crank mechanism, in order to obtain the required stroke, a rotating body with the same diameter as the stroke or a slider groove length is required, especially when a long stroke is required. Due to its structure, it had to be made larger.

Further, there is a method of converting the acceleration/deceleration feed motion by cranking the pinion. The crank motion of the pinion has the disadvantage that the swinging changes of the engaged feed rod are large, making it difficult to obtain stable operation, and that the device becomes large.

According to the present invention, the above problems are solved, and a stable device with a compact structure and reliable operation can be obtained.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In FIGS. 1, 2, and 3, a driving body (hereinafter referred to as a brake-motorized speed reducer) is fixedly attached to a base 2. As shown in FIGS. A sleeve-shaped engagement member 3 is rotatably supported on the output shaft of the brake motor-equipped reduction gear 1 and protrudes from the output shaft. The engaging member 3 has a serration hole 3.
A is bored, and the serration portion 4A of the elongated shaft 4 is engaged to be slidable in the axial direction.
A worm 4B is attached to the long shaft 4, and the rotation of the worm 4B is transmitted to a worm wheel 5, further decelerated, and transmitted to a rotating shaft 7 supported by a moving body 6. The brake motor-equipped speed reducer 1 can also be directly attached to the moving body 6. 8 is a cover that covers the worm wheel 5. The worm wheel 5 is fixed to one end of the rotating shaft 7 as shown in FIG.
Further, a rotating body (hereinafter referred to as gear 10) is fitted into the other end via a key 9 so as to be able to transmit rotational force. In order to convert rotational motion into linear motion, a rack 11A of a length necessary for the stroke is cut and engaged with the upper part of the gear 10, and the linear moving member 11 having the rack 11A is moved horizontally. It is arranged.

The linearly movable member 11 is slidably fitted into a holding member (hereinafter referred to as a bracket 12) provided with fitting inner diameter portions 12a and 12b so as to perform restraint movement only in the horizontal direction. The bracket 12 is fixed to the movable body 6 with a plurality of bolts 13. A block 14 is fixed to the side surface of the gear 10 with bolts. At the top of the block 14,
A crank pin 15 having a flange is rotatably fitted therein. The axial center position of the crank pin 15 is configured to match the pitch circle diameter of the gear 10 due to the block 14. However, the present invention is not limited to the examples shown, and the axis of the crank pin 15 does not necessarily have to coincide with the pitch circle diameter of the gear 10.

An engaging member (hereinafter referred to as a slider 16) is fitted into the crank pin 15, and the slider 16 is regulated without coming off in the axial direction by screwing a nut 17 onto the crank pin 15. . A base 18 fixed with a plurality of bolts is attached to the upper surface of the base 2. The slider 16 is fitted into a groove at the center of a plate-shaped portion 18C that stands upright from one side of the base 18, that is, a slider guide groove 18A, so as to be slidable only in the vertical direction. Further, the lower part of the movable body 6 forms guide parts 6A, 6A', and the base 18
It slides along the guide grooves 18B, 18B'. Further, in order to prevent the movable body 6 from floating upward, plates 19 and 19' are fixed to the upper surface of the base 18 with a plurality of bolts 20.

In the present invention, with the above configuration, when the gear 10 is rotated once at a constant speed, the linear moving body 11 performs one stroke of inconstant linear motion and moves forward, and also rotates the gear 10 in the reverse direction. Depending on this, it is possible to return the linearly moving member 11 to its starting position.

Hereinafter, the operation of the inconstant velocity crank motion device of the present invention will be explained in detail. Figures 4a to 4d
1 is a schematic mechanical diagram explaining a series of operations of the present invention. The crank pin 15 moves from the central axis O-O' to the gear 1 with the state shown in FIG.
0, the vehicle starts in the direction of the arrow at a constant speed in the rotational direction. Here, the angle formed between the crank pin 15 and the central axis OO' by rotating around the center O of the rotating shaft 8 is defined as a rotation angle θ. Further, the angular velocity when the gear 10 rotates at a constant speed due to the driving body D is assumed to be ω.

FIG. 4a shows the rotation angle θ=O°, that is, the state when the linearly moving member 11 is started. (At the same time, this is also the position after one stroke of the present inconstant velocity crank motion device, that is, the state when θ = 360° at rest.) The linearly moving member 11 meshed with the gear 10 moves depending on the angular velocity ω. Start smoothly in the direction of the arrow. Further, the slider 16 rotatably fitted into the crank pin 15 is connected to the base 1.
It is restrained to be slidable only in the vertical direction by the slider guide groove 18A of No. 8. As the rotation of the gear 10 progresses, the slider 16 begins to slide downward. Further, the movable body 6 of the rotation shaft 8 has guide portions 6A, 6A' at the lower part of the movable body 6, and can slide only in the horizontal direction along the guide grooves 18B, 18B' of the base 18. is restrained by. Said gear 1
As the rotation of 0 progresses, the moving body 6 starts sliding to the left (indicated by an arrow). That is, the fourth
From figure a to figure 4b, to the left, figure 4b
4c, rightward in FIG. 4c to FIG. 4d, and leftward in FIG. 4d to FIG. 4a.

When it is assumed that the moving body 6 is stopped, the rotation of the gear 10 causes the linear moving member 11 to move.
The actual speed of the linearly moving member 11 is defined as v ₁ and the speed at which the gear 10 moves in the horizontal direction by the guide portions 6A and 6A' is v ₂ . v is v = v ₁ - _{v 2} , and the speed v given to the moving platform (not shown) connected to the linear moving member 11 of this inconstant velocity crank motion device is the composite speed of v ₁ and v ₂ . It is. The linearly moving member 11 starts smoothly due to the combination of two correlated speeds and for the detailed reason described later,
It stops smoothly.

FIG. 4b shows the state when the rotation angle θ=90° is reached after a smooth start from the rotation angle θ=0°. The linearly moving member 11 is gradually accelerated and moving in the horizontal direction. Said slider 1
6 is slid downward along the slider guide groove 18A by the crank pin 15.
Further, the guide portions 6A, 6A' have a speed in the direction of the arrow.
v ₂ , and the gear 10 also moves accordingly. FIG. 4b shows a state in which the movable body 6 has moved to the leftmost end.

FIG. 4c shows the state when the rotation angle θ=180° is reached. The linear moving member 11
is further accelerated to reach the maximum resultant velocity at that position.
It becomes vmax. The slider 16 further advances in the vertical direction due to the crank pin 15 and reaches the lowest position. The guide portions 6A, 6A' are arranged in the slider guide grooves 18B, 1 by sliding of the slider 16.
8B' in the opposite direction to that described above, that is, in the same direction as the traveling direction of the linearly moving member 11. Therefore, since the direction of the speed v ₂ of the guide portions 6A, 6A' is changed, it is added to the moving speed v ₁ and further increased. Combined speed v of the linearly moving member 11
can be expressed as follows.

v=v ₁ +v ₂ (90°≦θ≦270°) The positions of the guide portions 6A, 6A' are the same as the positions when θ=O°.

FIG. 4d shows the state when the rotation angle θ=270° is reached. The linear moving member 11
In the rotation angle range of 180°≦θ≦360°,
As the rotation of the crank pin 15 progresses,
It is moving at a gradual deceleration. Said slider 1
6 has risen from the lowest position in the vertical direction and is at the position shown in the figure. The guide portions 6A, 6A' further advance to the right as shown in the figure, and this position is the final end of movement in the right direction.

When the rotation angle θ of the crank pin 15 reaches one rotation, that is, θ=360°, the resultant speed v of the linearly moving member 11 gradually decreases and stops smoothly. The position at θ=360° is the state shown in FIG. 4a and is the same as the position at the time of starting.

The inconstant velocity crank motion device according to the present invention completes one stroke of the linearly moving member 11 through the above strokes. Further, in order to return the linearly moving member 11 to the state at the time of starting, the gear 10 is reversely rotated.
This is possible by performing the reverse process to that described above.

According to the above explanation, the nature of the combination of the crank mechanism having the crank pin 15, the slider 16 that slides only in the vertical direction, and the slider mechanism of the guide parts 7A and 7A' that slides only in the horizontal direction is as follows. The horizontal movement speed v of the transfer bar 11 is made inhomogeneous to obtain an ideal transfer speed change.

Further, the operation of the present invention is theoretically analyzed as follows.

In FIG. 4a, the distance between the center O of the gear 10 and the center O _p of the crank pin 15 is assumed to be R. If the circumferential distance due to the rotation of the gear 10, that is, the displacement of the linearly moving member 11 is x ₁ , and the displacement of the guide portions 6A and 6A' is x ₂ , then the combined displacement of the linearly moving member 11 is x can be determined using the following relational expression.

x=x ₁ −x ₂ =R(θ−sinθ) (1) The resultant speed v of the linearly moving member 11 can be determined by the following relational expression.

v=v ₁ −v ₂ =dx/dt=dx/dθ・dθ/dt=R(1−cosθ)・ω (2) Furthermore, the acceleration α of the linearly moving member 11 is as follows. .

α=dv/dt=dv/dθ・dθ/dt=R・sinθ・ω ² ...(3) Figures 5a to 5c are based on the above-mentioned relational expression (1),
This is a graph of (2) and (3).

FIG. 5a is a <velocity v-rotation angle θ> diagram of the inconstant velocity crank motion device according to the present invention. The resultant speed v of the linearly moving member 11 starts smoothly from θ=O°, reaches vmax at θ=180°, and θ=
It can stop smoothly at 360° (one rotation).
it is obvious.

FIG. 5b is a <displacement x-rotation angle θ> diagram. The displacement x of the linearly moving member 11 draws an S-shaped locus and completes one stroke.

FIG. 5c is an <acceleration α-rotation angle θ> diagram. An ideal acceleration curve has been obtained.

According to the present invention, compared to the conventional method, one revolution is 1 rotation.
Since the stroke amount is obtained, it is easy to set the speed and moving distance. In addition, the structure can be made compact and the required space is small, making it possible to reduce costs.

Further, the acceleration of the linearly moving member 11 when it starts and stops is 0, and the speed is very smooth. Therefore, there is no adverse effect on the positioning clamp for the workpiece, etc., stable movement is achieved during conveyance, and it is possible to improve positioning accuracy.

Furthermore, since there is theoretically no swing change (vertical movement) of the linearly moving member 11, stable and reliable operation can be obtained.

The present invention is not limited to the above-described embodiments, but can also be applied to a conveying device such as a DNC line by using a sprocket as the rotating body and a chain as the linearly moving member, for example.

As stated above, the present invention is not limited to the configurations shown in the examples, and modifications are expected within the scope of the technical idea of the present invention as described in the claims. be.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional front view showing an embodiment of the inconstant velocity clamp motion device according to the present invention, FIG. 2 is a view taken in the direction of the arrow in FIG. 1, and FIG. 3 is a view taken in the direction of the arrow in FIG. figure,
FIGS. 4a to 4d are diagrammatic explanatory diagrams for explaining the steps of a series of operations of the present invention, and FIG.
is a diagram showing the position of rotation angle θ=O°, Fig. 4b
is a diagram showing the position of rotation angle θ = 90°, Figure 4c
is a diagram showing the position at a rotation angle θ=180°, and FIG. 4d is a diagram showing the position at a rotation angle θ=270°. FIG. 5a is a <speed v-rotation angle θ> diagram of the linearly moving member 11, FIG. 5b is a <displacement x-rotation angle θ> diagram of the linearly moving member 11, and FIG. 5c is
is <acceleration α−rotation angle θ of the linearly moving member 11
>Line diagram. In the figure, 1...Reducer with brake electric motor, 2
...Base, 6...Moving body, 6A, 6A'...Guiding part,
DESCRIPTION OF SYMBOLS 10... Gear, 11... Linear movement member, 15... Crank pin, 16... Slider, 18... Base, 18A,
18A'...Slider guide groove, 18B, 18B'...Guide groove, θ...Rotation angle, R...Distance between center O and crank pin center O _p .

Claims (1)

[Claims] 1 a base 18, a movable body 6 guided by the base 18 so as to be able to reciprocate linearly in a fixed direction, and the movable body 6
A rotating body 10 rotatably supported on the
and a driving body 1 that rotationally drives the rotating body 10,
an engaging member 16 that is pivotally supported at an eccentric position of the rotary body 10 and slidably provided in a groove cut in the base 18 in a direction perpendicular to the moving direction of the movable body; a linear moving member 11 that engages with 10 and converts the rotational motion of the rotating body into linear motion;
and a holding member 12 that maintains the transmission state of the rotating body 10 and the linearly moving member 11, and the linearly moving member 11 is moved in the linear direction at an inconstant speed and continuously by the rotation of the rotating body 10. An inconstant speed crank motion device characterized by the following: