JPS6225892B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorber used in a device for driving a reciprocating object with good stability and at a constant speed. In particular, the present invention relates to a shock absorbing device for use in a device for driving a reciprocating object by using a means such as a wire using rotational torque from a motor or a clutch directly connected to the motor.

The applicant of the present invention previously invented and disclosed a shock absorbing device as shown in FIG. 1 in Japanese Patent Application Laid-open No. 118058/1983. That is, in the figure, reference numerals 1 and 2 are fixed pulleys fixed to the main body side. Then, the wire 3 passes through the fixed pulley 1, the idler pulley 4, the tension pulley 5, the wire wrapping pulley 6, the tension pulley 7, and other guide grooves of the idler pulley 4, and reaches the fixed pulley 2.
Both ends of the wire 3 are fixed to the main body via a reciprocating object such as a document table or an optical system of a copying machine. Here, the idler pulley 4 is arranged to freely rotate around a fixed shaft 8, and the tension pulleys 5 and 7 are both rotatably mounted on a pulley mounting plate 9 that can swing around the shaft 8, but their arrangement is Fixedly attached. In the figure, when the wire moves in the direction of the arrow, it is the exposure process of the document.
At the moment when the exposure process begins, part 3a of the wire is on the tight side and part 3b is on the loose side. Therefore, the plate 9 is swung counterclockwise by the tension, and the tension pulleys 5 and 7 are respectively 5a and 5 when swung at their maximum.
Swing to position 7a. As a result, the slack of part 3b of the wire is reduced to 7a of tension pulley 7.
It is absorbed by the oscillation.

Conversely, when reversing the optical mirror from its exposed state,
The only difference is that the swinging state of the tension pulley is completely opposite to that described above, but the effect is exactly the same in terms of preventing the initial shock of the wire.

The present invention is a further improvement of the above-described invention, which increases the degree of freedom in design and reduces costs by saving space. That is, the present invention, which achieves the above object, provides a shock absorber that can apply reciprocating drive to a movable body by a cable from a rotary body that is rotated by being transmitted to a drive source without impact.
The present invention is characterized in that it has a shock absorbing rotary member that swings to a position where it can act on the cables at a portion where the cables face each other or intersect with each other.

An embodiment of the present invention will be described below, taking as an example a case in which it is applied to a mirror drive device of an exposure optical system of a copying machine. FIG. 2 is a perspective view of an optical system driving device to which an embodiment of the shock absorbing device of the present invention is applied. In the figure, a first mirror 10 is fixedly disposed on a first support member 11 at a fixed angle with respect to the horizontal, and a second mirror 12 is fixedly supported vertically by a second support member 13. has been done. Guide shafts 14, 15, 16 parallel to each other along the moving direction of the first mirror 10 and the second mirror 12 are provided at both ends of the first mirror 10 and the second mirror 12 via other members. It is arranged. First support member 11
One end is slidably fitted on the guide shaft 14, and the other end is supported so as to be able to slide on the guide shaft 16. A roller 17 is rotatably attached to the other end. Similarly, the second support member 13 has an arm portion 13 at one end.
a and 13b are slidably fitted on the guide shaft 15,
At the other end, a rotatably mounted roller 18 is supported so as to be able to slide on the guide shaft 16. The arm portions 13a and 13b of the second support member 13 include
A first movable pulley 19 and a second movable pulley 20 are respectively disposed so as to be freely rotatable. Guide shaft 14・
15, a first fixed pulley 21 is rotatably disposed at a fixed position further to the left of the movement range of the first support member 11 and at a position that does not interfere with the second support member 13. There is. Furthermore, the second fixed pulley 22 is also rotatably attached to a fixed position in the direction of the drawing relative to the movement range of the second movable pulley 19. At a lower intermediate position between the first fixed pulley 21 and the second fixed pulley 22, there is a wrap pulley 24 fixed to a drive shaft 23, and the drive shaft 23 can be rotated forward and backward by a motor or a combination of a motor and a clutch. placed in a fixed position. The optical drive wire 25 has one end 25C fixed to a fixed plate 26 fixedly attached to the main body, and is connected to the first support member 11 via the first movable pulley 20 to the fixed plate 26a.
Fixed by

Further, the wire 25 is connected to the first fixed pulley 21,
Idler pulley 2 via second fixed pulley 27
8. The tension pulley 29, the wire-wound pulley 24, the other circumferential surface of the tension pulley 29 and the other guide groove of the idler pulley 28, reach the fixed pulley 22, and the other via the second movable pulley 19. The end 25d is fixed to a fixed plate 26.

Now, when the winding pulley 24 rotates in the direction of the arrow, a portion 25a of the wire 25 is wound around the pulley 24, and conversely, a portion 25d of the wire 25 is let out by the same length. As a result, the first support member 11
moves in the direction of the arrow at the same speed as the wire winding speed of the pulley 24, and similarly, the first movable pulley 20 moves in the same direction as the first support member 11 at half the speed of the wire winding speed. The second support member to which the first movable pulley 20 is fixed is therefore the first support member 1
It moves in the same direction as 1 and at 1/2 the speed. On the other hand, the wire 25d loosens by that amount, but this is offset by the movement of the second movable pulley 19 in the direction of the arrow, and the wire 25d as a whole loosens by that amount.
5, no loosening occurs. Similarly, wrap pulley 2
4 rotates in the direction opposite to the direction of the arrow, the first support member 11 and the second support member 13 move at a speed of 2:1 in the direction opposite to the direction of the arrow in the drawing, respectively. In this way, it is ensured that the first mirror 11 and the second mirror 13 each move in the same direction and at a speed of 2:1, without changing the overall length of the wire 25.

Furthermore, a shock absorbing device according to an embodiment of the present invention will be explained in detail using FIG. 2, FIG. 2a, and FIG. 2b.

In the figure, the idler pulley 28 is rotatably disposed on a fixed shaft 30, and the tension pulley 29 is rotatably mounted on a pulley mounting plate 31 that is swingably attached to the shaft 30. Fixedly attached. Further, as shown in FIG. 2, the shaft 30 is connected to a substrate 3 fixed to the main body,
It is fixed at 1a. The pulley mounting plate 3
1 is sandwiched between brake shoes 32 and 33, and furthermore, there is a pressing plate 34 on the brake shoe 33 and a board 31a below the brake shoe 32.
A screw 35 and a compression spring 3 are used to hold these together.
6 and the nut 37, the plate 31 is connected to the substrate 31.
It is attached to a. The screw 35 is arranged at a position where it does not interfere with the swinging of the plate 31,
Furthermore, the pressing force of the compression spring 36 brings the brake shoe 32, plate 31, brake shoe 33, pressing plate 34, and base plate 31a into pressure contact.
When the plate 31 swings around the shaft 30, the friction between the shaft 30 and the brake shoe 32 exerts a braking effect to stop the swing of the plate 31. In FIG. 2 and FIG. 2a, the case where the wire advances in the direction of the arrow is the exposure process of the original. At the moment when the exposure process begins, part 25a of the wire is on the tension side, 2
5b is on the slack side, and its tension slowly moves the plate 31 in the counterclockwise direction (indicated by arrow a), and the tension pulley 29 moves to the position 29a shown in FIG. 2a. . As a result, the slack in the wire part 25b is removed from the tension pulley 29.
is absorbed by the movement to 29a. Further, the amplitude of the vibration of the wire at the time of starting exposure becomes smaller due to the above-mentioned braking effect, and at the same time, the attenuation of the vibration becomes extremely rapid. Conversely, when the optical mirror is reversed from the exposed state, the swinging state of the tension pulley is reversed to that described above, and the plate 31 swings clockwise to prevent the initial shock of the wire.

In this way, in this embodiment, the opposing wires 25
A tension pulley 29 is arranged in contact with the wire 25, and the slack of the wire 25 due to the forward and reverse rotation of the winding pulley 24 rotated by the driving force from the motor is absorbed by the swinging of the tension pulley 29, and the vibration of the wire 25 is absorbed. is reduced by the braking effect. Therefore, according to this embodiment, it is possible to reduce the shock caused by switching the tension direction of the wire, and furthermore, it is possible to quickly match the winding pulley speed and the mirror speed.

Further, in this embodiment, since the swinging pulley mounting plate 31 is sandwiched between the brake shoes 32 and 33 and tightened by a compression spring, energy at the time of shock can be absorbed.

In addition, in this example, adjusting the braking effect so as to absorb the initial shock of the wire and also suppress the elongation of the wire means changing the elastic force of the compression spring or the degree of friction of the brake shoe. Therefore, it is easy.

Still another embodiment is shown in FIG. This embodiment differs from the previous embodiments in the way the wires are wired.

In this embodiment, the wires 25 are parallel between the idler pulley 28 and the tension pulley 29, that is, they do not intersect as in the previous embodiments, so the wires do not rub against each other at this intersection point and wear out. , the durability of the wire can be increased.

Furthermore, another example will be shown. In this embodiment, the wire 25 is connected to the fixed pulley 21, the tension pulley 38 in the right drawing, and the wire-wrapped pulley 24.
Furthermore, it reaches the fixed pulley 22 via the fixed pulley 39 and the tension pulley 38 shown in the left drawing. A stand 40 on which the tension pulley 38 is attached is slidably provided on the base plate 31a. Its cross section is shown in FIG. The stand 40 is operated by a spring 41 with a brake 42,
It is sandwiched between 43. This spring 41 is attached to a shaft 45 by a clasp 44. Therefore, the table 40 moves within the range of the openings 46 and 47 while absorbing energy during shock along with the movement of the tension pulley 38 during vibration absorption.
Therefore, in the embodiment described above, the range of oscillation is naturally determined when the wire on the tension side is in a straight line, so the stroke for buffering it is relatively small, whereas in this embodiment In the example, the stroke can be made larger and a more sufficient damping effect can be provided.

Furthermore, in this embodiment, if the shock during driving of the wire-wrapped pulley 24 is large, the average tension of the wire tends to become excessive.
Since the tension is regulated within the range of 7, the average tension of the wire will not become excessive even if the shock during driving is large.

Furthermore, in this embodiment, even if the tension increases, the overall length of the wire does not change, so even this will not cause excessive tension.

FIG. 6 shows an example in which the tension pulley 38 is made up of two pulleys 38 ₁ and 38 ₂ having a single row of grooves. In this way, the tension pulley can be used as a common pulley with the fixed pulleys 21, 22, etc., which may further reduce costs.

Furthermore, another example will be shown.

In FIG. 7, the way the wire 25 is applied is the same as in the embodiment shown in FIG. 2a, but the tension pulley 4
The stand 40 on which No. 7 is attached is a board (not shown)
This is an example in which it is slidably attached to the
According to this embodiment, the tension pulley 38
Since the swing of the wire is limited by the openings 46 and 47, even if the shock during driving is large, the average tension of the wire will not become excessive.

As described above, the wire buffer device according to the present invention has a remarkable effect in that it reduces the shock caused by switching the direction of wire tension and quickly achieves a constant speed drive state, and is not normally used in, for example, copying machines. This has the advantage that the run-up section of the optical system can be shortened. Furthermore, in the present invention, both sides of the wire wound around the driving force transmitting pulley are crossed between the driving force transmitting pulley and the swing pulley, so it is possible to combine the swing pulleys into one. In this case, the degree of freedom in design can be increased by saving space. Moreover, by crossing both sides of the wire wrapped around the driving force transmitting pulley between the driving force transmitting pulley and the swing pulley, the contact angle of the wire with the driving force transmitting pulley and the swing pulley becomes an acute angle. The contact force between the wire and both rollers can be increased. This makes it possible to reliably transmit the rotational driving force of the driving force transmission pulley to the wire, which not only improves the transmission of driving force through the wire, but also quickly and reliably reduces the shock caused by the swinging pulley. be able to.

[Brief explanation of the drawing]

Fig. 1 is a side view of a shock absorbing device previously invented by the present applicant, Fig. 2 is a perspective view showing the optical system drive of a copying machine using an embodiment of the shock absorbing device of the present invention, and Fig. 2a 2b is a front view of the main part, FIG. 2b is a side view thereof, FIG. 3 is a front view of another embodiment, FIG. 4 is a front view of still another embodiment, and FIG. FIG. 6 is a side view of the pulley, and FIG. 7 is a front view of still another embodiment. In the figure, 1, 2... fixed pulley, 3... wire, 4...
Idler pulley, 11...first support member, 13
...Second support member, 21, 22...Fixed pulley,
24... Wire wrapped pulley, 25... Wire, 27... Second fixed pulley, 28... Idler pulley, 29... Tension pulley, 30...
Fixed shaft, 31...Pulley mounting plate, 31a...
Board, 32, 33... Brake shoe, 38...
Tension pulley, 40... stand, 41... spring,
42, 43...Brake, 47...Tension pulley.

Claims (1)

[Claims] 1. A reciprocating body, a pulley that transmits rotational driving force, a wire that transmits the rotational driving force of the driving force transmission pulley to the reciprocating body, and that swings about a swing fulcrum. A swinging plate, a swinging pulley attached to the swinging plate, a first pulley disposed on a fixed shaft, and second and third pulleys provided on both sides of the first pulley in the moving direction of the reciprocating body. and a pulley, both sides of the wire wound around the driving force transmitting pulley are crossed between the driving force transmitting pulley and the oscillating pulley, and the direction of both wires after crossing is changed via the fixed pulley. A shock absorber, characterized in that the shock absorber is connected to a reciprocating body via second and third pulleys, and is suspended in order to transmit the rotational driving force of the driving force transmitting pulley to the reciprocating body.