JPH01116661A - Cushioning member - Google Patents

Abstract

PURPOSE:To extend the service life and to obtain a stable performance as elapsed time by increasing the rubber hardness of a direct engaging area of a part to be engaged, lowering the rubber hardness of other area and forming two layers in terms of the rubber hardness. CONSTITUTION:A cushioning member 1 is formed as a roughly disk-like member consisting of an elastic member, and at a suitable position, a member to be engaged 2, for instance, a hole is formed, and an area 8 of the periphery of the hole 2, namely, for instance, an annular area where an engaging member of a driving member is engaged directly is formed to a state that rubber hardness is higher than that of other area. In this state, the cushioning member 1 itself repeats expansion and contraction due to a fluctuation of a load, but since the rubber hardness of the annular area is increased in a part where force is concentrated, namely, in a contact part of a pin and the annular area 8, the rupture strength increases, and a crack is scarcely generated. In such a way, the cushioning member having durability and a long service life is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used as a buffer member, specifically, in a drive device such as an optical system drive device of an image forming apparatus, and is disposed between a drive member and a driven member, and serves as a power transmission member. This invention relates to the buffer member used.

Conventionally, when an impact occurs when changing the drive direction, such as in a reciprocating optical system drive device of an image forming apparatus such as a narrow copying machine, the impact is prevented from being transmitted from the drive member to the driven member. It is widely known to use a buffer member. An engaged part that is disposed between a driving member and a driven member and that engages with an engaging part provided on the driving member and an engaged part that engages with an engaging part provided on the driven member. A buffer member made of an elastic material, such as a rubber damper, which transmits the rotation of the driving member to the driven member is often used as the above-mentioned buffer member. In many cases, a pin is used as the engaging part, and a hole into which the pin is inserted is used as the engaged part. In a rubber damper, as shown in Figure 10, the elastic member expands and contracts each time an impact is applied, and due to this repeated expansion and contraction,
The parts where force is concentrated, such as the hole 53 of the buffer member 52 where the pin 51 of the driving member engages and the hole 53 where the pin 54 of the driven member engages, gradually deform, crack, and break, causing damage to the damper. It becomes ineffective and reaches the end of its lifespan. Therefore, conventional shock absorbing members have problems in durability.

In particular, as shown in FIG. 11, when the buffer member 52 transmits rotation to the driven member due to the rotation of the drive member, the pins 51 and 54 as the engaging portion of the drive member or the driven member are connected to the buffer member 52. When the inner diameter surface of the buffer member 52 directly contacts the outer circumferential surface of the boss member 55 of the driving member or the driven member at the same time as the transmission is transmitted through the engagement of the hole 53 as the engagement portion, the buffer member 52 is moved due to the frictional resistance of the contact portion. It will not be able to deform smoothly and the damper effect will decrease.

When the boss 55 and the inner circumferential surface of the buffer member 52 come into contact with each other at a portion indicated by A, only a portion of the engaged portion, that is, a portion of the hole 53 that is the engaging portion, contacts due to the friction of the contact portion. While deforming, power is transmitted between the pin 51 of the driving member or the pin 54 of the driven member. This causes the force to concentrate on some of the holes 53, leading to premature breakage and shortening the service life.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional shock absorbing member described above and to provide a shock absorbing member that is durable and has a long life.

Structure In order to achieve the above object, the present invention provides that the inner diameter surface of the buffer member is supported by a collar, and the collar is rotatably supported by the boss portion of either the driving member or the driven member. Features.

The structure and operation of the present invention will be explained in detail based on the embodiment shown in the drawings.

1 and 2, a buffer member 1 according to the present invention is formed as a substantially disc-shaped member made of an elastic member, and an engaged member 2, for example, a hole, is formed at a suitable position. The area 8 around the hole 2, ie, the annular area where the engaging member of the drive member directly engages, is formed to have a higher rubber hardness than other areas.

The buffer member 1 is disposed between the driving member 4 and the driven member 5 as shown in FIG. 3, and the engaging portion 6 of the driving member 4 shown in FIG. 3 and FIG. It is inserted into and engaged with the engaged portion consisting of two parts. Further, an engaging portion 7, such as a pin, provided on a driven member 5, such as a gear, shown in FIGS. 3 and 5 is inserted into and engaged with the engaged portion formed by the hole 2. A collar 3 is fitted into the inner diameter surface of the buffer member l, and the inner diameter surface 1a is supported by the collar 3. The collar 3 is rotatably fitted to the outer periphery of a boss portion 5a of one of the driving member 4 and the driven member 5, in the illustrated example, the driven member 5.

With this structure, it is possible to prevent the buffer member from partially contacting the boss portion and deforming some of the engaged portions.

In order to strengthen the engaged portion, the region 8 around the hole 2, ie, the annular region, which is directly engaged with the engaging member of the drive member, is formed to have a higher rubber hardness than other regions. The pin 6 contacts an annular region 8 of large rubber hardness around the hole 2;
The rotation of the driving member 4 is transmitted to the buffer member 1 through the engagement between the pin 6 and the hole 2. In addition, the pin 7 of the driven member 5 directly contacts the annular region 8 of the hole 2 of the buffer member 1 having a high rubber hardness.
The rotation of the buffer member 1 is transmitted to the driven member 5 through the engagement between the hole 2 and the pin 7.

When there is no variation in the rotation of the driving member 4, the driven member 5 is also rotated uniformly without variation. The load on the drive member 4 fluctuates,
If rotational unevenness occurs, most of the buffer member 1, that is, the portion other than the annular region, is formed as a rubber portion with low rubber hardness, so the buffering member 1 deforms, absorbs the rotational unevenness due to fluctuating loads, and Almost no rotation and load fluctuations are transmitted to the drive member 5.

The buffer member 1 itself expands and contracts repeatedly due to changes in load, but the parts where the force is concentrated, that is, the pin and the annular region 8
In the contact area, the rubber hardness of the annular region is increased, so the breaking strength is increased and cracks are less likely to occur.

An example of a device that utilizes the above-mentioned buffer member is a drive device for a copying machine as shown in FIGS. 6 and 7. 6th
In the figures and FIG. 7, rotation of a first gear 12 attached to the output shaft of a motor 11 is transmitted to a photoreceptor drive gear 14 via a second gear 13. A photoreceptor drum (not shown) is rotated by the photoreceptor drive gear 14 .

The rotation of the photoreceptor drive gear 14 is transmitted to the input gear 17 of the forward/reverse drive unit 16 via the third gear 15 .

The input gear 17 includes a first output shaft rotatably supported by a casing 19, and an intermediate shaft rotatably supported by a second output shaft 20, which is also rotatably supported by the casing 19. It meshes with gear 21.

The connection between the input gear 17 and the first output shaft 18 is turned ON and OFF by the first electromagnetic clutch 22 . A first output gear 23 is fixed to the first output shaft 18 .

The connection between the intermediate gear 21 and the second output shaft 2.0 is turned on and off by a second electromagnetic clutch 24. Second output shaft 20
A drive member 4 shown in FIG. ing.

1st T1. When the if clutch 22 is turned on, the first output gear 23 is rotated counterclockwise in FIG.
When the ff clutch 24 is turned on, the second output gear 5 is rotated clockwise in FIG. 7 via the drive member 4 and the buffer member l.

The first output gear 23 and the second output gear 5 each have a pulley 2
5, and when the first electromagnetic clutch 22 is ON, the second electromagnetic clutch 2
4 is turned off, the pulley 25 is rotated clockwise in FIG. 7 by the first output shaft 23, and the optical system drive wire 26 wound around the pulley 25 is driven rightward in the figure.
Move the scanner or document table forward. Then, the first electromagnetic clutch 22 is turned off and the second electromagnetic clutch 24 is turned on.
When this happens, the drive transmission is changed from the first output gear 23 to the second output gear 5, the pulley 25 is reversed counterclockwise, and the optical system drive wire 26 moves back to the left in the figure.

At the time of reversal from forward movement to backward movement, fluctuations in the drive load are transmitted to the photoreceptor drive gear 14 via the gear train, and the rotational speed of the photoreceptor drops instantaneously. If the transfer process is performed at this time, there will be a problem that the image will be blurred, but by interposing the buffer member 1, the buffer member 1 absorbs the fluctuation of the load at the time of reversal, that is, the drive shock, and softens it. Can be done. As a result, rotational unevenness of the photoreceptor can be reduced and image blurring can be made less noticeable.

In the buffer member 1, the pin 6 of the driving member 4 and the pin 7 of the second output gear 5 as a driven member are in contact with the annular region 8 having high rubber hardness, so even if there is a load change on the driving member 4, the annular region itself It is difficult to deform and can sufficiently withstand concentrated force, and load fluctuation itself can be absorbed by deformation of the region outside the annular region where the rubber hardness is low. The buffer member 1 itself deforms in response to load fluctuations and absorbs shocks, etc., but the annular region around the hole 2 in which the pins 6 and 7 as engaging members engage is difficult to deform, so it does not break. This can be prevented.

According to the present invention, a collar 27 is disposed between the inner circumferential surface of the buffer member 1 and the outer circumferential surface of the boss member 5a of the driven member, as shown in FIGS.
By configuring the cushioning member to be inserted, problems caused by contact between the boss portion and the inner circumferential surface of the buffer member can be solved. That is, by providing the collar 27 as shown in FIG. 8, the buffer member 1 and the boss member 5a do not come into direct contact with each other, and even if the buffer member 1 and the collar 27 partially contact each other, the collar 27
Since no local frictional contact occurs between the pin 6.7 and the boss portion 5a, force is applied equally between the pin 6.7 and each person 2, causing local deformation of the buffer member l. can be avoided. If local deformation occurs, the collar 27 rotates, so that the local deformation is eventually eliminated. By making the annular region 8 around the hole 2 have a higher rubber hardness than the other regions, the hole 2 can be maintained in a state in which it is almost entirely engaged with the pin 6 without being deformed, as shown in FIG. It becomes like this.

Depending on the arrangement of the hole 2 in the buffer member 1 to which the pin 6.7 is engaged, only the hole 2 may be formed as shown in the figure in consideration of balance, although it is not used as the engaged part. can.

According to the present invention, the cushioning member has a rubber hardness that increases the rubber hardness of the direct engagement area of the engaged part where the engaging parts of the driving member and the driven member engage, and lowers the rubber hardness of other areas. Since it is formed to 2N, the engaging portion is reinforced and the life of the buffer member is extended, making it possible to obtain stable performance over time.

This reduced the frequency of replacing the buffer members and improved service costs.

[Brief explanation of the drawing]

The first is a front view of the buffer member according to the present invention, FIG. 2 is a side view, FIG. 3 is a cross-sectional view showing the state of the buffer member, driving member, and driven member before assembly, and FIG. 4 is a front view of the buffer member according to the present invention. 3 is a left side view of the driving member, FIG. 5 is a left side view of the driven member in FIG.
The figure is a schematic front view of an example of a drive device using this buffer member.
Fig. 7 is a cross-sectional view taken along the line #6, Fig. 8 is a front view of another example of the present invention at the time of modification, and Fig. 9 is a collar attached to the inner circumferential surface of the buffer member, and Fig. 10 is a diagram showing the deformation of a conventional shock absorbing member under load, and Fig. 11 is an explanatory diagram of the state under load when the rubber hardness of the conventional shock absorbing member is reinforced. It is a figure which shows the deformation when contacting a boss|hub part. ■...llt fji member 2...Engaged part 3
... Collar 4 ... Drive member 5 ... Driven member 6.7 ... Engagement part (1 other person) Fig. 8 Fig. 10 Fig. 9 Fig. 11

Claims (1)

[Scope of Claims] An engaged portion disposed between a driving member and a driven member, which engages with an engaging portion provided on the driving member, and an engaged portion that engages with an engaging portion provided on the driven member. The buffer member is made of an elastic material and has an engaging portion and transmits the rotation of the driving member to the driven member, wherein the inner diameter surface of the buffer member is supported by a collar, and the collar is connected to either the driving member or the driven member. A buffer member, characterized in that the buffer member is rotatably supported by a boss portion.