JPH01116660A - Cushioning member - Google Patents

Abstract

PURPOSE:To obtain a cushioning member having durability and a long service life by allowing an engaging area which is engaged directly to an engaging part of a driving member and a member to be driven in a part to be engaged of the cushioning member, to have rubber hardness being different each from other area. 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. An area 3 of the periphery of the hole 2, namely, for instance, an annular area where an engaging member of a driving member 4 is engaged directly is formed to a state that rubber hardness is higher than that of other area. In this case, the cushioning member 1 is placed between the driving member 4 and a member to be driven 5, and an engaging part 6 of the driving member 4, for instance, a pin is inserted and engaged to a part to be engaged, consisting of, for instance, a hole 2. In such a way, the engaging part 6 is reinforced and a service life of the cushioning member 1 is extended, and a stable performance with passage of time can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buffer member, specifically, a shock absorbing member, which is used in a drive device such as an optical system drive device of an image forming apparatus, and which 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.

BACKGROUND ART When an impact occurs when changing the driving direction, such as in a reciprocating optical system driving device of an image forming apparatus such as a copying machine, a buffer is used to prevent the impact from being transmitted from the driving member to the driven member. The use of members is widely known. The drive member is disposed between a driving member and a driven member, and has an engaged part 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. However, 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 the rubber damper, as shown in FIG. 9, the elastic member expands and contracts each time an impact is applied, and as a result of this repeated expansion and contraction, the hole 53 of the buffer member 52 and the driven member engage with the pin 51 of the driving member. As in the hole 53 where the pin 54 engages, the damper gradually deforms, cracks, and breaks in areas where force is concentrated, causing the damper to lose its effectiveness and reach the end of its life. Therefore, conventional shock absorbing members have problems in durability.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of conventional shock absorbing members 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 a retaining region in the engaged portion of the buffer member that directly engages with the engaging portions of the driving member and the driven member, which is made of rubber that is different from other regions. It is characterized by having hardness.

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 l 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. A region 3 around the hole 2, ie, an annular region with which the engaging member of the drive member directly engages, is formed to have a higher rubber hardness than the other region.

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. The pin 6 contacts the annular region 3 of high rubber hardness around the hole 2, and the rotation of the drive member 4 is transmitted to the buffer member 1 through the engagement of the pin 6 and the hole 2. Further, the pin 7 of the driven member 5 directly contacts the annular region 3 of the hole 2 of the buffer member 1 with high rubber hardness, and the rotation of the buffer member 1 is caused by the engagement of the hole 2 and the pin 7 with the driven member 5. transmitted to.

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 loose fIj member 1, that is, the portion other than the annular region, is formed as a rubber portion with low rubber hardness, so the buffer member 1 deforms and absorbs rotational unevenness due to fluctuating loads. Almost no rotation and load fluctuations are transmitted to the driven 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 3
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 photoconductor drive gear 14 is transmitted via the third gear 15 to the input gear 17 of the forward/reverse rotation drive unit 16 .

The input gear 17 is rotatably supported by a first output shaft 18 which is rotatably supported by a casing 19, and the intermediate gear is rotatably supported by a second output shaft 20 which is also rotatably supported by the casing 19. 21 is intertwined.

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 20 is turned on and off by a second electromagnetic clutch 24 . A driving member 4 shown in FIG. 3 is fixed to the second output shaft 20, and a second output gear 5 as a driven member is rotatably supported.
4 and the second output gear 5 are connected by a buffer member 1.

When the first electromagnetic clutch 22 is turned on, the first output gear 23
is rotated counterclockwise in FIG. 7, and the second electromagnetic clutch 2
4 is turned ON, the second output gear 5 is rotated clockwise in FIG. 7 via the drive member 4 and the buffer member 1.

The first output gear 23 and the second output gear 5 are
It meshes with a gear fixed or integrally formed with 25,
When the first electromagnetic clutch 22 is in QN, the second electromagnetic clutch 24 is turned off, and the pulley 25 is rotated clockwise in FIG. is driven rightward in the figure to move the scanner or document table forward. Then, the first electromagnetic clutch 22 is turned OFF and the second electromagnetic clutch 24 is turned OFF.
When N is set, 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 can absorb and soften the fluctuation of the load at the time of reversal, that is, the drive shock. 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 3 having high rubber hardness, so even if there is a load change on the driving member 4, the annular region itself is The shock absorbing member 1 itself deforms due to load fluctuations, so it can withstand concentrated forces sufficiently, and load fluctuations can be absorbed by deformation of the region with low rubber hardness outside the annular region. However, since the annular region around the hole 2 in which the pin 6.7 as an engaging member engages is not easily deformed, breakage can be prevented.

When the rotation of the driving member 4 causes the buffer member 1 to transmit rotation to the second output gear 5 as a driven member, the pin 7 and the hole 2
When the inner diameter surface of the buffer member 1 directly contacts the outer circumferential surface of the boss member 5a of the second output gear 5 at the same time as transmission due to the engagement of do. Conventionally, when the boss 55 of the driven member and the inner circumferential surface of the buffer member 52 come into contact at a part indicated by A as shown in FIG. Joining part, that is, some holes 53
The pin 51 of the driving member transmits the power while being deformed. This causes the force to concentrate on some of the holes 53, leading to premature breakage and shortening the service life. This problem can be solved by making the annular region around the hole of the present invention have high rubber hardness, but
Further, as shown in FIGS. 3 and 6, a collar 2 is provided between the inner peripheral surface of the buffer member 1 and the outer peripheral surface of the boss member 5a of the driven member.
7, that is, by inserting the collar 27 into the boss portion 5a, the problem can be solved even better.

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 and the boss member 5a do not come into contact with each other. Since no local frictional contact occurs between the pins 6, 7 and each person 2, force is applied equally between the pins 6, 7 and each person 2, and local deformation of the buffer member 1 can be avoided. If local deformation occurs, the collar 27 rotates, so that the local deformation is eventually eliminated.

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.

Floor placement 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 the other areas. Since it is formed in two layers, the engaging portion is reinforced and the life of the buffer member is extended, making it possible to obtain stable performance over time.

This reduces the need to replace shock absorbing members and improves service costs.

[Brief explanation of the drawing]

FIG. 1 is a front view of the buffer member according to the present invention, FIG. 2 is a side view, FIG. 3 is a 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 sectional view taken along the line ■-■ in FIG. 6, FIG. 8 is a front view of another example of the present invention when it is deformed, FIG. 9 is a diagram showing deformation of a conventional shock absorbing member under load, and FIG. The figure is a diagram showing deformation when the internal rotation of a conventional shock absorbing member comes into contact with a boss portion of a driven member. 1... Buffer member 2... Engaged portion 3... Annular region 4... Drive member 5... Driven member 6
, 7... Engaging part (1 idiot) Figure 1 Figure 2 Figure 3 Figure 8 Figure 9 Figure 10

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. In the buffer member made of an elastic material and having an engaging portion and transmitting the rotation of the driving member to the driven member, an engaging region of the engaged portion that directly engages with the engaging portion is different from other regions. A cushioning member characterized by having mutually different rubber hardnesses.