JP3405559B2 - Drum chucking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum chucking device, and is used, for example, in the manufacture of an electrophotographic photosensitive drum having a photosensitive material coated on the outer peripheral surface of the drum. The present invention relates to a drum chucking device that holds a cylindrical drum from its inner surface. 2. Description of the Related Art A photosensitive drum used in an electrophotographic copying machine includes a step of degreasing and cleaning an outer peripheral surface of an aluminum drum, a step of applying a photosensitive material to the outer surface of the degreased and cleaned drum, And a step of heating a photosensitive substance applied to the outer peripheral surface of the drum to form a photosensitive layer. In these processes, a drum chucking device that holds the drum from the inner peripheral surface side is used to protect the outer peripheral surface of the drum to which the photosensitive substance is applied and the photosensitive substance applied to the outer peripheral surface of the drum. Was. For example, in the step of degreasing and cleaning the outer peripheral surface of a drum, a large number of drums are vertically held by the drum chucking device and are sequentially transferred to a plurality of cleaning layers. In the step of applying a photosensitive substance to the outer peripheral surface of the degreased and cleaned drum, for example,
An immersion method is employed in which a drum is immersed vertically in a coating solution and then the drum is withdrawn from the coating solution at a predetermined speed in the axial direction of the drum. Even in such an immersion method, a drum chucking device that holds the drum from the inner peripheral surface side has been used. [0003] The conventional drum chucking device as described above has the following problems. (1) In the degreasing cleaning process of the outer peripheral surface of the drum used for the production of the electrophotographic photosensitive drum, the drum cannot be reliably held by the conventional drum chucking device for some reason. The drum may remain in the tank. In such a case, the drum is usually taken out of the washing tank by an operator directly pulling up the drum by hand or by lifting the drum by operating an appropriate jig. However, when the operator directly lifts the drum by hand, it is necessary to discharge the cleaning liquid in the cleaning tank when lifting the drum, which causes a problem that the workability is reduced. Further, after the cleaning liquid in the cleaning tank is discharged, an operator enters the cleaning tank, so that the inside of the cleaning tank may be contaminated with dust or the like, and the drum cleaning degree may be reduced. Further, the vapor of the cleaning liquid remaining in the cleaning tank may adversely affect the human body. On the other hand, when the drum is taken out of the cleaning tank by the jig, such a problem does not occur. However, the conventional jig has a problem that it is locked only to a drum having a specific inner diameter. Therefore, it is necessary to prepare various kinds of jigs according to the inner diameter of the drum. In addition, even when a jig having a size corresponding to the inner diameter of the drum is used, the drum is not stably held by the jig.
The drum may fall from the jig during the lifting. (2) The drum chucking device used in the step of applying the coating liquid to the outer peripheral surface of the drum can hold only a drum having a specific inner diameter, similarly to the above-mentioned jig for pulling up the drum. For this reason, every time the diameter of the drum is changed, it is necessary to replace the drum chucking device with one capable of holding a drum having a predetermined inner diameter, and workability is significantly reduced. Also, when replacing the drum chucking device,
Since dust is generated, there is a problem that the cleanliness of the drum coating chamber is reduced. In order to solve the problems in the prior art, the present invention has improved a drum chucking device, and has a drum which can operate smoothly and stably hold various drums having different inner diameters from an inner peripheral surface side. It is an object to provide a chucking device. [0004] In order to achieve the above object, the present invention provides a guide tube which is coaxially arranged on the axis of a drum to be held, and a guide tube which is provided on the guide tube. A movable shaft that is slidably supported in the axial direction, and a first shaft that is rotatably supported by the movable shaft at one end in a predetermined plane parallel to the axis of the movable shaft. Link members,
A second link member in the same plane as the predetermined plane, one end of which is rotatably supported by the guide cylinder;
The movable shaft is disposed so as to be located on the same circle around the axis of the movable shaft as a center, and the movable shaft is moved along with the relative movement of the movable shaft with respect to the guide cylinder in the axial direction. The first and second motors are moved so as to move while maintaining a parallel state by an equal distance in a radial direction with respect to the axis of the shaft body.
A plurality of holding arms respectively supported by the other ends of the link members, and a movable shaft attached to the guide cylinder so as to move each holding arm away from the axis of the movable shaft. And a biasing means for biasing the movable shaft body when the biasing means starts to bias the movable shaft body against the guide cylinder. The present invention is configured as a drum chucking device in which each of the first and second link members is disposed so as to pass through the inside of the supporting point on the holding arm side of the second link member. According to the present invention, a guide cylinder is disposed coaxially with the axis of a drum to be held, and a movable shaft is slidably supported in the axial direction of the guide cylinder, and the movable cylinder is slidably supported. One end of the first link member in a predetermined plane parallel to the axis of the shaft is rotatably supported by the movable shaft in the predetermined plane, and is in the same plane as the predetermined plane. One end of the second link member is rotatably supported by the guide cylinder in the same plane, and is located on the same circle around the movable shaft body around the axis of the movable shaft body. A plurality of holding arms arranged so as to move relative to the guide cylinder in the axial direction of the movable shaft body have an equal distance in a radial direction that comes and comes close to the axial center of the movable shaft body. The other ends of the first and second link members so as to move while maintaining the parallel state only. In this state, in order to move each holding arm in a direction away from the axis of the movable shaft body, when the movable shaft body starts to be urged by the urging means against the guide cylinder, The axis of the first link member is
The respective pivot points of the first and second link members are arranged so as to pass through the inside of the pivot point on the holding arm side of the second link member. Then, each holding arm is inserted into various drums having different inner diameters by applying an external force in an initial state in which the holding arms are brought close to the axis of the movable shaft body. If the external force is removed from the movable shaft in this state, when the urging by the urging means is started, an outward rotational moment is applied to each holding arm, so that the arms are easily separated from the initial state, and each arm is separated by an equal distance. Only in the radial direction away from the movable shaft. The inner peripheral surface of the drum is pressed by each of the moved holding arms, and the drum is stably held. The external force may be generated automatically by mechanical means or may be generated manually.
As a result, it is possible to obtain a drum chucking device that can smoothly operate and stably hold various drums having different inner diameters from the inner peripheral surface side. An embodiment of the present invention will be described below with reference to the accompanying drawings to facilitate understanding of the present invention. The following embodiment is an example embodying the present invention and is not intended to limit the technical scope of the present invention. Here, FIG. 1 is a front view showing a schematic configuration of a drum chucking device according to one embodiment of the present invention, FIG. 2 is an explanatory diagram showing a partial force relationship during operation of the drum chucking device,
FIG. 3 is an explanatory diagram showing a partial force relationship in an initial state of the drum chucking device. The drum chucking device according to the present embodiment is used, for example, to take out a drum used for manufacturing an electrophotographic photosensitive drum from a cleaning tank. The drum in the cleaning tank is placed vertically on the bottom of the cleaning tank while being immersed in the cleaning liquid. This drum chucking device includes a drum 1 to be held as shown in FIG.
A guide cylinder 2 disposed coaxially with the axis of the movable cylinder 3; a movable shaft 3 (corresponding to a movable shaft body) supported by the guide cylinder 2 so as to be slidable in the axial direction of the guide cylinder; Parallel links 4, 4 ′ which are rotatably supported on a movable shaft 3 at pivot points A, A ′ in a plane parallel to the axis.
(Corresponding to a first link member) and an auxiliary link 5 (second link) which is in the same plane as the above-mentioned plane and one end of which is rotatably supported by the guide cylinder 2 at a pivot B. Link member), and are disposed around the movable shaft 3 at equal intervals around the axis of the movable shaft 3 on the same circle, and the relative position of the movable shaft 3 with respect to the guide cylinder 2 in the axial direction. The other ends of the parallel links 4, 4 'and the auxiliary link 5 are moved so as to move while maintaining a parallel state by an equal distance in a radial direction which comes into contact with and separate from the axis of the movable shaft 3 with the movement. Fulcrum C,
Three holding arms 6 respectively supported at C 'and D
And a compression spring 7 (corresponding to urging means) for urging the movable shaft 3 against the guide cylinder 2 in order to move each holding arm 6 in a direction away from the axis of the movable shaft 3. When the movable shaft 3 is started to be urged against the guide cylinder 2 by the spring 7, the parallel links 4 and 4 'pass through the inside of the supporting point D of the auxiliary link 5 on the holding arm 6 side. 4,
4 'and the supporting points A to D of the auxiliary link 5 are arranged. [0007] The drum chucking apparatus of the present embodiment having the above-described structure is used as follows, for example, when removing the drum 1 remaining in the cleaning tank. First, the guide cylinder 2 is gripped by hand, and is pushed so that the flange 9 of the movable shaft 3 approaches the flange 8 of the guide cylinder 2 against the urging force of the compression spring 7. As a result, the movable shaft 3 moves downward in the drawing, and the holding arms 6 held by the parallel links 4 and 4 'and the auxiliary link 5 are radiated so as to approach the axis of the movable shaft 3. Move while maintaining the parallel state in the direction. When the movable shaft 3 is moved until the diameter of the circle formed by the outer surfaces of the three holding arms 6 becomes smaller than the inner diameter of the drum 1, each arm holding part is placed in a state where each holding arm 6 is placed on the lower side. 6 is inserted into the drum 1 (initial state). In this initial state, it is necessary to make each holding arm 6 as close as possible to the movable shaft 3 so as to be compact so as to be able to cope with a drum having a small inner diameter. As a result, the angle between the parallel links 4 and 4 'and the movable shaft 3 and the angle between the auxiliary link 5 and the guide cylinder 2 are all very small. This means that even if the pushing force applied to the movable shaft 3 in the next stage is released, the guide cylinder 2, the movable shaft 3, the parallel links 4, 4 ', the auxiliary links 5, The chain mechanism consisting of the holding arm 6 is connected to each of the pivot points A to D
It is difficult to operate against the frictional force on
It means that it is difficult to leave the initial state. Here, the departure condition from the initial state is derived using FIG. 2 (each link is represented by 4 in the figure). The urging force F applied to the movable shaft 3 by the compression spring 7 is composed of a component F1 in the axial direction of the link 4 and a component F in a direction perpendicular thereto.
It can be decomposed into two. The component force F2 in the direction perpendicular to the inner side is defined by the fulcrum C
Rotational moment M in the counterclockwise direction in the figure around
Is generated. On the other hand, the axial component F1 is applied to the shaft fulcrum A and the shaft fulcrum C via the link 4, and these shaft fulcrums A,
C generates a frictional force F1 '. The frictional force F1 'generates a reverse rotation moment M' in a direction opposite to the rotation moment M (clockwise in the drawing). Therefore, the above-mentioned departure condition is achieved when the rotational moment M exceeds the reverse rotational moment M ', and can be expressed by the following equation. M> M ′ (1) M = F2 · L = FL · sin θ (2) M ′ = 2F1 ′ · r = 2 μ · F · r · cos θ (3) where L is a pivot point A , C, θ is the angle between the link 4 and the axis of the movable shaft 3, μ is the friction coefficient, and r is the radius of the shaft fulcrums A and C. In the above equation (1), (2) and (3)
The following conditional expression was derived by substituting the expression. θ> tan ⁻¹ (2 μr / L) (4) In reality, compactness that does not satisfy the above conditional expression may be required. For this reason, in the drum chucking device of this embodiment, as described above, when the movable shaft 3 starts to be urged against the guide cylinder 2 by the compression spring 7, the axis of the parallel link 4, 4 ' Of the parallel link 4, 4 'and the auxiliary link 5 are arranged so as to pass through the inside of the shaft fulcrum D of the holding arm 6 side. This is schematically shown in FIG. 3 (parallel links are represented by 4 in the figure), and the basic principle of the operation is considered as follows.
In FIG. 3, the biasing force F applied to the movable shaft 3 can be divided into a component F1 in the axial direction of the parallel link 4 and a component F2 in a direction perpendicular thereto. The inner axial component force F1 is transmitted to the pivot fulcrum C via the pivot fulcrum A and the link 4, and generates an outward rotational moment m about the fulcrum D. Rotational moment m
Is given by the product of the axial component F1 and the distance l between the shaft fulcrum D and the axis of the link 4. The rotation moment m facilitates the departure from the initial state. The other links 4 'need to have the same arrangement. Next, when the pushing force applied to the movable shaft 3 is released, the movable shaft 3 is pressed by the urging force of the compression spring 7.
The flange 9 of the movable shaft 3 is relatively moved so as to be separated from the flange 8 of the guide cylinder 2. Then, the rotation moment m acts to urge the holding arm 6 outward.
Departure from the initial state is facilitated. After withdrawal,
The direction of the axis of the parallel links 4, 4 'changes, and accordingly, the rotational moment m gradually decreases.
The value becomes zero when the axis direction of the shaft 4 'coincides with the shaft fulcrum D. After that, they act in the opposite directions, but at this stage, the angle between the parallel links 4 and 4 'and the movable shaft 3 and the angle between the auxiliary link 5 and the guide cylinder 2 are all considerably large. The rotational moment m does not matter. And compression spring 7
Of the movable shaft 3 by the biasing force of
And the three holding arms 6 move in a radial direction so as to move away from the axis of the movable shaft 3 while maintaining a parallel state. The maximum diameter of the circle on which the outer surfaces of the three holding arms 6 are located is as follows.
, The outer surface of each holding arm 6 is pressed against the inner peripheral surface of the drum 1 before the compression spring 7 reaches the maximum length. The drums 1 are reliably held by the holding arms 6 so that the holding arms 6 press three equally-disposed positions in the circumferential direction of the inner peripheral surface of the drum 1 along the axis of the drum 1. When the drum 1 is held by each holding arm 6, the entire drum chucking device is lifted upward. Thereby, the drum 1 is taken out from the cleaning tank. As described above, in the drum chucking device of the present embodiment, since the three holding arms 6 are moved in the radial direction so as to approach and move away from the axis of the movable shaft 3, the drum 1 having a different inner diameter can be used.
It can be held without hindrance. Further, when taking out the drum 1 from the cleaning tank (not shown), there is no need to discharge the cleaning liquid from the cleaning tank, and there is no need to enter the cleaning tank. Further, since the drum 1 is securely held by the drum chucking device, there is no possibility that the drum 1 will be detached from the drum chucking device while the drum 1 is being taken out. As a result, it is possible to obtain a drum chucking device which can operate smoothly and stably hold various drums having different inner diameters from the inner peripheral surface side. In the above embodiment, three pairs of chain mechanisms are provided.
Pairs or four or more pairs may be provided. However, from the viewpoint of the drum holding performance and the processing accuracy of the apparatus, it is considered that three pairs are optimal. In the above embodiment, a parallel link composed of two links is used as the first link member. However, in actual use, one link or three or more parallel links may be used. However, two parallel links are desirable from the standpoint of drum holding performance. Further, the second link member may be a parallel link. In the above embodiment, the compression spring 7 is used as the urging means.
In the initial state, external force is applied manually, but instead of these, a drive source (mechanical means) such as a servomotor may be used to automatically generate the external force. In place of the flange 9 at the upper end of the movable shaft 3, it is necessary to provide a connection to this drive source. Since the drum chucking device according to the present invention is constructed as described above, each holding arm is brought close to the axis side of the movable shaft body in various drums having different inner diameters. After the insertion in the initial state, when the urging means starts the urging by the urging means, an outward rotational moment is applied to each of the holding arms, so that the arms can be easily separated from the initial state. After departure from the above initial state, the plurality of holding arms arranged around the movable shaft move while maintaining the parallel state by the same distance in the radial direction that comes and comes apart from the axis of the movable shaft. Therefore, various drums having different inner diameters can be reliably held. Therefore, there is no need to prepare a drum chucking device according to the inner diameter of the drum. In addition, since the drum is securely held from the inner surface side by each holding arm, there is no possibility that the drum is detached from each holding arm. As a result, it is possible to obtain a drum chucking device that can smoothly operate and stably hold various drums having different inner diameters from the inner peripheral surface side.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a schematic configuration of a drum chucking device according to an embodiment of the first invention. FIG. 2 is an explanatory diagram showing a partial force relationship applied during operation of the drum chucking device. FIG. 3 is an explanatory diagram showing a partial force relationship applied to an initial state of the drum chucking device. [Description of References] 1 ... drum 2 ... guide cylinder 3 ... movable shaft (corresponding to a movable shaft) 4, 4 '... parallel link (corresponding to a first link member) 5 ... auxiliary link (corresponding to a second link member) 6) Holding arm 7 ... Compression spring (corresponding to urging means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-27535 (JP, A) JP-A-51-35954 (JP, A) JP-A-5-66582 (JP, A) 51327 (JP, U) Fully open Showa 53-42375 (JP, U) Fully open Showa 55-107990 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05B 12/00-13 / 06 G03G 5/00-5/16

Claims (1)

(57) [Claim 1] A guide cylinder arranged coaxially with the axis of a drum to be held, and supported by the guide cylinder so as to be slidable in the axial direction of the guide cylinder. A movable shaft body, a first link member in a predetermined plane parallel to the axis of the movable shaft body, one end of which is rotatably supported by the movable shaft body; A second link member that is rotatably supported by the guide cylinder at one end thereof in the same plane as the above, and is formed around the movable shaft body on the same circle around the axis of the movable shaft body. The movable shaft is moved parallel to the guide cylinder in the axial direction by an equal distance in the radial direction which comes into contact with and separates from the axis of the movable shaft in accordance with the relative movement of the movable shaft in the axial direction. A plurality of shafts respectively supported by the other ends of the first and second link members so as to move while maintaining the same; A drum chucking device comprising: a holding arm; and urging means for urging the movable shaft against the guide cylinder so as to move each holding arm away from the axis of the movable shaft. When the urging means starts to urge the movable shaft body against the guide cylinder, the axis of the first link member is shifted from the axis fulcrum of the second link member on the holding arm side. A drum chucking device in which the fulcrum of each of the first and second link members is arranged to pass through the inside.