JPH0890762A - Mechanism and method for changing over attachment and detachment of rotary element used in printer - Google Patents

Abstract

PURPOSE: To certainly change over the attachment and detachment of a form- damping roller and a form roller with respect to a plate cylinder. CONSTITUTION: Respective recessed parts 2a, 2b, 2c are arranged to a positioning cam 2 so that the distances from a positioning cam shaft 3 to the respective recessed parts 2a, 2b, 2c become large successively. When revolving force is applied to the positioning cam shaft 3 in the direction shown by an arrow α, the positioning cam 2 is revolved in the direction shown by the arrow α. Even when revolving force in the direction shown by the arrow α is applied to an attaching and detaching cam 22 by the pressing forces from three cam followers 32, 42, 52, the attaching and detaching cam 22 is prevented from being energized to be rotated from this state at a stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary member attachment / detachment state switching mechanism used in a printing apparatus, and more particularly to improvement of the shape of a positioning cam.

[0002]

2. Description of the Related Art In offset printing, printing is performed by supplying water to the non-image area and supplying ink to the image area. In order to prevent the ink from being supplied to the non-image area, the water supply needs to be performed before the ink supply.

As a mechanism for supplying the water before the ink is supplied, there is known a detachment state switching mechanism 100 (hereinafter referred to as an attachment / detachment state switching mechanism) for a swimsuit roller and an ink inking roller shown in FIGS. . This attachment / detachment state switching mechanism includes a positioning cam 2, a positioning arm 6, an attachment / detachment cam 22, a swimsuit roller cam follower 26, a first ink replenishing roller cam follower 36, a second ink replenishing roller cam follower 46, a swimsuit roller 32, and a first inking attachment. Meat roller 4
2 and a second ink inking roller 52.

The positioning cam 2 rotates about the positioning cam shaft 3. The positioning cam 2 includes the recesses 2a, 2b, 2
c. The positioning arm 6 rotates about a shaft 8. In the hole 10 provided at one end of the positioning arm 6,
One end of the spring 12 is hooked. The other end of the spring 12 is fixed. A roller 7 is provided at the other end of the positioning arm 6. This roller 7 is a positioning cam 2
Engages with the concave portion 2a, the concave portion 2b, or the concave portion 2c.

A detachable cam 22 connected to the positioning cam 2 by a link 14 is provided apart from the positioning cam 2. The attachment / detachment cam 22 rotates about an attachment / detachment cam shaft 24. The detachable cam 22 includes a swimsuit roller cam follower 26,
The first ink inking roller cam follower 36 and the second ink inking roller cam follower 46 are in contact with each other. The swimsuit roller cam follower 26 is attached to the shaft 27 by the arm 28.
Is rotatable about the center of the arrow and is biased in the β1 direction by a spring (not shown). The swimsuit roller cam follower 26 is connected to the swimsuit roller 32 via the link 29.
Is connected with. Similarly, the first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 are also biased in the β2 direction and the β3 direction, respectively, and are connected to the ink replenishing rollers 42 and 52 via the links 39 and 49. Has been done.

The cam surface of the removable cam 22, the swimsuit roller cam follower 26, and the first ink inking roller cam follower 3
6 and the relationship with the second ink inking roller cam follower 46 will be described.

In the state shown in FIG. 12, the swimsuit roller cam follower 26, the first ink inking roller cam follower 36,
And the second ink inking roller cam follower 46,
It is in contact with the convex portion of the cam surface, and both the swimsuit roller 32 and the ink inking rollers 42, 52 are separated from the plate cylinder 60 (in a detached state). From this state, when the operator moves a lever (not shown) fixed to the shaft 3 to rotate the shaft 3 in the direction of the arrow α by a predetermined pitch, the positioning cam 2 rotates in the direction of the arrow α. As shown, the roller 7 contacts the recess 2b. At the same time, the attachment / detachment cam 22 is connected via the link 14.
Rotates in the direction of arrow α. Swimsuit roller cam follower 26
Comes into contact with the swimsuit roller concave portion 54 and approaches the detachable cam shaft 24 by that amount. As a result, the swimsuit roller 32 contacts the plate cylinder 60. The first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 also come into contact with the ink replenishing roller intermediate recesses 56 and 66, respectively, but the step difference is small and the ink replenishing rollers 42 and 5 are small.
2 is separated from the plate cylinder by a distance d1. As a result, water is supplied to the plate of the plate cylinder.

From this state, further, by the operator,
When the shaft 3 is rotated in the direction of the arrow α by a predetermined pitch, the positioning cam 2 is similarly rotated in the direction of the arrow α, as shown in FIG.
As shown in, the roller 7 contacts the recess 2c. At the same time, the attachment / detachment cam 22 rotates in the direction of the arrow α via the link 14. As a result, the first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 also come into contact with the ink replenishing roller recesses 57 and 67, respectively, and the ink replenishing rollers 42 and 52 also form the plate cylinder. Abut. In this way, after water is supplied to the plate of the plate cylinder,
Ink is supplied.

[0009]

However, the above-mentioned attachment / detachment state switching mechanism has the following problems. Regarding the rotation pitch of the positioning cam 2,
If the operator operates it, the rotational torque for sensuously rotating it by a predetermined pitch is applied, so that FIG.
There is no problem because the state can be switched in order from the state of FIG. 13 to the state of FIG. 14 through the state of FIG. However, if automatic switching is to be performed automatically, it is necessary to control the rotational torque applied to the shaft 3 so that the positioning cam 2 sequentially rotates. This is because the detachable cam 22 includes the swimsuit roller cam follower 26, the first ink inking roller cam follower 36, and the second ink inking roller cam follower 46.
Since the turning force in the direction of the arrow α is applied by the pressing force of the arrows γ1, γ2, and γ3 from, the positioning cam 2 is easily rotated in the direction of the arrow α. Therefore, as shown in FIG.
From the state of FIG. 14 to the state of FIG.
This is because if the ink is rotated, the ink may be supplied to the non-image area, the printing quality may be deteriorated, and the constituent parts may be subjected to excessive force to impair the durability.

In order to solve such a problem, it may be possible to provide a mechanism such as an air cylinder to surely rotate the positioning cam shaft 3 at a predetermined pitch. However, because of such a mechanism, the entire apparatus becomes complicated and maintenance becomes complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a switching state holding mechanism or a method thereof which can surely switch attachment / detachment of a rotating body used in a printing apparatus without separately providing a complicated mechanism. To do.

[0012]

According to a first aspect of the present invention, there is provided a switching state holding mechanism which has three or more recesses formed adjacent to each other and which rotates about a positioning cam shaft.
An engagement portion that engages with any one of the recesses, and an engagement portion that sequentially engages with each recess when the positioning cam rotates, and a member that presses the engagement portion toward the engaged recess. In the switching state holding mechanism including the joining portion pressing means, each of the recesses is formed such that the maximum riding angle in each of the recesses is gradually increased or decreased.

In the switching state holding mechanism according to claim 2,
By increasing or decreasing the distance between the positioning cam shaft and the bottom surface of each of the recesses sequentially, the maximum riding angle in each of the recesses is sequentially increased or decreased.

According to a third aspect of the present invention, there is provided a rotary member attachment / detachment state switching mechanism for use in the printing apparatus, wherein
A detachable cam that is coupled to a positioning cam of the state holding mechanism by a coupling mechanism and that rotates when the positioning cam rotates about an attach / detach cam shaft and that has an uneven cam surface. A driven body connected to a rotating body, which is in contact with the cam surface of the removable cam and moves in a direction toward or away from the removable cam shaft, thereby attaching or detaching the rotating body to or from the removable body. And a driven body urging means for urging the driven body in a direction approaching the removable cam shaft, the distance from the positioning cam shaft to each of the recesses is sequentially reduced in the first direction. When the positioning cam is rotated in the direction opposite to the first rotation direction, the cam surface of the detachable cam is
It is configured to move the driven body in a direction away from the removable cam shaft.

In the rotating body attachment / detachment state switching method used in the printing apparatus according to the fourth aspect, the attachment / detachment state of the rotation body used in the printing apparatus is switched by the cam surface of the attachment / detachment cam. When the rotational force for rotating the shaft is given, at least three recesses provided in the positioning cam are sequentially engaged with the engaging portions pressed in the direction of each recess, thereby maintaining the detached state. In the switching method, each of the recesses is formed such that the maximum riding angle in each of the recesses is successively increased or decreased.

[0016]

In the switching state holding mechanism according to the first aspect of the present invention, the recesses are formed so that the maximum riding angle in the recesses increases or decreases successively. Therefore, as the positioning cam rotates in the direction in which the maximum ride-over angle in each recess gradually increases, the engagement portion becomes less likely to ride over and difficult to rotate in that direction.

In the switching state holding mechanism according to claim 2,
By sequentially increasing or decreasing the distance between the positioning cam shaft and the bottom surface of each of the recesses, the maximum riding angle in each of the recesses is sequentially increased or decreased. Therefore, the maximum riding angle in each recess is
As the positioning cam rotates in the increasing direction, it becomes difficult for the engaging portion to get over, and it becomes difficult to rotate in that direction.

In the rotating body attachment / detachment state switching mechanism used in the printing apparatus of claim 3, when the positioning cam rotates in a direction opposite to the first rotation direction, the cam surface of the attachment / detachment cam is , The driven body is moved in a direction away from the removable cam shaft. Therefore, it becomes difficult for the positioning cam to rotate in the direction opposite to the first rotation direction. That is, it becomes difficult for the positioning cam to rotate in either direction. Therefore, accurate positioning can be performed without separately providing a mechanism for accurately rotating the positioning cam shaft with a pitch.

According to another aspect of the present invention, there is provided the method for changing the state of attachment / detachment of a rotating body, wherein the recesses are formed so that the maximum riding angle at each recess becomes larger or smaller successively. Therefore, as the positioning cam rotates in the direction in which the maximum ride-over angle in each recess gradually increases, the engagement portion becomes less likely to ride over and difficult to rotate in that direction. As a result, it is possible to maintain the attachment / detachment state of the rotating body used in the printing apparatus to / from the detachable body.

[0020]

An embodiment of the present invention will be described with reference to the drawings. First, an overall outline of a printing apparatus that employs this switching mechanism will be described. The printing device 110 shown in FIG.
This is an example adopted in a double-sided offset printing apparatus.

The printing apparatus 110 includes a plate cylinder 60, a first moisturizing device 122 and a first inking device 124, and water and ink necessary for printing on a plate (not shown) held on the plate cylinder 60. Is supplied, and printing is performed via the blanket cylinder 114. The same applies to the lower unit.

FIG. 4 shows the water and ink supply mechanism.
Will be explained. Note that FIG. 4 is shown upside down with respect to FIG. The attachment / detachment state switching mechanism 1 shown in FIG. 4 is a mechanism for attaching / detaching the swimwear roller 32 and the ink inking rollers 42, 52 to / from the plate cylinder 60, which is an object to be attached / detached. The attachment / detachment state switching mechanism 1 includes a positioning cam 2, a positioning arm 6,
Attachment / detachment cam 22, swimsuit roller cam follower 26, first ink inking roller cam follower 36, second ink inking roller cam follower 46, swimwear roller 32, first ink inking roller 42, and second ink inking roller 52 is provided.

The positioning cam 2 rotates about a shaft 3. In addition, in this specification, rotation means rotation in forward and reverse directions. The positioning cam 2 is provided with a recess 2a that is a first recess, a recess 2b that is a second recess, and a recess 2c that is a third recess adjacent to each other. It should be noted that “adjacent to each other” includes a case where there is a space between each recess. The shapes of the recesses 2a, 2b, 2c will be described with reference to FIG. The rollers 7 come into contact with the corresponding recesses 2a, 2b, 2c depending on the rotating state of the positioning cam 2. When the distances from the positioning cam shaft 3 to the contact surfaces of the recesses 2a, 2b, 2c are L21, L22, L23, respectively, the following relationships are established for L21, L22, L23.

L21 <L22 <L23 When the angle between the straight line L21 and the straight line L22 is θ1 and the angle between the straight line L22 and the straight line L23 is θ2,
The angle θ1 and the angle θ2 are substantially equal.

The positioning arm 6 rotates about the shaft 8. Hole 10 provided at one end of positioning arm 6
One end of a spring 12, which is a biasing means, is hooked on. The other end of the spring 12 is fixed. A roller 7 is rotatably held at the other end of the positioning arm 6.

As described above, the roller 7 includes the positioning arm 6
A pressing force is applied in the direction of the recess to be engaged by the spring 12 and the spring 12. In addition, from the positioning cam shaft 3 to the recess 2a,
Assuming that the first rotation direction α is a direction in which the respective distances to the contact surfaces of the recesses 2b and 2c become smaller, in the figure, L
21 <L22 <L23 means that the concave portions 2a, 2
This means that the maximum overcoming angle of the roller 7 in b and 2c is sequentially increased.

The maximum riding angle will be described with reference to FIG. The maximum overriding angle means the maximum angle in the concave portion among the angles formed by the straight line defined by the contact point between the engaging portion and the concave portion, the center of the positioning cam shaft, and the normal line at the contact point. In this case, in the recess 2a, the contact point P1 between the roller 7 and the recess 2a, the straight line m1 defined by the center O of the positioning cam shaft 3, and the contact point P
The angle ψ1 formed by the normal line m11 at 1 is defined. Similarly, the angles ψ2 and ψ3 are obtained for the recesses 2b and 2c, respectively. As can be seen in the figure, each recess 2a, 2b, 2
In c, the maximum overcoming angle is gradually increasing.

As described above, the roller 7 is less likely to be overridden by increasing the maximum overriding angle in sequence.

Incidentally, the maximum overcoming angle can be similarly obtained in the case other than the roller. For example, the maximum crossover angles in the recesses 2a, 2b, 2c as shown in FIG. 9 are angles ψ11, ψ12, ψ13.

In FIG. 1, L21 <L22 <L
By setting 23, when the positioning cam rotates in the first rotation direction α, the pressing force applied to the roller 7 increases. Therefore, even if a rotational force for rotating the positioning cam shaft 3 in the first rotation direction α is applied, it is possible to more reliably prevent the roller 7 from jumping over the recess 2b and engaging with the recess 2c. it can.

As shown in FIG. 4, the removable cam 2 connected to the positioning cam 2 via the arm 4 and the link 14.
2 are provided. The detachable cam 22 rotates about the detachable cam shaft 23. The detachable cam 22 includes a swimsuit roller cam follower 26, a first ink inking roller cam follower 3
6 and the second ink inking roller cam follower 46 are in contact with each other.

The swimsuit roller cam follower 26 includes the arm 2
It is rotatable about a shaft 27 by 8 and is biased in the β1 direction by a spring (not shown). The swimsuit roller cam follower 26 is connected to the swimsuit roller 32 via a link 29. Similarly, the first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 are similarly biased in the β2 direction and the β3 direction, respectively, and further, the first ink is fed via the links 39 and 49, respectively. It is connected to the inking roller 42 and the second ink inking roller 52. In the present embodiment, the swimsuit roller cam follower 26, the first ink inking roller cam follower 36 and the second ink inking roller cam follower 46 constitute a driven body, and the swimsuit roller cam follower 26
A spring (not shown) for urging the valve in the β1 direction, and
Similarly, the first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 are also respectively β2.
A spring (not shown) that urges in the direction .beta.3 constitutes the driven body urging means.

The detachable cam 22 will be described with reference to FIG. The removable cam 22 has a cam surface on the outer circumference. The cam surface includes a swimsuit roller recess 54, a swimsuit roller protrusion 53, a first ink replenishing roller recess 57, a first ink replenishing roller intermediate protrusion 56, and a first ink replenishing roller for use. Convex portion 55, second ink inking roller concave portion 67, first
And an intermediate convex portion 66 for the ink replenishing roller and a first convex portion 65 for the ink replenishing roller. The shape of the cam surface will be described with reference to FIG.

The step S1 between the swimsuit roller concave portion 54 and the swimsuit roller convex portion 53 is represented by S1 = L15-L16.

Further, the first ink replenishing roller recess 5
7. Step S with the first convex portion 56 for ink inking roller
2 and the step S3 between the first ink replenishing roller concave portion 57 and the first ink replenishing roller convex portion 55 is represented by S2 = L11-L12 S3 = L11-L13.

Note that S1 = S3.

Therefore, the swimsuit roller cam follower 26
Can take a two-step state of a position closer to or separated from the detachable cam shaft 24 by the step difference S1 depending on the abutting portion. On the other hand, the first ink replenishing roller cam follower 36 can take not only the above-described two-stage state but also a three-stage state which is an intermediate state thereof depending on the abutting portion. The second ink inking roller cam follower 46 can also be in the three-stage state in the same manner.

Next, referring to FIG. 7, the positioning cam shaft 3
An automatic feed mechanism 90 that gives a turning force to the will be described.
The automatic feeding mechanism 90 shown in FIG.
That is, it is the state viewed from the opposite side.

A ratchet 71 is fixed to the positioning cam shaft 3. Therefore, when the ratchet 71 rotates, the positioning cam 3 also rotates in the same rotation direction.
An arm 77 is rotatably attached to the positioning cam shaft 3. The arm 77 is connected to the link 85 by a shaft 87. The other end of the link 85 is attached to a shaft 83 that is offset from the center of rotation of the rotary plate 81. Therefore, when the rotary plate 81 rotates, the arm 77 moves the positioning cam shaft 3
It reciprocates around. A ratchet pawl 78 is attached to one end of the arm 77 while being biased clockwise around a shaft 80 in the figure.

When the link 89 is pulled by the solenoid 91 while rotating the rotary plate 81, the arm 73 rotates about the shaft 75 in the clockwise direction in the figure. Therefore, the tip of the ratchet pawl 78 has the teeth 93 of the ratchet 71.
Swings in a direction to engage with. In this state, when the arm 77 reciprocally rotates, the ratchet claw 78 rotates the ratchet 71 clockwise. That is, 1 of the rotary plate 81
By operating the solenoid 91 during rotation,
The positioning shaft 3 can be given a turning force in a clockwise direction in the drawing. The other end of the arm 77 has a ratchet pawl 10 having the same function as the ratchet pawl 78.
1 is provided. Therefore, by operating the solenoid 97, it is possible to apply a turning force in the opposite direction to the positioning shaft 3.

Next, referring to FIGS. 4 to 6, the removable cam 2 will be described.
The relationship between the second cam surface, the swimsuit roller cam follower 26, the first ink inking roller cam follower 36, and the second ink inking roller cam follower 46 will be described.

The state shown in FIG. 4 is the first rotation state in which the first recess 2a is engaged with the roller 7. In this state, the swimsuit roller cam follower 26 is in contact with the swimsuit roller convex portion 53, and the first and second ink replenishment roller cam followers 36 and 46 are respectively the first and second ink replenishment rollers. It is in contact with the convex portions 55 and 65. Therefore, the bathing suit roller 32, the first ink inking roller 42, and the second ink inking roller 52 are both in the state of being separated from the plate cylinder 60.

From this state, the automatic feeding mechanism shown in FIG. 7 applies a turning force in the direction of arrow α to the positioning cam shaft 3 in FIG. This causes the positioning cam 2 to move toward the arrow α.
It rotates in the direction, and as shown in FIG. 5, the roller 7 comes into contact with the recess 2b. As described above, in the positioning cam 2, the distance between the positioning cam shaft 3 and the second recess 2b is larger than the distance between the positioning cam shaft 3 and the first recess 2a. The distance between the positioning cam shaft 3 and the third recess 2c is larger than the distance between the shaft 3 and the second recess 2b. In this way, since the respective concave portions are arranged so that the distances from the positioning cam shaft 3 to the respective concave portions 2a, 2b, 2c are sequentially increased, even if the attaching / detaching cam 22 is caused by the pressing force from the three cam followers. Even if the turning force in the direction of the arrow α is applied to the detachable cam 22
Does not turn from the state of FIG. 4 to the state of FIG. 6 all at once.

That is, when the roller 7 comes into contact with the second concave portion 2b, the momentum is urged so that the second concave portion 2b and the third concave portion 2b.
It is possible to prevent the roller 7 from coming into contact with the third concave portion 2c by overcoming the convex portion between and.

As a result, the ink is not supplied to the non-image area, the quality of printing is deteriorated, and the durability is not impaired by applying unreasonable force to each component. As a result, FIG.
Even if an automatic feed mechanism having no pitch feed mechanism as shown in FIG. 3 is used, the state in which the roller 7 is in contact with the concave portion 2b (second rotating state) can be maintained.

At the same time as the positioning cam 2 is rotated, the attachment / detachment cam 22 is rotated in the arrow α direction via the link 14. The swimsuit roller cam follower 26 is the recess 5 for the swimsuit roller.
4 and comes closer to the detachable cam shaft 24 by that much.
As a result, the swimsuit roller 32 contacts the plate cylinder 60. The first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 also contact the ink replenishing roller recesses 56 and 66, respectively. However, the first and second ink follower roller cam followers 36,
46 abuts on the first and second intermediate ink replenishing roller convex portions 56 and 66, respectively. As a result, only the step S2 (see FIG. 2), the ink replenishing roller cam followers 36, 4
6 approaches the detachable cam shaft 23. That is, as shown in FIG. 5, the ink inking rollers 42 and 52 are separated from the plate cylinder by a distance d1.
Is held at a distance only. As a result, only water is supplied to the plate of the plate cylinder, and the ink inking rollers 42 and 52 approach the plate cylinder 60 up to a distance d1.

From this state, a turning force is similarly applied to the positioning cam shaft 3 in the direction of arrow α. As a result, the positioning cam 2 rotates in the direction of the arrow α, and as shown in FIG.
The roller 7 contacts the concave portion 2c (third rotation state). At the same time, the attachment / detachment cam 22 rotates in the direction of the arrow α via the link 14. As a result, the first ink replenishing roller cam follower 36 and the second ink replenishing roller cam follower 46 are also respectively provided with the ink replenishing roller recesses 57 and 67.
And the ink inking rollers 42 and 52 also come into contact with the plate cylinder. In this way, the plate held by the plate cylinder 60 is
After the water is supplied, the ink is supplied.

At this time, the first and second ink replenishing rollers 4
Both 2 and 52 once come close to each other from the distance d2 to the distance d1, and then become worn on the plate cylinder 60. Therefore, the contact shock can be softened.

As described above, the attachment / detachment cam 22 applies the turning force in the arrow α direction by the three cam followers, while making the positioning cam 2 difficult to rotate in the arrow α direction. As a result, the rotational couple for rotating the positioning cam shaft 3 in any direction can be made constant. Therefore, each component moves stably, no excessive force is applied, and the component is not damaged.

As described above, in the rotating body attachment / detachment state switching mechanism used in the printing apparatus according to the present invention, the respective rotational states can be reliably switched in the following manner. In the first rotation state, the swimsuit roller cam follower abuts on the swimsuit roller convex portion, and the first and second ink inking roller cam followers respectively contact the first and second inks. It contacts the convex portion for the inking roller.
Therefore, the swimsuit roller, the first ink inking roller, and the second ink inking roller are both in the separated state from the plate cylinder.

By the way, the first concave portion and the second concave portion are arranged so that the distances from the positioning cam shaft to the respective concave portions are gradually increased.
And a third recess. The rollers are in contact with the respective recesses. The positioning arm and the biasing means apply a pressing force to the roller. Therefore, the positioning cam moves from the first recess to the second recess,
As the second recess moves to the third recess, the pressing force that presses the roller against each recess increases. That is, the positioning cam is hard to rotate in the first rotation direction.

Therefore, even if the rotational force in the first rotation direction is applied to the positioning cam shaft, the second rotation state can be reliably achieved without suddenly changing from the first rotation state to the third rotation state. It is in a rotating state. In this state, the swimsuit roller cam follower comes into contact with the swimsuit roller concave portion, and the swimsuit roller is in a state of being attached to the plate cylinder. On the other hand, the first and second ink follower roller cam followers are
The first and second ink replenishing rollers both come into contact with the plate cylinder by coming into contact with the first and second intermediate ink replenishing roller convex portions, respectively. That is, only the swimsuit roller is turned on to the plate cylinder. As a result, water is supplied to the non-image portion of the plate surface held by the plate cylinder.

Further, when a rotational force in the first rotation direction is further applied to the positioning cam shaft, the second rotation state is changed to the third rotation state. In this state, the swimsuit roller cam follower is brought into contact with the swimsuit roller recess to bring the swimsuit roller into contact with the plate cylinder, and the first and second ink inking roller cam followers are respectively It comes into contact with the recesses for the first and second ink replenishing rollers and comes into contact with the plate cylinder. That is,
Both the swimsuit roller and the first and second ink inking rollers are turned on to the plate cylinder. Therefore, ink is supplied to the image area of the plate.

In this way, from the first rotation state,
By reliably switching between the second rotation state and the third rotation state, ink is not supplied to the non-image portion, and an excessive force is applied to the constituent portion to impair durability. Nor. Accordingly, it is possible to provide a switching state holding mechanism that can reliably switch attachment / detachment of the rotating body used in the printing apparatus without separately providing a complicated mechanism.

Therefore, even if it is automated, since water and ink are supplied in order, a good printed matter can be easily and surely obtained from the beginning of printing. As a result, the number of times the plate surface is cleaned is reduced, workability is improved, and the occurrence of erroneous printed matter at the beginning of printing can be prevented.

In this embodiment, by setting L21 <L22 <L23 in FIG. 1, the maximum overpass angle is gradually increased and the first rotation direction α
When turning to, the pressing force applied to the roller 7 is increased. However, the present invention is not limited to this, and only the maximum crossover angle may be sequentially increased. For example, as shown in FIG. 10, θ21 <θ22
Then, from the center O to the center P20, P21, P2 of the recess
It is possible to sequentially increase only the maximum crossover angle without changing the distance up to 2.

On the contrary, only the pressing force applied to the roller 7 may be increased. In order to increase the pressing force applied to the roller 7, for example, by a mechanism as shown in FIG. 11, one end of the spring 12 is moved as the positioning cam 2 is rotated in the first rotation direction α. You can leave it. In FIG. 11, an arm 45 that rotates together with the positioning cam 2 is provided. When the positioning cam 2 rotates in the first rotation direction α, the arm 45 pushes the link 44 in the arrow δ direction. One end 48 of the spring 12 is
Since it is provided so as to be movable along the long hole 47, the elastic force of the spring 12 increases.

In the above embodiment, the cam followers for the swimsuit roller and the ink follower roller cam followers are controlled by one cam, but separate cams may be used.

Further, in the present embodiment, the printing apparatus using the two cam followers for the ink replenishing roller has been described, but one cam follower for the ink replenishing roller may be used, or three or more may be adopted. .

The detachable cam may be another cam instead of the rotating cam.

In the present embodiment, the swimsuit roller cam follower 26 is configured to move away from the plate cylinder 60 to separate the swimsuit roller 32 from the plate cylinder 60. The swimsuit roller 32 may be moved closer to the plate cylinder 60 by moving 26 in a direction away from the plate cylinder 60.
In this case, the unevenness of the cam surface is opposite to that of this embodiment.

In this embodiment, the roller 7 rotatably held is used as the engaging portion, but the roller 7 may be held so as not to rotate, and a member other than the rollers may be encountered.

In this embodiment, the case of performing the switching in three stages has been described, but the same can be applied to the case of three or more stages.

In this embodiment, the case where the swimsuit roller and the ink replenishing roller are attached to and detached from the plate cylinder has been described as an example, but the present invention is also applied to the case where other rollers such as a paper feed roller are attached and detached. be able to. Further, not only the roller but also the cylinder, for example, the plate cylinder, the impression cylinder, and the attachment / detachment of the blanket cylinder can be similarly applied.

In the present embodiment, the double-sided printing device has been described as an example, but the present invention can be applied to other offset printing devices as well as other printing devices.

[0066]

In the switching state holding mechanism according to the first or second aspect of the present invention, the recesses are formed so that the maximum riding angle at each recess becomes larger or smaller in order. Therefore, as the positioning cam rotates in the direction in which the maximum ride-over angle in each recess gradually increases, the engagement portion becomes less likely to ride over and difficult to rotate in that direction. Accordingly, it is possible to provide a switching state holding mechanism that can reliably switch attachment / detachment of the rotating body used in the printing apparatus without separately providing a complicated mechanism.

In the rotating body attachment / detachment state switching mechanism used in the printing apparatus according to claim 3, when the positioning cam rotates in the direction opposite to the first rotation direction, the cam surface of the attachment / detachment cam is , The driven body is moved in a direction away from the removable cam shaft. Therefore, it becomes difficult for the positioning cam to rotate in the direction opposite to the first rotation direction. That is, it becomes difficult for the positioning cam to rotate in either direction. Therefore, accurate positioning can be performed without separately providing a mechanism for accurately rotating the positioning cam shaft with a pitch. Accordingly, it is possible to provide a switching state holding mechanism that can reliably switch attachment / detachment of the rotating body used in the printing apparatus without separately providing a complicated mechanism.

In the rotating body attachment / detachment state switching method used in the printing apparatus according to the fourth aspect of the present invention, the recesses are formed so that the maximum riding angle in the recesses increases or decreases sequentially. Therefore, as the positioning cam rotates in the direction in which the maximum ride-over angle in each recess gradually increases, the engagement portion becomes less likely to ride over and difficult to rotate in that direction. As a result, it is possible to maintain the attachment / detachment state of the rotating body used in the printing apparatus to / from the detachable body. That is, it is possible to provide a switching state holding method capable of reliably switching the attachment / detachment of the rotating body used in the printing apparatus without separately providing a complicated mechanism.

[Brief description of drawings]

FIG. 1 is a diagram showing three recesses of a positioning cam according to the present invention.

FIG. 2 is a diagram showing a cam surface of a removable cam according to the present invention.

FIG. 3 is a schematic diagram of a printing apparatus according to the present invention.

FIG. 4 is a diagram showing a positioning cam and an attachment / detachment cam in which a swimsuit roller and an ink inking roller are in a detached state.

FIG. 5 is a view showing a positioning cam and a detachable cam in which only the swimsuit roller is worn.

FIG. 6 is a diagram showing a positioning cam and an attachment / detachment cam in which a swimsuit roller and an ink inking roller are in a worn state.

FIG. 7 is a view showing an automatic feeding mechanism.

FIG. 8 is a diagram for explaining a maximum overcoming angle.

FIG. 9 is a diagram for explaining a maximum overcoming angle.

FIG. 10 is a diagram showing another embodiment in which the maximum riding angle is increased.

FIG. 11 is a diagram showing an example in which the pressing force of the roller 7 is increased.

FIG. 12 is a view showing a positioning cam and a mounting / demounting cam in a detached state of a swimsuit roller and an ink inking roller in a conventional mechanism.

FIG. 13 is a view showing a positioning cam and a detachable cam in a conventional mechanism in which only a swimsuit roller is attached.

FIG. 14 is a diagram showing a positioning cam and a mounting / demounting cam in which a swimsuit roller and an ink replenishing roller in a conventional mechanism are in a worn state.

[Explanation of symbols]

2 ・ ・ ・ ・ ・ ・ Positioning cam 2a ・ ・ ・ ・ Recessed portion 2b ・ ・ ・ ・ Recessed portion 2c ・ ・ ・ ・ ・ Recessed portion 6 ・ ・ ・ ・ ・ ・ ・ ・ Positioning arm 7・ ・ ・ ・ ・ ・ ・ ・ Roller 12 ・ ・ ・ ・ ・ ・ Spring 22 ・ ・ ・ ・ ・ ・ ・ ・ Detachable cam 26 ・ ・ ・ ・ Swimsuit roller cam follower 36 ・ ・ ・ ・ ・ ・ ・ ・ First Ink inking roller cam follower 46 ···· Second ink inking roller cam follower 32 ···· Swimsuit roller 42 ··· First ink inking roller 52 ···・ ・ ・ ・ ・ Second ink coating roller 53 ・ ・ ・ ・ ・ ・ Swimsuit roller protrusion 54 ・ ・ ・ ・ ・ ・ Swimsuit roller recess 55 ・ ・ ・ ・ ・ ・ First ink deposit Meat roller protrusion 56 ······························································ 1 Roller recessed portion 65 ... First ink replenishing roller protrusion 66 .... First ink replenishing roller intermediate protrusion 67..Second Recess for ink inking roller

Claims (4)

[Claims] 1. A positioning cam which has three or more recesses formed adjacent to each other and which rotates about a positioning cam shaft, and an engaging portion which engages with any one of the recesses, said positioning A switching state holding mechanism including: an engaging portion that sequentially engages with each of the recesses when the cam rotates; and an engaging portion pressing means that presses the engaging portion in the direction of the engaged recess. A switching state holding mechanism, characterized in that each of the recesses is formed so that the maximum riding angle increases or decreases in sequence. 2. The switching state holding mechanism according to claim 1, wherein the maximum riding angle in each of the recesses is successively increased or decreased by gradually increasing or decreasing the distance between the positioning cam shaft and the bottom surface of each of the recesses. A switching state holding mechanism characterized in that. 3. The switching state holding mechanism according to claim 2, which is connected to the positioning cam of the state holding mechanism by a connecting mechanism, and is a detachable cam that rotates about the detachable cam shaft when the positioning cam rotates. A detachable cam having an uneven cam surface, and a follower connected to a rotating body, which comes into contact with the cam surface of the detachable cam and moves in a direction toward or away from the detachable cam shaft. A driven body for switching the attachment / detachment state of the rotating body to / from the attached / detached body; and a driven body urging means for urging the driven body in a direction approaching the attachment / detachment cam shaft. A direction in which the distance to the recess gradually decreases is defined as a first rotation direction, and when the positioning cam rotates in a direction opposite to the first rotation direction, the cam surface of the detachable cam is Attach the follower to the removable Rotator detachment state switching mechanism used that is configured to move in a direction away from the axis, the printing apparatus according to claim. 4. A method for switching the state of attachment / detachment of a rotating body used in a printing device to / from an attached / detached body by a cam surface of the attaching / detaching cam, wherein positioning is performed when rotational force for rotating the positioning cam shaft is applied. In the switching method of maintaining the detached state by sequentially engaging the engaging portions pressed in the direction of each recess with at least three recesses provided in the cam, the maximum ride-over angle in each recess increases sequentially. Alternatively, each of the recesses is formed so as to be small.