JPH0367843A - Film tension control mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film transport system, and particularly to a film tension control mechanism suitable for applying a constant film tension.

[Conventional technology]

Conventionally, in a film tension control mechanism for applying a constant film tension, for example, Japanese Patent Laid-Open No. 62
- As described in Publication No. 20898, a mechanism that directly sandwiches the film between tension rollers and applies a constant tension to the film regardless of the film roll diameter, and a mechanism that presses the roller against the side of the film roll and connects it to this roller. 4- A mechanism that applies a resistance force proportional to the displacement of the film roll diameter to the film roll shaft using a sliding member; Mechanisms have been discussed that apply a resistance force proportional to the radial displacement to the film roll axis and provide approximately constant film tension. A similar mechanism for converting changes in film roll diameter into resistance changes and electrically obtaining constant tension is disclosed in Japanese Patent Application Laid-Open No. 58-148.
This is also discussed in Publication No. 145.

Furthermore, Japanese Patent Application Laid-open No. 49-37036 discusses a mechanism for obtaining a constant tension by detecting the running length of a layer to be wound during winding and electrically processing this to change the winding speed. ing.

Further, Japanese Patent Application Laid-Open No. 61-47287 discusses a mechanism that doubles the change in the mass of the ink ribbon and mechanically maintains the tension of the ribbon at a constant level.

[Problem to be solved by the invention]

With conventional film tension mechanisms, the addition of accessory parts such as tensioning rolls makes the device complicated.
In addition, there are problems in that the capacity is large, the number of assembly steps increases, the device becomes expensive, and it is difficult to miniaturize the device.

Furthermore, even when the tension is controlled by measuring the roll diameter using an electrical sensor, there is a similar problem in that the device is expensive.

The purpose of the present invention is to:
It is an object of the present invention to provide a film tension control mechanism that can apply a fairly constant tension to a film and is small and easy to assemble.

[Means to solve the problem]

In order to achieve the above object, the film tension control mechanism according to the present invention is a film tension control mechanism provided in a film transport system that winds the film from a supply side film roll loaded with film to a winding side film roll. At least one of the film rolls is provided with a torque limiter that controls the rotational torque of the film roll using frictional force according to changes in the diameter of at least one of the film rolls, and keeps the film tension of the film almost constant. The structure is such that it is included in the film tension applying section provided.

In a film tension control mechanism provided in a film conveyance system that transfers the film from a supply-side film roll loaded with film to a take-up-side film roll, an input part that is connected to an opening source and rotates; The structure may also include a torque limiter comprising an output part that transmits a predetermined rotational torque by the frictional force between the two film rolls, and an adjustment part that adjusts the frictional force according to a change in the diameter of at least one of the film rolls. .

In addition, in the film tension control mechanism provided in the film transport system that winds the film from the film roll loaded with film on the supply side to the film roll on the winding side, a fixed device that is inserted concentrically with the torque transmission shaft and rotates together with the torque transmission shaft is used. A rotating plate that contacts one side of the fixed plate and outputs rotational torque by the frictional force between the plate and is inserted into the torque transmission shaft, and a rotating plate that contacts one side of the rotating plate and inserted into the torque transmission shaft. A pressing plate that contacts one side of the intermediate pressing plate and is inserted through the torque transmission shaft to lock the rotation.
The pressing is carried out by an adjustment ring that engages with one surface of the plate, is inserted into the torque transmission shaft, and has means for moving in the direction of the rotation axis according to changes in the diameter of the film roll, and an adjustment ring that The amount of compression of the spring is adjusted through a spring that contacts and changes the amount of compression by the axial movement of the adjustment ring, a spring pushing plate that contacts one end face of the spring and is inserted through the torque transmission shaft, and the spring pushing plate. In addition, a structure may be adopted in which a torque limiter including a semi-fixed plate that rotates together with the torque transmission shaft is provided in a film tension applying section arranged in parallel with at least one of the film rolls.

The torque limiter must perform one of the following movements: a movement corresponding to the drive source, a movement corresponding to the rotation of the film roll, a movement corresponding to a change in the diameter of the film roll, or a movement corresponding to the film transport system. It is the composition.

Further, the spring is composed of a fixed spring that always generates a constant pressing force, and a variable spring whose pressing force is changed according to changes in the diameter of the film roll.

Furthermore, the torque limiter has a structure in which the torque transmission shaft is supported by a pressing plate, and the pressing plate is a bearing mechanism, and after each part is assembled from one direction of the shaft, the film is transported as one set. The configuration is such that it is connected to the system.

Further, the torque limiter is configured to adjust the rotational torque initially output by the final assembled parts.

[Effect]

According to the present invention, since the film tension control mechanism is equipped with a torque limiter that changes the frictional force according to the diameter of the film roll and controls the film tension to be approximately constant, the torque limiter can be assembled from one direction of the shaft, and connected to the film transport system as a set. By moving the semi-fixed plate, which is the final assembled part, in the axial direction, the amount of compression of the spring is adjusted, and the initial rotational torque output value is set. Further, the arm is displaced in response to a change in the diameter of the film roll, thereby causing a mu-cling rotation.

Therefore, the rectangular protrusion of the adjustment ring is guided by the slope of the trapezoidal protrusion of the plate when pressed, so the amount of deflection of the spring changes and the friction between the rotating plate and the fixed plate or intermediate pressing plate that outputs rotational torque changes. Power changes.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, in a film tension control mechanism provided in a film transport system that winds a film from a film roll 1 on a supply side loaded with film to a film roll on a winding side, at least one of A torque limiter 3 that controls the rotational torque of the film roll 1 using frictional force in response to changes in the diameter of the film roll 1, for example, and keeps the film tension of the film substantially constant.
0, at least one of the film rolls 1
The structure is such that the film tension applying section 40 is provided in parallel with the film tension applying section 40 .

In a film tension control mechanism provided in a film conveyance system that winds a film from a film roll l on a supply side loaded with film onto a film roll on a winding side, the limiter is connected to a drive source (motor) 5 and a motor gear 6 to rotate. an input section consisting of a gear 7, a torque transmission shaft 16, etc.; an output section that transmits a predetermined rotational torque to the film roll gear and the film roll shaft 2 via the rotary plate 9 by the frictional force between the input section; and at least It may also be configured to include a torque limiter 30 comprising an adjusting section such as a semi-fixed plate 15 that adjusts the frictional force according to a change in the diameter of one of the film rolls 1, for example.

In addition, in a film tension control mechanism provided in a film conveyance system that winds the film from a supply side film roll 1 loaded with film to a take-up side film roll, the torque transmission shaft 16 is inserted concentrically with the torque transmission shaft 16.
The fixed plate 8 that rotates together with the fixed plate 8 and the rotating plate 8 that contacts one side of the fixed plate 8 and outputs rotational torque by the frictional force with the surface and transmits torque 1- The rotating plate 8 that is inserted into the shaft 16 and one side of the rotating plate 8 An intermediate pressing plate 10 that contacts one side surface and is inserted into the torque transmission shaft 16, a pressing plate 11 that contacts one side surface of the intermediate pressing plate 10 and is inserted through the torque transmission shaft 16 to lock its rotation; is board 11
an adjustment ring 12 that is inserted into the torque transmission shaft 16 by engaging with one surface of the adjustment ring 12 and having means for moving in the direction of the rotation axis according to changes in the diameter of the film roll 1; and one surface of the adjustment ring 12. a spring 13 in contact with the spring 13 whose compression amount changes as the adjustment ring 12 moves in the axial direction; a spring pushing plate 14 in contact with one end surface of the spring 13 and inserted into the torque transmission shaft 16;
A torque limiter 30 consisting of a semi-fixed plate 15 that adjusts the amount of compression of the spring 13 via a spring pushing plate 14 and rotates together with the torque transmission shaft 16 is installed in parallel with at least one of the film rolls 1, for example. The structure may be provided in the film tension applying section 40.

The torque limiter 40 performs a motion corresponding to the drive source (motor) 5, a motion corresponding to the rotation of the film roll 1, a motion corresponding to a change in the diameter of the film roll 1, or a motion corresponding to the film transport system. It is a configuration that performs one of these movements.

The spring 13 is composed of a fixed spring 13b that always generates a constant pressing force, and a variable spring 13a whose pressing force can be changed according to changes in the diameter of the film roll.

Furthermore, the torque limiter 30 has a configuration in which the torque transmission shaft 16 is supported by the pressing plate 11, and the pressing plate 11 is a bearing mechanism, and the 1-Low limiter 30 is configured such that the torque transmission shaft 16 is supported by the pressing plate 11, and the torque transmitting shaft 16 is supported by the pressing plate 11 as a bearing mechanism. , are connected to the film transport system as one set.

Further, the torque limiter 30 is configured to adjust the rotational torque initially output by the final assembled parts.

That is, the torque transmission shaft 16 is rotationally driven by the motor 5 via the motor gear 6 and the limiter gear 7, the fixed plate 8 is concentric with the torque transmission shaft 16 and fixed to the torque transmission shaft 16, and the torque transmission shaft 16 is connected to the torque transmission shaft 16. A rotary plate 9 that is concentric with the fixed plate 8 and transmits torque, and an intermediate pusher that is concentric with the torque transmitting shaft 6 and slides while being pressed against the rotary plate 9 while being rotated in synchronization with the torque transmitting shaft 16. The plate 10 is concentric with the torque transmission shaft 16 and has an intermediate punching process O.
The pressing member, which is fixed to the mechanical system while being pressed by the plate 11, is concentric with the l/lux transmission shaft 16 and is in contact with the outer periphery of the film roll 1-, and changes as the diameter of the film roll 1 changes. An adjustment ring 12 having a chevron-shaped protrusion that rotates and moves in the axial direction as the arm 4 is displaced; A spring 13 whose amount changes, a spring pressing plate 14 which is concentric with the torque transmission shaft 16 and pressed by one end of the spring 13 while making the same rotational movement as the adjustment ring 12, and a spring pressing plate 14 which is concentric with the torque transmission shaft 16 and is pressed by one end of the spring 13. It is characterized by consisting of a semi-fixed punch 5 which is pressed against and fixed to the 1-lux transmission shaft while sliding therewith.

The operation of this embodiment will be explained with reference to FIG. The torque limiter of this embodiment adjusts the amount of shrinkage of the spring 13 using the semi-fixed plate 15 so that a predetermined film tension can be obtained when the film roll 1 is not in use. That is, the semi-fixed plate 15 has a structure that is movable in the axial direction and rotates together with the torque transmission shaft 16. For example, the semi-fixed plate 15 is screwed onto the torque transmission shaft 16 using a threaded structure, and adjusts the amount of screw rotation in the direction of arrow A. This allows the amount of compression of the spring 13 to be adjusted.

Therefore, due to the reaction force, the torque is transmitted to the shaft 1 via the semi-fixed plate ↓5.
6 receives an axial force in the direction of arrow B, and the fixing plate 8 and the intermediate pressing plate 1
1 and the rotary plate 9 is adjusted. On the other hand, the motor 5 applies a rotational force in a direction that provides resistance to the film supply through the adjustment ring 12, and a predetermined torque is applied to the film roll l through the rotary plate 9 and the film roll gear 3. That is, while the motor 5 is rotating, the adjustment ring 12 and the spring pressing plate 14 are in the position of the semi-fixed plate 1.
The arm 4 fixed on the adjustment ring 2 is pressed against the film roll 1 by the rotational force due to the frictional force between the arm 4 and the adjustment ring 2, and is displaced as the diameter of the film roll 1 decreases. As the arm 4 changes i'l, the adjustment lever 15-puffer 12 rotates and smoothly moves along the chevron-shaped protrusion in a direction that reduces the amount of compression (amount of compression) of the spring 13. Since the pressing force is reduced, the output torque from the rotary plate 9 to the film roll gear 3 is also reduced. The shapes of the chevron-shaped protrusions on the pressing plate 11 and the adjusting ring 12 should be determined from the shapes of each element of the mechanism so that the rate of decrease in the diameter of the film roll l and the rate of decrease in the amount of shrinkage of the spring 13 are equal. Accordingly, a constant film tension can be obtained regardless of the diameter of the film roll 1.

For example, as shown in FIG. 2, when the arm 4 is displaced as the diameter of the film roll l decreases and the adjustment ring 12 rotates in the direction of the arrow A, the circumference of the adjustment ring 12 provided in the direction of the arrow A is A plurality of rectangular protrusions 12a facing each other are provided on the plate 11 and are inclined at an angle 1 rising in the direction of the arrow.
The adjusting ring 12 is moved in the direction of arrow B by being guided by the slope ↓lb of the plurality of trapezoidal protrusions 11a in the circumferential direction. Therefore, the amount of deflection of the spring 13 is reduced, and the axial force in the direction of arrow 16-A of the torque transmission shaft]6 via the semi-fixed plate 15 is reduced, and the friction between the fixed plate 1, the intermediate pushing plate 10, and the rotating plate 9 is reduced. A constant film tension will result from the reduction in force.

Furthermore, by selecting a combination of materials with a small friction coefficient, such as a combination of aluminum and duralumin, for the pressing plate 11 and the adjusting ring 12, the adjusting ring 12 can move more smoothly in the axial direction, and the rotating plate 9, the output torque changes more smoothly.

Even when the film roll diameter increases, a constant film tension can be obtained in the same way.

Another embodiment of the invention will be described with reference to FIG.

In this embodiment, in addition to the spring 13a whose shrinkage amount changes with the displacement of the adjustment ring 12, a fixed spring 13b whose shrinkage amount is always constant is provided. Suitable for relatively small cases.

In the film tension control mechanism of the present invention, the initial output torque is adjusted by adjusting the position of the semi-fixed plate, but the decrease in output due to wear of the sliding surface due to long-term use can also be caused by adjusting the position of the semi-fixed plate. Adjustments can be made easily.

Next, FIGS. 4 and 5 show an embodiment of the arm 4 which is displaced as the diameter of the film roll 1 changes. FIG. 4 shows an arm 4 whose contact portion with the film roll 1 is a flat plate with a small coefficient of friction, thus simplifying the structure. Further, FIG. 5 shows an arm 4 whose contact portion with the film roll 1 is a roller, so that the arm 4 has a structure that allows the film roll 1 to rotate easily.

FIG. 6 shows an embodiment regarding the state of connection between the adjustment ring 12 and the arm 4. The arm 4 is rigidly connected to the adjustment ring 12 by adhesive or the like, or is integrally formed by injection molding or the like.

Figures 7 and 8 show the diameter r of the film roll 1 and the arm 4.
The relationship between the rotation angle θ and the pressing at the rotation angle θ indicates the protrusion amount X+ΔX of the protrusion 11a of the plate 11. The initial diameter of the film roll 1 is R, the distance between the axes of the film roll 1 and the adjustment ring 12 is set, and the spring constant of the spring 13 is set to K.
, the repulsive force of the spring 13 is P, the output torque of the torque limiter is T(1, and the film tension at this time is TR), then the following equation holds true.

Furthermore, in the slip type torque limiter, the following equation generally holds true, where α is an arbitrary constant.

Pα=T(1...(2) The following equation is obtained from the above equation.

Δx= (TRLsinθ)/(αK)... (
3) When the relationship between the angle of rotation θ of the pressing plate 11 and the amount of change ΔX in the amount of protrusion of the protrusion 11a on the pressing plate 11 satisfies the above equation, the film tension can be kept almost constant. However, when ΔX=O, TR is the desired film tension, x= (TRR)/(αK)...
...Determine the amount of shrinkage X of the spring 13 so as to satisfy (4)9. Even if the relationship between θ and ΔX does not satisfy Equation (3), it is possible to realize a film tension control mechanism with small torque fluctuations by satisfying an arbitrary relationship close to Equation (3).

An example of the operation of the torque limiter when replacing the film roll 1 is shown in FIGS. 9 and 10. After use, the supply film roll 1 becomes smaller in diameter as shown in FIG. 9, and the arm 4 is also displaced accordingly. When replacing the film roll 1, the arm 4 is positioned on the entry path of the film roll 1 as shown in FIG. 10, so that the arm 4 returns to its initial position and the torque limiter is reset. As for the take-up roll, since a force is applied to the arm 4 to press it against the film roll 1 during use, the arm 4 naturally returns to its initial position and the torque limiter is reset.

As another embodiment of the present invention, an example of application to a thermal transfer facsimile is shown in FIG. The ink film is transported from the supply side film roll 1b to the guide roller 21, platen roller 20. It passes through a separator roller 20-19 and is wound onto the winding side film roll 1a.

Torque limiters 17a and 17b as a film tension control mechanism of the present invention each
a, lb, and is a mechanism in which a constant film tension is always applied to the film by inputting a rotational force in the direction of the arrow in FIG. Furthermore, it is also possible to use the mechanism of the present invention as a tension applying mechanism on either the supply side or the winding side, and in this case, the mechanism of the present invention can be used as the tension applying mechanism on either the supply side or the winding side. The film tension is always constant.

〔Effect of the invention〕

According to the present invention, since the film tension control mechanism is equipped with a torque limiter that changes the frictional force according to the diameter of the film roll and controls the film tension to be approximately constant, it is small and easy to assemble, and can be assembled as a single set. It can be connected to the film transport system, and has the effect of making it easy to set the initial rotational torque.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams showing one embodiment of the present invention, FIG. 3 is a block diagram showing another embodiment of the present invention, and FIG. 4 is a perspective view showing one embodiment of the arm of the present invention. Figures 5 and 6 are perspective views showing other embodiments of the arm of the present invention, Figures 7 and 8 are diagrams illustrating the shape of the protrusion of the pressing plate of the present invention,
9 and 10 are diagrams for explaining the operation of the arm of the present invention, and FIG. 11 is a perspective view of the present invention applied to a thermal transfer facsimile. 1... Film roll, 4... Arm, 8 - Fixed plate. 9...Rotating plate, 10...Middle push plate, 11...Pushing plate, ↓2...Adjustment ring, 13-Spring, 14...Spring push plate, 15...Semi-fixed plate. 30...torque limiter, 40...film tension applying section.

Claims (1)

[Claims] 1. A film tension control mechanism provided in a film transport system that winds the film from a supply-side film roll loaded with film to a take-up-side film roll,
At least one of the films is provided with a torque limiter that controls the rotational torque of the film roll by frictional force in response to a change in the diameter of at least one of the film rolls, and keeps the film tension of the film substantially constant. A film tension control mechanism, characterized in that the film tension control mechanism is provided in a film tension applying section arranged in parallel with a roll. 2. In a film tension control mechanism provided in a film transport system that winds the film from a supply-side film roll loaded with film to a take-up-side film roll,
an input section that is connected to a drive source and rotates; an output section that transmits a predetermined rotational torque by a frictional force between the input section; A film tension control mechanism characterized by comprising a torque limiter consisting of an adjustment section that adjusts force. 3. In a film tension control mechanism provided in a film transport system that winds the film from a supply-side film roll loaded with film to a take-up-side film roll,
A fixed plate that is inserted concentrically with the torque transmitting shaft and rotates together with the torque transmitting shaft, and a fixed plate that contacts one side of the fixed plate and outputs rotational torque by the frictional force with the surface, and is inserted into the torque transmitting shaft. a rotating plate that contacts one side of the rotating plate and is inserted through the torque transmission shaft; and an intermediate pressing plate that contacts one side of the intermediate pressing plate and is inserted through the torque transmission shaft so that rotation is locked. a pressing plate that engages with one side of the pressing plate, is inserted into the torque transmission shaft, and has an adjustment ring that rotates in response to changes in the diameter of the film roll and has means for moving in the axial direction; a spring that contacts one surface of the adjustment ring and whose compression amount changes as the adjustment ring moves in the axial direction; a spring push plate that contacts one end surface of the spring and is inserted through the torque transmission shaft; A film tensioning section that adjusts the amount of compression of the spring via a spring pusher plate and includes a semi-fixed plate that rotates together with the torque transmission shaft is installed in a film tension applying unit that is arranged in parallel with at least one of the film rolls. A film tension control mechanism characterized by comprising: 4. The torque limiter is one that makes any one of the following movements: a movement corresponding to the driving source, a movement corresponding to the rotation of the film roll, a movement corresponding to a change in the diameter of the film roll, or a movement corresponding to the film transport system. The film tension control mechanism according to claim 1 or 2, characterized in that: 5. The spring is a fixed spring that always produces a constant pressing force,
4. The film tension control mechanism according to claim 3, further comprising a variable spring that changes the pressing force in accordance with changes in the diameter of the film roll. 6. The film tension control mechanism according to claim 3, wherein the torque limiter supports the torque transmission shaft with a pressing plate, and the pressing plate is a bearing mechanism. 7. The film tension control mechanism according to claim 3, wherein the torque limiter is connected to the film transport system as a set after each component is assembled from one direction of the shaft. 8. The film tension control mechanism according to claim 3, wherein the torque limiter adjusts the rotational torque initially output by the final assembled parts. 9. A plurality of rectangular protrusions guided by the slopes of a plurality of trapezoidal protrusions protruding on one side of the pressing plate and provided on the other side of the adjustment ring, and one end fixed to the adjustment ring. A torque limiter characterized in that the adjustment ring is provided with a moving means comprising an arm whose other end contacts the outer periphery of the film roll and rotates the adjustment ring according to changes in the diameter of the film roll. 10. A thermal transfer facsimile machine that winds an ink film from a supply film roll via at least a platen roll to a take-up film roll at a predetermined film tension, the film tension control mechanism according to any one of claims 1 to 8. A thermal transfer facsimile characterized by being equipped with.