JP3676533B2 - Sliding doctor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a doctor device that removes foreign matter such as paper sheets from an outer peripheral surface by pressing a doctor blade against the outer peripheral surface of a roll such as a paper machine roll.
[0002]
[Prior art]
Doctor devices are widely used in fields where rolls are used in manufacturing or processing processes such as in the paper industry. For example, a doctor device is used to remove foreign substances such as paper sheets attached to the surface of a paper machine roll.
[0003]
The doctor device includes a doctor blade having a length over the entire outer peripheral surface width (length in the axial direction) of a target roll. By pressing the blade edge of the doctor blade against the outer peripheral surface of the roll rotating with an appropriate pressure contact force, foreign matter can be scraped off from the outer peripheral surface of the roll.
[0004]
In order to appropriately perform the foreign substance scraping operation (doctor ring), it is necessary to form a state in which the blade edge of the doctor blade is pressed against the outer peripheral surface of the roll with a uniform pressing force over the entire width. However, the roll surface is not flat but slightly uneven. There is also a manufacturing error on the blade edge side of the doctor blade.
[0005]
For this reason, the pressure contact force may be too high in some parts of the blade edge of the doctor blade, and the pressure contact force may be too low in other parts. In this case, wear of the blade edge of the doctor blade becomes severe at a portion where the pressure contact force is too high. On the contrary, in the portion where the pressure contact force is too low, the foreign matter is not scraped off sufficiently and remains on the outer peripheral surface of the roll.
[0006]
On the other hand, in order to perform doctoring of a long roll, it is necessary to use a long doctor blade corresponding to the roll width. In this case, as a whole, the required pressure contact force may not be obtained unless the doctor blade is pressed against the roll with a large force.
[0007]
[Problems to be solved by the invention]
As described above, in a generally used doctor apparatus, it may be difficult to set the pressure contact force of the doctor blade to an appropriate state.
[0008]
An object of the present invention is to propose a doctor device capable of always pressing an outer peripheral surface of a roll in an appropriate state with a blade edge of a doctor blade and always performing an appropriate foreign material scraping operation.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a doctor blade having a width sufficiently narrower than the width of the target roll (length in the axial direction) is prepared, and the doctor blade having this narrow width is rolled. A configuration is adopted in which foreign matter is scraped off while sliding in the roll axis direction while being pressed against the outer peripheral surface. That is, by moving the doctor blade in the axial direction of the roll, foreign matters are removed from the outer peripheral surface of the roll at different positions in the axial direction.
[0010]
The width of the doctor blade is set to be not more than half of the length of the target roll in the axial direction . In the most general case, the width of the doctor blade is set in the range of 50 mm to 500 mm . Furthermore, in a preferred embodiment, it is set to 100 mm .
[0011]
As described above, in the present invention, the foreign matter is scraped off from the outer peripheral surface of the roll while sliding the doctor blade in the roll axis direction. Therefore, a doctor blade having a narrower width than the roll width can be used. As a result, it becomes easy to form a state in which all portions of the blade edge of the doctor blade are pressed against the outer peripheral surface of the roll with an appropriate pressing force. Further, since the width of the doctor blade is narrow, the necessary pressure contact force can be generated without pressing the doctor blade against the roll with a large force as a whole.
[0012]
Furthermore, this invention employ | adopts the structure which removes the foreign material adhering to the blade edge of the said doctor blade by spraying a fluid on the blade edge of a doctor blade. By adopting this configuration, it is possible to avoid the adverse effect that foreign matter adheres to the cutting edge of the doctor blade and the scraping operation is not appropriately performed.
[0013]
Here, you may employ | adopt the structure which can move the said doctor blade at a different speed | rate toward the axial direction of the said roll. If this structure is employ | adopted, the time which the part which a foreign material adheres easily to the blade edge | tip of a doctor blade can be made longer than the other part among roll outer peripheral surfaces. Therefore, the scraping operation of only a specific portion of the outer peripheral surface of the roll can be sufficiently performed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
1 to 3 show an example in which the present invention is applied to a doctor device for doctoring the outer peripheral surface of a roll for a paper machine.
[0016]
As shown in these drawings, the doctor device 1 is supported by support frames 21 and 22 on both sides, a doctor bag 3 rotatably supported by the frames 21 and 22, and the doctor back 3. A linear slide mechanism 4, a blade holder 5 supported by the linear slide mechanism 4 in a state where linear reciprocation is possible, and a doctor blade 6 held by the blade holder 5.
[0017]
The configuration of each part will be described in detail. First, the doctor back 3 is provided with support shafts 31 and 32 at both ends thereof, and these support shafts 31 and 32 are rotatably supported by bearings on the frames 21 and 22 side, respectively. The linear slide mechanism 4 supported by the doctor back 3 is, for example, a belt type LM guide manufactured by THK Corporation.
[0018]
The linear slide mechanism 4 includes a base 41 attached to the doctor bag 3, front and rear linear slide rails 42 and 43 formed on the base 41, and a slide table 44 that linearly reciprocates along the linear slide rails 42 and 43. It has. The rear surface of the slide table 44 is connected to the driving belt 45. The driving belt 45 is stretched between a driving pulley 46 on one end side and a driven pulley 47 on the other end side, and extends in parallel with the slide rails 42 and 43. The drive pulley 46 is fixed to the output shaft of an AC servo motor 48 that is a drive source. When the motor 48 is driven, the slide table 44 is linearly moved along the rails 42 and 43 by the driving belt 45. If the motor 48 is reversed, it moves linearly in the opposite direction.
[0019]
A blade holder 5 is mounted on the slide table 44. The blade holder 5 includes a top plate 51 and a number of fingers 52 attached to the back side of the top plate 51. Between the front end portions of these members 51 and 52, the original end portion of the doctor blade 6 is sandwiched and held in a detachable state. Each finger 52 has a rod 53 passing through a central portion thereof. Both ends of the rod 53 are supported on the slide table 44 side in a rotatable state.
[0020]
Here, a gap is formed between the back surface of the finger 52 and the slrite table 44, the rod 53 is sandwiched, a small gap is formed on the front side (that is, the roll 10 side), and a large gap is formed on the rear side. Has been. A small-diameter air tube 54 and a large-diameter air tube 55 are mounted in these gaps. By adjusting the amount of air supplied to these tubes 54 and 55, the doctor blade 6 can be switched between a pressure contact state in which the doctor blade 6 is in pressure contact with the outer peripheral surface 10a of the roll and an open state in which the doctor blade 6 is separated from the center. it can. That is, the pressure contact force with respect to the roll outer peripheral surface 10a of the cutting edge 6a of the doctor blade 6 can be increased by expanding the large-diameter tube 55 on the rear side and contracting the small-diameter tube 54. Conversely, the pressure contact force of the doctor blade can be reduced by expanding the small diameter tube 54 and contracting the large diameter tube 55. Furthermore, the doctor blade 6 can be in an open state away from the outer peripheral surface of the roll (this state is indicated by an imaginary line in the figure).
[0021]
Next, with reference to FIG. 2, the length of each part and the movement range will be described. As shown in the figure, the surface length (length in the axial direction) of the roll 10 is L10. The length L3 of the doctor back 3 supporting the linear slide mechanism 4 is set to be sufficiently longer than the roll surface length L10. As a result, the moving range of the slide table 44 of the linear slide mechanism 4 can be set to be wider than the roll surface length L10.
[0022]
In this example, the length L5 of the blade holder 5 is set to 120 mm, for example, and the length L6 of the doctor blade 6 held here is set to 100 mm, for example. In order to enable the doctor blade 6 to slide from one end of the outer peripheral surface of the roll to the other end, that is, in FIG. 2, it can move from one end indicated by a solid line to the other end indicated by an imaginary line. The blade movement amount L is set to be smaller by 50 mm on the left and right sides than the roll surface length L10.
[0023]
In order to control the movement range of the doctor blade 6 in this way, limit switches or the like for defining the movement range are arranged, and the motor 48 is controlled based on the output signals of these limit switches. Good. In FIG. 2, the motor 48 is connected with a power cable lead 48b and a detector cable 48c for transmitting a signal from a limit switch or the like, to the control board.
[0024]
In the doctor apparatus 1 of this example configured as described above, the doctor blade 6 is pressed against the surface 10A of the rotating roll 10 with an appropriate pressure contact force, and the blade holder 5 holding the doctor blade 6 by the motor 48 is placed on the roll axis. Move back and forth in the direction. As a result, the doctor blade 6 performs doctoring of the roll outer peripheral surface 10A while sliding in the axial direction along the roll outer peripheral surface 10A.
[0025]
Since the width of the doctor blade 6 of this example is narrow, it is possible to easily adjust the pressure contact force with respect to the roll outer peripheral surface 10A. Further, if a motor 48 having a variable rotational speed is used, the sliding speed of the doctor blade 6 can be changed. In this way, in the outer peripheral surface 10A of the roll, the doctoring of the portion where foreign matters such as paper sheets are likely to adhere is sufficiently performed with a low sliding speed, and the sliding speed is increased for the other portions. By doing so, efficient doctoring can be realized.
[0026]
In the present invention, as shown by an imaginary line in FIG. 1, a cover 11 is attached to the blade holder 5 so as to cover the moving blade holder 5, and a chemical solution or air is applied to the blade tip portion of the doctor blade 6 inside the cover 11. A nozzle 12 that can be sprayed is attached . Adopting this configuration is preferable because foreign matter such as paper scraps scraped off at the cutting edge of the doctor blade 6 can be efficiently discharged to the outside.
[0027]
【The invention's effect】
As described above, the doctor device of the present invention is configured to perform doctoring on the outer peripheral surface of the roll by sliding a narrow doctor blade in the axial direction in a state of being pressed against the outer peripheral surface of the roll. Yes. Therefore, it is possible to easily adjust the pressure contact force of the doctor blade as compared with a doctor device configured to use a doctor blade having the same width as the roll width used in the prior art. In addition, a sufficient pressure contact force can be applied to the cutting edge of the doctor blade. Furthermore, since rolls with different roll widths can be dealt with simply by changing the movement range of the doctor blade, there is no need to use a doctor blade corresponding to the roll width.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a doctor apparatus to which the present invention is applied.
FIG. 2 is an explanatory diagram for explaining a length relationship of each part and a movement range of a doctor blade in the doctor apparatus of FIG. 1;
FIG. 3 is a partially enlarged view showing an enlarged portion of a doctor blade and a blade holder in the doctor device of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Doctor apparatus 3 Doctor back 4 Linear slide mechanism 5 Blade holder 6 Doctor blade 10 Roll 10A Roll outer peripheral surface 10a Roll axis

Claims (4)

A doctor device for removing foreign matter adhering to the outer peripheral surface by pressing a doctor blade having a certain width against the outer peripheral surface of the roll, the doctor blade being moved along the outer peripheral surface of the roll by moving in the axial direction, the removal of foreign matter from the outer peripheral surface of the roll rows that have at different positions in the axial direction,
The width of the doctor blade is set to be not more than half of the length in the axial direction of the target roll,
A sliding doctor device that removes foreign matter adhering to the cutting edge of the doctor blade by spraying a fluid onto the cutting edge of the doctor blade . 2. The sliding doctor device according to claim 1, wherein a width of the doctor blade is in a range of 50 mm to 500 mm. 3. The sliding doctor device according to claim 2, wherein a width of the doctor blade is 100 mm. The sliding doctor device according to claim 1, wherein the doctor blade is movable at different speeds in the axial direction of the roll.

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