JPH02480Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a dryer doctor device for cleaning the surface of a paper machine dryer. This invention relates to a dryer doctor device designed to remove the dryer.

With this type of conventional dryer doctor device,
The doctor blade was always pressed against the dryer surface with a constant pressure while keeping its contact angle (rake angle) constant.

However, the dirt and grime attached to the dryer surface,
Depending on the type, shape, etc., there is a unique rake angle that is suitable for removing dirt, and conventional doctor blades with a constant pressing force and rake angle can only remove a specific type or shape of dirt. Therefore, conventional dryer doctor devices have not been able to sufficiently clean the dryer surface. Incidentally, if dirt and the like on the surface of the dryer are not sufficiently removed, the surface condition of the paper to be made will not be constant, resulting in variations in product quality and lowering the commercial value of the product.

In order to improve the problems of the conventional dryer doctor device as described above, the present applicant proposed a paper machine dryer in which the rake angle of the doctor blade with respect to the dryer surface can be changed at appropriate intervals within a predetermined angle range. We have already applied for a patent for the surface cleaning method (Japanese Patent Application No. 121210/1982).
In this previously applied application, the doctor device main body is moved toward or away from the dryer surface by a doctor advance/retreat device, thereby changing the rake angle of the doctor blade with respect to the dryer surface. However, in such a device in which the entire doctor device main body is moved forward and backward, there is a problem in that the mechanism is large-scale.

In addition, as a doctor device for the surface of a paper machine dryer with variable rake angle of the doctor blade,
There is one disclosed in Japanese Patent Application Laid-open No. 11296/1983.
This known example of the doctor device changes the pressure contact force of the doctor blade against the dryer surface by expanding and contracting an air cylinder at regular intervals, and utilizes the elastic deformation of the doctor blade at that time. The rake angle relative to the surface can be changed.
However, in this known example of a doctor device, it is necessary for the doctor blade itself to have an elastic deformation function, and the material and shape of the doctor blade (the length from the blade attachment part to the tip part is required to be elastically deformable). There was a problem in that the rake angle of the doctor blade could not be changed over a large range.

In view of the above-mentioned problems, the present invention makes it possible to change the rake angle of the doctor blade with a simple configuration, and is not limited to the material, shape, etc. of the doctor blade. The purpose of the present invention is to propose a dryer doctor device in which the rake angle can be changed over a wide range of angles, and the doctor body, which serves as the mounting base for the doctor blade, is driven by an eccentric doctor shaft. This is characterized in that the rake angle of the doctor blade relative to the paper machine dryer is changed.

Hereinafter, the dryer doctor device of the present invention will be explained based on the illustrated embodiment. The dryer doctor device of the embodiment shown in FIGS.
A doctor shaft 3 is pivotally supported so as to be rotated or oscillated by an appropriate power device 2, and a thin plate-like strip is supported on the doctor shaft 3 so as to be rotatable and slidable in the axial direction. doctor blade 7
By rotating the doctor body 6 with respect to the doctor shaft 3, the doctor blade 7 is attached to the surface 1 of the dryer 1.
a pressing device 8 that acts to press against the doctor body 6; and a drive device 9 that is interposed between the doctor body 6 and the doctor shaft 3 and acts to repeatedly slide the doctor body 6 in the axial direction with respect to the doctor shaft 3. It is composed of:

The doctor shaft 3 has bearings 10, 10 at both ends thereof.
It is mounted on a shaft so that it can rotate freely. Note that both ends of this doctor shaft 3 serve as supporting shaft portions 4, 4.

A power unit 2 consisting of a geared motor in this embodiment is connected to one end side of the doctor shaft 3, and is configured to continuously rotate the doctor shaft 3 at a low speed. Note that this doctor shaft 3 is not moved in its axial direction. Also, the doctor shaft 3
In other embodiments, it may be repeatedly oscillated within a predetermined angular range (eg, 180°) by an appropriate method.

The doctor shaft 3 has a large diameter shaft having an axis Q-Q slightly inwardly offset from the axis P-P of the support shaft 4 by a predetermined distance e. Eccentric shaft portions 5, 5 are formed.

The doctor body 6 is formed into a cylindrical shape, and bearings 11, 11 are attached to the inner surfaces of the openings at both ends of the doctor body 6, respectively.
And this doctor body 6 has both bearings 1
1 and 11 are both eccentric shaft portions 5 and 5 of the doctor shaft 3.
It is attached by fitting on the outside of the Furthermore, the inner surface of the bearing 11 of the doctor body 6 and the outer surface of the eccentric shaft portion 5 of the doctor shaft 3 are mutually rotatable and slidable in the axial direction, so that the doctor body 6 is free to rotate relative to the doctor shaft 3. It is designed to be able to rotate and slide in the axial direction.

A blade holder 12 is fixed to the upper surface of the doctor body 6, and the doctor blade 7 is supported and fixed diagonally upward by the blade holder 12.

The doctor blade 7 does not need to have any particular elasticity, and therefore there are no restrictions on its material, shape (length from the blade attachment part to the tip), etc.

Place the doctor blade 7 on the surface 1a of the dryer 1.
The pressing devices 8 which act to press the doctor body 6 are provided one each near both ends of the doctor body 6. This pressing device 8 is connected to the doctor body 6
It is composed of an arm 14 fixed on the upper surface side and an air cylinder 15 connected to the arm 14. By extending the air cylinder 15, the doctor body 6 can be rotated ( clockwise rotation direction in Fig. 2), thereby causing the doctor blade 7 to
It is designed so that it can be pressed into contact with a predetermined pressure. The connecting portion between the arm 14 and the rod 16 of the air cylinder 15 and the pivoting portion between the base 17 of the air cylinder 15 and the bracket 18 for supporting the air cylinder are connected to the doctor body 6 as described later.
When the air cylinder 15 is repeatedly slid in the axial direction, the air cylinder 15 can be tilted. The doctor blade pressing device 8 may have an appropriate configuration instead of the air cylinder 15, as long as it rotates the doctor body 6 and presses the doctor blade 7 against the dryer surface 1a with a predetermined pressure. Can be adopted. For example, a spring or a weight of an appropriate weight may be attached to the arm 14 to apply rotational moment to the doctor body 6.

A drive device 9 for repeatedly sliding the doctor body 6 in the axial direction includes a geared motor 20 attached to the longitudinally intermediate portion of the doctor body 6 and an eccentric ring 2 fixed to a drive shaft 21 of the geared motor 20.
2 and an eccentric ring guide 23 provided on the doctor shaft 3 side. Eccentric ring 22
The center X is eccentric by a width W with respect to the axis Y of the drive shaft 21, and each time the drive shaft 21 rotates once, the doctor body 6 is shifted by a length twice the eccentric width W. It is designed to be able to slide in any direction.
That is, when the drive shaft 21 rotates, the eccentric ring 22
However, since the doctor shaft 3 cannot be moved in the axial direction, the doctor body 6 swings relative to the doctor shaft 3.

In the illustrated dryer doctor device, if the power source (geared motor) 2 is driven, the doctor shaft 3
rotates slowly, and along with this, the doctor body 6 begins to move around the doctor shaft 3 due to the action of the doctor shaft eccentric portion 5. That is, the doctor body 6 itself does not rotate, and the center of the doctor body 6 (same as the center Q of the doctor shaft eccentric part 5) draws a circle with a radius e around the axis P of the doctor shaft support shaft part 4. Move like this. At the position where the doctor body 6 approaches the dryer surface 1a (the position shown in FIG. 2), the dryer surface 1a
Angle between a and doctor blade 7 (rake angle)
θ becomes smaller (θ=θ ₁ ), and the doctor body 6
is away from the dryer surface 1a (fourth position)
position), the rake angle θ becomes larger (θ=
θ ₂ ). Note that the doctor body 6 is constantly pressed by the pressing device 8 so that the doctor blade 7 is pressed against the dryer surface 1a.
Since the doctor blade 7 is urged to rotate in the direction in which it comes into pressure contact with the dryer surface 1a, the doctor blade 7 is brought into contact with the dryer surface 1a with a substantially constant pressure regardless of the position of the doctor body 6. The variation range of the rake angle θ of the doctor blade 7 can be changed as appropriate by changing the eccentric width e between the axial center of the support part 4 of the doctor shaft 3 and the axial center of the eccentric shaft part 5. If the angle θ is varied within the range of 15° to 30°, the removal effect of dirt etc. adhering to the dryer surface 1a will be improved.

Further, in the illustrated dryer doctor device, the geared motor 20 of the doctor body drive device 9 is also driven at the same time, but at that time, the doctor body 6
slides repeatedly in the axial direction in the range from the state shown in FIG. 1 (leftward) to the state shown in FIG. 5 (rightward), and the contact position of the doctor blade 7 with the dryer surface 1a changes in the axial direction. There is an effect that the cleaning action on the dryer surface 1a is performed more uniformly.

Next, to explain the effects of the present invention, the dryer doctor device of the present invention has the following effects.

(1) A doctor body 6 is rotatably supported on the eccentric shaft part 5 of a doctor shaft 3 with an eccentric shaft part 5, and the doctor body 6 is held by the doctor body 6 by rotating or swinging the doctor shaft 3. Since the rake angle of the blade 7 with respect to the dryer surface 1a can be changed, it is possible to easily remove various types of dirt attached to the dryer surface 1a regardless of the specific rake angle that each type of dirt has. This allows for efficient cleaning of the dryer surface.

(2) Since the rake angle of the doctor blade 7 can be changed by rotating or swinging the doctor shaft 3 having the eccentric shaft portion 5, the rake angle of the doctor blade 7 can be changed with a simple configuration. In addition, when changing the rake angle, for example, JP-A-57-
As shown in Publication No. 11296, there is no need to bend the doctor blade itself, so there are no restrictions on the material and shape of the doctor blade 7 (length of protrusion from the blade attachment part to the tip), and there is no need to bend the doctor blade 7. By changing the eccentric width e with respect to the eccentric shaft portion 5, the variation range of the rake angle of the doctor blade 7 can be adjusted, and the width of the rake angle variation range can be freely set.

(3) Due to the effect of (1) above, the surface condition of the paper to be made is made uniform, there is no variation in product quality, and the commercial value can be increased.

(4) By eliminating dirt from adhering to the dryer surface 1a, heat conduction from the dryer surface 1a to the wet paper becomes better and drying efficiency improves.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of a dryer doctor device according to an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views of FIG. 1, and FIGS. FIG. 3 is an explanatory diagram of the operation of the dryer doctor device shown in the figure. DESCRIPTION OF SYMBOLS 1... Paper machine dryer, 1a... Dryer surface, 2... Power device, 3... Doctor shaft, 4...
... Support shaft portion, 5 ... Eccentric shaft portion, 6 ... Doctor body, 7 ... Doctor blade, 8 ... Doctor body pressing device.

Claims (1)

[Scope of utility model registration request] It has an eccentric shaft part 5 which is eccentric by a predetermined dimension l with respect to the support shaft part 4, and is pivotally supported so as to be rotated or swung about the support shaft part 4 by an appropriate power device 2. A doctor body 6, which serves as a mounting base for a doctor blade 7, is relatively rotatably supported on the eccentric shaft portion 5 of the doctor shaft 3, and the doctor body 6 is pressed against the doctor blade 7 by an appropriate pressing device 8. A dryer doctor device characterized in that the device is rotatably biased in a direction in which it is brought into pressure contact with a paper machine dryer 1.