JP2000291771A - Friction mechanism and material winding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction mechanism for preventing the wear of a brake member and the drop of a brake force and a material wind mechanism provided with this friction mechanism by exerting a desired friction force to a rotary body without press-contacting the brake member to the rotary body. SOLUTION: A friction mechanism F is provided with a rotary damper 10A having a gear 12 turnable against the resistance of a viscous fluid enclosed in a damper main body 11, a sun gear 29 fixed concentrically with a shaft 22, a damper housing 31 arranging the damper main body 11 around the sun gear 29 so that the gear 12 of the rotary damper 10A is meshed with the sun gear 29. Plural dampers 10A are arranged around the sun gear 29 at the equal angle mutually. Further, the shaft 22 integrated with a wind reel 20 is fixed to the sun gear 29 and the turnable drive pulley 26 installed on the shaft 22 is connected to the housing 31 and a material wind mechanism such as a filter paper 300 is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction mechanism using a rotary damper to apply a predetermined frictional force to a rotating body, and a material winding mechanism provided with the friction mechanism.

[0002]

2. Description of the Related Art FIG. 4 is a front view showing a main part of a β-ray absorption type dust meter for measuring dust concentration in a gas.
In the figure, 110 is a supply reel on which a filter paper 300 for collecting dust is wound, 120 is a take-up reel on which the filter paper 300 is wound, 130 is a pinch roller unit, 140 is a capstan, 150 is a tension roller, and 200 is Measuring instrument, 210 is the upper block, 220 is the lower block, 2
Reference numeral 30 denotes a lifting mechanism of the lower block 220. The upper block 210 and the lower block 220 are provided with a pipe for introducing and discharging a sample gas, a β-ray irradiator, a β-ray detector (none is shown), and the like.

As is well known, in this type of dust meter, dust is collected by sucking gas onto the filter paper 300 sandwiched between the upper and lower blocks 210 and 220 of the measuring instrument 200.
The transmitted β-ray intensity of the filter paper 300 before and after collection is measured, and the dust concentration in the gas is obtained from the measured value. here,
The filter paper 300 after the dust collection and measurement cannot be used again. Therefore, once the measurement is completed, the elevating mechanism 230 is lowered to release the filter paper 300 between the upper and lower blocks 210 and 220 and the take-up reel 120 Is driven to feed out the filter paper 300 by a certain length from the supply reel 110 side, and control is performed so that a new portion of the filter paper 300 is supplied between the upper and lower blocks 210 and 220, and thereafter the measurement is performed again. Such an operation is repeatedly performed at predetermined time intervals.

In the above-described mechanism for winding and supplying the filter paper 300, when the winding speed of the winding reel 120 for winding the filter paper 300 is kept constant, the winding reel 1
The peripheral speed increases as the amount of winding of the filter paper 300 in 20 increases (the winding diameter increases). For this reason, the take-up reel 1
When the filter paper 300 is moved by rotating 20 by a certain angle,
The take-up amount in the take-up reel 120 is small (the take-up diameter is short)
Since the moving distance of the filter paper 300 is longer than in the case, a portion not used for the filter paper 300 is generated. Therefore,
It is necessary to rotate the take-up reel 120 while applying a brake so that the angular velocity of the take-up reel 120 decreases as the take-up amount increases.

As one prior art for that purpose, there is a method of applying a frictional force along the axial direction to the shaft portion of the take-up reel 120 to brake the shaft portion. FIG. 5 shows a take-up reel 120.
FIG. 3 is a schematic side sectional view of the filter paper winding mechanism along the axial direction of FIG. In FIG. 5, the rotation shaft 121 of the take-up reel 120 is integrated with a shaft 161 on the same axis.
1 has a flange 162. And the shaft part 161
Are the bearing box 163 and the bearings 164,1
It is rotatably supported by 65. The flange 1
A drive pulley 167 is disposed adjacent to 62.
The drive pulley 167 is attached to the shaft 161 via a bearing 166. 168 is a drive pulley 16
7 is a timing belt for rotating the motor 7, and is driven by a motor (not shown). A pressing plate 169 constantly urged in the direction of the arrow by the restoring force of the spring 170 is disposed at the end of the shaft portion 161, and the pressing plate 169 connects the driving pulley 167 to the flange 162 via a thrust bearing 171. It is pressed against the side. 172 is a flange 162 and a driving pulley 167
Friction surface (pressure contact surface).

In the configuration shown in FIG.
When the driving pulley 167 is rotated by the power transmitted from the shaft 68, the static friction force of the friction surface 172 is initially large,
The rotation shaft 61 and the rotation shaft 121 rotate integrally with the driving pulley 167. When the winding of the filter paper proceeds and the tension applied to the winding reel 120 increases, this tension acts on the shaft 161 in the direction opposite to the rotation direction of the driving pulley 167.
The shaft portion 161 slides on the friction surface 172 between the flange 162 and the driving pulley 167 while the driving pulley 1
It rotates later than 67. That is, the take-up reel 120
Is rotated later than the drive pulley 167 while receiving the sliding frictional force applied to the flange 162 from the drive pulley 167 by the pressing plate 169, and a kind of brake is applied.

The structure of the bearing on the supply reel 110 side in FIG. 4 is also substantially the same as that in FIG. 5, but a pulley corresponding to the drive pulley 167 in FIG. 5 is fixed and power cannot be transmitted from the outside. The pulley functions as a simple bearing that rotatably supports the shaft of the supply reel 110 (corresponding to the shaft 161 in FIG. 5).

[0008]

As shown in FIG. 5,
According to the method of applying a friction force along the axial direction to the shaft portion 161 (flange 162) of the take-up reel 120 to apply braking, the sliding surface (both axial side surfaces) of the flange 162 that generates a sliding friction force and The side surface of the bearing box 163 and the side surface of the drive pulley 167 pressed against them may be worn or broken, and minute fragments and dust scattered around and damage or contaminate the filter paper 300. There was something. There is also a problem that the braking force decreases with time due to wear of each member. Further, the sliding surface and the like of the flange 162 are required to be flat with high precision, and a great deal of cost is required for the processing.

Therefore, the present invention provides a friction mechanism that obtains a desired frictional force by utilizing the viscous resistance of a rotary damper, instead of applying a frictional force by pressing a rotating body against pressure. An object of the present invention is to provide a material winding mechanism that can prevent breakage and contamination of a winding material such as filter paper by including the friction mechanism.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a rotary damper having a gear rotatable while resisting the resistance of a viscous fluid sealed in a damper body, and a shaft. A sun gear fixed concentrically to the portion, and a damper housing arranged around the sun gear by meshing the sun gear with a gear of a rotary damper. In such a configuration, when a torque equal to or more than a predetermined value is relatively applied to the gear (planetary gear) of the rotary damper from the sun gear, the rotary damper uses the resistance of the internal viscous fluid as a frictional force and the shaft portion together with the damper housing. And around the sun gear. By utilizing this effect, a part of the rotational force applied to the damper housing can be reduced and transmitted to the shaft portion by the frictional force.

Further, when a plurality of the rotary dampers are arranged at equal angles around the sun gear, the frictional force between the rotary damper and the sun gear is evenly distributed. As a result, the transmission of force is not biased.

Further, in the material winding mechanism according to a third aspect of the present invention, a winding member such as a winding reel for winding a band-shaped material or a linear material is integrally rotated with a shaft of the friction mechanism. A drive pulley that is movable and driven by a motor or the like is mounted around the shaft via a bearing, and the drive pulley is integrally connected to a damper housing of the friction mechanism. Here, when the tension of the material transmitted from the winding member to the shaft portion exceeds a predetermined force determined by the rotary damper, a slip occurs between the driving pulley and the shaft portion, and the rotation speed of the shaft portion, that is, the rotation speed of the winding member. Is slower than the driving pulley. Accordingly, the winding member is rotated while being braked, so that a material having a substantially constant length can always be fed out from the supply side and wound regardless of the amount of the material wound by the winding member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 3 is a plan view (FIG. 3A) and a side view (FIG. 3B) of the rotary damper 10 used in the friction mechanism of the present embodiment. This rotary damper 10 encloses a viscous fluid such as silicone oil inside a hollow disk-shaped damper body 11, and
The rotating shaft 13 of the gear 12 outside the main body is connected to the resistance piece 1 inside the main body.
4 are connected. And gear 1 from outside
When the torque applied to 2 reaches a predetermined value (operating torque), the gear 12 and the resistance piece 14 rotate while resisting the resistance of the viscous fluid. Reference numeral 15 denotes a mounting portion projecting from the main body 11.

Next, FIG. 1 is a sectional view of a winding mechanism of a filter paper 300 having a friction mechanism F of the present embodiment, FIG. 2 is a front view thereof, and FIG. 1 is a sectional view taken along line XX of FIG. Is equivalent. In these drawings, reference numeral 20 denotes a take-up reel serving as a take-up member on which the filter paper 300 is taken up. The reel 20 is integrally fixed to the first shaft portion 21. First
A second shaft portion 22 is coaxially fixed to the center of the shaft portion 21. Reference numeral 23 denotes a substantially hat-shaped bearing box fixed to the partition 41, and bearings 24, 2 are provided at the center thereof.
5, the second shaft portion 22 penetrates. A drive pulley 26 is disposed adjacent to the bearing box 23, and the center of the pulley 26 is a bearing 2.
The second shaft portion 22 penetrates through 7, 28. The drive pulley 26 has a drive source such as a motor (not shown).
, A timing belt 42 connected thereto is wound.

Next, the configuration of the friction mechanism F according to this embodiment will be described. The friction mechanism F includes a sun gear 29 integrally fixed together with a nut 30 at a tip end of the second shaft portion 22, and the sun gear 29
Are provided with three rotary dampers 10A, 10B, 10C meshing with each other as planetary gears, and a damper housing 31 to which each main body 11 of these rotary dampers 10A, 10B, 10C is fixed. Rotary dampers 10A, 10B,
Each main body 11 of 10C and the driving pulley 26 are integrally connected. At least one rotary damper
The number of the rotary dampers 10A, 10B, and 10C is equal to or larger than the sun gear 29 as in the embodiment.
Are arranged at equal angles around each other, the frictional force between the rotary damper and the sun gear 29 is evenly distributed, and the transmission of the force is not biased.

Further, a connecting belt 43 is stretched around the outer peripheral surface of the damper housing 31. Here, although not shown, a friction mechanism F similar to that shown in FIG. 1 is also attached to the shaft of the supply reel, and the link belt 43 is hooked on the damper housing of the friction mechanism F on the supply reel side. I have. For this reason, a force in the direction opposite to the rotation direction of the damper housing 31 on the take-up reel 20 is applied to the damper housing on the supply reel side. Although a pulley corresponding to the drive pulley 26 in FIG. 1 is disposed between the bearing box and the friction mechanism on the supply reel side, power from the timing belt is applied to the pulley on the supply reel side. Instead, the pulley is fixed and functions as a simple bearing that rotatably supports the shaft on the supply reel side.

Next, the operation of this embodiment will be described. First, when a rotating power is transmitted from the timing belt 42 to the driving pulley 26 for a certain time, the power is transmitted to the damper housing 31 and the rotary dampers 10A, 10B, 10C.
, A gear (planetary gear) 12, a sun gear 29, and a second shaft portion 22 in this order.

At this time, the sun gear 29 on the second shaft portion 22 side
Torque applied to the gears 12 of the rotary dampers 10A, 10B and 10C from the rotary damper 10
Assuming that the operating torque is less than A, 10B, and 10C,
Each gear 12 cannot rotate (rotate) with respect to the sun gear 29, and the drive pulley 26, the damper housing 31, the rotary dampers 10A, 10B, 10, the sun gear 29, and the second shaft portion 22 are all integrated. To rotate a predetermined angle. At this time, the rotary dampers 10A, 10B, 1
Each gear 12 of 0C revolves while remaining engaged with the sun gear 29. Accordingly, the first shaft portion 21 and the take-up reel 20 connected to the second shaft portion 22 also rotate by a predetermined angle in the direction in which the filter paper 300 is wound.

When the winding amount of the filter paper 300 in the winding reel 20 increases and the winding diameter becomes longer, the first shaft portion 21, the second shaft portion 22, and the sun gear 29 due to the tension from the filter paper 300. Is gradually increased, and when the rotating power is transmitted to the driving pulley 26 in this state, the torque is reduced by the rotary dampers 10A, 1A.
When the operating torques of the rotary dampers 10A, 10B, and 10C exceed the operating torques of 0B and 10C, the gears 12 of the rotary dampers 10A, 10B, and 10C slightly start to rotate.
B, 10C are the sun gear 2 together with the damper housing 31.
Start revolving around 9. Also, in this state, a part of the torque applied to the drive pulley 26 is also supplied to the friction mechanism F.
Is transmitted to the second shaft portion 22 through the second shaft portion 22.
Is rotatable.

Here, the rotary dampers 10A, 10A
B, 10C and the damper housing 31
6 and the sun gear 29 is integrally connected to the second shaft 22, so that the drive pulley 26 relatively rotates about the second shaft 22. That is, the drive pulley 26 rotates while sliding about the second shaft portion 22, and the second shaft portion 22 rotates by a small angle later than the drive pulley 26. For this reason, the second shaft portion 22
The rotation angle of the take-up reel 20 integrated with the take-up reel 20 is also reduced, and the moving distance of the filter paper is not increased more than necessary even if the peripheral speed of the filter paper 300 in the take-up reel 20 is large.

In other words, from a different point of view, a part of the force applied to the drive pulley 26 from the timing belt 42 is absorbed by the frictional force due to the viscous resistance of the rotary dampers 10A, 10B, 10C, and the take-up reel 20 is braked. Is in the same state as was applied. The frictional force of the friction mechanism F can be arbitrarily set by selecting the operating torque of the rotary damper, changing the number thereof, changing the diameter of the sun gear or the planetary gear, or the like.

Further, by applying a force in the direction opposite to that of the take-up reel 20 to the shaft of the supply reel through the connecting belt 43, the shaft rotates in the same direction as the take-up reel 20 against this force. A kind of braking force also acts on the supply reel to be applied, so that the filter paper 300 can be given a certain tension to prevent its slack, and when the winding operation on the take-up reel 20 side is stopped, inertia occurs. This also contributes to preventing the supply reel from rotating excessively.

Incidentally, the friction mechanism according to the present invention comprises:
In addition to the winding mechanism described in the embodiment, the present invention can be applied to various uses as a component of a rotating mechanism that applies a desired frictional force to a rotating body. Furthermore, the material take-up mechanism according to the present invention is not only a filter paper take-up mechanism in a dust meter, but also in the field of analyzers, a tape take-up mechanism of a gas analyzer using a tape that develops a color in response to a specific gas. The present invention can be applied to a winding mechanism for various band-like materials and linear materials in other fields.

[0024]

As described above, according to the friction mechanism of the present invention, a frictional force is applied to the rotating body by utilizing the viscous resistance of the rotary damper. Compared to a method of generating frictional force by pressing a braking member against pressure, there is no risk of contaminating the winding material or the surrounding environment due to wear of the member or deteriorating the braking force. Further, there is no burden of flattening the sliding surface of each member with high precision, which is advantageous in processing cost. Further, according to the material winding mechanism of the present invention, an appropriate braking force can be applied to the winding member by using the above-mentioned friction mechanism, and the material is always kept at a substantially constant length regardless of the amount of the material winding. It can be unwound from the supply side only. Therefore, if the present invention is applied to a mechanism that winds a material by a substantially constant length and successively feeds the material to a predetermined position, such as a filter paper winding mechanism in a dust meter described as an embodiment, the material is economical without waste. It is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a filter paper winding mechanism to which an embodiment of the present invention is applied.

FIG. 2 is a front view of the winding mechanism of FIG.

FIG. 3 is a plan view (FIG. 3A) and a side view (FIG. 3B) of a rotary damper used in the embodiment of the present invention.

FIG. 4 is a front view showing a main part of a β-ray absorption type dust meter.

FIG. 5 is a schematic side sectional view of the filter paper winding mechanism in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C Rotary damper 11 Damper main body 12 Gear (planetary gear) 13 Rotating shaft 14 Resistance piece 15 Mounting part 20 Take-up reel 21 First shaft part 22 Second shaft part 23 Bearing box 24, 25, 27, 28 Bearing 26 Drive Pulley 29 Sun Gear 30 Nut 31 Damper Housing 41 Partition 42 Timing Belt 43 Connecting Belt 300 Filter Paper F Friction Mechanism

Claims (3)

[Claims] 1. A rotary damper having a gear rotatable while resisting the resistance of a viscous fluid sealed in a damper main body, a sun gear fixed concentrically to a shaft, and a rotary damper attached to the sun gear. And a damper housing for disposing the damper body around a sun gear so that the gears mesh with each other. 2. The friction mechanism according to claim 1, wherein a plurality of the rotary dampers are arranged at an equal angle around a sun gear. 3. A driving pulley, which enables a winding member for winding a material to rotate integrally with the shaft portion of the friction mechanism according to claim 1 or 2 and rotates by a driving force. A material winding mechanism, wherein the driving pulley is attached to the periphery of the shaft via a bearing, and the driving pulley is integrally connected to the damper housing.