JPH0133284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a drum shear, in which twisting of the drum shaft of a drum to which a cutting blade is attached is reduced, and an increase in knife gap due to reaction force of a driving gear, etc. is prevented. .

The drum shear that cuts the material to be cut between runs is the first
As shown in the figure, a pair of drums 3 and 4 to which cutting blades 1 and 2 are attached are driven to rotate in opposite directions to feed and cut a material to be cut 5 in the direction of arrow A. These drums 3, 4 are supported by bearings at both ends of drum shafts 6, 7, which serve as their rotational axes.
As shown in the figure, drive gears 8 and 9 are respectively attached to one end of the drum shafts 6 and 7 in order to drive the drums 3 and 4 to rotate in opposite directions and to reduce twisting of the drum shafts 6 and 7. At the same time, tuning gears 10 and 11 are respectively attached to the other end. The connection with the driving source is, for example,
When the upper cutting blade 1 precedes the lower cutting blade 2 in the feeding direction A of the material to be cut 5, the torques T _T and T _B generated on the respective drum shafts 6 and 7 are as shown in FIG. The torque of the upper drum shaft 6 changes as shown, T _T
is reversed from positive to negative, while the torque T _B of the lower drum shaft 7 is only a positive value and is larger than the torque T _T of the upper drum shaft 6, so the lower drum shaft 7, whose torque does not reverse, is driven. The upper drum shaft 6 on which the torque is reversed is connected to a drive source P and driven,
During cutting, the driving gears 8, 9 and the synchronizing gears 10, 1
The direction of load No. 1 is prevented from reversing. Further, the phase of the teeth of the drive gears 8, 9 and the synchronizing gears 10, 11 is such that the teeth of the gears 8, 9 and 10, 11 are on the rear side R with respect to the rotation direction, as shown in FIGS. 4a and 4b. The drive gear 9 is fitted with a backlash removal gear 12 using a spring or the like to remove backlash.

When cutting with the drum shear having the above structure, the force applied to the cutting blades 1 and 2 is as shown in Fig. 11.
Since they can be considered separately into a vertical component P and a lateral component F, the torques T _T and T _B of the upper and lower drum shafts 6 and 7 are respectively expressed by the following equations.

T _T =P·r·sinθ−F·r·sinθ T _B =P·r·sinθ+F·r·sinθ Therefore, T _B > _TT .

On the other hand, consider a model as shown in Figure 5.
In this model, if the left and right torsional rigidities of the upper and lower drum shafts 6 and 7 are symmetrical and equal, the upper drum shaft 6 has smaller torsion than the lower drum shaft 7, as is clear from the above equation. Therefore, the torque transmitted to each part of the upper and lower drum shafts 6 and 7 is T ₁ , T ₂ ,
As T ₃ , these torques flow in the direction shown by the arrow in the figure. (In other words, T _B flows separately into T ₂ and T _3. ) Here, the spring constants of the upper and lower drum shafts 6 and 7 are both K, and the torsion angles of each part with respect to the drive shaft are θ ₁ , θ ₂ ,
Assuming θ ₃ and θ ₄ , the following formula is derived.

T ₁ =K(θ ₂ −θ ₁ ) …(1) T ₂ =K(θ ₄ −θ ₁ )…(2) T ₃ =K(θ ₄ −θ ₃ )=K(θ ₃ −θ ₂ ) …(3) T _B =T ₂ +T ₃ …(4) T ₁ =T _T +T ₃ …(5) θ ₄ −θ ₁ = θ ₂ −θ ₁ +θ ₃ −θ ₂ +θ ₄ −θ ₃ …(6 ) By substituting equations (1), (2), and (3) into equation (6), the following equation is obtained.

T ₂ =T ₁ +2T ₃ ...(7) Furthermore, by solving equations (4), (5), and (7) as simultaneous equations, the following equation is obtained.

T ₁ = 3/4T _T + 1/4T _B T ₂ = 1/4T _T + 3/4T _B T ₃ = 1/4 (T _B −T _T ) T ₁ +T ₂ =T _T +T _BHere , drive gear 8 , 9 and tuning gear 10,
The torques T ₂ and T ₃ transmitted by the gears 11 are the reaction forces P 2 generated by these gears since there is a relationship of T _B > T _T between the torques T _T and T _B of the upper and lower drum shafts 6 and _7. ，
P ₃ and the resulting deformation of the upper and lower drum shafts 6 and 7 are shown in Fig. 6, and the upper and lower cutting blades 1 and 2
It acts to widen the knife gap g.

In this case, the knife gap may also increase due to the reaction forces P ₂ and P ₃ generated by the gears.

As described above, with the drum shear of the conventional structure, there is a risk of cutting defects due to an increase in the knife gap.

SUMMARY OF THE INVENTION An object of the present invention is to provide a drum shear which eliminates such conventional drawbacks, has a simple structure, and can suppress an increase in knife gap. The configuration of the present invention that achieves this object is such that in a drum shear that feeds and cuts a material to be cut between a pair of drums each having a cutting blade attached thereto and rotating in opposite directions, the material is The drum shaft of a drum equipped with a trailing cutting blade is connected to a drive source, and the tooth surfaces of the drive gear attached to one end of the drum shaft of the pair of drums mesh on the front side with respect to the rotational direction, and the drum shaft The device is characterized in that the tooth surfaces of the synchronizing gear attached to the other end mesh with each other on the rear side with respect to the rotation direction.

Hereinafter, an embodiment in which the drum shear of the present invention is applied to an upper blade leading type will be described in detail.

As shown in FIG. 7 showing the structure of the drum shear of the present invention, a pair of drums 3 and 4, to which cutting blades 1 and 2 are attached, are attached to drum shafts 6 and 7, which serve as their rotation axes. , 7 are rotatably supported by bearings 13. The two drum shafts 6 and 7 are driven to rotate in opposite directions, but in this embodiment, the upper cutting blade 1 is the upper cutting blade leading type, as shown in FIG. Since the lower drum shaft 7 is the one that precedes the feed direction A of the material to be cut 5, the lower drum shaft 7 is connected to a drive source (not shown) as a drive shaft. A drive gear 9 is attached to one end of the lower drum shaft 7, which is the drive shaft, via a key 14, and a drive gear 8 that meshes with the drive gear 9 is attached to one end of the upper drum shaft 6 via a key 14. Furthermore, tuning gears 10 and 11 are attached to the other ends of these upper and lower drum shafts 6 and 7 in order to suppress twisting of the drum shafts, and pressure fluid passages 15 are formed in order to adjust the meshing state of the tooth surfaces. and communicates with the mounting hole.

These driving gears 8, 9 and tuning gears 10, 1
As shown in FIGS. 8a and 8b, when the drive gears 8 and 9 are engaged on the front side F in the rotational direction of the drum shafts 6 and 7, that is, on the working surface, the synchronizing gears 10 and 1 are engaged with each other. 11 is adjusted so that the diameter of the mounting hole is enlarged by the pressure fluid supplied from the pressure fluid passage 15, and the drive gears 8 and 9 are engaged with each other at the rear side R in the rotational direction.

When the drum shear configured in this manner is loaded with torques T _T and T _B as shown in FIG.
Torques T ₄ to T ₆ are transmitted as shown in the figure.
Here, assuming that the torsional rigidities on the left and right sides of the drum axis are symmetrical and equal as in the conventional explanation, the following relationships hold for the torques T ₄ to _{T 6} of each part.

T ₄ = 3/4T _T + 1/4T _B T ₅ = 1/4T _T + 3/4T _B T ₆ = 1/4 (T _B −T _T ) T ₄ +T ₅ = T _T +T _BHere , drive gear 8 , 9 and tuning gear 10,
The torques T ₄ and T ₆ transmitted in the upper and lower drum shafts 6 and 7 are as shown in Fig. 8 a and b since there is a relationship of T _B > T _T between the torques T _T and T _B of the upper and lower drum shafts 6 and 7. It is transmitted through the meshing of gears as shown in the figure. That is, since the lower drum shaft 7 is the driving shaft of the driving gears 8 and 9, the meshing is as shown in FIG. 8a. on the other hand,
In the synchronized gears 10 and 11, because of the relationship T _B > T _T , the lower drum shaft 7 is twisted more than the upper drum shaft 6, and since the upper drum shaft 6 suppresses this, the torque is increased in the meshing state shown in FIG. 8b. is transmitted in the direction of T ₆ . Therefore, the reaction force generated on these gears
As shown in Fig. 10, P ₄ and P ₆ are the same drum shaft but have opposite directions, resulting in deformation of the center of the drum shaft and knife gap g of the upper and lower cutting blades 1 and 2.
The increase in can be suppressed.

In addition, in this case as well, the reaction forces generated in the gears P ₄ , P ₆
It is also conceivable that the knife gap is reduced due to the fact that P ₂ and P ₃ are in the opposite direction from the conventional P 2 and P 3 in FIG.

Further, since the meshing states of the driving gears 8, 9 and the synchronizing gears 10, 11 are reversed as described above, a backlash removing device is not required, and the structure is simplified.

In this embodiment, an upper blade leading type drum shear has been described, but in the case of a lower blade leading type, the upper drum shaft is driven, the other configurations are the same, and the same effects are achieved.

As described above in detail with the embodiments, according to the present invention, the trailing cutting blade drives the drum shaft to which the trailing cutting blade is attached, and the driving gear at one end of the drum shaft is moved toward the front side in the rotational direction. The blades mesh with the tooth surface which is the working surface of the knife, and the synchronizing gear at the other end meshes with the tooth surface on the rear side in the rotational direction, thereby preventing an increase in the knife gap during cutting. Further, the structure becomes simple since a de-blash removal device is not required.

[Brief explanation of drawings]

Figure 1 is a schematic explanatory diagram of the upper blade leading type drum shear.
Figure 2 is a schematic explanatory diagram of the drive system of a conventional drum shear, Figure 3 is a graph showing changes in torque generated on the upper and lower drum shafts, and Figures 4 a and b are diagrams of the drive gear and synchronizing gear of a conventional drum shear. FIG. 5 is an explanatory diagram of the torque transmitted to each part of a conventional drum shear. FIG. 6 is an explanatory diagram of the reaction force generated in the gears of the conventional drum shear. FIG. 7 is an explanatory diagram of the drum shear of the present invention. A central sectional view of one embodiment, FIGS. 8a and 8b are explanatory diagrams of the meshing state of the driving gear and the synchronizing gear of the drum shear of the present invention, and FIG. 9 is an illustration of the torque transmitted to each part of the drum shear of the present invention. FIG. 10 is an explanatory diagram of the reaction force generated in the gear of the drum shear of the present invention, and FIG. 11 is an explanatory diagram of the force applied to the cutting blade during cutting. In the drawing, 1 and 2 are the upper and lower cutting blades, and 3 and 4 are the upper and lower cutting blades.
Lower drum, 5 is the material to be cut, 6 and 7 are upper and lower drum shafts, 8 and 9 are drive gears, 10 and 11 are synchronization gears,
13 is a bearing, 14 is a key, 15 is a pressure fluid flow path,
A is the feeding direction of the material to be cut, and F and R are the front side and the rear side in the rotation direction.

Claims (1)

[Claims] 1. A drum shear that feeds and cuts a material to be cut between a pair of drums each having a cutting blade attached thereto and rotating in opposite directions, which is equipped with a cutting blade that follows in the feeding direction of the material to be cut. The drum shafts of the drums are connected to a drive source, and the tooth surfaces of a drive gear attached to one end of the drum shafts of the pair of drums mesh on the front side with respect to the rotational direction, and the teeth of a synchronizing gear attached to the other end of the drum shafts. A drum shear characterized by being mounted so that the surfaces engage on the rear side with respect to the direction of rotation.