JPH08173U - Fore-cutting device for sheet-fed printing press - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the vibration of the paper feeding unit front device which is a problem when the sheet-fed printing press is rotated at high speed. [Structure] Separate the front guide and front guide, increase the diameter of the front support shaft to increase rigidity and prevent its flexural vibration.
In addition, the movement of the front guide is made into a swinging motion centered on a point on the front strike by the cam follower attached to the front striker and the cam formed on the facing surface of the front guide, and the swing angle (previously 22 °) is set. It is made small (13 °) to reduce the inertial force and prevent the leading edge of the front guide from damaging the sheet.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a front device in a sheet feeding section of a sheet-fed printing press.

[0002]

[Prior art]

 The sheet-fed printing press used to have a rotation speed of 10,000 rpm (r.p.h), but recently it has become faster and has reached 15,000 rotations. In the structure, a vibration phenomenon occurred and it was impossible to rotate at high speed. In the conventional device, the sheet advancing in the direction of the arrow from the paper feeding boat 1 as shown in FIG. 1 hits the front pad 2 and maintains a fixed position, but it may jump upward due to the forward momentum. is there. In order to suppress this jump, the guide 3 is attached to the front pad to perform the same movement as the front pad. That is, the front contact 2 swings between the retracted positions 2'with the front contact shaft 4 as the center, and does not hinder the forward movement of the sheet. In this case, the rocking angle is 22 °. When the number of rotations increases and the number of swings increases, the swinging motion of the front abutment shaft becomes unsmooth due to the inertial force of the front contact guide 3 fixed by screws 5, 5'above the front abutment, causing a slight bending vibration. Leading to. To prevent this vibration phenomenon, the diameter of the front contact shaft should be made thicker to increase its rigidity. However, as shown in FIG. When the center is moved to 0 ', the evacuation curve at the tip of the front contact guide changes from the circle of the solid line A to the circle of the dotted line B, and hits the sheet C and damages it. If the axes 0 and 0'are aligned, the front contact position will move to the left in the figure, and when it retreats, it will collide with the melon base and be unable to swing.

[0003]

[Problems to be solved by the device]

 As mentioned above, in order to solve the problem that the front contact shaft is strengthened and its diameter cannot be increased with the current structure, it is necessary to change the structure.

[0004]

[Means for Solving the Problems]

 The front guide, which used to be fixedly attached to the front pad, was separated from the front pad, and was pivotally attached to one point of the front guide lever, which was pivoted on the front pad. The surface of the id facing the front pad is formed into a cam shape, and is pressed against a cam follower provided on the front pad so that the rocking movement of the front pad makes a rocking movement of another system. It avoids the collision of. In addition, because of the swinging mechanism of such front guide, the front swing can be moved with the minimum swing of the front swing shaft, and the swing angle of the front swing can be greatly reduced to reduce the inertial force and vibrate. Prevented.

[0005]

【Example】

FIG. 3 shows a front contact structure of the present invention. Reference numeral 6 indicates a front contact guide vertical lever for swinging a front contact shaft (circular in section) 7 having a larger diameter than the conventional one, and a bearing 8 fixed to the lever. A swing shaft 10 of the front guide 9 is pivotally supported. Before the surface for pre-hook part 11 ₀ of this guide 9 forms a cam 12. Numerals ₁₁₀ and 11 are front stops attached to the tip of the front guide guide vertical lever 6, and are covered by the front guide guide 9. 13 is a roller Kamuforoa mounted rotatably prior to those 11 ₀ side, is pressed via a spring (although not shown) to the cam 12. When the front and swing around the front contact 11 _0, 11 front contact shaft 7 by those guide vertical lever 6, front contact 11 is shifted to the position of 11 ', Kamuforoa 13 presses rolling cam 12 surface, The front guide 9 is moved to the 9'position around the swing shaft 10. In that case, the locus of the front end of the front guide 9 is separated from the back surface of the sheet 14 whose front end is gripped by a ginger melon (not shown), and the paper is not damaged. 4 (A), (B), and (C) are diagrams showing the movement of the front contact and the front guide based on the rotation of the front contact shaft. (A) is the origin of the rotation angle 0, and (B) is the same. 10 ° and (C) represent the state at the same 13 °. Since the rotation angle of the front hitter of the conventional device was 22 °, the inertial force of the front hitter was reduced by reducing the rotation angle to nearly half, and troubles due to high speed rotation could be eliminated. At the same time, the front guide performs a swinging motion with a short radius around its swinging axis by utilizing the contact pressure between the cam and the cam follower, so the vibration phenomenon due to high speed rotation does not occur.

[0006]

[Effect of device]

 According to the present invention, the front-end device of the sheet-fed printing press does not cause a problem such as a vibration phenomenon even when the conventional printing speed of 10,000 rotations or less is increased to 15,000 rotations, and the smooth operation is achieved. It is possible to improve printing efficiency and quality.

[0007]

[Description of sign]

▲ 9 before this guide, 10 oscillation axis, 11, 11 ₀ front contact, 12 a cam,
▲ 13 Cam follower roller, ▲

▲

[Brief description of drawings]

FIG. 1 Conventional front hitting device

FIG. 2 is an explanatory view of a case where a front contact shaft diameter of a conventional type is increased.

FIG. 3 is a schematic view of the device before the present invention.

4 (a), (b) and (c) are diagrams showing state changes with respect to swing angle of the front contact shaft.

Claims (1)

[Scope of utility model registration request] 1. The front support has a larger swing shaft diameter than the conventional one, and the front guide and the front support are separated from each other.
It is supported by a swing shaft attached to the front pad through a spring, and the front pad guide forms a cam on the surface facing the front pad and presses it against the cam follower on the front pad side to reduce the swing angle of the front pad, and The front contact device for sheet-fed printing presses is characterized by increasing the rigidity of the front contact shaft to prevent vibration at high speed rotation.