JPH01320169A - Printing press - Google Patents

Abstract

PURPOSE:To reduce the damage of a printing press as much as possible by mounting an overload detector which detects the hydraulic pressure over an allowable set printing pressure in a hydraulic chamber, opens a closing valve at an oil discharge part, and retracts an impression cylinder or a platen so that it is spaced more than a predetermined gap distance from a corresponding cylinder. CONSTITUTION:When a non-plastic material having a thickness more than a predetermined gap distance is inserted between a blanket cylinder B and an impression cylinder I, the impression cylinder I is applied with an overload more than an allowable set printing pressure downward from the blaqnket cylinder B. A slide bearing part 2 supporting the impression cylinder I presses down a protector ram 13, whereby the hydraulic pressure in a hydraulic chamber 5 is increased over the allowable set printing pressure and transmitted to a hydraulic chamber 11 of an overload detector 8 to lower a detection ram 9 downward against the air pressure in a pneumatic chamber 10 which is preset to the allowable set printing pressure. In this manner, the tip end of a plunger 17 on the side of the ram 9 is separated from a limit switch 12 to open the switch 12, whereby the closing valve 6 at the oil discharge part 7 is opened through a predetermined relay circuit.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to an impression cylinder, platen, or plate in a circular pressure type, rotary type letterpress printing machine, offset printing machine, or gravure printing machine. The present invention relates to a printing press equipped with an overload protector mechanism that lowers and retracts an impression cylinder and a platen when a load (overload) that exceeds at least an allowable setting printing pressure is applied.

(Prior Art) In general, in conventional printing machines, for example, in the case of a circular pressure printing machine such as a proof printing machine, there is a space between the printing transfer cylinder and the plate surface plate or pressure platen, or in the case of a letterpress printing machine, the plate cylinder. In the case of an offset printing press, place a non-plastic object (for example, a spanner , tools such as screwdrivers, folded printing paper, polymerized printing paper, etc.), the uniformity of metal-based printing cylinders, plate plates, pressing plates, blanket cylinders, impression cylinders, etc. Scratches and depressions occur on the surface of the cylinder, which has a high degree of precision, and the normal printing pressure is no longer applied to these areas, causing problems in printing quality and making mechanical repairs extremely difficult.

Conventionally, if a metal or wooden tool, bolt, or nut accidentally enters between the blanket cylinder and the impression cylinder during printing operation or adjustment of the printing press, only the drive system or drive transmission mechanism of the machine can be damaged. Therefore, an excessive load is applied between the relative cylinders. However, if the shark (safety pin) in the drive transmission section between the driving force side and the blanket cylinder and impression cylinder side breaks, the forced rotational power transmission from the drive source to the blanket cylinder and impression cylinder is cut off. This made it possible to stop the driving rotation of the blanket cylinder and impression cylinder. However, the occurrence of dents and distortions on the surface of the printing cylinder is unavoidable, and subsequent repairs take a considerable amount of time and are costly.

(Objective of the Invention) The present invention minimizes damage such as dents to the printing transfer cylinder, plate cylinder, impression cylinder, etc. that occurs when a non-plastic object with a thickness greater than the specified printing thickness enters the printing pressure gap of the printing press. The purpose is to reduce repair time and repair costs.

(Structure of the Invention) A first aspect of the present invention is to provide a slide portion that supports the rotating shaft of the impression cylinder or the platen, and a slide portion that supports the impression cylinder or the platen to the surface of the blanket cylinder, plate cylinder, or printing transfer cylinder through the slide portion. an overload protector comprising a protector ram, a hydraulic chamber, an oil introduction part, and an oil discharge part supported by hydraulic pressure higher than the allowable set printing pressure so as to have a predetermined gap; The apparatus is characterized by comprising an overload detector that detects oil pressure and opens an on-off valve of the oil discharge section to move the impression cylinder or platen away from the relative cylinder to a gap greater than a predetermined amount. It's a printing machine.

A second invention of the present invention provides a vibrating pressure detection head that includes a slide bearing that supports a rotating shaft of an impression cylinder, and a vibrating pressure detecting terminal member that is integrally provided with the bearing and that contacts the lower outer circumference of the rotating shaft. an overload protector comprising a protector ram, a hydraulic chamber, an oil introduction section, and an oil discharge section that support the impression cylinder through the bearing with a hydraulic pressure higher than an allowable set printing pressure; an overload detector that detects a vibration pressure that is higher than an allowable setting printing pressure and opens an on-off valve of an oil discharge section to separate and retract the impression cylinder to a gap greater than a predetermined distance with respect to the relative cylinder. This printing machine is characterized by:

A third aspect of the present invention is that a plate plate and a pressure plate are provided on the base of the printing press main body so as to be slidable in the vertical direction, and the plate plate and the pressure plate are arranged upwardly with respect to the relative cylinder. An overload protector includes a protector ram supported at a predetermined gap, a hydraulic chamber, an oil introduction part, and an oil discharge part, and an overload protector that opens an on-off valve of the oil discharge part by detecting a hydraulic pressure higher than the allowable setting printing pressure of the protector. ,
This printing machine is characterized by being equipped with an overload detector that moves the plate surface plate and the pressure surface plate away from the relative cylinder to a gap greater than a predetermined amount.

(Action of the invention) The present invention provides a rotary type letterpress printing machine, an offset printing machine,
Or, during cylinder insertion between the plate cylinder and the impression cylinder, between the blanket cylinder and the impression cylinder, or between the printing transfer cylinder and the plate surface plate, or between the impression surface plate in a printing machine such as a circular pressure proof printing machine, WAl &
If a non-plastic object with a value larger than the gap enters the predetermined gap during printing, the printing pressure applied to the plate cylinder or platen should be at least higher than the allowable setting for normal printing (or the first opening/closing valve of the printing press should be opened). By discharging the oil in the hydraulic chamber, the protector ram is lowered, and the impression cylinder and pressure platen can be separated from the relative one by a predetermined gap or more. It can be carried out in a short time and the overload can be released instantaneously.Therefore, the response time is shorter than the conventional method of moving the center of the pressure shaft by rotating the eccentric metal in the impression cylinder bearing. A large amount of gap can be directly obtained by using a fast, small amount of motion and by the reciprocating method, and the degree of damage such as dents to the impression cylinder, pressure platen, and printing transfer cylinder can be reduced compared to the conventional method.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example in which an impression cylinder shaft of a rotary printing press (offset printing press) is supported by a slide bearing part. It is supported by an overload protector, and the gap 1 between the pressure 'fAI and the blanket 1iilB is
is set, and the slide bearing 2 that pivotally supports the impression cylinder shaft 1 can be moved vertically up and down with respect to the printing press main body frame, or in a straight line passing through the respective shaft centers of the blanket cylinder 3 and the impression cylinder 1. A protector ram 13 having a protect rod 3 that supports the bearing 2 upward from the bottom is provided below the bearing 2, and a hydraulic chamber 5 is provided below the ram 13. An overload protector 4 is provided.The hydraulic chamber 5 has an oil discharge section 7 that communicates with the outside via an on-off valve 6, and a load that is the sum of the load of the impression cylinder I and the assumed overload pressure inside the hydraulic chamber 5. A hydraulic device Po is provided via a check valve 15 to apply a hydraulic pressure sufficient to support the pressure.The hydraulic pressure from the hydraulic device Po is applied via the oil introduction section 14 and the overload hydraulic pressure introduction section 16 to detect overload pressure. It communicates with container 8.

The overload pressure detector 8 includes a detection ram 9 and a plunger 17 on the upper side of the ram 9. A limit switch 12 is pressed by the tip of the plunger 17, and the switch 12 is closed. A hydraulic chamber 11 is provided above the ram 9, and a pneumatic chamber 10 is provided below. Pneumatic pressure equivalent to the allowable set printing pressure or higher is applied.

When a non-plastic object having a thickness greater than a predetermined gap enters between the blanket cylinder 8 and the pressure ff4I, the impression cylinder 1 is overloaded downward with respect to the blanket cylinder by more than the allowable set printing pressure, and the pressure is increased. The slide bearing part 2 supporting the barrel 2 presses the protector ram 13 downward, and the hydraulic pressure in the hydraulic chamber 5 increases.
The printing pressure exceeds the allowable setting preset by the regulator device Pa, and is transmitted to the hydraulic chamber 11 of the overload detector 8 via the overload hydraulic pressure introduction part 16, and is applied between the blanket cylinder 8 and the impression cylinder 1 of the printing press. The detection ram 9 is moved downward against the pneumatic pressure in the pneumatic chamber 10 that is set to the permissible setting printing pressure. As a result, the tip of the plunger 17 on the upper side of the ram 9 is separated from the limit switch 12.
The switch 12 is opened, and the on-off valve 6 of the oil discharge section 7 is opened via a predetermined relay circuit. (At this time, the rotation of each printing cylinder such as blanket cylinder B and impression cylinder I is also stopped.) Then, by opening the on-off valve 6, the hydraulic pressure in the hydraulic chamber 5 is released, the protector column 13 is lowered, and The supported slide bearing portion 2 and the pressure 11ii11 are lowered to widen the gap between the blanket cylinder B and the impression cylinder I to a predetermined gap or more.

FIG. 2 shows an embodiment of the present invention, in which an overload pressure detection head 18 is integrally mounted on a slide bearing portion 2 that supports an impression cylinder shaft 1.
The installation is fixed. The detection head 18 includes a contact member 19 that is in close contact with the lower outer periphery of the impression cylinder shaft 1, and a contact member 19 that is in close contact with the lower outer circumference of the impression cylinder shaft 1;
It consists of a detection ram 20 integrally attached to the lower side of 9 and a hydraulic chamber 21 provided below the ram.

As shown in FIG. 2, the hydraulic chamber 21 of the head 18 communicates with the overload detector 8 via the overload hydraulic pressure introduction part 16. The overload detector 8 includes a detection ram 9 and a plunger 17 above the ram.
The tip of the plunger 17 contacts the limit switch 12 to close the switch 12. A hydraulic chamber 11 is provided on the upper side and a pneumatic chamber 10 is provided on the lower side via the ram 9, and the hydraulic chamber 11 communicates with the hydraulic pressure introduction section 16. The pneumatic chamber 10 includes a regulator device pa that supplies a regulator pressure for setting an allowable set printing pressure.
It communicates with

In the embodiment shown in FIG. 2, for example, when an overload pressure is applied to the impression cylinder I, the contact member 19 with the shaft 1 of the detection head 18 is pushed down, thereby causing the detection ram 2
0, the hydraulic pressure in the hydraulic chamber 21 rises above the allowable setting printing pressure (or the maximum allowable pressure), and the hydraulic pressure is transmitted to the hydraulic chamber 11 of the detector 8 via the introduction part 16. Therefore, the hydraulic pressure exceeding the allowable pressure transmitted to the hydraulic chamber 11 is transmitted to the pneumatic chamber 11.
Push down the detection ram 9 against the regulator pressure of 0,
The tip of the plunger 17 is moved away from the limit switch 12, the switch 12 which is in the closed state is opened, and the on-off valve 6 is opened via a predetermined relay circuit. and,
By discharging the oil in the hydraulic chamber 5 from the discharge part 7, the oil pressure is recovered, the protector ram 13 is lowered, and the impression cylinder shaft 1 and the pressure lNi1 are moved to the blanket J via the slide bearing part 2.
iiiB.

Incidentally, in the above embodiment, an electric load cell can be used for the detection head 18, and the overload can be converted into an electric signal using the cell, and the opening/closing valve 6 can be opened and closed based on the signal. It is.

FIG. 3 shows another embodiment of the present invention in which an overload protector is attached to the plate surface plate and pressure surface plate of a circular pressure printing press, and 22 is attached to the horizontal base frame F of the main body of the circular pressure printing press. A plate surface plate or a pressure surface plate provided so as to be slidable in the vertical direction, 2
3 is an overload protector, 24 is a printing transfer cylinder around which a blanket is wound, 25 is a pinion gear provided at both ends of the transfer cylinder, and 26 is a rack gear.

In addition, in the present invention, a photocolumn is provided at the front stage in the printing direction in the vicinity of the gap between the impression cylinder (1) or the plate surface plate or the pressure surface plate 22 and the relative plate, and is provided close to and parallel to the impression cylinder circumferential surface and the surface plate surface. A sensor and a detector are installed to act as an emergency rotation stop switch, and the detector first detects an intruding object in the previous stage that enters the gap, and based on the signal, the printing machine is immediately turned off for winter use. It is possible to stop the rotation of the protector and then operate the protector using the overload detector of the present invention.

(Effects of the Invention) According to the present invention, a thickness greater than a predetermined gap is formed in a predetermined gap between a plate cylinder and an impression cylinder, a blanket cylinder and an impression cylinder, and a printing transfer cylinder and an impression plate that face each other in a printing press. If an object, especially a non-plastic object, enters, immediately widen the gap beyond the specified gap,
It is possible to alleviate damage to the printing press as much as possible, and it has a remarkable effect on shortening the repair time of the printing press and reducing repair costs.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the invention, and FIGS. 2 and 3 are side views of other embodiments of the invention. B...Blanket cylinder ■...Impression cylinder "...Main frame!...Gap 1...Pressure IJliil
Shaft 2...Slide part 3...Protector rod 4...Protector 5...Hydraulic chamber 6
...Opening/closing valve 7...Oil discharge part 8...Detector 9...Detection ram 10...Pneumatic chamber 11...
Hydraulic chamber 12...Limit switch 13...Protector ram 14...Hydraulic pressure introduction part 15
...Check valve 16...Overload hydraulic pressure introduction part

Claims (1)

[Scope of Claims] 1) A slide part that supports the rotating shaft of the impression cylinder or the platen, and a predetermined gap between the impression cylinder or the platen and the surface of the blanket cylinder, plate cylinder, or printing transfer cylinder through the slide part. an overload protector comprising a protector ram, a hydraulic chamber, an oil introduction part, and an oil discharge part supported by a hydraulic pressure at least equal to or higher than an allowable set printing pressure, and detecting a hydraulic pressure of the hydraulic chamber at least equal to the allowable set printing pressure; and an overload detector that opens an on-off valve of the oil discharge section and retracts the impression cylinder or platen to a predetermined gap or more with respect to the relative cylinder. 2) A slide bearing that supports the rotation shaft of the impression cylinder; a vibration pressure detection head that is integrally provided with the bearing and has a vibration pressure detection terminal member that contacts the lower outer circumference of the rotation shaft; An overload protector includes a protector ram, a hydraulic chamber, an oil introduction part, and an oil discharge part that are supported by a hydraulic pressure higher than an allowable set printing pressure via a bearing, and the vibration pressure detection head detects vibrations higher than the allowable set printing pressure of the protector. 1. A printing press comprising: an overload detector that detects pressure and opens an on-off valve of an oil discharge section to move the impression cylinder to a predetermined gap or more with respect to the relative cylinder. 3) A plate surface plate and a pressure surface plate are provided on the base of the printing press main body so as to be able to slide vertically, and a protector ram that supports the plate surface plate and pressure surface plate upward, a hydraulic chamber, and an oil introduction part are provided. An overload protector equipped with an oil discharge section detects oil pressure that is higher than the allowable setting printing pressure of the protector and opens the on-off valve of the oil discharge section to set the plate plate and pressure plate in a predetermined position relative to the relative cylinder. 1. A printing machine characterized by comprising: a detector for separating and retracting by a distance greater than a gap amount.