Driving system for a rotary press

Abstract: The known driving system for a rotary press including a plurality of printing units (1, 2, 3), a main shaft (5) for driving all the printing units, a plurality of branch shafts (11) provided as branched from the main shaft, and drive units each consisting of a clutch (7) and an individual drive motor and disposed on the main shaft for the respective printing units, is improved so as to be adapted for auto­ mation of a plate exchange work, to save time and labor for exchanging a plate, and to increase a working effi­ ciency of a rotary press. The improvements reside in that each of the printing units (1, 2, 3) is provided with an approach switch (16, 16') for detecting a particular position of a plate drum (9, 9') and a plate drum positioning device (18) for correcting the position of the plate drum to the particular position in the proximity of the particular position of the plate drum, and that each of the drive units is provided with an elec­ tromagnetic brake for stopping rotation of the plate drum in response to the approach switch and a main shaft posi­ tioning device on the respective sides of the clutch for correcting a phase deviation of a clutch coupling section.

Description: BACKGROUND OF THE INVENTION: Field of the Invention: The present invention relates to a driving system for a rotary press. Description of the Prior Art: At first, description will be made on a driving system for a rotary press in the prior art with reference to Figs. 8 and 9. The known driving system for a rotary press is illustrated generally in Fig. 8, and a plate clamping device of a plate drum used in the known rotary press is shown in cross-section in Fig. 9. In Fig. 8, reference numerals 01, 02 and 03 respectively designate printing units in the known rotary press, and numeral 04 designates a folding machine in the same. In this rotary press, a main shaft 05 consists of main shaft sections connected in series along a straight line via a plurality of couplings 06 over the entire length of the rotary press so that it can be rotated synchronously, but for each of the printing units is formed a drive unit 010 which can rotate plate drums 09 and 09′ in each printing unit in a forward or reverse direction at a very slow speed (about 10 rpm) by means of an individual drive motor 08 by disconnecting a clutch 07. (In Fig. 8, the respective drive units 010 are encircled by double-dot chain line frames.) Reference numeral 011 designates branch shafts branched via bevel gear boxes 012, and numeral 013 designates electromagnetic brakes. In Fig. 9, a plate clamping device 014 is provided for the purpose of stretching and securing a plate 015 onto the drum circumference of the plate drum 09, clamping and dismounting of the plate 015 is effected by means of this device and upon performing this operation it is necessary to stop the plate drum 09 at such location that manipulation of the plate clamping device 014 can be effected easily. To that end it is commonly effected that the drive unit 010 is isolated by disconnecting the clutch 07, the plate drum is made to rotate in a forward or reverse direction at a very slow speed of about 10 rpm by means of the individual drive motor 08 and when the plate clamping device 014 has come to a position where mounting operation is easy, the plate drums 09 and 09′ are stopped by means of the electromagnetic brake 013 by manipulating a switch button, but in many cases the plate drums would stop at a position considerably deviated from a desired stop position. Even if a method of stopping the plate drums by making provision such that the electromagnetic brake may be automatically actuated by an approach sensor, is employed to eliminate this shortcoming, a precision of the stop position is of the order of ± 10 mm on the circumferential surface of the plate drum due to fluctuations of a load. This method is insufficient in precision for employing the recently developed automatic plate exchange system. Furthermore, since the clutches in the respective drive units were disconnected for exchanging the plates in the respective printing units, after finishment of the plate mounting work, phase matching of whole of the respective printing units must be effected by connecting the respective clutches again at predetermined positions, and the deviation of the plate drum stop position in each printing unit is enlarged on the main shaft due to the gear ratio to a deviation angle of phase of about four folds. Therefore, the methods employed in the prior art were those described in the following: (1) Upon connecting a clutch, a mark on a wheel mounted on a main shaft is aligned with a mark on the opposite member by manually rotating the latter, then the clutch is jointed by means of a push-out device (by making use of an air cylinder or the like), and thereby the clutch members are jointed at such position that a pin-shaped inter-unit phase-matching guide can enter into the opposite member. (2) A clutch device having a wedge mechanism is used. Though a stop position of a plate drum has become to be required to be realized at a severe precision in accordance with employment of automation of plate exchange, the above-described system in the prior art cannot satisfy this requirement, the stop position would vary every time due to fluctuations of a load, and the precision of stoppage has mounted to even ± 10 mm on the circumference of the plate drum. In addition, since plate exchange is effected for each printing unit, it is carried out after a clutch in each drive unit has been disconnected, and when the plate exchange has been finished, again synchronous operation must be carried out by connecting this clutch to bring the respective printing units into the same phase as a whole. However, in the above-described system in the prior art, the deviation of the stop position of each plate drum is enlarged on the main shaft due to the gear ratio to a deviation angle of phase of about four folds, hence in a meshing type clutch which performs fixed position connection, coupling cannot be done and coupling would be effected after phase matching has been carried out separately, and therefore, more time and labor were necessitated. Furthermore, even if a correcting device having a wedge mechanism is employed for phase matching of a clutch, a frictional resistance is large at the slide portion of the wedge, and so, a large-sized device becomes necessary. A coupling mechanism in a driving system of a rotary press for individually coupling main shaft sections arranged in series to extend over the entire length of the rotary press to interconnect and rotate a plurality of printing units synchronously is described in FR-A-1 365 695. In this coupling mechanism a slidable bolt is shifted via a hydraulically actuated lever and a sliding sleeve to interconnect flanges respectively arranged at opposing ends of the shaft sections. From US-A-1 877 387 there is known a printing press in which individual drive motors are provided for each of the printing units and folders instead of a single main motor. The motors are interconnected and synchronized by shaft sections, whereby a clutch is provided in each of the shafts in order to allow the units to be disconnected from one another. SUMMARY OF THE INVENTION: It is therefore one object of the present invention to provide an improved driving system for a rotary press that is free from the above-described disadvantages of the driving system in the prior art. A more specific object of the present invention is to provide a driving system for a rotary press, in which when a plate is to be exchanged on a plate drum, the plate drum can be easily brought to a predetermined stop position for facilitating automation of a plate exchange work. Another specific object of the present invention is to provide a driving system for a rotary press, in which a main shaft positioning device can be small-sized, saving of time and labor for exchanging a plate is realized, and hence a working efficiency of a rotary press can be enhanced. According to one feature of the present invention, there is provided a driving system for a rotary press including a plurality of printing units, a main shaft for driving all the printing units, a plurality of branch shafts provided as branched from the main shaft and drive units each consisting of a clutch and an individual drive motor and disposed on the main shaft for the respective printing units, which further comprises the features of the characterizing portion of claim 1. According to another feature of the present invention, there is provided the above-featured driving system for a rotary press, in which there is further provided a fixed position coupling device for connecting the clutch at a particular position on the main shaft. According to the present invention, when a plate is to be exchanged, in order to stop the plate drum, the clutch is disconnected and the plate drum is rotated at a very slow speed by means of the individual drive motor. Under such a condition, the stop position of the plate drum is detected with the aid of the approach switch and rotation of the plate drum is stopped by the electromagnetic brake. Subsequently, the stop position is corrected at a high precision by means of the plate drum positioning device. In addition, a phase deviation at the clutch coupling section is corrected by means of the main shaft positioning device provided at the clutch section. As a result, the driving system for a rotary press according to the present invention is adapted for automation of a plate exchange work. Moreover, since the main shaft positioning device is required to correct only the deviation caused by a backlash of the gears between the plate drum and the main shaft, the main shaft positioning device can be small-sized, also shortening of the time necessitated for the plate exchange work becomes possible, and a working efficiency of a rotary press can be increased. The above-mentioned and other objects, features and advantages of the present invention will become more apparent by reference to the following description of one preferred embodiment of the present invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS: In the accompanying drawings: Fig. 1 is a general construction view of a driving system for a rotary press according to one preferred embodiment of the present invention; Fig. 2 is an enlarged partial view of the structure in Fig. 1; Fig. 3 is a side view showing a plate drum in Fig. 2; Fig. 4 is a front view showing a plate drum positioning device; Fig. 5 is a plan view of the device shown in Fig. 4; Fig. 6 is a front view showing a main shaft positioning device; Fig. 7 is a cross-section view showing a clutch section; Fig. 8 is a general construction view of a driving system for a rotary press in the prior art; and Fig. 9 is an enlarged partial cross-section view showing a mode of mounting a plate onto a plate drum. DESCRIPTION OF THE PREFERRED EMBODIMENT: Now the present invention will be described in greater detail in connection to the preferred embodiment illustrated in Figs. 1 to 7. In Fig. 1, a main shaft 5 for driving a plurality of printing units 1, 2 and 3 and a folding machine 4, a plurality of branch shafts 11 provided as branched from the main shaft, clutches 7 which are provided on the same main shaft 5 for the respective printing units and which enable disconnection and fixed position coupling, and individual drive motors 8 jointly form drive units 10, 10 and 10 corresponding to the respective printing units. Furthermore, the main shaft 5 has a construction consisting of synchronously rotatable main shaft sections connected in series along a straight line via a plurality of shaft couplings 6 over the entire length of the rotary press. With reference to Figs. 2 and 3, in each printing unit, approach switches 16 for detecting particular positions of the plate drums 9 and 9′, respectively, are mounted to a machine frame to perform position detection for detection pieces 17 mounted on one side surfaces of the plate drums 9 and 9′, respectively. The detection piece 17 is mounted at such position on the plate drum 9 that it can cooperate with the approach switch 16 to stop the plate drum 9 at a position where the plate clamping device 14 can be easily manipulated. In addition, electromagnetic brakes 13 for stopping rotation of the main shaft 5 in response to a detection signal issued from the respective approach switches 16 are provided in the respective drive units 10, 10 and 10. It is to be noted that approach switches 16′ and detection pieces 17′ provided on the other side of the plate drums 9 and 9′ are those for use upon reverse rotation. The plate drum 9 is provided with a plate drum positioning device 18 for performing phase matching between the respective units upon clutch coupling. The operation of this device 18 is effected after the plate drum 9 has stopped in the proximity of the particular stop position in response to operation of the approach switch 16 and the electromagnetic brake 13 has been released. In the plate drum positioning device 18, as shown in Figs. 4 and 5, a terminal end of an air cylinder 20 is coupled via a pin 21 to a member 19 supported from a machine frame, and the other end of the air cylinder is formed as a retractable rod and coupled via a pin 23 to the top end of an arm 22. The arm 22 is swingable as pivotably supported from the member 19 via a shaft 24, the outer end of the arm 22 is bifurcated, and a roller 26 is rotatably supported via a pin 25 by the bifurcated end portion. The roller 26 is so machined that it can fit at a high precision in a groove 28 formed in a member 27 fixedly secured to the side end of the plate drum 9, and in the proximity of this groove 28 are provided guide slant surface portions 29 for the roller 26 to be used for correcting a deviation of the plate drum stop position. Furthermore, on the opposite sides of the clutch 7 in the driving system are provided main shaft positioning devices 30 which correct a phase deviation at the clutch coupling section caused by a backlash of the gears between the plate drum 9 and the clutch 7 after operation of the plate drum positioning device 18, and thereby coupling at a fixed position of the clutch 7 can be effected. The main shaft positioning device 30 transmits the motion of a retractable bottom end rod of an air cylinder 31 as a swinging motion of an outside bifurcated end portion of an arm 32 as shown in Fig. 6, and the bifurcated end portion has a roller 34 rotatably secured thereto via a pin 33. The roller 34 is so machined that it can fit at a high precision in a groove 37 of a member 36 which is fixedly secured to the main shaft 5 via a key 35, and this groove 37 is provided with guide slant surface portions 38 for the roller 34. As shown in Fig. 7, a fixed position coupling device 40 for the clutch 7 is composed of an external gear 41 fixedly secured to a shaft end 5a, an external gear 42 fixedly secured to a shaft end 5b, a slide internal gear 43 capable of simultaneously meshing with the gear 41 and the gear 42, a slide ring 45 fitted around the same gear 43 via rolling bearings 44, a swing arm 46, a guide ring plate 47 fixedly secured to a flange portion 41f of the external gear 41 and having a guide hole 47h, and a guide pin 48 studded in the slide internal gear 43, and when the guide hole 47h and the guide pin 48 fit to each other at a high precision and the external gears 41 and 42 are simultaneously meshed with the internal gear 43, or the meshing is released, the function as a clutch is realized. Owing to the provision of the guide hole 47h and the guide pin 48, the clutch 7 can incorporate the fixed position coupling capability. Now description will be made on the operation of the driving system for a rotary press according to one preferred embodiment of the present invention which has the above-described construction. In order to stop the plate drum so that the plate clamping device 14 on the plate drum 9 may stop at a particular stop position, the detection piece 17 mounted to the side surface of the plate drum 9 is detected in position by means of the fixed approach switch 16, and in response to a detection signal issued from the approach switch 16 the electromagnetic brake 13 for the main shaft 5 is actuated to stop and fix the plate drum. Subsequently, since this stop position is subjected to fluctuations over a considerably large range due to variation of a loading condition, at first the electromagnetic brake is released, and positioning of the plate drum is effected by actuating the plate drum positioning device 18. Thereby the main shaft 5 can be corrected in phase from the drive gears of the plate drum and the like via the branch shaft 11, and hence a phase deviation at the portion of the clutch 7 is reduced to the order of the total amount (about 2 - 3 mm) of the backlashes of the connected gear train. Furthermore, a deviation of phase on this main shaft is corrected by the main shaft positioning device 30. As a result of this correction, a precision in position of the order of ± 0.1 mm can be attained at the clutch gear meshing portion. Under this condition, fixed position coupling of the clutch becomes possible, and clutch connection is effected. The above-described respective working processes can be achieved through electric remote control or through continuous automatic control, hence it is possible to promote rationalization of work by eliminating waste caused by manual operations which was a problem to be resolved in the prior art, and the driving system can be adapted for automation of plate exchange by making use of a robot. As described in detail above, according to the present invention, since a stop position of a plate drum can be corrected to a predetermined position by means of the plate drum positioning device after the plate drum has been stopped in the proximity of the predetermined position, the driving system for a rotary press can be adapted for automation of a plate exchange work. In addition, since the main shaft positioning device is required to correct only the deviation caused by a backlash of the gears between the plate drum and the main shaft, the main shaft positioning device can be small-sized, also shortening of the time necessitated for the plate exchange work becomes possible, and a working efficiency of a rotary press can be increased.

Claims: A driving system for a rotary press including a plurality of printing units (1, 2, 3), a main shaft (5) for driving all said printing units (1, 2, 3), a plurality of branch shafts (11) provided as branched from said main shaft (5), and drive units (10) each comprising a clutch (7) and an individual drive motor (8) and being disposed on said main shaft (5) for said respective printing units (1, 2, 3); characterized in that each said printing unit (1, 2, 3) is provided with: an approach switch means (16, 17) for detecting a predetermined position of a plate drum (9, 9'); an electromagnetic brake (13) operable in response to said approach switch means (16, 17) to stop the plate drum (9, 9') at an initial stopped position in the proximity of said predetermined position; a plate drum positioning device (18) for correcting the position of said plate drum (9, 9') from said initial stopped position to said predetermined position; and a main shaft positioning device (30) on the respective sides of said clutch (7) for correcting a phase deviation of a clutch coupling section. A driving system for a rotary press as claimed in claim 1, characterized in that there is further provided a fixed position coupling device (40) for connecting the clutch (7) at a particular position of the main shaft (5).

Inventors: AKIKAZU SEO MIHARA MACHINERY W, MITSUNAO MIYAKE MIHARA MACHINE, AKIKAZU, SEO MIHARA MACHINERY WORKS OF, MITSUNAO, MIYAKE MIHARA MACHINERY WORKS OF
Applicants: MITSUBISHI HEAVY IND LTD, MITSUBISHI JUKOGYO KABUSHIKI KAISHA
Application year: 1988
Main classification: B41F13
IPC codes: B41F33, B41F13