US3668919A

US3668919A - Combination hydraulic shearing and pressbrake machine

Info

Publication number: US3668919A
Application number: US71451A
Authority: US
Inventors: Toshio Hongo
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-12
Filing date: 1970-09-11
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13
Also published as: JPS518232B1

Abstract

A combination hydraulic shearing and pressbrake machine is disclosed which includes auxiliary hydraulic cylinders in addition to main cylinders to actuate the ram. The auxiliary cylinders are held at rest during the shearing mode of operation but actuated together with the main cylinders during the pressbrake operation, in which the auxiliary cylinders serve particularly to support and maintain maximum parallelism of the ram. A control device is also disclosed which switches the operation of the auxiliary cylinders relative to the main cylinders and which further regulates the upper and lower limit positions of the reciprocating ram.

Description

United States Patent Hongo 1 June 13, 1972 [54] COMBINATION HYDRAULIC 1,333,201 3/1920 Beatty ..s3 s1s SHEARING AND PRESSBRAKE 3,550,425 12/ 1970v Cailloux ..72/386 MACHINE Primary ExaminerCharles W. Lanharn [72] Inventor: Toshio Hongo, 7-1 1, 5-chomc Konodai, Assistant Examine, Gene p Crosby lchikawa- Japan Artorney-Linton & Linton [22] Flled. Sept. 11, 1970 [57] ABSTRACT [21] Appl.-No.: 71,451

Y A combination hydraulic shearing and pressbrake machine is ['30] Foreign Application priority Data disclosed which includes auxiliary hydraulic cylinders in addition to main cylinders to actuate the ram. The auxiliary cylin- Sept. 12, Japan ders are at rest i g the shearing mode ofoperation but [52] U.S.C| ..'..'....72/453, 72/324, 83/618, a u d og her wi h the main cylinders during the press- 83/639 brake operation, in which the auxiliary cylinders serve par- [51] Int. Cl. .Q ..B21j 9/02 ticularly to support and maintain maximum parallelism of the [58] Field of Search ..72/453, 324, 326, 330, 332, ram. A control device is also disclosed which switches the 72/337, 338, 380, 385, 386, 389, 404, 325; 83/639, operation of the auxiliary cylinders relative to the main cylin 519 ders and which further regulates the upper and lower limit positions of the reciprocating ram. [56] References Cited 5 Claims, 10 Drawing figures UNITED STATES PATENTS Sevey ..83/618 PATENTEDJUM 13 I372 SHEET 1 OF 6 INVENTOR. TOSH/O HO/VG 0 WM AT'T'QENELS PATENTEDJUNISIQYE 3,668,919

SHEET 20F s INVENTOR. TOSH/O HO/VGO ATTORNEYS PATENTEDJUH 13 1972 SHEET 4 0F 6 FIGJ INVENTOR, TOSH/O HO/VGO ATTORNEYS PATENTEDJun 13 I972 SHEET 5 0F 6 FIG.8

RTTORNEVJ PATENTEDJUN 1 3 I972 SHEET 6 [IF 6 PIC-3.10

27 H l'h. I

INVENTOR. TOSH/O HUNG 0 WM A TToR/VEYS COMBINATION HYDRAULIC SHEARING AND PRESSBRAKE MACHINE This invention relates generally to machine tools and particularly to a Working machine of the'type including in combination a hydraulic guillotine and a pressbrake for shearing and bending aworkpiece through the operation of a single ram.

The utility of machines of the class described is mainly in the space-saving advantage. I However, many of these machines presently available have the drawback that the position of shearing is held considerably apart from the position of bending owing to the increased effective height or cross-sectional coefficient of the ram which is required to withstand large bending stress applied during the pressbrake operation. Insufficient cross-sectional coefficient of the ram results in deflected working plane of the ram and hence in inaccurate work finish. The distance between the shearing and the pressbrake position will be necessarily greater the greater the bending strength of the ram, which would lead to difiicult maneuvering of the machine and hence to retarded working speed. Means have been proposed to eliminate this difficulty, and such means for example include a removable plateform of sufficient height to permit the operator to work at a level adjusted to increased height of the ram. The provision of such plateform has requird additional floor space, or in some cases an underfloor pitto enable the plateform to retract therein.

Whereas, it is the primary object of the present invention to eliminate the above-noted difficulties of existing machines.

It is a specific object of the invention to provide an improved combination shear and press machine including a single reciprocating ram of relatively low profile.

It is another object to provide an improved machine including main hydraulic cylinder to actuate the ram and auxiliary hydraulic cylinders to support and maintain maximum parallelism of the ram during bending operations.

It is a further object to provide means for controlling and switching the operation between the main and the auxiliary set of cylinders. These and other objects and features of the invention will be better understood from the following detail description taken in connectionv with the accompanying drawings illustrating a preferred embodiment, and in the drawings:

FIG. I isa front elevation of a combination shear and press machine embodying the invention;

FIG. 2 is a cross-sectional view .of thesame taken on the line Il-ll of FIG. 1;

FIG. 3 is a cross-sectional view on enlarged scale taken along the line Ill-Ill of FIG. 1; FIG. .4. is a cross-sectional view taken on the line lVlV of FIG. 3, showingthis section (left-hand side) as connected to the change-over valves righvhand side) which are employed to change the direction of flow of oil in the hydraulic system according to the invention;

FIG. 5 is a cross-sectional view taken on the line V-V line of FIG. 3;

FIG. 6 is a perspective view of a part of the machine showing a rotary lever and its associated cam member;

FIG. 7 is a cross-sectional view showing a cam in pressbrake position taken on the line VII-VII of FIG. 3;

FIG. 8 is a cross-sectional view taken on the line VIII-VIII of FIG. 3;

FIG. 9 is a view similarto FIG. 7 but showing the-cam as in shearing position;

FIG. 10 is an oil path circuit utilizedto schematically illustrate the switching between the pressbrake mode of operation and the shearing mode of operation.

' The machine 10 according to the invention generally comprises a frame structure 1 1 including a pair of laterally spaced side plates 12, upper front plate 13 and lower front plate 14. A ledge 15 extends rearwardly of the machine from the upper front plate 13 and has mounted thereon an oil pressure generator 16 and a drive motor 17. The generator 16 compactly accommodates therein a pump, tank, control valves,

pilot valves, conduits and so on all in a manner well known in the art. A rod 18 extends between and is connected to the opposed side plates l2 adjacent to the lower front plate 14. A ram actuating pedal 19 is attached to the rod 18. The frame structure 11 further includes a transverse beam member 20 extending between the side plates 12, to which beam is secured a work bed 21 extending forwardly of the machine for supporting-thereon a workpiece during the shearing mode of operation. A stationary cutter 22 is secured to the inner end of the beam 20.

The upper front plate l3'has its lower end portion recessed as at 23 for inserting one end'of a tool bracket 25 which is secured in place by means of bolts 26. Subjacent to and in vertical alignment with the tool bracket 25 is provided a ram 27 which has secured to its lower portion a moving cutter 28 coacting with the stationary cutter 22. The bracket 25 has a tapered edge or male die 29 for engagement with a correspondingly chamfered female die 30 secured by clamping bolts 31 to the upper end of the ram.

In front of the ram 27, there is provided a retaining plate 32 which is secured at two extreme ends to the side plates 12 by means of bolts 33 and across compression springs 34. This retaining plate is forced downwards against tension in the springs 34 by descending ram 27 and will retain a workpiece in position. The retainer 32 returns to normal position by the action of the springs 34 as the ram 27 ascends back to its rest position. The function of the springs 34 may be of course replaced by a hydraulic cylinder where heavy duty operations are required. I

The height of the bed 21 above the floor is normally about 60 to 70cm, while the distance between the floor and the upper end of the ram 27 is about to cm, so that the difference of the operational level between shearing on the bed 21 and bending on the. die 30 of the ram is about 15 to 30cm, preferably about 25cm for maximum operators comfort.

Projecting rearwardly from the ram 27 is a support member 35 adapted to secure thereto a back gage 36 comprising a screw shaft 37 joumalled in an elongated open-bottom box 38 and a slider 39 having a threaded member 40 for threaded engagement with the screw shaft 37. Manual or powered rota tion of the screw shaft 37 moves the slider 39 longitudinally of the shaft 37. The slider'39 has an end stop 41 disposed in abutting relation to a workpiece for determining the length of the latter to be cut corresponding to the distance between the stop 41 and the cutting position of the ram 27.

There are provided main hydraulic cylinders 42 having their respective piston rods 43 connected to the opposite ends of the ram 27 for actuating the same in the shearing and bending cycles of operation. There are further provided according to the invention auxiliary hydraulic cylinders 44 at symmetric positions inwardly of the main cylinders 42 as shown in chain line in FIG. 1. These auxiliary cylinders 44 have their respective piston rods 45 disposed in abutting relation to but normally apart from the ram 27. The piston rods 45 of the auxiliary cylinders 44 are arranged to move upwardly into contact with a medial portion of the ram 27 together with the upward stroke of the main cylinders 42 during the bending cycle of operation in which a workpiece is pressed and bent on the

die members

20 and 30. During the shearing cycle of operation, the auxiliary cylinders 44 are held at rest and need not operate to support and protect the ram 27 against the load of shearing which is usually relatively small. However, the stress of bending which occurs during the pressbrake operation of the machine is considerably large and pronounced at the medial area of the ram, which would often produce physical deflection in the ram and adversely affect the accuracy to which a workpiece is pressed and bent, unless proper remedy is provided. This problem has been solved by the arrangement according to the invention in which the piston rods 45 of the auxiliary cylinders 44 approach at the time of pressbrake and engage in abutting relation with the lower end face of the ram 27, thereby supporting the same against the influence of bending load applied during the pressbrake mode of operation. The

operation of the auxiliary cylinders 44 relative to the main cylinders 42 will be described more fully hereinafter.

Designated at 46 is a plate chute extending from behind the stationary cutter 22 and having a downwardly inclined slide surface for transferring therealong and removing the machined workpiece out of the machine. The chute 46 has an opening 47 through which the piston rod 45 of the auxiliary cylinder 44 moves into and out of abutting engagement with the ram 27.

Now, referring to FIG. 10, there is schematically shown an oil path switching circuit 50 for controlling the supply of oil pressure to the main and auxiliary cylinders. The circuit 50 includes a main valve 51, a change-over valve 52, a pump P, an oil reservoir RV and various oil passage lines connecting between the valves and the hydraulic cylinders. More specifically, the main valve 51 has an outlet A connected via line 53 to the approach side of the main cylinder 42 in pressbrake position and another outlet B connected via line 54 to the return side of the main cylinder 42. The change-over valve 52 associated with the auxiliary cylinder 44 is connected via branch line 55 to line 53 on the approach side of the main cylinder 42. The change-over valve 52 has an outlet C connected via line 56 to the approach side of the auxiliary cylinder 44 and another outlet D via line 57 to the return side of the auxiliary cylinder 44. A plunger 51a of the main valve 51 is connected by connecting rod 51b to an oil path switching device later described. A plunger 52a of the change-over valve 52 is connected by connecting rod 52b through a link 520 to the switching device.

While the left-hand side half of the circuit 50 just described is omitted in FIG. 10, it is obvious that a similar circuit may be connected there in parallel for the same purpose.

An oil path switching device 60 according to the invention essentially comprises a main valve and change-over valve control unit and a ram stroke regulating unit. The device 60 is shown in FIG. 3 through FIG. 8 as set in the pressbrake position of the tool machine 10.

The valve control unit includes a frame member 61 provided at its upper end portion with a yoke 62 for supporting a bell crank 63, at its intermediate portion with a bearing 64 and at its lower end portion with a bearing 65, both bearings being adapted to journal therein a cam shaft 66. The frame 61 is further provided with a bearing 67 intermediate between the upper and

lower bearings

64 and 65 for supporting a rotary lever 68. The cam shaft 66 has at its upper portion a reduced neck 69 at which one end of the bell crank 63 is attached. The cam shaft 66 is recessed as at 80 adjacent to the upper end face of the bearing 64 for engagement with a shifting lever 81. The shaft 66 has a cam 83 attached thereto intermediate between the upper and

lower bearings

64 and 65, and further has a recess 83 adjacent to the upper end face of the lower bearing 65 for receiving a lever member 84.

Designated at 85 is a pin connecting the bell crank 63 pivotally to the yoke 62. One end of the bell crank 63 is secured, as already stated, to the reduced neck 69 of the cam shaft 66, and the other end of the crank 63 is connected to the connecting rod 51b of the main valve 51. With this arrangement, vertical movement of the cam shaft 66 rotates the bell crank 63 which in turn actuates the plunger 510 so as to open and close the main valve 51.

The shifting lever 81 is partly fitted within the recess 80 in the cam shaft 66 and secured to a supporting member 86 mounted on the cam shaft 66. The lever support 86 has one end connected to the connecting rod 52b, as seen in FIG. 4, which rod is further connected via suitable link 520 to the plunger 52a of the changeover valve 52. With this arrangement, rotation of the shifting lever 81 changes the operating position of the change-over valve 52.

The rotary lever 68 is rotatably mounted on a shaft 87 journalled in the bearing 67 and has its front end connected to one end of a pull bar 88 (FIGS. 6 and 7). The other end of the bar 88 is connected to a pedal 89 resiliently supported on a spring 90 as seen in FIG. 3. The rotary lever 68 is provided at its side facing the cam shaft 66 and at symmetrical positions with

cam followers

91a and 91b as shown in FIGS. 6 and 7. The cam shaft 66 is provided centrally with the cam 82 which is substantially triangular in plane and which has integral therewith

cam dogs

92a and 92b on the side of a ram stroke regulating unit later described. The cam dogs 92a and 92b are disposed for engagement respectively with a lower limit dog 109 and a shearing upper limit dog 114, in the ram stroke control. The cam 82 is provided with

grooves

95a and 95b at positions engageable with the

cam followers

91a and 91b, respectively, when the shifting lever 81 is rotated.

It will be appreciated that the rotary lever 68 may be alternatively provided with a groove for receiving a pin or roller attached to the cam 82 instead of the foregoing arrangement. It will be also understood that the shifting lever 81 need not necessarily be separately installed, or any other suitable means may be employed for rotating the cam 82. The shifting lever may be for example attached to the cam, in which case the connecting rod 52b may be connected directly to the cam.

The ram stroke regulating unit according to the invention comprises a vertical base secured to the ram 27 and provided at its upper part with a bearing 101 for rotatably supporting a screw rod 102. The screw rod 102 is threaded throughout its lower half portion and has a bevel gear 103 fixedly mounted at its top, which gear 103 is driven by a mating bevel gear 103'. The drive bevel gear 103 is secured to one end of a shaft 104 joumalled in bearing 105 and extending horizontally across the ram 27. The other end of the shaft 104 has a handle 106 secured in place by means of a nut 107. The screw rod 102 has mounted thereon an upper limit dog 108 and a lower limit dog 109 for limiting the stroke of the ram 27 during the pressbrake mode of operation. The lower limit dog 109 is loosely mounted on the non-threaded portion of the screw rod 102 and has one side slidably inserted in a guide groove 110 in the base 100 and normally urged against the wall of the groove 110 by a push screw 111 having a handle 112 as shown in FIG. 8. Releasing the push screw 111 from the lower limit dog 109 permits this dog to move in the guide groove 110 and along the screw rod 102, so as to set the lower limit position of the ram 27 during the pressbrake operation. In this position, the lower limit dog 109 is held in abutment against the upper face of the cam dog 92b as seen in FIG. 3. The upper limit dog 108 is held in threaded engagement with the threaded part of the screw rod 102 and has one side slidably inserted in a guide groove 113 formed in the base 100, so that the dog 108 may move up and down with rotation of the screw rod 102 so as to set the upper limit position of the ram 27 during the pressbrake position. In the pressbrake mode of operation, the upper limit dog 108 moves upward with the ram 27 and comes in abutment with the lower face of the cam dog 92a.

There is provided another limit dog 114 for limiting the upward stroke of the ram 27 during the shearing operation. This dog 114, hereinafter referred to as shear limit dog, is disposed side by side with the lower limit dog 102 and attached to the side of the base 100. When the machine is switched into a shearing mode of operation, the shear limit dog 1 14 is brought into contact with the lower face of the cam dog 92a as shown in FIG. 9. It is to be noted here that it is not necessary to provide a limit dog for limiting the downward stroke of the ram 27 during the shearing operation.

In the embodiment above described, there is further provided means for imparting a positive motion to the ram 27 during the shearing operation. This means comprises a cam 115 and a lever member 84 as specifically shown in FIG. 8. The cam 1 15 is secured to the lower end face of the shear limit dog 114 and has an inclined face disposed on the side of the cam shaft 66. The lever 84 is pivotally connected by pin 116 to the bearing 65 of the cam shaft 66 and has one end in threaded engagement with a screw 117. The screw 117 has its forward end disposed in abutting relation to the inclined face of the cam 115. A spring 118 has one end secured to the frame member 61 and the other end to the tip end of the lever 84 so as to retain the lever 84 resiliently in position. As the cam shaft 66 ascends until the recess 83 reaches the lever 84, the lever 84 fits into this recess, with the result that the ram 27 can move even with the pedal 89 released during the shearing operation.

Having thus described the construction of the machine embodying the present invention, the following description will now deal with its operation. i In the pressbrake mode of operation, the cam follower 91a is engaged in the cam groove 95a. Now, depressing the pedal 89 to pull the rod 88 causes the rotary lever 68 to rotate clockwise, which in turn lowers the cam shaft 66 to move the bell crank 63 counter-clockwise. This actuates the plunger 51 to open the outlet A of the main valve 51, thereby effecting the approach operation of the main cylinder 42. Simultaneously as this occurs, the oil pressure flows through the branch line .55, change-over valve 52, line 56 into the auxiliary cylinder 44 to actuate this cylinder to make an upward stroke. Operation of both main and auxiliary cylinders moves the ram 27 upwards until the upper limit dog 108 abuts against the lower end face of the cam dog 95b, and the cam 82 is lifted, whereupon the cam shaft 66 begins to ascent to cause the bell crank 63 to move clockwise. This movement of the bell crank 63 causes the plunger 51:: to move back to close the main valve 51 and stop the ram 27.

Releasing the pedal 89 lifts the cam shaft 66 to its upper limit position, in which the main valve plunger 51a is withdrawn so as to open the outlet B of the main valve 51. This causes the ram 27 to descend until the lower limit dog 109 abuts against the upper end face of the cam dog 95b, when the cam 82 and the cam shaft 66 begin to descend and return to the position shown in FIG. 3.

A desired lower limit position of the ram 27 in the pressbrake mode of operation may be easily selected and set by slackening the screw 111 and changing the position of the lower limit dog 109. The upper limit position of the ram 27 may be determined by the position of the upper limit dog 108 which is variable by manipulating the screw rod 102.

Rotating the shifting lever 81 clockwise moves the ram 27 upwards until the shear limit dog 114 abuts against the lower end face of the cam dog 95a and stops the ram 27 in the upper limit position in the shearing mode of operation. This rotation of the lever 81 setsthe change-over valve 52 in closed position, so that the auxiliary cylinder 44 is held at rest during the shearing operation.

With the machine set in the shearing mode of operation, the cam follower 91b is engaged in the groove 95b of the cam 82. In this position, depressing the pedal 89 causes the cam shaft 66 to move upwards and the bell crank 63 to move clockwise to pull the plunger 51a, which in turn opens the outlet B of the main valve 51 to impart a downward movement to the ram 27. In this instance, with ascending cam shaft 66, the lever 84 fits into the recess 83 to lock the shaft 66 in position. Therefore, the pedal 89 may be readily released.

According as the ram 27 moves downwards, the screw 117 of the lever 84 is pushed by the cam 115 so that the lever 84 disengages from the recess 83, whereupon the pedal 89 is lifted under the influence of the spring 90. This causes the cam shaft 66 to descend and the ram 27 to ascend until the shear limit dog 1 14 contacts the lower end face of the cam dog a, lifting the cam 82 and hence the cam shaft 66. The bell crank 63 begins to rotate and the main valve 51 closes to stop the ram in the upper limit position in the manner already described.

Where the machine is not equipped with the cam and lever 84, the pedal 89 may be kept depressed until a shearing cycle is completed and may be released upon completion of the shearing operation, whereupon the pedal is urged upwards by the spring 90 to repeat the foregoing procedure to bring the ram back into its upper limit position.

While the invention has been described with a specific embodiment relative to a shearing and bending machine, it will be appreciated that the principles of this invention may be equ ly applied to an apparatus for testing the tension and compression of materials. It will be also understood that the invention is not to be limited to the specific form and construction of the machine herein advanced, but many modifications and changes may be made therein without departing from the scope of the appended claims.

What is claimed is:

l. A combination hydraulic shearing and pressbrake machine which comprises a reciprocating ram, a set of main hydraulic cylinders actuating said ram and a plurality of auxiliary hydraulic cylinders each having a piston rod disposed normally in spaced apart relation to said rarn during the shearing mode of operation, said auxiliary hydraulic cylinders being arranged to operate in the pressbrake mode of operation together with said main cylinders to actuate the ram.

2. In a combination hydraulic shearing and pressbrake machine of the class described including main cylinders and auxiliary cylinders, an oil path switching device which comprises a main and change-over valve control unit and a ram stroke regulating unit, said valve control unit including a frame, a cam shaft slidably journalled in bearings secured to said frame, a bell crank having one end secured to said cam shaft, a main valve supplying an oil pressure to the main cylinders, a plunger connecting between the other end of said bell crank and said main valve, cam means mounted on said cam shaft, a rotary lever pivotted on said frame and disposed to engage said cam means, a pedal resiliently held in position and connected to said rotary lever, a shifting lever connected to said cam shaft, a change-over valve supplying an oil pressure to the auxiliary cylinders, and a plunger connecting between said shifting lever and said change-over valve, and said ram stroke regulating unit including a screw rod parallel with said cam shaft and rotatably mounted in said frame and means operatively associated with said screw rod for setting the upper and lower limit positions of the ram.

3. The machine as defined in claim 2 wherein said cam means is provided with grooves for receiving said rotary lever.

4. The machine as defined in claim 2 wherein said cam means is contacted by cam follower means.

5. The machine as defined in claim 2 wherein said ram stroke regulating unit further includes dog members movable along said screw rod to select the upper and lower limit positions of the ram.

Claims

1. A combination hydraulic shearing and pressbrake machine which comprises a reciprocating ram, a set of main hydraulic cylinders actuating said ram and a plurality of auxiliary hydraulic cylinders each having a piston rod disposed normally in spaced apart relation to said ram during the shearing mode of operation, said auxiliary hydraulic cylinders being arranged to operate in the pressbrake mode of operation together with said main cylinders to actuate the ram.