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公开(公告)号：EP1150794B1
公开(公告)日：2002-11-27
申请号：EP00906317.3
申请日：2000-02-10
申请人： HYDEA s.r.l.
IPC分类号： B23D15/14
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2.发明公开
公开(公告)号：EP1161710A1
公开(公告)日：2001-12-12
申请号：EP00925121.6
申请日：2000-03-17
申请人： HYDEA s.r.l.
CPC分类号： B23Q15/013 , G05B2219/49062 , G05B2219/49078
摘要： The invention relates to a device for controlling the working feed speed of the work unit of a processing machine (1) which machines a workpiece (11) by material removal. The device comprises a double-acting hydraulic cylinder (17) serving as drive element for the work unit whose feed speed is controlled by a restriction of the hydraulic oil flow which in feed mode flows through a throttle passage (49) and out of a pressure chamber (36) of the hydraulic cylinder. Said throttle passage comprises an adjustment throttle (59) which on the input side is connected to the hydraulic cylinder, as well as a pressure balance (63) which is arranged between said adjustment throttle and the reservoir (42) of the pressure-supply unit (41) and functions as a control throttle. The pressure balance comprises a balance piston (63) which on one side, on a control surface (91) having a value Aw, is subjected to the input pressure pL of the adjustment throttle (59) and can thus be displaced against the restoring force of a balance spring (86) with a view to reducing the flow section of the control throttle. The invention also provides for a control device (94, 96, 98) which as soon and for as long as the total pressure drop along the throttle passage (41) is lower than a defined threshold value pLS mediates, monotonically to the change in said pressure difference, an equivalent decrease or increase in the restoring force acting on the balance piston (63).
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公开(公告)号：EP1150794A1
公开(公告)日：2001-11-07
申请号：EP00906317.3
申请日：2000-02-10
申请人： HYDEA s.r.l.
IPC分类号： B23D15/14
摘要： The invention relates to a sheet-metal shearing machine (10) for great lengths of cut with a stationary lower blade (14) and a vertically reciprocal upper blade (17) that can be actuated in a controlled manner. The inventive shearing machine is provided with hydrocylinders (27, 28) for actuating the cutting and withdrawal movement of said upper blade. Said hydrocylinders are coordinated in such a manner that the forces of feed produced by the two hydrocylinders have equal amounts and that the share of load is evenly distributed onto the two hydrocylinders. A main control valve (73) that is pressure-controlled by an electrically controlled pilot valve (83) is provided to control the drive of the hydrocylinders. The shearing machine is also provided with a hydraulic hold-down device (29) with which the metal sheet (11) is clamped down to the base of the shearing machine. A hydraulic accumulator (88) is provided as a source of pressure for the hold-down device (29). Said hydraulic accumulator can be charged by way of a fixed displacement pump (63) in at least one stationary phase of the upper blade (17). The main control valve (73) is configured as a slide valve whose piston (76) has two ranges of stroke Δh1 and Δh2 that directly neighbor each other via an intermediate position (0) and that correspond to alternative operational positions (II and I) of the main control valve (73). A copy stop (128) concurrently performs the feed and withdrawal movement of the upper blade (17) and copies the end position of the upper blade that is facing away from the metal sheet onto the central intermediate position of the main control valve (73). A valve chamber (106) into which the initial pressure of the fixed displacement pump (63) is fed and the hydraulic accumulator (88) are linked with each other so as to communicate in the copying position of the piston (76) and within a stroke range that extends on both sides of the intermediate position (0) that is smaller than the overall stroke (Δh1 + Δh2) of the piston (76). The shearing machine is also provided with a pressure-controlled accumulator-charge valve arrangement (131) that switches the fixed displacement pump (63) to the circulation mode after a charge cycle of the hydraulic accumulator (88). An electrohydraulic control unit (72) activates first the hold-down device (29) before the main control valve (73) reaches the operational position (II) that corresponds to the cutting mode.
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