Patent Application
20170252911
1. Field of the Invention
The present invention relates to a hydraulic pump for a hydrodynamic compression and/or cutting tool and to a hydrodynamic compression and/or cutting tool.
2. Description of the Related Art
Hydrodynamic compression and/or cutting tools are often used to perform determined connection operations, e.g. for crimping connectors about electrical wires or hydraulic pipes and for compressing rivets, or for determined cutting operations, e.g. cutting electric wires during electric system installation and maintenance.
Such tools comprise an electric motor and a hydraulic pump which causes an increase of a hydraulic liquid pressure operating on a piston to move the latter against the bias of a pressure spring. In turn, the piston is connected to a movable jaw so as to move the jaw, during the compression operation, with respect to a fixed jaw of the tool. The jaws may be shaped and/or provided with interchangeable accessory elements so as to adapt to a particular object, e.g. an electrical contact to be compressed or a metallic bar to be cut.
The compression tools are very often used in external environments, e.g. along railway lines far from buildings provided with a connection to the electric power network, and require an electric energy source of their own, i.e. a portable electric accumulator either integrated in or applied on the tool. The accumulator provides a limited amount of electric energy which determines the autonomy, i.e. the number of compression/cutting operations which can be performed by the tool. Hence, a need is felt to control and perform the work cycles of the compression and/or cutting tool so as to reduce electric energy consumption.
Most compression and cutting operations, in particular those performed on electric cables, are hindered by very narrow space conditions or are performed in conditions (live electric conductors) which are potentially very dangerous for the operator and harmful for the tool. Therefore, the need is felt to design the compression and/or cutting tool so as to reach the part to be compressed or cut easily while reducing the risk of injury to the operator and limiting potential damage to the tool itself.
A third need is that of being able to control the result of the compression and cutting operations with appropriate rapidly in order to reduce the time needed to perform the job.
It is thus the object of the present invention to provide an electro-hydraulic pump for hydrodynamic compression and/or cutting tools, having features such to solve at least some of the drawbacks mentioned with reference to the prior art.
These and other objects are achieved by means of an electro-hydraulic pump according to as recited in the appended claims. The dependent claims relate to advantageous embodiments.
According to an aspect of the invention, an electro-hydraulic pump for hydrodynamic compression and/or cutting tools comprises:
The pressure hose allows to access the part to be cut or compressed by means of the work head of the tool only, thus being able to operate in extremely small work spaces and position the pump housing at a distance such as not to interfere with the work space and to be protected against possible damage, e.g. due to explosions, sparks, flames in case of cutting and compressing of live electric cables or pipes of explosive or flammable materials.
The flexible control cable and the hand held remote control, provided with display and push-button panel, allow to select and visually check the selected operation mode near the work space and when the work head is positioned on the part to be either compressed or cut, without needing to move away from the work space to set the operation mode on the pump body and without needing to approach the entire pump body to the work space. Being able to perform the steps of positioning of the work head, select the pump operation mode and visually check the correspondence between the operation to be performed (cutting, compressing, opening the jaws and closing force adapted to the size and the material of the part) and the selected operation mode, in a single place and without movements of the pump body and of the operator, saves time and reduces the possibility of errors.
Finally, during a cutting or compressing operation, the operator may choose his or her position, e.g. away from both the work space and the pump body or in a position from where the work space but not the pump body can be observed, or vice versa, but by means of the display on the hand held remote control can always visually control the operation mode, modify it and view further parameters or information related to the compression/cutting being performed or which has just ended, before even deciding to re-approach the work space to prepare the successive work cycle.
In order to understand the invention and better appreciate the advantages thereof, the description of some embodiments will be provided below by way of non-limiting example with reference to the drawings, in which:
Figures from 4A to 16 show exemplary screenshots of a multifunction display of a hand held remote control of the hydraulic pump according to embodiments.
With reference to the figures, an electro-hydraulic pump 2 for hydrodynamic compression and/or cutting tools 1 comprises:
The hand held remote control 15 comprises a push-button panel 16 which allows to manually start the electric motor 6 and manually select an operation mode of the electro-hydraulic pump 2 from a plurality of pre-set operation modes, as well as a multifunction display 17 (directly fitted on the hand held remote control 15) which shows the selected operation mode.
The flexible pressure hose 8 allows to access the part to be cut or compressed by means of the work head 11 alone of the tool 1, thus being able to operate in extremely small work spaces and position the pump housing 3 at a distance such as not to interfere with the work space and to be protected against possible damage, e.g. due to explosions, sparks, flames in case of cutting and compressing of live electric cables or pipes of explosive or flammable materials.
The flexible control cable 12 and the hand held remote control 15 are provided with display 17 and push-button panel 16 for selecting and visually checking the operation mode near the work space and when the work head 11 is positioned on the part to be either compressed or cut, without needing to move away from the work space to set the operation mode on the pump body 3 and without needing to approach the entire pump body 3 to the work space. By being able to perform the steps:
Finally, during a cutting or compression operation, the operator may choose his or her position, e.g. away from both the work area and the pump body or in a position from where the work space but not the pump body can be observed, or vice versa. By virtue of the display 17 on the hand held remote control 15, the operator can always visually control the operation mode, modify it and view further parameters or information related to the compression/cutting which is being performed or has just ended, even before deciding to approach the work space to prepare the successive work cycle.
The work head 11 may comprise a body 19 with an actuation cylinder 27 which receives an actuation piston 20 movable by means of the pressure fluid.
The work head 11 further comprises two jaws 21, 22 connected to the body 19 in mutually movable manner and connected to the driving piston 20 so that, in response to the movement of the driving piston 20, the jaws 21, 22 perform a relative movement between an open position and a closed position to perform either the compression or the cutting.
A return spring 23 acts on the actuation piston 20 so as to elastically bias it to a rest position, in which the jaws 21, 22 are in the open position.
The work head 11 is removably connectible to the pressure pipe 8. Alternatively or additionally, the pressure hose 8 may be removably connected to the pump housing 3.
According to an embodiment, the hydrodynamic pump 7 comprises a tank 24, a pumping cylinder-piston group and a maximum pressure valve 25.
The pumping cylinder-piston group may comprise a pumping cylinder with an intake opening connected to the tank 24 by means of a non-return valve, which allows the flow of hydraulic oil from the tank 24 into the pumping cylinder, and a discharge opening in communication with the pressure hose 8 and, therefore, with the actuation cylinder 27 of the work head 11. A non-return valve is arranged in the discharge opening to allow the flow of hydraulic oil from the pumping cylinder towards the actuation cylinder 27, but not the other way. A pumping piston may be accommodated in the pumping cylinder and coupled so as to translate together with a pivoting member actuated by the electric motor 6.
The maximum pressure valve 25 may be arranged in a return pipe 26 which connects the actuation cylinder 27 to the tank 24.
In this manner, the actuation of the electric motor 6 operates the hydrodynamic group 7 (pumping group) and moves the jaws 21, 22 from the open position either towards or to the closed position until a predetermined maximum calibration pressure is reached in the actuation cylinder 27. When the maximum calibration pressure is reached, the maximum pressure valve 25 automatically opens the fluid return duct 26 to discharge (at least part of) the pressurised liquid from the actuation cylinder 27 into the tank 24.
The selectable operation modes may comprise a working or hydraulic liquid pressurisation mode (often characterised by an interruption criterion of the pressurisation or of the actuation of the motor 6) and a return mode of the actuation piston 20 towards its rest position (open jaws) or of hydraulic fluid de-pressurisation.
In a first return mode (manual return), which can be selected by means of the push-button panel 16 and viewed by means of the display 17, after the hydraulic liquid pressurisation ends and thus the work cycle is completed, the hydraulic liquid depressurisation (e.g. by opening the return valve 25 performed by means of a valve opening actuator, e.g. a solenoid valve, actuated by the control circuit 28) and the consequent return of the jaws 21, 22 either to or towards their open position occurs by pressing the manual release button 29 of the push-button panel 16 for the time needed to reach the desired opening width of the jaws 21, 22.
In a second return mode (voluntary semi-automatic return), which can be selected by means of the push-button panel 16 and viewed by means of the display 17, after the hydraulic liquid pressurisation ends and thus the work cycle is completed, the depressurisation or a further depressurisation and hydraulic liquid return (e.g. by opening the return valve 25 performed by means of a valve opening actuator, e.g. solenoid, actuated by the control circuit 28) and the consequent return of the jaws 21, 22 either to or towards their open position is delayed until the manual pressure on the manual actuation button 18 is released, and only when the manual actuation button 18 is released the return and the further depressurisation of the hydraulic liquid begins (e.g. by opening the return valve 25 performed by means of a valve opening actuator, e.g. solenoid, actuated by the control circuit 28) and continues automatically until the manual actuation button 18 is pressed again, and in absence of a timely actuation of the actuation button 18, until the rest position of the actuation piston 20, which corresponds to the open position of the jaws 21, 22, is reached.
In a third return mode (involuntary automatic return), which can be selected by means of the push-button panel 16 and viewed by means of the display 17, after having ended the hydraulic liquid pressurisation and thus the work cycle is completed, the hydraulic liquid depressurisation (e.g. by opening the return valve caused by the pressure of the hydraulic liquid or actuated by the control circuit 28) and the consequent return of the jaws 21, 22 either to or towards their open position, occurs automatically and without voluntary activation by the operator. This operation mode, although provided as possible embodiment, however displays the disadvantage of depriving the operator from the possibility of checking the final state reached when the compression cycle is completed.
In a first operating mode, which can be combined with any one of the first, second or third return modes and either preset or selectable by means of the push-button panel 16 and viewed by means of the display 17, the control circuit 28 stops the motor 6 automatically when the maximum pressure valve 25 opens when the maximum calibration pressure is reached.
In a second work mode, which can be combined with any one of the first, second or third return modes and with the first work mode, and which can be possibly selected by means of the push-button panel 16 and viewed by means of the display 17, the control circuit 28 stops the motor 6 automatically in dependency of a comparison of at least one predetermined reference parameter (pressure limit, temperature limit) with a respective work parameter which is detected (detected pressure, detected temperature) by means of a sensor (pressure sensor, temperature sensor).
This contributes to saving electric energy and increasing the autonomy of the tool 1.
In all cases, the electric motor 6 is stopped by the control circuit 28 when the actuation button 18 is released. The stopping of the electric motor 6 determines the completion or interruption of the step of hydraulic liquid pressurising.
In a third operating mode, which can be combined with any one of the first, second or third return modes and which can be selected by means of the push-button panel 16 and viewed by means of the display 17, the control circuit 28 either controls or influences the motor 6 and/or the hydrodynamic unit 7, in dependency of a predetermined work scheme for a compression operation.
In a fourth operating mode, which can be combined with any one of the first, second or third return modes and which can be selected by means of the push-button panel 16 and viewed by means of the display 17, the control circuit 28 controls or influences the motor 6 and/or the hydrodynamic unit 7, according to a predetermined work scheme for a cutting operation.
In a fifth operating mode, which can be combined with any one of the first, second or third return modes and which can be selected by means of the push-button panel 16 and viewed by means of the display 17, the control circuit 28 controls or influences the motor 6 and/or the hydrodynamic unit 7, according to a predetermined work scheme for a punching operation.
The third, fourth or fifth work modes may include the second work mode and mutually differ, e.g. in the choice of the work parameter and/or of the comparison reference value and/or in the viewing mode of the display 17.
The compression mode is used to deform a connector on a conductor by means of inserts applied on the work head, wherein the end of the work cycle is defined by the reaching of a preset maximum pressure and the consequent stopping of the motor.
The work parameter or parameters mentioned above with reference to the second work mode may be indicative for:
According to embodiments, the work parameters may comprise one or more of the following:
The hydraulic pump 2 or, more generally the tool 1, may comprise one or more of the following:
The electronic control circuit 28 is configured to process the signals coming from one or more of the sensors 30; 31; 32 and to control the electric motor 6 and/or the maximum pressure valve 25 or other valve of the hydrodynamic group 7, according to the actuation of the push-button panel 16 and of the quantities detected by the sensors 30;31;32.
The control circuit 28 comprises a processing unit (CPU), a memory associated with the processing unit (CPU), a communication interface associated with the processing unit (CPU) and adapted to receive signals (pressure, current, temperature) from the sensor 30, 31, 32 and to transmit the control signals to the electrical motor 6. The control circuit 28 further comprises a program for electronic processor loaded in the memory and configured to process the signals and the operations needed to implement the operation methods. The control circuit 28 is connected to the accumulator 5 when the accumulator 5 is coupled to the accumulator seat 4 and could also have its own battery, possibly adapted to be charged when the control circuit 28 is connected to the accumulator 5. The accumulator seat 4 is preferably formed in the pump housing 3.
The hand held remote control 15 may be shaped as a joystick with an elongated lower gripping portion 34, on the front side of which the actuation button 18 (at the index finger) and the return button 29 (at the middle finger) are arranged, and an upper portion 35 which is wider with respect to the gripping portion 34, so as to rest on the hand without having to constantly tighten the fingers.
In an embodiment, the hand held remote control 15 comprises lighting means 33, preferably distanced from the display 17, e.g. one or two LED illuminators, adapted to work as a torch during the use of the hydraulic pump 2 or of the tool 1.
The lighting means 33 light up automatically with a light pressing on the actuation button 18 and/or with a light pressing on the return button 29, and remain on for a predetermined period of time, e.g. 25 seconds. The lighting means 33 may be deactivated by means of the push-button panel 16 in a guided procedure with the help of the display 17.
Advantageously, the lighting means 33 have a different direction of lighting different from a viewing direction of the display 17, preferably substantially parallel to the plane of the screen of the display 17.
The lighting means 33 are positioned in a front face of the upper portion 35, on the same side as the actuation 18 and return 29 buttons. The display is positioned on an upper side of the upper portion 35 and facing upwards (in use position). Furthermore, a touch key or mechanical button 36 is arranged either near or on the display 17 for selecting the operation mode, the functioning mode of the lighting means 33 (if included), and for selecting the viewing mode of the display 17 (if included).
The hand held remote control 15 may further comprise an acoustic warning device 37, which emits alarm or warning signals in fault situations, e.g. motor overheating or lack of hydraulic liquid.
In an embodiment, in case of disconnection of the hand held remote control 15 from the pump housing 3, and thus from the control circuit 28, the control circuit 28 automatically switches to “cutting” work mode, while the return mode remains that previously set by means of the push-button panel 16 of the hand held remote control 15. For the work cycles performed in this condition, the control circuit 28 registers the missing hand held remote control 15 condition and the “cutting” work mode.
By reconnecting the hand held remote control 15 to the control circuit 28, the control circuit 28 restores the operation mode selected before disconnection. For the work cycles performed in this condition, the control circuit 28 registers, for each cycle, the selected operation mode and one or more work parameters detected by means of sensors during the work cycle.
In an embodiment, the hydraulic pump 2 comprises a further push-button panel 38 and a further display 39 fitted on the pump housing 2, also connected to the control circuit 28 for controlling the hydraulic pump 2.
Advantageously, the connection of the hand held remote control 15 to the control circuit 28 disables the further push-button panel 38, and preferably also the further display 39.
The display 17 comprises for example a LCD or LED or OLED display.
The control circuit 28 controls the display 17 to view one or more of the following, in addition to the selected operation mode:
a value indicative of a maximum compression force reached during a work cycle,
a confirmation, e.g. “OK”, of the compression or cutting process result as a function of at least one comparison of one or more work parameters detected during the work cycle with a corresponding preset or preselected reference value,
an error warning, e.g. “FAIL”, of the compression process result as a function of at least one comparison of one or more work parameters detected during the work cycle with a corresponding preset or preselected reference value,
an overload warning of one of the components of the hydraulic pump or of the tool, e.g. thermal overload or electric overload of the motor 6,
an instantaneous value of one of the work parameters detected by means of the sensors 30, 31, 32 (motor temperature, hydraulic oil pressure etc.).
When the hydraulic pump 2 is off and the control circuit 28 is started for the first time, the display 17 shows the selected operation mode for a minimum preset time, e.g. 2 seconds.
Figures from 7 to 12 show exemplary screen shots for the following six possible operation modes:
Figures from 4A to 6B diagrammatically show exemplary screenshots containing completion confirmation, the operative modes and the maximum pressure reached (where applicable) for a work cycle according to the six operation modes described above.
Holding button 36 pressed for a long time, e.g. 2 seconds, will store the selection.
In an embodiment, the control circuit 28 with push-button panel and display 17 allows to select a pressure measuring unit from at least two measuring systems, e.g. Imperial and UNI measuring systems.
Return mode can be selected by means of a cursor viewed near the icon which represents the currently selected return mode. Holding button 36 pressed for an intermediate time, e.g. one or two seconds, will open selection mode. Touching button 36 will switch the selection from one icon to the next. Holding button 36 pressed for a long time, e.g. 2 seconds, will store the selection.
According to a further embodiment, when the temperature sensor 32 detects a temperature of the motor 6 higher than a maximum temperature, e.g. 90° C., the control circuit 28 completes the current work cycle and then performs a safe shutdown of the motor 6 until the detected temperature drops under a threshold value, e.g. lower than 80° C.
During the safety shutdown, the display 17 shows a motor overheating warning message.
In an embodiment (
In an embodiment (
In an embodiment, the flexible control cable 12 may be replaced by a wireless signal connection.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102016000022002 | Mar 2016 | IT | national |
