IT201800004796A1 - PNEUMATIC MODULES AND SYSTEM FOR PROPORTIONAL CONTROL - Google Patents

Description

DESCRIPTION

The present invention relates to pneumatic modules and a system for the proportional control of pressure or flow.

Several products are already known for specifically performing proportional pneumatic tasks. For example, the following control valves are already available on the market:

- 2/2 way proportional valves to provide variable flow;

- 2-way pressure control valves with integrated measurement sensor and closed loop electronic circuit;

- 3-way pressure control valves with integrated measurement sensor and closed loop electronic circuit.

Depending on the specific task within an application, these valves can be used as standalone products or need to be combined with, or on top of, additional manifolds. Furthermore, for the specific application of a closed loop flow control, external flow sensors must be individually combined with valves and electronic circuits.

To exchange process data between these combinations, various digital communication protocols are available on the bus, which require to be connected by dedicated cables and controlled by fieldbus master devices.

An object of the present invention is to integrate some proportional control functions, such as those mentioned above, in a modular and stackable system. Another purpose of the invention is to provide a proportional control system in which pneumatic modules are interconnected without external wiring or dedicated external communication devices.

These purposes are achieved with a master pneumatic module according to claim one, a master - slave module according to claim 7 and with a system according to claim 11. The dependent claims describe preferred embodiments of the invention.

The characteristics and advantages of the modules and the system according to the invention will in any case be evident from the following description of its preferred examples of implementation, given for information only and not limitative, with reference to the attached figures, in which:

- Figures 1 and 1a are perspective and side views of a master pneumatic module according to the invention;

Figure 1b is a block diagram of the closed loop flow control function of the master module;

- figures 2 and 2a are a perspective view and a side view of a slave pneumatic module suitable to be connected to the master module of figure 1;

- Figures 3, 3a and 3b are perspective, side and front views of a master-slave module according to the invention;

- figure 4 is a block diagram of the master-slave module; And

- figure 5 is an example of a stackable system made up of two master-slave modules.

Figures 1, 1a and 1b show a master pneumatic module 1 for proportional pressure or flow control. The master module 1 comprises a valve body of the master module 10 in which bushes are formed for a flow of pressurized air. In one embodiment, the master module valve body 10 has a rectangular parallelepiped shape.

These busggi connect a master pneumatic input port 12 to a first master pneumatic output port 14 for a direct pneumatic connection to a load and a second master pneumatic output port 16 for a pneumatic connection to a pneumatic input port of a slave module which can be connected to the master module, and which will be described below.

A master proportional solenoid valve 18 is mounted on a master module valve body 10. In one embodiment, the master proportional solenoid valve 18 is mounted on a face 10a of the parallelepiped body 10, for example on one of the smaller bases.

The master proportional solenoid valve 18 is suitable for supplying the first and second master pneumatic output ports 14, 16 with a regulated flow of pressurized air that enters the master module through the pneumatic input port 12.

The master module 1 also includes a relative pressure sensor 20 to detect the pressure of the regulated flow of pressurized air downstream of the master proportional solenoid valve 18.

The master proportional solenoid valve 18 is electrically controlled by an electronic control unit 22, for example implemented with a microprocessor. The electronic control unit 22 is also configured to control a proportional or on / off slave solenoid valve of a respective slave module.

In one embodiment, the master and slave proportional solenoid valves are controlled by respective PWM drivers 24, 24 '.

The master and slave proportional solenoid valves are controlled on the basis of a pressure signal supplied by the relative pressure sensor 20, so as to implement a closed loop control of flow or pressure. The electronic control unit 22 is also configured to implement a digital communication interface on the bus for exchanging data with other master modules. In one embodiment, a Can-bus protocol is used for digital bus communication.

The master module 1 is equipped with a male type electronic master input connector 26 and a female type master output connector 28 to receive and transmit analog and digital electronic signals.

The relative pressure sensor 20 and the electronic control unit 22 are mounted on an electronic printed circuit board 30.

The male electronic master input connector and the female master output connector 26, 28 are mounted on opposite parallel sides of the electronic printed circuit board 30 of the master module.

In one embodiment, the master module 1 also comprises, downstream of the master proportional solenoid valve 18, a nozzle or orifice 32 for a flow control of the regulated flow of pressurized air. In particular, the combination of the relative pressure sensor 20 and the nozzle or orifice 32 allows to perform, in addition to the pressure control, a simplified flow control.

In one embodiment, the master module 1 is also provided with a differential pressure sensor 34 to detect the difference in pressure upstream and downstream of the nozzle or orifice 32.

Preferably, the differential pressure sensor 34 is also operationally connected to the electronic control unit 22, for example to perform a complete flow control in closed loop.

In a preferred embodiment, the electronic master input and output connectors 26,28 and the electronic printed circuit board 30 are configured to receive and transmit digital bus communication and power supply signals. In one embodiment, the power supply for the electronic components of the printed circuit board 30 (5 V) is separated from the power supply of the proportional solenoid valve (for example 12 V or 24 V).

In one embodiment, the electronic interface of the master module also comprises a terminal for inserting an analog setpoint and a terminal for the output of a feedback signal.

In accordance with an embodiment, the electronic printed circuit board 30 of the master module is directly connected to the electrical terminals 18 'of a solenoid 18a of the master proportional solenoid valve 18.

The master printed circuit board 30 extends parallel to the valve body of the master module 10.

In one embodiment, the master printed circuit electronic board 30 is supported by the electrical terminals 18 'and, on the opposite side, by support columns 19 that extend from the valve body of the master module 10.

In addition, the electronic input and output connectors 26,28 are configured to be connected to the printed circuit board of another pneumatic master module or a slave module in such a way that all the electronic printed circuit boards lie in one. same floor.

In order to allow a side-by-side approach of master modules, or of a master module and a slave module, as will be described below, the master pneumatic input door 12 and the first master pneumatic output port 14 are formed in a face 10b of the master module valve body 10 opposite the master proportional solenoid valve (Figure 5) or in a face 10c opposite the electronic printed circuit board 30 (Figures 1, 1a). The second master pneumatic output port 16 is obtained (10d) in one of the side faces of the valve body of the master module perpendicular to the electronic printed circuit board 30.

In one embodiment, the second master pneumatic output port 16 is divided into two output conduits 16a and 16b: a first output conduit 16a bybus the master proportional solenoid valve 18 and is directly connected to the input port 12; the second output duct 16b is connected to the output of the master proportional solenoid valve 12, as shown in figure 4. In this way, it is possible to choose between a series or parallel pneumatic connection between the master module 1 and the respective slave module. In fact, if the first outlet duct 16a is plugged and the second outlet duct 16b is left open, a series operation of the master - slave assembly is obtained. If the first outlet duct 16a is open, the second outlet duct 16b is plugged, parallel operation is obtained in order to double the flow capacity.

In one embodiment, the electronic printed circuit board 30 has substantially the same width as the valve body of the master module 10.

Figures 2, 2a show a slave module 200 suitable to be connected to and controlled by a respective master module 1 so as to form a master - slave module 300.

The slave module 200 comprises a valve body of the slave module 210 in which bushes are formed for a flow of pressurized air. These busggi connect a slave pneumatic entry door 212 to a slave pneumatic exit door 214.

The slave module 200 can be equipped with a proportional slave solenoid valve 218 or an on / off slave solenoid valve 2180. In any case, the slave solenoid valve 218; 2180 is connected between the slave pneumatic input port 212 and the slave pneumatic output port 214. Each of the proportional or on / off solenoid valves 218; 2180 is controlled by a control signal supplied by the master module 1.

The slave module 200 is equipped with an electronic slave input connector of male type 226 suitable for being releasably connected to the female type master output connector 28 of the master module and to a slave output connector of female type 228 suitable for be releasably connected to the male-type master electronic input connector 26 or to another master module 1.

The electronic input and output slave connectors 226,228 are suitable for receiving and transmitting analog and digital electronic signals, in particular power supply signals and digital bus communication signals.

The male type slave input electronic connector 226 and the female type slave output connector 228 are mounted on opposite parallel sides of the slave circuit board 230, so that the master circuit board 30 and the circuit board circuit boards slave 230 lie on the same plane.

In addition, the slave valve body 210 has a lateral face 210d in which the slave pneumatic inlet port 212 is formed and which is suitable for contacting a lateral face 10d of the master valve body, so that the second outlet port pneumatic master 16 and the pneumatic slave entrance door 212 can be directly and hermetically connected, for example with the interposition of a sealing element 40.

In a preferred embodiment, the valve body of the slave module 210 has the same external shape and the same dimensions as the valve body of the master module 10.

In one embodiment, the slave printed circuit board 230 has substantially the same width as the valve body of the slave module 210.

In a preferred embodiment, the entire slave module 200 has the same external shape and the same dimensions as the master module 1.

Figures 3, 3a and 3b show the master module 1 and the slave module 200 connected together to form a master - slave module 300.

As explained above, the master module 1 and the slave module 200 are positioned side by side in such a way that the second master pneumatic output port 16 is aligned and in direct communication with the slave input port 212, without the interposition of no external connecting element, in addition to the sealing element.

The master module 1 and the slave module 200 are connected by the coupling of respective electrical connectors 28,226.

In one embodiment, the master proportional solenoid valve 18 is a 2-way valve and the slave solenoid valve 218; 2180 is also a 2-way valve.

Therefore, the master module 1 alone can perform 2-way functions, while the master - slave module 300 can perform 3-way functions.

Master 1 modules and / or 300 master - slave modules can be linked to form a system of 400 stackable control modules.

The system 400 comprises a digital communication bus 410, at least one pneumatic master module 1 and / or at least one pneumatic master - slave module 300, each master module 1 or each master - slave module 300 exchanging data through the digital communication bus 410.

In system 400, at least two identical master modules 1 are directly connected to each other through the electrical master output connectors 28 and input 26. In system 400, a master module 1 is electrically connected to the slave output electronic connector 228 of slave module 200 of a master - slave module 300. In this case, the slave module 200 acts as a bridge to transmit to the master module 1 downstream at least one electrical signal of the digital communication bus 410.

To summarize, such a stacked control module system can include:

- master modules with proportional solenoid valve, sensors and control unit;

- slave modules with proportional or on / off solenoid valve only.

The system can perform:

- 2-way functions only with master module;

- 3-way functions with master module and slave module; - operations in series or in parallel, selectable according to need;

- pressure control by means of relative pressure sensors;

- simplified flow control through the nozzle and relative pressure sensor;

- total flow control through the nozzle and relative and differential pressure sensors;

- position control by means of external feedback sensors;

- their combinations.

As for the position control through an external feedback sensor, for example, through the combined use of a master - slave module connected to the rod side of a pneumatic cylinder and a master - slave module connected to the tube side of the cylinder, it is possible to control this cylinder in closed-loop positioning mode by reading an analog input signal that contains information on the position of the cylinder and intercommunication through the digital communication bus between the two master-slave modules.

To the embodiments of the modules and the system according to the invention, a person skilled in the art, to meet contingent needs, may make changes, adaptations and replacements of elements with other functionally equivalent ones, without departing from the scope of the following claims. Each of the features described as belonging to a possible embodiment can be realized independently of the other described embodiments.

Claims (13)

CLAIMS 1. Pneumatic master module for proportional control of pressure or flow, comprising: - a master module valve body in which passages for the flow of pressurized air are obtained, said passages connecting a master pneumatic inlet port to a first master pneumatic outlet port for a direct pneumatic connection to a load and to a second pneumatic master output port for a pneumatic connection to a pneumatic input port of a slave module that can be connected to the master module; - a master proportional solenoid valve suitable for supplying the first and second master pneumatic output ports with a regulated flow of pressurized air that enters the master module through the pneumatic input port; - a relative pressure sensor to detect the pressure of the regulated flow of pressurized air downstream of the master proportional solenoid valve; - an electronic control unit suitable for controlling the master proportional solenoid valve and a proportional slave solenoid valve or on / off of a respective slave module according to a pressure signal supplied by the relative pressure sensor, the electronic control unit being also configured to implement a digital bus communication interface for data exchange with other master modules; - a male electronic master input connector and a female master output connector to receive and transmit analog and digital electronic signals, wherein the relative pressure sensor and electronic control unit are mounted on an electronic printed circuit board, the male input type master electronic connector and the female type master output connector being mounted on parallel opposite sides of the electronic master printed circuit board. 2. Pneumatic master module according to claim 1, further comprising, downstream of the master proportional solenoid valve, a nozzle or orifice for flow control of the regulated flow of pressurized air. 3. Pneumatic master module according to claim 2, further comprising a differential pressure sensor to detect the difference in pressure upstream and downstream of the nozzle or orifice, the differential pressure sensor being operationally connected to the electronic control unit. 4. Pneumatic master module according to any of the preceding claims, in which the input and output master electronic connectors and the electronic printed circuit board are configured to receive and transmit power signals and digital bus communication signals. 5. Pneumatic master module according to any one of the preceding claims, wherein: - the master module valve body has a rectangular parallelepiped shape; - the master proportional solenoid valve is mounted on one of the faces of the master valve body; - the master printed circuit electronic board is supported by electrical terminals of the master proportional solenoid valve and extends parallel to the valve body of the master module, the electronic input and output connectors being configured to be connected to the electronic printed circuit board of another pneumatic master module or a slave module in such a way that all electronic printed circuit boards lie in the same plane; - the master inlet pneumatic port and the first master pneumatic outlet port are obtained in one face of the valve body of the master module opposite the master proportional solenoid valve or the electronic printed circuit board; - the second master pneumatic outlet port is located on one of the side faces of the valve body of the master module perpendicular to the electronic printed circuit board. 6. Pneumatic master module according to any one of the preceding claims, wherein the master printed circuit electronic board has substantially the same width as the valve body of the master module. 7. Pneumatic master-slave module for proportional control of pressure or flow, comprising a master module according to any one of the preceding claims and a slave module electronically and pneumatically connected to the master module and comprising: - a valve body of a slave module in which passages are obtained for a flow of pressurized air, said passages connecting a slave pneumatic input port to a slave pneumatic output port, the slave pneumatic input port being connected to a second pneumatic output port of a master module; - a proportional slave solenoid valve or an on / off slave solenoid valve connected between the slave pneumatic input port and the slave pneumatic output port, called proportional solenoid valve or on / off being controlled by a control signal provided by the master module; - a male type electronic slave input connector releasably connected to the female type master output connector of the master module and a female type slave output connector adapted to be releasably connected to an electronic master input connector of male type of another master module, the input and output slave electronic connector being suitable for receiving and transmitting analog and digital electronic signals, wherein the male type slave input electronic connector and the slave type output connector female are mounted on parallel opposite sides of a slave PCB, so that the master PCB and the slave PCB lie in the same plane, and in which the slave valve body has a lateral face in which the slave pneumatic inlet port is obtained and which abuts against a lateral face of the master valve body, so that the second pneumatic master outlet port and the pneumatic slave input are directly and hermetically connected. 8. Pneumatic master-slave module according to claim 7, in which the slave input and output electronic connectors and the slave printed circuit electronic board are configured to receive and transmit power signals and digital bus communication signals. Pneumatic master-slave module according to claim 7 or 8, wherein the valve body of the slave module has the same external shape and the same dimensions as the valve body of the master module. Pneumatic master-slave module according to any one of claims 7-9, wherein the slave printed circuit electronic board has substantially the same width as the valve body of the slave module. 11. System for a pressure or flow control, comprising: - a digital communication bus; - at least one pneumatic master module according to any one of claims 1-6 and / or at least one master slave pneumatic module according to any one of claims 7-10, each master or master-slave module exchanging data through the digital communication bus. 12. System according to claim 10, wherein at least two identical master modules are directly connected to each other through the electronic master input and output connectors. 13. System according to claim 10, wherein a master module is electrically connected to the slave output electronic connector of a slave module of a master-slave module, said slave module acting as a bridge to transmit to the downstream master module at least electrical signals of the digital communication bus.