ITUB20155149A1 - Hydraulic pressure multiplication process, hydraulic pressure multiplier device and relative hydraulic pressure multiplication circuit and hydraulic pressure multiplication procedure. - Google Patents

Description

Title: Hydraulic pressure multiplication procedure, hydraulic pressure multiplier device and relative hydraulic pressure multiplication circuit and hydraulic pressure multiplication procedure.

DESCRIPTION

The present invention relates to a hydraulic pressure multiplication process. The invention is particularly suitable for increasing the pressure of the oil or other fluid and has been made with particular reference to hydraulic applications, even if any type of hydraulic fluid used or any type of application is not excluded. The invention also relates to a hydraulic pressure multiplier device and a hydraulic pressure multiplier circuit comprising this device.

In the hydraulic sector it is often necessary to have high pressures of the hydraulic oil destined to power actuator devices or motors of great power. Some examples, given by way of non-exhaustive examples, are applications for parts of earthmoving machinery, agricultural machinery, lifting machinery, etc.

In these sectors often the hydraulic oil must have a continuous pressure, that is hopefully it should not have unwanted reductions or interruptions. Furthermore, the oil pressure should be easily adjusted, always without unwanted reductions or interruptions.

However, this is not easy to achieve, often high-power hydraulic pumps are used to have high pressures, but these have a high cost and consumption.

Alternatively, systems are used which comprise pumps of lower power to generate oil at a first predetermined pressure, where this oil enters continuous pressure multipliers which bring it to the desired value.

However, the current multipliers do not have the ability to make the oil make a very high pressure jump.

A general purpose of the present invention is therefore that of solving all or part of the problems of the known art by satisfying the need indicated above.

In particular, an object of the present invention is to obtain a high pressure multiplication.

A further object of the present invention is to obtain a continuous multiplied pressure.

Another further object of the present invention is to provide a pressure multiplier device and a hydraulic circuit which are easy to manufacture, low cost and high efficiency.

According to one of its first aspects, the invention relates to a hydraulic pressure multiplication process, characterized in that it comprises the following steps:

generate a first continuous hydraulic pressure;

using the first continuous hydraulic pressure to generate a plurality of periodic hydraulic pressures of greater magnitude than the continuous pressure;

combine the periodic hydraulic pressures to generate a second continuous hydraulic pressure of greater magnitude than the first continuous hydraulic pressure.

Advantageously, by means of the concept of decomposition and recomposition of the pressure, it is possible to obtain continuous pressures which are significantly higher than the continuous starting pressures. According to some particularly preferred embodiments, the process comprises the following steps:

bring a hydraulic fluid to the first continuous hydraulic pressure;

- using the fluid at said first pressure to exert alternating linear thrusts on first predetermined areas of first slider means;

transferring the alternating linear thrusts to second half cursors;

- exerting linear thrusts alternating between them on a hydraulic fluid with predetermined areas of the second slider means smaller than the first predetermined areas to obtain alternating pressures of greater magnitude than the first continuous pressure;

- combine the alternating pressures to obtain hydraulic fluid at the second continuous pressure.

Advantageously, by means of the linear thrusts it is possible to obtain a high multiplication of pressure and the multiplied pressures, ie the second continuous pressures are easily modulated by simply modulating the first continuous pressure.

The predetermined areas are for example given by the thrust surfaces of pistons, depending on the bores, such as those of the examples described below. According to a second general aspect thereof, the invention relates to a hydraulic pressure multiplier device comprising at least one motor hydraulic cylinder and at least one hydraulic cylinder guided by the motor hydraulic cylinder, where the motor cylinder has a larger bore than the guided cylinder.

In this way it is advantageously possible to implement a linear thrust capable of generating a high multiplication of pressure.

Preferably, the larger bore is double the smaller bore.

According to some preferred embodiments of the invention, the driving cylinder is double-acting and the driven cylinder is also double-acting, or the double-acting engine cylinder and drives at least two single-acting guided cylinders, both of which have a smaller bore than the engine cylinder. .

In this way it is possible to use a continuous pressure of low value to feed the motor cylinder, to generate periodic pressures of much higher value and to combine them to obtain a new continuous pressure multiplied. Since the double-acting cylinders can operate continuously, there is no interruption in the continuous multiplied pressure.

Preferably, the driving cylinder and the guided cylinder are coaxial for simplicity and economy of construction.

According to a preferable general characteristic, the drive cylinder comprises at least one guide piston connected to at least one guided piston of the at least one cylinder guided by a rod, so as to form a single slider.

According to a third aspect thereof, the invention comprises a hydraulic pressure multiplication circuit comprising at least one pressure multiplier device of the type indicated above, at least one continuous pressure generator unit, at least one hydraulic fluid tank, at least one hydraulic user, and one plurality of hydraulic connection lines between them.

Preferably the at least one driving cylinder is double-acting and the circuit comprises a hydraulic distributor connected to the at least one driving cylinder to alternatively supply its chambers with the hydraulic fluid at the continuous pressure generated by the generator, the driving cylinder moves at least one double-acting guided cylinder or at least two single-acting guided cylinders, where valves are placed at the inlet and outlet of the active chambers of these guided cylinders to allow or deny the flow of fluid to at least two hydraulic connection lines intended to contain fluid to periodic pressures, the two lines being joined in the user or before it to generate an area intended to contain fluid at continuous pressure, multiplied with respect to the pressure of the generator.

According to some embodiments of simpler and cheaper embodiment, the drive cylinder and the guided cylinder or the guided cylinders each comprise at least one opening in connection with the fluid reservoir.

Further characteristics and advantages of the present invention will become clearer from the following detailed description of its preferred embodiments, made with reference to the attached drawings and given by way of non-limiting example. In such drawings:

figure 1 schematically shows a hydraulic pressure multiplier device according to the present invention in longitudinal section;

figure 2 shows an alternative embodiment to the device of figure 1;

- figure 3 schematically shows a pressure multiplication hydraulic circuit comprising the device of figure 1, e

- Figures 4a to 4d show the trend over time of the hydraulic pressures in the circuit of Figure 3.

With reference to Figure 1, the hydraulic pressure multiplier device is indicated as a whole with the reference number 1 and comprises:

- a double-acting primary cylinder 10, a piston 15, called motor piston, runs inside the sheath,

- two secondary cylinders 20 and 30, in which a second piston 25 and a third piston 35 slide respectively, moved by the primary piston, and therefore also called guided pistons.

The multiplier device 1 has a longitudinal axis X coinciding with the direction of travel of all three pistons 15, 25 and 35. For example, the secondary cylinders are placed at opposite axial ends of the primary. In particular, in the illustrated embodiment, the driving piston 15 is connected to the center line of a rod 16 at the distal ends of which the guided pistons 25 and 35 are placed. Preferably the three cylinders are coaxial.

In general, the bore of the primary cylinder 10 is larger than the bores of the secondary cylinders 20 and 30, so that the first is also called the major cylinder and the second cylinders are minor. Figure 1 shows the particularly preferred case in which the bores of the smaller cylinders 25 and 35 are the same, where a particularly preferred bore value for each of them is half the bore of the larger cylinder 15.

The motor piston 15 divides the primary cylinder 10 into two chambers 11 and 12, both of which have at least one distal opening 13, 14 for the inlet and / or outlet of the hydraulic oil. Preferably, there is at least one opening 13, 14 per chamber which acts both as an inlet and an outlet, as indicated in the example of Figure 1, but it is not excluded that there are several openings with differentiated inlet and outlet functions.

The guided pistons 25 and 35 divide the relative cylinders into a distal chamber 21, 31 with respect to the primary cylinder and into a proximal chamber 22, 32. Only the distal chambers are equipped with at least one distal opening 23, 24, 33, 34 for the '' hydraulic oil inlet and / or outlet. Preferably there are at least one inlet opening 23, 33 and at least one outlet opening 24, 34 distinct, as indicated in the example of Figure 1, but it is not excluded that there is only one opening with double inlet and outlet function.

In use, hydraulic oil at a first pressure is sent alternately into one and the other chamber of the primary cylinder 10 so that the motor piston 15 is moved to exert a thrust alternately in the two directions of travel according to the X axis. the motor piston 15 slides in a first direction pushes one of the two guided pistons 25, 35 in the direction of the relative distal limit switch and drags the other in the direction of the relative proximal limit switch. The consequence is that the guided piston 25, 35 pushed distally exerts a pressure on the oil contained in the distal chamber 21, 32 of its own cylinder, with relative expulsion therefrom at a pressure multiplied with respect to the first pressure. The expulsion takes place through the relative opening 24, 34. Hydraulic oil is sucked into the distal chamber 21, 32 of the other guided piston 25, 35, generally at a pressure lower than the first pressure. Suction takes place through the relative opening 23, 24, 33, 34.

When the engine piston 15 has reached the end of its stroke, it reverses its motion and the operation of the two guided pistons reverses, so that what was previously in suction is now in thrust and what was in thrust is now in suction.

According to a practical example, assuming as an example that the oil enters the chamber 11 at the first pressure, the piston 35 compresses the oil in the chamber 32 and pushes it into expulsion from the relative outlet 34, while the piston 25 sucks oil into the chamber 21 from the relative opening 23. At the stroke end of the piston 15, the pressurized oil begins to enter the chamber 12 and pushes the piston 15 in the opposite direction to the previous one. The oil in the chamber 11 is thus expelled, but above all the piston 25 compresses the oil in the chamber 21 while the piston 35 sucks it into the chamber 32. The chambers 22 and 31 are in this example inactive, in the sense that they do not suck or compress oil.

Although an embodiment has been described hereinafter in which the double-acting primary cylinder drives two single-acting secondary cylinders with aligned strokes placed at its opposite axial ends, this is not the only possible configuration. For example, the two secondary cylinders can be replaced with a single double-acting cylinder having a smaller bore than the primary, or it is possible to arrange the secondary cylinders all on the same side of the primary, coaxial or with parallel axes. More generally, any arrangement of the secondary cylinders, as long as they are guided by the primary, is possible. Nor is it excluded that the double-acting engine cylinder is replaced by two single-acting cylinders, each of which drives one of the two secondary ones, although this is a less preferred solution, as the return of these cylinders does not exploit a hydraulic principle and it therefore guarantees less readiness to reverse the motion and therefore the continuity of the multiplied final pressure.

Figure 2 illustrates a multiplier device 101 according to an alternative embodiment to that of Figure 1 and more compact, where elements equal or similar to the previous ones are indicated with the same reference number increased by 100. Here there is only one secondary cylinder 130 placed on one side of the primary cylinder 110. Also the secondary cylinder in this case is double-acting, ie both its chambers 131 and 132 are active, both having the possibility of expelling and sucking oil through relative openings (in the previous example the two cylinders 20 and 30 were single-acting). The example shows an inlet port 133 and an oil outlet port 134 for each chamber.

When the primary cylinder 110 is with oil at a first pressure which enters from the opening 113 into the chamber 111, it pushes the piston 115 towards the secondary cylinder 130 thus guiding the piston 135 of smaller bore to compress the oil in the chamber 132 and expelling it from the relative opening 134 at a pressure greater than the first pressure. At the same time the chamber 131 sucks oil from the relative opening 133 at a lower pressure than the chamber 132.

When the piston 115 is at the end of its stroke, the oil at the first pressure begins to enter the chamber 112 from the opening 114, reversing the thrust direction of the piston. Consequently, the pressure chamber of the secondary cylinder 130 becomes 131 and the intake chamber 132.

With reference to Figure 3, an example of a hydraulic circuit comprising the device 1 of Figure 1 is now described and illustrated.

The circuit is indicated as a whole with the reference number 50 and comprises:

- a device 1;

a continuous hydraulic pressure generator unit 55

a hydraulic user 60 (for example an actuator or a hydraulic motor intended to be moved by the oil at a pressure multiplied by the device 1;

various hydraulic connection ducts between the parts and valves as better explained below;

- a tank of hydraulic oil 65.

The inlet and outlet openings 13 and 14 of the chambers 11 and 12 of the double-acting primary cylinder 10 are alternatively operatively connected to the pressure generator assembly 55 and to the oil tank 65 by means of a hydraulic distributor 70.

In general, the hydraulic distributor 70 is capable of simultaneously putting one chamber of the primary cylinder into communication with the pressure generator 55 and the other with the reservoir 65, so that the pressurized oil moves the piston 15 in a first direction. When this has reached the end of its stroke, the hydraulic distributor 7 0 controls the inversion of the connections of the two chambers, so that the one that was previously connected to the pressure generator 55 is now connected to the tank 65 and the one that was connected to the tank 65 is now connected to generator 55.

The hydraulic distributor 70 in general is preferably of the type automatically controlled by the oil pressure in the chambers of the primary cylinder 10, such as for example a distributor 70 of the drawer type with four ways indicated in the figure with the letters T P A B. The connection is such whereby in a first configuration it connects respectively P with B allowing the flow of oil at a first pressure from the generator group 55 to the chamber 12, and T with A allowing the flow of low pressure oil from the chamber 11 to the tank 65. When the piston 15 is at the end of the stroke. The pressure increase automatically reconfigures the distributor 70 in such a way that P is in communication with A allowing the flow of oil at the first high pressure in the chamber 11, and T is in communication with B allowing the flow of low pressure oil from chamber 12 to tank 65.

To do this, there is a first high pressure connection line 72 from the generator group 55 to the P port at the inlet to the hydraulic distributor 70, and a second low pressure connection line 74 from the T port at the outlet from the hydraulic distributor 70 to the tank 65. .

It can be observed that in the example illustrated one-way valves associated with the openings 13 and 14 are not necessary, so that, as seen, they are advantageously used both as inlet and outlet routes for the oil from the primary cylinder 10.

It is observed that the generator group 55 preferably takes the oil from the tank 65.

It is possible to provide a heat exchanger 76, for example placed along the line 74.

Turning now to describe the hydraulic connections of the secondary cylinders 20 and 30, it is observed that each of the outlet openings 24 and 34 are connected to the hydraulic user 60 by means of an oil line 80, 82 at the multiplied pressure. Preferably the lines 80 and 82 flow into a single line 84 before the user 60. The user 60 can then discharge the oil into a tank, preferably the tank 65, through the discharge line 89.

Each outlet opening 24 and 34 is associated with a one-way valve 86, 88 which allows the oil to flow towards the user 60 and prevents it from flowing in the opposite sex.

Each of the inlet openings 23 and 33 are connected to a low pressure oil line for drawing oil from a tank, in the illustrated example they are connected to line 74 for drawing from tank 65.

Each inlet opening 23 and 33 is associated with a one-way valve 90, 92 which allows the oil to flow towards the respective chambers 21 and 32 inside the cylinders 20 and 30 and prevents it from flowing in the opposite direction.

With the configuration just described, a single oil tank 65 is advantageously sufficient to enslave / receive from all the cylinders.

In use, when the primary cylinder 10 is commanded in the thrust direction of the cylinder 30, the one-way valve 88 opens and allows the oil to flow under multiplied pressure from the cylinder 30 to the user 60. At the same time the one-way valve 92 it's close. As for the other secondary cylinder 20, its one-way valve 86 is closed, preventing oil from escaping, while valve 90 is open, allowing low pressure oil to be sucked from tank 65. When the primary piston 15 reverses the direction of motion, the previously closed one-way valves automatically open and the previously open ones close so that it is the cylinder 30 that sucks and the cylinder 20 that pushes.

The two pistons 20 and 30 therefore exert an alternating oil thrust, where the alternating pressures recombine in a single continuous pressure in the line 84, so that the user 60 is supplied with oil at a continuously multiplied pressure. The combination synchronization is generated by the fact that the hydraulic distributor is hydraulically controlled to automatically reverse the motion of the pistons at each stroke end. However, other types of hydraulic distributors are not excluded, such as, for example, electronically controlled distributors based on pressure sensors.

The regulation of the amount of pressure does not alter the continuity of pressure at the user, as it depends on the pressure exerted with the generator group 55 and does not alter the operation just described.

As regards an example of possible performances, it is observed that in the case in which the bore of the piston 15 is double the bore of the pistons 25 and 35, against a pressure at the inlet of the cylinder 10 of 100 bar has been recorded a multiplied pressure at the outlet of the secondary cylinders 20 and 30 of 400 bar.

Graph 4a shows an example of the trend over time of the continuous pressure generated by the generator group 55 and at the inlet to cylinder 10.

Graph 4b shows an example of a trend over time of the alternating multiplied pressure leaving cylinder 20 and graph 4c shows an example of a trend over time of the alternating multiplied pressure leaving cylinder 30.

Graph 4d shows the continuous multiplied pressure in the line 84 at the input to the user 60 and which is obtained by combining the alternating pressures of the cylinders 20 and 30.

These graphs therefore generally show the concept of multiplication starting with a first continuous pressure, multiplying it in the form of periodic pressures by means of alternating thrust sliders, such as the pistons of the various cylinders described, and combining the periodic pressures multiplied to obtain a pressure multiplied constant.

It is generally observed that in this document the definitions of "distal" and "proximal" position are given by taking as reference the center of the primary cylinder 10, 110.

Naturally, the embodiments and the variants described and illustrated up to now are purely by way of example and a person skilled in the art, in order to meet specific and contingent needs, may make numerous modifications and variants, including for example the combination of said embodiments. and variants, all however contained within the scope of protection of the present invention as defined by the following claims.

Claims (10)

CLAIMS 1. Hydraulic pressure multiplication process, characterized in that it includes the following steps: generate a first continuous hydraulic pressure; using the first continuous hydraulic pressure to generate a plurality of periodic hydraulic pressures of greater magnitude than the continuous pressure; combine the periodic hydraulic pressures to generate a second continuous hydraulic pressure of greater magnitude than the first continuous hydraulic pressure. 2. Pressure multiplication process according to the preceding claim, characterized in that it comprises the following steps: bring a hydraulic fluid to the first continuous hydraulic pressure; - using the fluid at said first pressure to exert alternating linear thrusts on first predetermined areas of first slider means (15, 115); transferring the alternating linear thrusts to second half cursors (25, 35, 135); - exerting linear thrusts alternating between them on a hydraulic fluid by means of predetermined areas of the second slider means smaller than the first predetermined areas to obtain alternating pressures of greater magnitude than the first continuous pressure; - combine the alternating pressures to obtain hydraulic fluid at the second continuous pressure. 3. Hydraulic pressure booster device comprising at least one motor hydraulic cylinder (10, 110) and at least one hydraulic cylinder driven (20, 30, 130) by the motor hydraulic cylinder, where the motor cylinder (10, 110) has a larger bore than the cylinder guided (20, 30, 130). 4. Device according to the preceding claim, characterized in that the larger bore is double the smaller bore. 5. Device according to claim 3 or 4, characterized in that the drive cylinder (10, 110) is double-acting and the driven cylinder (30) is also double-acting, or the double-acting drive cylinder (10, 110) drives at least two single-acting guided cylinders (20, 30) both of which have a smaller bore than the engine cylinder. 6. Device according to any one of the preceding claims, characterized in that the drive cylinder (10, 110) and the driven cylinder (20, 30, 130) are coaxial. Device according to any one of the preceding claims, characterized in that the drive cylinder (10, 110) comprises at least one guide piston (15, 115) connected to at least one guided piston (25, 35) of the at least one guided cylinder by means of a stem (16), so as to form a single slider. 8. Hydraulic pressure booster circuit comprising at least one pressure booster device (1, 101) according to any one of the preceding claims, at least one continuous pressure generator unit (55), at least one hydraulic fluid tank (65), at least one hydraulic user (60), and a plurality of hydraulic connection lines between them (72, 74, 80, 82, 84). 9. Hydraulic circuit according to the preceding claim, characterized in that the at least one drive cylinder (10, 110) is double-acting and the circuit comprises a hydraulic distributor (70) connected to the at least one drive cylinder (10, 110) to supply its chambers (11, 12, 111, 112) alternately with the hydraulic fluid at the continuous pressure generated by the generator (55), the motor cylinder (10, 110) moves at least one double-acting guided cylinder (130) or at least two single-acting guided cylinders (20, 30), where valves (86, 88, 90, 92) are placed at the inlet and outlet of the active chambers (21, 22, 31, 32, 131, 132) of these guided cylinders ) to allow or deny the flow of fluid to at least two hydraulic connection lines (80, 82) intended to contain fluid at periodic pressures, the two lines being joined in the user (60) or before it to generate a zone (84 ) designed to contain fluid at continuous pressure multiplied with respect to generator pressure (55). 10. Circuit according to the preceding claim, characterized in that all the cylinders (10, 20, 30, 110, 130) communicate with the fluid reservoir (65).