JPS60157501A - Electricity-liquid pressure apparatus of reciprocal liquid pressure motor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a double-acting hydraulic system in which the inflow and outflow of pressure medium to both motor connections can be performed independently of each other by means of proportional pilot valves. Position adjustment port
Related to hydraulic equipment.

PRIOR ART Such a device is disclosed in German Patent Application No. 28
49653, in which the direction and speed of a double-acting hydraulic motor is controlled by a two-boat valve under the influence of the changing load direction of an external load. For volumetric flow control, a two-boat throttle valve configured as a seat valve and pilot-controlled by a four-point three-position servo valve is used, and for directional control a total of four two-port seat valve cartridges are used. Ru. The disadvantage of this device is the high cost of the valve. This is because all these valves and the additional check valves for the differential connection must be adjusted to the required rating values. Furthermore, a large number of hydraulic components are required for the control side of the built-in valve.

Additionally, Federal Republic of Germany Patent Application No. 3011088
A hydraulic device for controlling a double-acting hydraulic motor is known from the specification, in which the pressure medium supply to both connections of the hydraulic motor is
Controlled by a boat sliding valve, pressure medium discharge is controlled by two two-boat built-in valves of seat valve design. The disadvantage of this case is that the degree of freedom of the control system is not only limited by the attachment of 3-port sliding valves to both motor connections, but also that the entire hydraulic pressure of each built-in valve can be controlled without position adjustment. ° be played. Here too, a rated value check valve is required for additional functionality, which increases the construction cost.

Furthermore, from Figure 5 of Kanazume's "O1P" Hydraulic and Pneumatic Pressure 26 (1982) No. 9, page 640, the i! +! I-type electro-hydraulic devices are known. Again, the individual resistors are configured as 2-port, 2-position valves with integrated valves for volumetric flow and 1
Two electro-mechanical converters are provided for proportional control of pressure and pressure.

The disadvantage of this device is that here again the valve outlay in relation to the rated value is relatively high and therefore requires complex valve means in the control circuit.

Additionally, Federal Republic of Germany Patent Application Publication No. 2357274
An electro-hydraulic device for controlling a double-acting injection cylinder of an injection molding machine is known from the No. 1 patent, in which an electronic control device controls the feed of the screw in dependence on a large number of process variables. The disadvantage of this device is that here again a two-boat valve is used and no differential connection is considered.

According to the invention, the proportionally operated built-in valves are each configured as a three-boat series valve, each having a longitudinally sliding valve body, and the load connection of the series valve is connected to the motor connection in each case W: The inlet connection and the return connection are respectively connected in parallel directly to the pressure medium supply device and the return device.

Effects of the Invention The electro-hydraulic device according to the invention has the advantage of allowing a proportional division of volume flow and pressure with the lowest possible outlay of valves in proportional technology. This device requires a relatively small number of electro-mechanical converters in terms of its possible functions and a small number of valves in terms of rated values. Furthermore, additional requirements can be easily realized by appropriate programming of the electronic control unit. Particularly with the low outlay of the electronic control unit, additional requirements such as differential connections, fail-safe functions, force limitations or avoidance of underpressure can also be fulfilled.

Further, in this control device, a critical edge overlap can be obtained in the main valve at an affordable manufacturing cost, and furthermore, by the means listed in the embodiments of the claims, the control device is characterized by a better fail-safe operation. Advantageous developments and improvements of the device indicated in item 1 are possible. It is particularly advantageous to use this device for controlling the clamping cylinder of an injection molding machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A practical example of the invention is shown in the drawings and will be explained in detail below.

FIG. 1 shows an electro-hydraulic device for controlling a double-acting hydraulic motor 11.
0, and an external load 13 whose load direction changes acts on the piston rod 12 of this hydraulic motor. A first motor connection port 14 is attached to the cylinder space of the hydraulic motor 11, and a second motor connection port 15 is attached to the annular space around the piston rod 12.

In order to control the inflow and outflow of the pressure medium to the hydraulic motor 11, a first three-boat continuous valve 16 is attached to the motor connection port 14 of Ml, and a second three-boat continuous valve 16 of the same structure is attached to the second motor connection port 15. A 3-boat continuous valve 17 is attached. Since the three boat continuous valves 16 and 17- are constructed in the same way, only the first continuous valve 16 will be described in detail below.
Identical components in the second 3-port continuous valve 17 have the same numbers but with a prime. In order to further explain the three-boat continuous valve 16, we will introduce the following at the same time.

See also Figure 2.

The three-boat continuous valve 16 is configured as a slide valve of cartridge structure whose pilot portion is hydraulically divided and whose position is adjusted. As shown in detail in FIG. 2, the continuous valve 16 has a housing 18 with a sliding valve body sleeve 19 fixed to the housing, on which a vertically sliding valve body 21 configured to be hollow slides without leaking. It is guided into the sleeve 19 like this. The inlet connection P is indicated at 22, the return connection R at 23 and the load connection A at 24.

The vertical sliding valve body 21 is loaded by a spring 25 in the direction of an initial position 26, in which position the load connection 1 24 is relieved of pressure into the return connection 23 and the inflow connection 22 is blocked. The pressure in the control connection 27 brings the vertical sliding valve body 21 over the neutral position against the force of the spring 25 to the connection position 928, in which the inflow ff connection 022 is connected to the load connection 02.
4, and the return connection port 23 can be blocked.

As can be seen from FIG. 2, the vertical sliding valve body 21 has a neutral position shown in FIG. 2 between the two positions 26 and 28, in which both control edges 29 of the vertical sliding valve body 21 is closed, thus blocking the load connection 24. Vertical sliding valve body 21
The position of is retrieved by an electro-mechanical displacement transmitter 31, and the signal is transmitted by the electro-mechanical displacement transmitter 31. The signal from the displacement transmitter 31' in the second 3-port continuous valve 17 is also sent to the electronic control device 133 via I32.

The load connection 24 of the first three-boat continuous valve 16 is connected via a hydraulic conduit 34 to the first motor connection 14 and the second
A conduit 35 connects the second three-boat series valve 17 to the second motor connection 15 in the same manner. Both continuous valves 16.
The seventeen inlet connections 22, 22' are connected via mutually parallel inlet lines 36, 37 to a common pump 38 as a pressure medium supply device. The return connection 23, 23' is depressurized via a return conduit 39.41 into a tank 42 as a return device. The control connection 27 on the first three-boat series valve 16 is controlled by a first proportional pilot valve 43 .

The pilot valve 43 is configured as a four-point, four-position valve and is flanged directly to the housing 18, as shown in detail in FIG. The control sliding valve body 44 has a spring 4
5 is held in a safe position 46, in which the first motor connection port 47 is connected to the second motor connection port 48,
At the same time, it is connected to the inflow connection port 51 via the throttle 49 . At the same time, the outflow connection port 52 is blocked. The control sliding valve body 44 is sequentially moved to the first operating position by applying the force of the spring 45 by the proportional electromagnet 53! 54, second operating position 55 and third operating position f! It is possible to move to 56. First operating position 54
, the inflow connection 51 is connected only to the motor connection 47 of Ml, the other two connections 52 and 48 are blocked, and in the second operating position 55 all connections 47148151152
is blocked. In the third operating position 56 only the first motor connection 47 is depressurized to the outflow connection 52 and the connections 51 and 48 are blocked. The inflow connection 51 and the outflow connection 52 connect to the inflow conduit 36 and the return conduit 3 via control conduits.
9 and the first motor connection port 47 is connected to the control conduit 57
is connected to the control connection port 27 of the first continuous valve ]6 via. From the second motor connection 48 an outflow conduit 58 leads to the tank 42 , into which a proportional pressure control valve 59 is inserted, the proportional electromagnet 61 of which is controlled by the electronic control unit 33 . The proportional electromagnet 53 of the pilot valve 43 is adjusted in position so that the position of its armature is detected by the electro-mechanical displacement transmitter 62. The proportional m magnet 53 of the first pilot valve 43 is also electronically controlled! 11133
controlled by

The second proportional pilot valve 63 provided for controlling the second three-boat continuous valve 17 is also roughly the same in structure as the first pilot valve 43, and the control sliding valve body 44' is partially different in connection. It differs from the first pilot valve only in its direction. It should be noted that the same components of the second pilot valve 63 have the same symbols as the first pilot valve 43, but with a dash. In the safe position 46', the two motor connections 47', 48' are connected to each other and to the outflow connection 52', and the inflow connection 51' is blocked. First operating position 54' and third operating position 56
', the connections are only switched compared to the first pilot valve 43, so that in the first operating position 54' the first motor connection 47' is connected to the outflow connection 52', and the third In the operating position 56', the first motor connection 4
7' is connected to the inflow connection port 51'. Note that the position of the proportional electromagnet 53' is also adjusted and controlled by the electronic control device 33.

The position of the piston rod 12 of the hydraulic motor 11 is monitored by an electro-mechanical displacement transmitter 64 whose electrical output signal is fed to the electronic control system M33. Further, the electronic control device includes a function generator 65 used as a target value transmitter.
It is connected to the.

Furthermore, each motor connection 14 , 15 is associated with a pressure sensor 66167 , the signal of which is supplied to the electronic control unit 33 .

The operation of the device 10 is as follows.

In this electro-hydraulic device 10, each motor connection 14.15 of the hydraulic motor 11 as a hydraulic cylinder can be separated from the three-boat series valve 16.1'7 and controlled accordingly. Its S electronic control unit 33 operates as a programmable regulator and, depending on the measured values for pressure and volumetric flow, operates according to an adjustment algorithm adapted to the respective operating task and for this purpose adjusts the performance. It has a good high speed microcomputer. The control device [33 is therefore connected to both proportional pilot valves 43 and 6 via two mutually independent control lines 6L69.
3. Both 3 boat continuous valves 16 accordingly
and 17 are operated separately. In continuous valves 16, 17, the two control edges on the control sliding valve body 21 and the sliding valve body sleeve 19 for each valve must correspond to each other. The synchronization of the respective two pairs of control edges on the two continuous valves 16 and 17 takes place electronically via a position adjustment, which can thus be easily adjusted. In this case, the three-boat continuous valve 16, 17 has the advantage that the hole forming the control edge 29 is short compared to the diameter of the vertically sliding valve body 21 and can therefore be manufactured precisely and inexpensively.

The fact that the two motor connections 14.15 of the hydraulic motor 11 can be controlled separately and independently by means of electrical signals is advantageous from a regulating technology point of view, as it allows the electronic control unit 33 to operate according to a particularly efficient regulating algorithm. It is advantageous in this respect.

This is especially the case if the pressure on both sides of the hydraulic motor 11 is detected by the pressure sensor 66 and its electrical signals are processed together in a cascade pressure regulating circuit by the control device 33.

Additional functions are realized particularly advantageously by the device 10. That is, in the event of a failure of the electronic control device 33, both pilot valves 4
Fail-safe operation is obtained when the 3.63 proportional electromagnet 53.53' is no longer energized. Their control sliding valve bodies 44, 44' are then respectively in the safe position 46.
．． 46', so the vertical sliding valve body 2 of the continuous valve 16.17
+, 2]' can also take its initial position 26.26'. Both motor connections 14 , 15 of the hydraulic motor 11 are thus depressurized into the tank 42 . Critical failures and passive failures of the four control edges in the two three-way valves 16, 17 are therefore not avoided without excessive expenditure.

Another additional function that is often required is a differential connection of the hydraulic motor 11, which can be electrically preselected by the device 1°. During normal operation of the device 1o, both 3-boat continuous valves +6117 are in their respective neutral positions when the hydraulic motor 11 is stopped, and are moved in opposite directions from the neutral position by electric control signals from the electronic control unit 33. It will be done.

For differential operation of the hydraulic motor 11, a constant control signal brings the second continuous valve 17 into its connecting position 28', connecting the load connection 24' to the inflow connection 22', and also with a variable opening. It is only necessary to modulate the pressure and volume of the pressure medium flow to the first motor connection 14 via the first continuous valve 16 with the signal. For the differential operation of the hydraulic motor 11, no additional valves with rated values are therefore required in addition to the continuous valves 16,'I7.

Another additional feature is force limitation, which is especially necessary when the hydraulic motor 11 is used as a clamping cylinder in an injection molding machine. In this case, pressure protection must be possible to avoid damage to the mold. To initiate such clamping protection, the first proportional pilot valve 43 is brought into its safe position 46, whereby the first continuous valve 1
No. 6 embellishment connection port 27 is connected to proportional pressure control valve 59 . Since the pressure of this pressure control valve 59 does not exceed the force of the spring 25, the first 3-boat continuous valve 1
This does not affect the fail-safe operation of 6. Furthermore, the second three-boat series valve 17 is electrically brought into its initial position 26 in which the load connection 24 is relieved of pressure into the tank 42. The position of the first continuous valve 16 then continues to be adjusted via the proportional pressure control valve 59. Since this continuous valve 16 can operate like a pressure reducing valve at the same time, electrical restriction of the target value for adjusting the position of the continuous valve 16 supplied to the pressure control valve 59 can also control the desired value during the mold clamping operation of the hydraulic motor 11. Pressure limitation to pressure levels ° can be carried out. A description of such pressure protection is known from DE 31 40 397 A1.

Another additional function in the device 10 is protection against negative pressure when the piston rod 12 is withdrawn, for example due to a tensile load 13, and there is a risk of cavitation at the first motor connection 14. □Now, in the device 10, the first
It is possible to apply a predetermined low pressure to the large active surface of the hydraulic motor 11 corresponding to the motor connection 14 of the motor 11 by means of a pressure reduction function made possible by the first continuous valve 16 in conjunction with the proportional pressure control valve 59. . At the same time, the control device 33 controls the flow of pressure medium flowing out of the second motor connection 15 via the second continuous valve 17 and throttles this pressure medium flow accordingly, so that the rapid Also in case of braking, the first
Cavitation does not occur at the motor connection port 14 of the motor.

In this device 10 it is also possible to adapt the nominal value of the continuous valves 16, 17 to the correspondingly large piston surface of the hydraulic motor 11. When the device IO is used in an injection molding machine, the same drive element, ie, the continuous valve 16, is used on both the injection side and the mold clamping side.
．． 17 can be used.

Without departing from the spirit of the invention, the illustrated apparatus 10
It is of course possible to change. In particular, an additional pressure regulating circuit for controlling the output of the device 10 can be used.

[Brief explanation of the drawing]

Fig. 1 is a schematic connection diagram of an electro-hydraulic device for opening a double-acting hydraulic motor, Fig. 2 is a diagram of a three-way system with a proportional pilot valve installed.
FIG. 2 is a partially longitudinal side view of the boat continuous valve. lO...Electrohydraulic device, 11...Hydraulic pressure motor, 14
, 15...Motor connection port, '16.17...Continuous valve, 21.21'...Vertical sliding valve body, 22.2'...
・Inflow connection port, 23.23' ...Return connection port, 24
．． 24'...Load connection port, 33...Electronic control device, 38...Pressure medium supply device (pump) 42...Return device (tank), 43.63...Proportional pilot valve, 53. 53' ・・・Proportional electromagnet

Claims (1)

[Claims] The inflow and outflow of pressure medium to both motor connections of a 1M hydraulic motor can be controlled independently of each other by proportional pilot valves and can be opened by integrated valves in the position adjustment circuit. In the case where the electronic control device attached to the position adjustment circuit is linked to the electromagnet of the pilot valve, each of the built-in proportional valves is configured as a 3-boat continuous valve (16, 17),
Each of them has a vertical sliding valve body (21, 21'), and the load connection port (24°24') of this continuous valve (16117) is connected to the motor connection port (14, 15), respectively, and the inflow connection port ( 22, 22') and the return connection (23° 23') are respectively connected in parallel directly to the pressure medium supply device NF38) and the return device (42). Electro-hydraulic device for direction and speed control. 2 Vertical sliding valve body (21, 2) of continuous valve (16, 16')
1') receives the load of the spring (25) and returns to the initial position (26,
26'), remove the pressure at the load connection (24) at this position, and the pressure at the control connection (27) to the connection position (2B).
2. Device according to claim 1, characterized in that the device can be connected to the inlet Jl' inlet (22). 3 The vertical sliding valve body (21, 21') assumes a neutral position, in which the load connection port (24, 24') is in particular connected to the control edge (2
9) The device according to claim 1, wherein the device is hydraulically shut off when the critical type occurs. 4 Each proportional pilot valve (43, 63) has a spring (
It has a control sliding valve body (44, 44') that receives the load of 45), and this control sliding valve body is moved by a spring to the safe position (46,
46'). 5. Device according to claim 1, characterized in that the hydraulic motor (11)' is constructed as a differential cylinder. 6 At the safety position (46) of the pilot valve belonging to the cylinder side (14), open the split connection port (2) of the continuous valve (16).
5. Device according to claim 4, characterized in that the pressure of step 7) is variable by means of a proportional pressure divider valve (59). 7 An electro-hydraulic device is connected to the displacement transmitter (al, 31') of the continuous valve (16+17) and the pilot valve (43, 6).
Pressure sensors (66, 67) interlocked with the proportional electromagnets (53, 53') of 3) and especially located at the motor connection ports (14, 15)
The device according to claim 1, characterized in that it has an electronic control device 1 (33) interlocked with. 8. Claim 7, characterized in that the child image forming device (33) is linked to a pressure control valve (59), particularly a displacement transmitter (64) located in the hydraulic motor (11). The device described. 9 In the safe position of the first pilot valve (43),
Claim 6, characterized in that the pressure control valve (59) is cooperable with a first continuous valve (16) as a pressure-limiting pressure reducer of the first motor connection (14). The device described in. 10. The device according to claim 1, which is used for controlling a mold clamping cylinder of an injection molding machine.