JPS6052322B2 - hydraulic control device - Google Patents

Description

[Detailed description of the invention] This invention relates to a hydraulic control device.

A commonly used slide spool type directional control valve consists of a sleeve and a spool that have cylindrical surfaces that slide against each other.The sleeve has several ports for oil flow, and the spool has several ports installed relative to the sleeve. The several passages and lands constitute several passage closing mechanisms, and the spool moves linearly in the axial direction within the fixed hollow cylindrical sleeve. The flow direction is controlled by opening and closing the ports at the same time. By the way, the performance of a directional control valve is determined by this closing performance and flow resistance.

That is, the clearance between the land of the sleeve and the spool must be at least 7 to maintain oil tightness, and the flow path must also minimize flow resistance and reduce pressure loss. In order to satisfy these requirements, high rigidity and advanced processing technology (especially honing selective fitting for the sleeve and spool fitting) are required to cover the distortion caused by the complex and highly accurate cross section of the valve body. ) is required. Therefore, it is common knowledge that existing directional control valves are large in size and expensive for their functions. In view of the above-mentioned drawbacks, this invention solves the problem by dividing the relatively installed closing mechanisms found in conventional directional control valves, making each one independent, simplifying the cross section of the valve body, and reducing the pressure loss in the flow path. Furthermore, the mating length of the sleeve and spool has been shortened, the difficulty of processing has been reduced, unit parts can be shared, productivity has been improved, and the size has been reduced in preparation for multiple control. The configuration of the present invention will be explained below with reference to the drawings. First, the structure and operating state of the directional control valve used in the present invention will be explained with reference to FIGS. 1 and 2.

Figure 1 shows a normally open 3 port, 2 positions, and an electromagnetic actuator.
A spring return type directional control valve (NO), 1 is a sleeve having a hollow cylindrical surface, 2, 3, and 3'' are first, second, and third ports that are oil flow ports provided in the sleeve 1; 4 is a spool consisting of a passage 4a that serves as an oil flow path and a land 4b that has approximately the same diameter as the hollow cylindrical surface of the sleeve 1 and serves as an oil seal; 5 is used to press the spool 4 against the seat 6; The spring 7 is a solenoid that electromagnetically operates the spool 4 in the axial direction.

In the state shown in the drawing, the first, second, and third ports 2
, 3, and 3'' are connected through a passage 4a, and when the solenoid 7 is energized, the spool 4 is attracted and moved to the right in the figure against the spring 5, and the port 2 is blocked by the land 4b. However, the second port 3 and the third port 3'' are always in communication via the passage 4a. Then, when the current is cut off and the external pulling force of the solenoid 7 is removed, the spool 4 is pressed against the seat 6 by the elasticity of the spring 5! It returns to its original position, and the first port 2 passes through the passage 4a and immediately connects to the second and third ports 3,
3''. Fig. 2 shows an electromagnetically actuated, spring return type directional control valve (NC) with normally closed 3 ports and 2 positions; 31 is a sleeve having a hollow cylindrical surface; 9, 10, 10
″ are oil flow ports provided in the sleeve 8;
and a third port 11 is a spool consisting of a passage 11a that serves as an oil passage and a land 11b that has approximately the same diameter as the hollow cylindrical surface of the sleeve 8 and serves as an oil seal;
12 is a spring for pressing the spool 11 against the normal seat 13, and 14 is a solenoid for electromagnetically operating the spool 11 in the axial direction.

In the illustrated state, the first port 9 is blocked by the land 11b, and the spool 11 to which the solenoid 14 is energized is attracted and moved to the left in the figure against the spring 12, and the first port 9 closes the passage 11b. It is connected to the second and third ports 10, 1' via the port. However, the second port 10 and the third port 1' are always in communication via the passage 11a. Then, when the current is cut off and the external force that draws the solenoid 14 is removed, the spool 11 moves to the spring 12.
Due to the elastic force, the first port 9 is pressed against the seat 13 and returns to its original position, and the first port 9 is immediately blocked by the land 11b. This invention uses the above-mentioned directional control valves NO and NC to construct an operating hydraulic piping.Hereinafter, the structure of the operating hydraulic piping and its functions, which are the gist of this invention, will be explained.

In FIG. 3, 15, 16, 17, and 18 are hydraulic pressure generating unit circuits composed of normally open directional control valves, and 19
, 20, 21 are double-acting hydraulic cylinders, 22, 23, 2
4, 25, 26, 27 are normally closed directional control valves, the directional control valves 22, 23 control the hydraulic cylinder 19, the directional control valves 24, 25 control the hydraulic cylinder 20, and the directional control valve 26
, 27 drive and control the hydraulic cylinder 21.

Direction control valves 22, 24, 26 are hydraulic cylinders 19, 20
, 21 are connected to the piston back chambers 19'', 2'', 21'' by piping 28, 29, 30, respectively, and the direction control valves 22, 25, 27 are connected to the piston front chambers 19'', 2'', 21'' of the hydraulic cylinders 19, 20, 21, respectively. Piping 31 to 20″ and 21″,
32 and 33, respectively. 34 is an oil tank, 35 is a hydraulic pump for generating pressure oil in the hydraulic system, and the pressure oil generated here passes through a pipe 36 and is controlled to a specified pressure value through a relief valve 37 provided in the middle.

Each directional control valve is connected to piping 38 . . . 48 as shown to form an operating hydraulic piping, and the pressure oil is supplied thereto. In the drawings, 49 and 50 are both oil tanks, which are the same as 34, and are shown clearly in this way to avoid complicating the drawings. SOL-1...SOL-10 are solenoids of each directional control valve, Al and Bl are push button switches of the hydraulic cylinder 19, A2 and B2 are push button switches of the hydraulic cylinder 20, and A3 and B3 are push button switches of the hydraulic cylinder 21. , hydraulic cylinder 19 with push button switches Al, A2, A3,
The piston rods 19-2 of the hydraulic cylinders 19, 20, 21 are extended and actuated by the push button switches Bl, B2, B3.
2 ``'', 21'''' is activated for retraction. 51 is the power supply;
52 indicates a power switch.

An electric circuit is formed by connecting the above-mentioned electric components with electric wires shown by dashed lines as shown in the figure. The above is the structure of the operating hydraulic piping according to the present invention, and its operation is illustrated in FIGS. 4 to 6.
The diagram will be explained. Figure 4 shows directional control valves 15, 16,
17, 18 are opened, and the directional control valves 22, 23, 24 are opened.
, 25, 26, 27 are closed, and the hydraulic cylinders 19, 20
, 21 is in a kept state in which the pressure oil generated by the hydraulic pump 35 is not pumped.

To operate the hydraulic cylinder 19 in this state,
First, turn on the power switch 52. And push button switch A
1 is set to 0N, the current flows through the switch A1 to the solenoids SOL-1, S0L-4, S0L-5, S0L-6, and the solenoids SOL-1, S0L-4, S0L-
5. By energizing S0L-6, each spool is attracted against the spring, so that the directional control valves 15, 18, 22, and 23 are switched as shown in FIG.
Then, the pressure oil generated by the hydraulic pump 35 is transferred to the pipes 36 and 38.
, directional control valve 17, piping 39, directional control valve 15, piping 4
3, directional control valve 26, piping 45, directional control valve 2 male piping 4
7. Hydraulic cylinder 19 via directional control valve 22 and piping 28
The oil in the piston back chamber 19'' flows into the piston back chamber 19'', and the oil in the piston front chamber 19'' flows through the piping 31, the directional control valve 23, the piping 48, the directional control valve 25, the piping 46, the directional control valve 27, and the piping 4 male directional control valve 16. , the oil flows back to the oil tank 50 via the piping 41, so the hydraulic cylinder 19 operates to extend the piston rod 195'' to the right.Next, push button switch A1 is set to 0F.
When set to F, the current is cut off and the solenoids SOL-1, S0
The excitation of L-4, S0L-5, and S0L-6 is released, and each spool is automatically pushed back by the elasticity of the spring, and the direction control valves 15, 18, 22, and 23 are switched, and from then on, the hydraulic cylinder 19 Piston rod 1 ``'' without sending pressure oil to
stops extending and maintains its position. Next, to move the piston rod 19''''' in and out, press push button switch B.
Set 1 to 0N.

Then, the current flows through the same switch B1 to the solenoid SOL-
2, energize S0L-3, S0L-5, S0L-6, solenoid SOL-2, S0L-3, S0L-5, S0L
-6 is energized and energized, each spool is attracted against the spring, so that the directional control valves 16, 17, 22, and 23 are switched as shown in FIG. Then, the pressure oil generated by the hydraulic pump 35 flows through the pipe 36, the direction control valve 18, the pipe 40, the direction control valve 16, the pipe 4, the direction control valve 27, the pipe 46, the direction control valve 25, the pipe 48, and the direction control valve 23. The oil in the piston front chamber 19'' of the hydraulic cylinder 19 flows through the piping 31, and the oil in the piston back chamber 19'' flows through the piping 28, the directional control valve 22, the piping 47, and the directional control valve 24.
, piping 45, directional control valve 26, piping 43, directional control valve 1
5. Since the oil is returned to the oil tank 50 via the pipes 42 and 41, the piston rod 19''' of the hydraulic cylinder 19 is moved in and out to the left. Next, turn push button switch B1 to 0F.
When set to F, the current is cut off and the solenoids SOL-2, S0
The excitation of L-3, S0L-5, and S0L-6 is released, and each spool is automatically pushed back by the elasticity of the spring, and the direction control valves 16, 17, 22, and 23 are switched, and from then on, the hydraulic cylinder 19 Piston rod 1 "" without sending pressure oil to
The retraction operation of ゛ is stopped and the position is maintained. The above is a series of operations of the hydraulic cylinder 19. Regarding the drawings shown in FIGS. 4 to 6, the operation of the hydraulic cylinder 19 has been explained, but if the hydraulic cylinders 20 and 21 are also operated in the same manner, they can be operated in the same manner. is possible. In addition, in the electric circuit of this hydraulic piping for operation, push button switches Bl, Al, B2,
A2, B3, A3 as power sources 53, 54, 55, 56, 57
After wiring as shown in the diagram, when push button switch B1 is set to 0N, the current from this point on will be cut off, and push button switch A will be turned off.
Even if 1, B2, A2, B3, and A3 are set to ON, the hydraulic cylinder 19 only moves in and out, and no other operations are performed. Furthermore, although the above explanation is about a system that is operated by installing three hydraulic cylinders, it is assumed that one hydraulic cylinder and one hydraulic cylinder are installed in a basic circuit consisting of a set of four normally open directional control valves NO. By connecting a circuit including two control valves NC in series, it is possible to operate a large number of hydraulic cylinders in the same way.
As explained above, this invention has three functions: electromagnetic operation and spring return.
Port, 2-position type directional control valves are combined with only 2 types - normally closed and normally related, and each is operated by applying an electrically controlled signal to achieve multi-directional, multi-position, multi-sequence hydraulic control. In order to make this possible, the relatively installed closing mechanisms found in conventional directional control valves are divided and made independent, simplifying the valve body cross section, reducing pressure loss in the flow path, and further reducing the sleeve and spool. This shortens the mating length, reduces the difficulty of machining, allows common use of unit parts, improves productivity, and allows for miniaturization in preparation for multiple control.

Furthermore, the hydraulic pressure generating unit circuit and the actuator can be separated and installed at any location, reducing pressure loss in the pipeline and simplifying the piping. Specifically, to operate one double-acting cylinder, it is sufficient to use four normally open 3-port 2-position solenoid valves and two normally-closed 3-port 2-position solenoid valves. Every time you increase the number of dynamic cylinders by one, you just need to increase the number of the above two normally closed solenoid valves.
The advantages increase as the number of connections increases.

[Brief Description of the Drawings] Fig. 1 is a sectional view of a normally open directional control valve according to the present invention;
FIG. 2 is a sectional view of a normally closed directional control valve according to the present invention;
FIG. 3 is a symbolic diagram of an electrical-hydraulic combination circuit showing an embodiment of the hydraulic control device of the present invention, and FIGS. 4 to 6 are electrical-hydraulic combination circuit diagrams showing the operating states of the hydraulic cylinders in the above embodiment. be. NO... Normally open directional control valve, 1... Sleeve, 2, 3, 3''... Port, 4...
...Spool, 5...Spring, 6...
... Seat, 7...Solenoid, NC...
Normally closed directional control valve, 8...Sleeve, 9,1
0,1 ``...Port, 11...Spool, 1
2... Spring, 13... Seat, 14
·····solenoid.

Claims (1)

[Claims] 1 3 ports in 2 positions, in the open position the 3 ports communicate with each other, in the closed position only the 1st port is closed and the 2nd and 3rd ports communicate with each other. Four return type directional control valves are used, the first ports of two of them are connected in parallel to the hydraulic pump, and the first ports of the other two directional control valves are connected in parallel to the oil tank. and the second port of the two directional control valves connected to the pump side and the third port of the two directional control valves connected to the tank side.
The two ports connected to the pump side are connected to each other independently.
A hydraulic pressure generation unit circuit in which the third ports of the two directional control valves are closed and the second ports of the two directional control valves connected to the pump side are respectively connection ports to the hydraulic control circuit of the hydraulic actuator; Equipped with a double-acting hydraulic actuator, two normally-closed directional control valves having the above configuration are used for each double-acting hydraulic actuator, and the first ports of these two directional control valves are connected to the corresponding double-acting hydraulic actuators. In addition to connecting each to the dynamic hydraulic actuator, the second and third ports of the two directional control valves of each hydraulic actuator are connected in tandem (skewered).
A hydraulic control circuit for a hydraulic actuator, in which the second port of the final stage directional control valve is closed, and the third port of the first stage directional control valve is connected to the connection port of the hydraulic pressure generation unit circuit. Two switches are provided for each double-acting hydraulic actuator to simultaneously energize the two directional control valves of each double-acting hydraulic actuator. Of the four directional control valves in the generation unit circuit, one of the directional control valves connected to the pump side and one connected to the tank side are energized, and when the other switch is activated, the other one connected to the pump side and the tank side are activated. A hydraulic control device comprising an operating electric circuit configured to switch and control the direction of hydraulic pressure supply from a hydraulic pressure generation unit circuit to a hydraulic actuator control circuit by energizing the other side connection at the same time.