JPH04101873U - composite control valve - Google Patents

Abstract

(57) [Summary] [Purpose] Without increasing the overall structure of the complex control valve,
Preventing the natural drop of the load operated by the specific directional valve. [Structure] A drift reduction valve 50 for a specific direction switching valve 16 is disposed within an inner core 52 provided to be connected to one supply/discharge port 24a of the switching valve. In order to configure the inner core 52, the supply/discharge ports 24a and 22a of each of the specific direction switching valve 16 and the upstream direction switching valve 14 adjacent thereto are sequentially shifted to the upstream position.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to complex control valves used in civil engineering construction machinery, etc., and in particular to actuator control valves. Minimize the natural fall due to the weight of the load lifted and lowered by the motor and actuator. This invention relates to a composite control valve that can

0002

[Conventional technology]

As shown in FIG. 5, this type of composite control valve 10 generally has a A plurality of directional control valves (four in this example) 14, 16, 18, and 20 are arranged in parallel. The supply/discharge ports 22a, 22b...28a, 28b of these directional control valves are connected to each other. Actuators are connected to each. In the figure, the pipes 32a and 32b are one actuator connected to the second directional control valve 16 from the bottom in the figure through Only 34 are shown. In such a configuration, the discharge from the pump 30 Outgoing oil flows into the pressure oil inflow port 36, and when the directional control valves 14 to 20 are in the neutral state, tank from the pressure oil outflow port 37 through a center bypass oil passage (not shown). For example, if the directional control valve 16 is operated to the left in the figure, The oil discharged from the pump is supplied to the actuator from the supply/discharge port 24a through the piping 32a. It flows into the piston rod side oil chamber 34a of the eater 34 and operates the load W, while the piston The oil in the ton head side oil chamber 34b is supplied to the supply/discharge port 24b via the piping 32b, and the pressure oil flow It is configured to flow out through an outlet port 37 into a tank 38 .

0003 By the way, in such a construction machine, the actuator 34 is In the case of actuators for excavators, etc., the directional control valve generally has a certain predetermined amount. , the actuator 34 and the load W naturally fall to ensure safety. It causes problems all over. Therefore, in this type of composite control valve, the specific direction From the piston rod side oil chamber 34a of the actuator 34 to the switching valve 16, A drift reduction valve 40 that prevents backflow of oil is installed on the pipe 32a as shown by the two-dot chain line. provided and configured to prevent said natural descent. In addition, the reference numeral 42 is , overload relief or anti-cavity for the directional valve 16 Although the attached valve is shown for use in the In this case, this attached valve 42 is also connected to a drill as shown by the two-dot chain line due to the operational relationship of the valve. It is arranged between the foot reduction valve 40 and the actuator 34.

0004

[Problem that the idea aims to solve]

However, in the conventional technology, the drift reduction valve and the attached valve are external. Since it is installed on top of the main pipe, it requires a considerable amount of space and the attached casing It also requires drain piping, which has the disadvantage of increasing costs. Also, the direction If the piping distance between the switching valve and the drift reduction valve is long, the compressibility and Expansion of the piping causes momentary actuator and negative This had the disadvantage of causing the load to fall.

[0005] Therefore, the purpose of this invention is to install the drift reduction valve inside the casing of the composite control valve. By configuring it so that it can be installed close to the directional valve, unnecessary space is saved. At the same time, we removed the equipment and removed the actuator that was generated when the drift reduction valve was released. Provides a combined control valve that can prevent instantaneous drops in ether and load There is a particular thing.

[0006]

[Means to solve the problem]

In order to achieve the above objective, the composite control valve according to the present invention has a plurality of directional control valves. Composite controls are arranged in parallel inside the casing sequentially from the upstream side to the downstream side of the pressure oil supply. Specific directional control valves in which the amount of internal leakage of pressure oil must be minimized. and one supply/discharge port of the adjacent upstream or downstream directional control valve, respectively. deviate to the upstream or downstream position sequentially, and place it on the upper part of the specific direction switching valve. A casing inner core is provided to connect with the supply/discharge port, and a casing inner core is provided inside the casing inner core. A pilot pressure-operated drift reduction valve that activates or deactivates the pressure oil backflow prevention function. It is characterized in that it is configured to be arranged.

[0007]

[Effect]

According to the composite control valve according to the present invention, the drift reduction valve is the supply/discharge port of the directional control valve. provided within the casing inner core that connects to the casing. In other words, the casing of the composite control valve The directional control valve is configured to be disposed in close proximity to the directional control valve within the directional control valve. Also, drift The reduction valve and the directional control valve are connected by an internal passage in the casing, and the drain piping are also connected inside the casing.

[0008] As described above, according to the composite control valve of the present invention, the case for installing the drift reduction valve is Eliminates unnecessary space and equipment outside the singe, and eliminates drift reduction valves. A momentary drop of the actuator and load upon release is also prevented.

[0009]

【Example】

Next, details of an embodiment of the composite control valve according to the present invention will be described below with reference to the attached drawings. Explain in detail. For convenience of explanation, the same components as the conventional structure shown in FIG. The same reference numerals are given, and detailed explanation thereof will be omitted.

0010 First of all, the embodiment shown in FIGS. 1 to 4 corresponds to the conventional composite control valve shown in FIG. The technology according to the present invention is applied thereto. Therefore, the basic configuration of both is the same. Therefore, to briefly explain this below, the composite control valve 10 is located inside the casing 12. It consists of four directional control valves 14, 16, 18, and 20 arranged in parallel. The supply/discharge ports 22a, 22b...28a, 28b of each of these directional control valves have respective ports. the actuator is connected. Here, the directional control valve 16 is connected to the pressure oil inflow port 36. The amount of internal leakage is particularly minimized with respect to the flow of pressure oil from the pump 30 that flows in from the pump 30. The specific directional valve required is shown in the illustration. 16 supply/discharge ports 24a, 24b via piping 32a, 32b. Only the actuator 34 shown is shown. Next, Figure 2 shows the flow of pressure oil in cross section. , 3 and 4, each directional control valve 14 to 20 is in a neutral state. When the pump 30 is in the The oil is discharged into the tank 38 via the Ipass passage 56 and the pressure oil outflow port 37. Then an example For example, when the spool 58 of the specific direction switching valve 16 is operated to the left in the figure, this When the center bypass passage 56 is closed, the oil discharged from the pump 30 is supplied. From the oil passage 60, the oil supply/discharge port passes through the oil supply/discharge passage 62a which is operated in communication with the oil passage 60. The oil chamber 3 on the piston rod side of the actuator 34 is connected to the piston rod side oil chamber 3 of the actuator 34 through 4a and increases the load W, while the oil in the piston head side oil chamber 34b flows into the piping. 32b, the supply/discharge port 24b, the oil supply/discharge path 62b, and the tank oil path 64. It flows out from the outlet port 37 to the tank 38. Next, the spool 58 is When the pump 30 is operated to the right, the oil discharged from the pump 30 is communicated with this from the supply oil passage 60. Passing through the oil supply and discharge passage 62b that is operated in the state, the supply and discharge port 24b and piping 32b The oil flows into the piston head side oil chamber 34b of the actuator 34 through the On the other hand, the oil in the piston rod side oil chamber 34a flows through the piping 32a and the supply/discharge port 24. a, passing through the oil supply/drainage path 62a and the tank oil path 64 to the tank from the pressure oil outflow port 37 It is leaked to 38.

[0011] However, in the composite control valve of the present invention, the fluid is not supplied to the specific direction switching valve 16. A pilot pressure-operated drift reduction valve 50 that activates or cancels the backflow prevention function of the One supply/discharge port of the specific direction switching valve 16, that is, the piston of the actuator 34 A casing connected to the supply/discharge port 24a on the side connected to the tongue rod side oil chamber 34a. The casing is disposed within the inner core 52 and the casing for the specific direction switching valve 16. They are connected by an internal passageway 54. Then, in order to configure the inner core 52, Each of the specific directional switching valve 16 and the upstream directional switching valve 14 adjacent thereto The supply/discharge ports 24a and 22a on the other side are sequentially shifted to the upstream position.

0012 This drift reduction valve 50 is a main poppet disposed inside the inner core 52. 50a and a control section 50b that controls this. And this control section 50 b is actuated by pilot pressure to control the spool 58 of the specific direction switching valve 16. When the is operated to the left in the figure, this operation connects the oil supply and drain passage 62b and the tank. Immediately before the oil passage 64 is connected, the spool 58 is operated to the right in the figure. When the oil supply/drainage path 62a and the tank oil path 64 are connected by this operation, , respectively, to release the lock of the main poppet 50a, that is, to release the lock of the main poppet 50a. is configured to cancel the stop function. Also, when the spool 58 is in the neutral state, If the main poppet 50a is locked, that is, the backflow prevention function is not activated. There is. Note that the attached valve 42 is interposed between the specific direction switching valve 16 and the drift reduction valve 50. is configured to operate properly regardless of the arrangement of the drift reduction valve 50. In addition, the drain piping of the drift reduction valve 50 is properly connected within the casing 12. It is connected to the tank oil line 64 and is configured so that no special external piping is required. .

[0013] Therefore, according to the composite control valve of the present invention having such a configuration, it is possible to switch in a specific direction. When the spool 58 of the switching valve 16 is operated to the left in the figure, as described above, Immediately before the oil supply/drainage path 62b and the tank oil path 64 are connected, the drift reduction valve 50 is Since the flow prevention function is canceled, the oil discharged from the pump 30 will not flow into the oil supply/drainage path 62a. push up the drift reduction valve 50 (main poppet 50a) and pass through the piston. It flows into the rod side oil chamber 34a and increases the load W, while the piston head side oil chamber 34 The oil in b passes through the oil supply/drainage path 62b and the tank oil path 64 and flows out to the tank 38. . In addition, when the spool 58 is operated to the right in the figure, the supply The backflow of the drift reduction valve 50 occurs immediately before the drain oil passage 62a and the tank oil passage 64 are connected. Since the prevention function is released, the oil discharged from the pump 30 is discharged from the oil supply and drainage path 62b. The oil flows into the head side oil chamber 34b and lowers the load W, while the piston rod side oil The oil in the chamber 34a is blocked by the drift reduction valve 50 in the oil supply/drainage path 62a. The liquid flows without any movement and flows out from the tank oil passage 64 to the tank 38. However, the spool 58 is in the neutral state, the backflow preventer of the drift reduction valve 50 is activated as described above. Since the function is activated, the specific direction switching valve for oil in the piston rod side oil chamber 34a is activated. 16 is prevented, and the natural drop of the load W is prevented. Furthermore, the drift The load reduction valve 50 and the directional control valve 16 are in very short contact via the casing internal passage 54. Since the load W when the backflow prevention function of the drift reduction valve 50 is canceled is The instantaneous natural descent of is also prevented.

[0014] In this way, according to the composite control valve of the present invention, the drift reduction valve is installed inside the casing. Since it can be installed without rearranging other attached valves, it is possible to use a complex control valve. The entire system can be provided compactly and at low cost. Moreover, in the past, often The momentary load when the backflow prevention function of the drift reduction valve was released was Natural descent can also be prevented, further improving safety. In addition, the book In the example, when the specific direction switching valve is placed at the second position from the upstream side However, the above position is another position, for example, the most upstream side or two points from the downstream side. It is clear that it may be the second position, and in this case, the former In the latter case, only one supply/discharge port on the most upstream side goes to the upstream side, and in the latter case, the most downstream side and It is easy to understand that one of the supply and discharge ports and the second one are respectively offset to the downstream side. It is a place where you can

[0015] Although the present invention has been described above with reference to preferred embodiments, the present invention is limited to the above-mentioned embodiments. Many design changes are possible without departing from the spirit of the invention. It is.

[0016]

[Effect of the idea]

As explained above, the composite control valve of the present invention minimizes the amount of internal leakage of fluid. Activates or deactivates fluid backflow protection for specific directional valves that require A pilot pressure-operated drift reduction valve to be Since it is arranged in the inner core of the casing connected to the An actuator operated by a directional valve and by this actuator Increase the natural fall due to the weight of the lifted/lowered load by increasing the overall structure of the composite control valve. It can be achieved without fail. Furthermore, the drift reduction valve becomes a specific direction switching valve. As a result of being placed in an extremely short position, the drift that often occurs in the past This also prevents the instantaneous natural drop in load when the check valve's backflow prevention function is released, resulting in safety. The completeness can be further improved. Note that the drift reduction valve is an overload valve. Can be installed without rearranging attached valves such as leaf or anti-cavitation valves. Since the function of the attached valve is not impaired, and the overall function of the combined control valve is The structure is compact and can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of a composite control valve according to the present invention.

FIG. 2 is a cross-sectional plan view of FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 1.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1.

FIG. 5 is a plan view showing a conventional composite control valve.

[Explanation of symbols]

10...Composite control valve 12...Casing 14, 18, 20...Directional switching valve 1
6... Specific direction switching valve 20a, 20b to 28a, 28b... Supply/discharge port 3
0... Pump 32a, 32b... Piping 34... Actuator 34a... Piston rod side oil chamber 34b... Piston head side oil chamber 3
6...Pressure oil inflow port 37...Pressure oil outflow port 38...Tank 4
2, 44... Attached valve 50... Drift reduction valve 50a... Main poppet 50b... Control section 52... Inner core 5
4...Casing internal passage 56...Center bypass passage 5
8... Spool 60... Supply oil path 62a, 62b... Oil supply/drainage path 64... Tank oil path

Claims (1)

[Scope of utility model registration request] [Claim 1] In a composite control valve in which a plurality of directional switching valves are sequentially arranged in parallel in a casing from the upstream side to the downstream side of the pressure oil supply, it is necessary to minimize the amount of internal leakage of the pressure oil. The supply/discharge port of a specific directional control valve and one of the upstream or downstream directional control valves adjacent thereto is sequentially shifted to the upstream or downstream position, respectively, and the supply/discharge port is placed in the upper part of the specific directional control valve. A composite control valve comprising: a casing inner core connected to a discharge port; and a pilot pressure-operated drift reduction valve for activating or canceling a pressure oil backflow prevention function disposed in the casing inner core. .