JPH0514001Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a control valve used in a hydraulic circuit, etc., and is particularly concerned with a control valve that combines working fluids supplied from two fluid pressure sources, and This invention relates to a fluid pressure control valve that can control the direction of the fluid pressure.

(Prior art) In construction machinery equipped with multiple hydraulic pumps, a small-load work machine is driven by one hydraulic pump, and a large-load work machine is driven by two hydraulic pumps. The discharged oil is combined and supplied.

FIG. 6 shows a conventional merging valve used in such a case.

As is clear from this figure, in normal use with the spool in the right position, the supply ports P ₁ , P ₂ connected to the hydraulic pump are connected to the discharge ports P ₃ , P connected to the corresponding work equipment, respectively. It is connected to ₄ . Then, when the spool is moved to the left position, the supply ports P ₁ and P ₂ communicate with the common merging port A. Therefore, a heavy-load working machine connected to the merging port A can be driven.

This merging valve is quite common, and it is difficult to find any literature describing it, but for example, in Japanese Patent Application Laid-Open No. 56-6832, there is a connection between two units by similarly switching the directional control valve. A system is described in which working oil discharged from a hydraulic pump is merged or guided to separate loads.

FIG. 7 shows a conventional system having a merging function and a direction control function.

As can be seen from this figure, this system has two conventional directional control valves located side by side, with their respective supply ports P ₁ and P ₂ connected to separate hydraulic pumps, and their merging ports A ₁ and P 2 connected to separate hydraulic pumps. The oil passages from A ₂ and merging ports B ₁ and B ₂ are arranged to merge, respectively, and the merging oil passages are connected to the working machine. Therefore, by simultaneously moving the spools of the two valves to the right or left, it is possible to merge the oil discharged from the two hydraulic pumps and to control the direction of the flow. When driving a small-load work machine that can be handled by the capacity of one hydraulic pump, it is only necessary to switch one directional control valve.

Although it is not exactly the same as this system, a system based on a similar principle was published in 1987-47287.
It is disclosed in the publication No.

(Problem that the invention attempts to solve) However, what is shown in Figure 6 is
Since it does not have a direction control function, it has the problem that it can only be used as is for working machines such as hydraulic breakers and hydraulic generators that do not require switching the flow direction of hydraulic oil. In order to drive working machines such as clam shell buckets and rear scrapers that require switching the flow direction of hydraulic oil, the merging port A is also required.
It is necessary to provide a directional switching valve in the converging oil passage connected to the pipe and operate the directional switching valve.

The one shown in Fig. 7 can be used for any of the above-mentioned types of work machines, but it can also be used to support two hydraulic pumps so that the two work machines can be operated independently. It cannot be driven by Furthermore, it not only requires two valves, but also requires accompanying piping and mechanical or electrical interlocking mechanisms, resulting in a complicated structure and high cost. .

The present invention was developed in view of the above circumstances, and its purpose is to drive separate working machines with working fluid supplied from two fluid pressure sources in normal use. With,
When it is necessary to drive heavy-duty work equipment,
The object of the present invention is to obtain a directionally controllable merging valve that can combine and supply working fluids from these fluid pressure sources and can freely control the direction of the flow.

(Means for Solving the Problems) To achieve this objective, the present invention provides a valve housing having a valve hole with a pair of first supply ports adjacent to each other, each connected to a separate fluid pressure source. A pair of merging ports are drilled on the outside of each of the first supply ports to be connected to a heavy-load working machine, and a pair of return ports are drilled on the outside of each of the ports to be connected to a tank. , a second supply port branching from the first supply port is bored on each outside of the return port, and a pair of discharge ports each connected to a separate work machine is bored on each outside of the second supply port. I am trying to set it up.

On the other hand, the spool that is slidably fitted into the valve hole has a first large-diameter portion that cuts off the pair of first supply ports, and a first large diameter part that cuts off each merging port when the spool is in the neutral position. a second large-diameter portion that cuts off between each discharge port and each second supply port;
The fourth part is located on the outside of the large diameter part and the discharge port.
A large diameter portion is provided, and a first small diameter portion, a second small diameter portion, and a third small diameter portion are provided between the large diameter portions, respectively. Their large diameter part and small diameter part are
When the spool moves from the neutral position to either the left or right position, the merging port on the side in the direction of movement communicates with the pair of first supply ports via the pair of first small diameter parts, and the merging port on the side opposite to the direction of movement communicates with the pair of first supply ports The merging port is configured to communicate with the adjacent return port via the second small diameter portion. At that time, each of the second supply ports is cut off.

(Function) With this configuration, when the spool is in the neutral position, the working fluid discharged from each fluid pressure source passes through the second supply port, the third small diameter portion, and the discharge port to each work. supplied to the machine. Therefore, each fluid pressure source independently drives the corresponding work implement.

When driving a heavily loaded working machine, the spool is moved from the neutral position in one direction. Then, the working fluids respectively supplied from the two fluid pressure sources to the first supply ports merge through the first small diameter portion of the spool, and are supplied to the work machine from one of the merge ports. The return fluid from the working machine is then returned to the tank through the other merging port, the second small diameter portion, and the return port. When the spool is moved in the opposite direction, the merged fluid is sent out from the merge port into which the return fluid had been flowing, and the return fluid begins to flow into the merge port from which the merged fluid has been sent out. In this manner, by moving the spool from side to side, the direction of flow of working fluid to the working machine is controlled.

When driving a heavily loaded working machine that does not require switching the flow direction of the working fluid, separate working machines can be connected to the two merging ports. By moving the spool left and right, each working machine can be selectively driven.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In the figure, Figures 1 to 5 show an embodiment of the merging valve according to the present invention. Figure 1 is a horizontal cross-sectional view showing the spool in a neutral position, and Figure 2 is a cross-sectional side view thereof. It is. Moreover, FIG. 3 is a horizontal sectional view showing a state where the spool is in the left position, and the fourth
The figure is a horizontal sectional view showing the spool in the right position. FIG. 5 is a circuit diagram showing how this merging valve is used.

As is clear from FIG. 5, the oil discharged from the two hydraulic pumps 1a and 1b, which are a pair of fluid pressure sources, passes through the merging valve 2 in the neutral position and the pair of directional control valves 3a and 3b. The power is supplied to two hydraulic motors 4a and 4b, which are actuators of a small-load working machine. Each of the hydraulic motors 4a, 4b has a respective direction control valve 3.
By switching a and 3b, forward, reverse, and stop operations can be performed independently.

When supplying discharge oil from the two hydraulic pumps 1a and 1b to the double-acting cylinder 5, which is the actuator of a heavy-load work machine, the spool 6 of the merging valve 2
For example, move to the left. Then, the combined oil flows into the front chamber 5a of the double-acting cylinder 5, and the piston 7
Press to the right. At this time, the return oil from the rear chamber 5b of the cylinder 5 is returned to the oil tank 8 via the merging valve 2. When the spool 6 of the merging valve 2 is moved to the right, the flow direction of the hydraulic oil is reversed and the piston 7 is pushed to the left. In this way, by switching the merging valve 2, the discharged oil from the two hydraulic pumps 1a, 1b can be merged, and the piston 7 of the double-acting cylinder 5 can be reciprocated.

The hydraulic pressure supplied from each hydraulic pump 1a, 1b is controlled to a constant pressure by relief valves 9a, 9b.

Next, the specific structure of the merging valve 2 will be explained based on FIGS. 1 to 4.

As is clear from FIGS. 1 and 2, the valve housing 2a of the merging valve 2 is provided with a cylindrical valve hole 2b. Then, a pair of first supply ports P ₁ , P ₂ , and
Merging ports A, B, return motors T ₁ , T ₂ , second supply ports P ₁ ′, P ₂ ′, and discharge ports P ₃ , P ₄ are
Perforations are made sequentially from the center to both outer sides. Valve hole 2
a first supply port that opens adjacent to the center of b;
P ₁ and P ₂ are connected to two hydraulic pumps 1a and 1b, respectively. Merging ports A and B, which open at respective outer positions of the first supply ports P ₁ and P ₂ , are connected to the front chamber 5a and rear chamber 5b of the double-acting cylinder 5, respectively. Return ports T ₁ and T ₂ that open at respective outer positions of the merging ports A and B are connected to the oil tank 8 via the collecting oil passage 10 . Also, its return port T ₁ ,
The second supply port P ₁ ′ opens at a position outside T ₂ ,
P ₂ ' branches off from the first supply ports P ₁ and P ₂ and is configured to receive oil discharged from the hydraulic pumps 1a and 1b, respectively. Further, hydraulic motors _4a and 4b are connected to discharge ports P3 and _P4 , which open at respective outer positions of the second supply ports P1 _' and P2 _' , respectively.

The first supply port, as shown in FIG.
P ₁ , P ₂ and the second supply ports P ₁ ′, P ₂ ′ are connected to the valve hole 2.
b toward one side of the valve housing 2a, and return ports T ₁ and T ₂ are provided on the opposite side of the valve hole 2b. In addition, merging ports A and B and discharge ports P ₃ and P ₄ are provided in a direction perpendicular to these, respectively.

In this embodiment, the valve housing 2a
The relief valves 9a and 9b are provided in the first and second relief valves 9a and 9b.
Supply ports _P1 , _P2 are provided on the sides of _P1 ', _P2 ' and are opened and closed by the hydraulic pressure in the ports.
When the hydraulic pressure exceeds a set value, the hydraulic oil is returned to the oil tank 8 through a collecting oil passage 10.

A spool 6 is slidably fitted into the valve hole 2b, and can be switched to three positions, a neutral position and a left/right position, by a manual or a solenoid. As shown in FIG. 1, the spool 6 is provided with a first large-diameter portion 11 in its center that blocks the first supply ports P ₁ and P ₂ in the neutral position. and,
On both sides of the first large diameter portion 11, first small diameter portions 12a, 12b, second large diameter portions 13a, 13b,
Second small diameter portions 14a, 14b, third large diameter portion 15a,
15b, third small diameter portions 16a, 16b, and fourth large diameter portions 17a, 17b are formed in this order. When the spool 6 is in the neutral position, the second large diameter portions 13a and 13b are in a position to block the merging ports A and B, respectively, and the third large diameter portions 15a and 15b are in the return port.
The _fourth large-diameter portions _17a , _17b are located at positions outside of the discharge ports _{P3 , P4} , respectively. It is made to be. Therefore, at this time, the second supply ports P ₁ ′, P ₂ ′ and the discharge ports P ₃ , P ₄ communicate with each other through the third small diameter portions 16a, 16b.

Next, the operation of the merging valve 2 configured in this way will be explained.

When the spool 6 is in the neutral position as shown in FIG. 1, the first supply ports P ₁ , P ₂ ,
The merging ports A and B and the return ports T ₁ and T ₂ are
are cut off from each other. Therefore, the oil discharged from the two hydraulic pumps 1a, 1b is pumped through the second supply ports P1 _' , _P2 ', the third small diameter portions 16a, 16b, and the discharge ports _P3 , _P4 , respectively. It is supplied to motors 4a and 4b.

When the spool 6 is moved to the left as shown in FIG.
The supply port P ₁ is moved to the opening position, and the first supply ports P ₁ and P ₂ communicate with each other via the first small diameter portion 12b on the right side, and further communicate with each other via the first small diameter portion 12a on the left side. It communicates with merging port A. On the other hand, at this time, the second supply port P ₁ ′ on the left side is blocked by the third large diameter portion 15a, and the second supply port P ₂ ′ on the right side is blocked by the third large diameter portion 15b and the fourth large diameter portion 17b. It is blocked by. Therefore, the oil discharged from the two hydraulic pumps 1a and 1b is combined and supplied from the merging port A to the front chamber 5a of the double-acting cylinder 5. Further, since the merging port B communicates with the return port _T2 via the second small diameter portion 14b, the return oil from the rear chamber 5b of the double-acting cylinder 5 is returned to the oil tank 8.

Conversely, if the spool 6 is moved to the right as shown in FIG.
P ₁ communicates with the first supply port P 2 on the right side via the first small diameter portion 12a, and further communicates with the first supply port P ₂ on the right side through the first small diameter portion 12a.
P ₂ communicates with the merging port B via the first small diameter portion 12b, so the merging oil flows into the rear chamber 5 of the double-acting cylinder 5.
b. The return oil from the front chamber 5a is returned to the oil tank 8 through the merging port A, the second small diameter portion 14a, and the return port _T1 .

In the above-mentioned embodiment, the double-acting cylinder 5 is used as the actuator of a heavy-load working machine, and one double-acting cylinder 5 is connected to the merging ports A and B. When using an actuator such as a single-acting cylinder that does not need to change direction, connect one actuator to each merging port A and B,
It is possible to selectively drive the merging valve 2 by switching the merging valve 2. As the working fluid, in addition to oil, liquids such as water and alcohol, or gases such as compressed air can be used.

(Effect of the invention) As is clear from the above explanation, according to the invention, when the spool is in the neutral position, a pair of supply ports connected to two fluid pressure sources are connected to a corresponding pair of discharge ports. When the spool is moved in one direction, the pair of supply ports communicate with one merging port and the other merging port communicates with the return port, so for example, when two hydraulic pumps Therefore, in construction machinery in which the left and right traveling devices are driven separately to travel and turn, it is possible to drive a heavy-load working machine by merging the discharge oil of the two hydraulic pumps. It can be done.
Moreover, such heavy-duty work equipment may be of a type such as a clamshell bucket that requires switching the direction of the flow of hydraulic oil, or a hydraulic breaker that requires switching of the flow direction of hydraulic oil. Even if it is a type that does not require switching the direction, it can be applied to any type.

Further, since only one valve is required and the structure is very simple, it can be manufactured easily and at low cost.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the merging valve according to the present invention.
2 is a horizontal cross-sectional view showing the spool in the neutral position; FIG. 2 is a cross-sectional side view of the merging valve;
Fig. 4 is a horizontal sectional view showing the spool in the left and right positions, Fig. 5 is a circuit diagram showing how the merging valve is used, and Fig. 6 shows a conventional merging valve. Circuit diagram FIG. 7 is a circuit diagram showing a conventional merging system using a directional control valve. 1a, 1b...hydraulic pump (fluid pressure source), 2...
...Merge valve, 2a...Valve housing, 2b...Valve hole, 4a, 4b...Hydraulic motor (actuator for small-load work equipment), 5...Double-acting cylinder (actuator for large-load work equipment), 6 ……spool,
8... Oil tank, 11... First large diameter part, 12a,
12b...first small diameter part, 13a, 13b...second
Large diameter part, 14a, 14b... second small diameter part, 15
a, 15b...Third large diameter section, 16a, 16b...
3rd small diameter part, 17a, 17b...4th large diameter part,
A, B...Merge port, _P1 , _P2 ...First supply port, P1 _' , _P2 '...Second supply port, _P3 , _P4 ...
...Discharge port, T ₁ , T ₂ ...Return port.

Claims (1)

[Claims for Utility Model Registration] A spool 6 is attached to a valve housing 2a provided with a valve hole 2b that is slidably fitted between a neutral position and a left-right position, adjacent to the valve hole 2b at the center. A pair of first supply ports P ₁ and P ₂ are opened and fluid is supplied from the fluid pressure sources 1a and 1b, respectively, and each of the first supply ports P ₁ and P ₂ is opened to the valve hole 2b at each outer position. There are merging ports A and B that are connected to the heavy-load work machine 5, and return ports T 1 and T that open to the valve holes 2b and are connected to the tank 8 at the outer positions of the merging ports A and B, _respectively . ₂ , and a second supply port P 1 ' that branches from the first supply ports P ₁ and P ₂ and opens into the valve hole _2b at each outer position of the return ports T ₁ and T ₂ , respectively.
P ₂ ′, and a discharge port that opens into the valve hole 2b at each outer position of the second supply ports P ₁ ′ and P ₂ ′ and is connected to the small-load working machines 4a and 4b, respectively.
P ₃ , P ₄ , and the spool 6 is provided with the first
First large diameter portion 11 that blocks supply ports P ₁ and P ₂
and adjacent to both sides of the first large diameter portion 11, and when the spool 6 moves to either the left or right position, communicates between the first supply ports P ₁ and P ₂ ,
A pair of first small diameter portions _12a , 12b that communicate the first supply ports P1, _P2 with the merging port A or B on the moving direction side of the spool 6, and adjacent to each outer side of the first small diameter portions 12a, 12b. However, when the spool 6 is in the neutral position, the merging ports A and B are respectively shut off, and when the spool 6 moves to either the left or right position, the merging port A or B on the side of the moving direction and the return port T ₁ are closed.
Alternatively, second large diameter portions 13a and 13b that cut off the connection between the merging port B or A on the opposite side of the moving direction and the first supply ports _{P1 and P2} , Adjacent to each outside of the second large diameter portions 13a, 13b, when the spool 6 moves to either the left or right position, the merging port B or A on the opposite side to the direction of movement is returned to the port _T2 or _T1. second small diameter portions 14a, 14b communicating with the second small diameter portions 14a, 14b, and adjacent to the outside of each of the second small diameter portions 14a, 14b, the return ports _T1 , _T2 and a second supply port;
In addition to blocking the connection between P ₁ ′ and P ₂ ′,
When the spool 6 moves to either the left or right position, the third large diameter portion 15a, 15b blocks the second supply port P1 _' or _P2 ' on the side in the moving direction; 15b, and when the spool 6 is in the neutral position, the second
Supply ports P ₁ ′ and P ₂ ′ are respectively connected to the discharge port.
Third small diameter portions 16a and 16b communicated with P ₃ and P ₄
and a discharge port P ₄ adjacent to the outside of each of the third small diameter portions 16a, 16b and opposite to the direction of movement when the spool 6 moves to either the left or right position.
Or the fourth large diameter portions 17a, 17 that block P ₃
A directional controllable merging valve formed by b and b.