JPS5948883B2 - Composite control valve with attachment valve added - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite control valve equipped with an attachment valve.

Many types of compound control valves have already been developed, and a typical example will be described with reference to FIG.

The valve body 12 of the composite control valve 11 has a population chamber 1 provided on one side thereof.
Pressure oil from the pump 14 is sent to each spool 1 when the spools 15 to 17 are in the neutral position shown.
It passes through a bypass passage 18 provided near the center of tanks 5 to 17 and is discharged into a tank 19 in an unloaded state.

Further, each of the spools 15 to 17 is supplied with pressure oil by being in contact with side passages 20 and 21 divided into two from the inlet chamber 13.

When the spool 16 is now moved to the right, the bypass passage 18 is closed by the shaft of the spool 16, the hole 22 of the spool 16 contacts the side passage 20, and the axial hole (not shown) of the spool 16 connects to the hole 23 and It is sent through chamber 24 to one side of the actuator (not shown).

On the other hand, oil on the other side of the actuator returns from chamber 25 through holes 26 and 27 to tank 19 via return passage 28.

When the composite control valve 11 is used in a construction machine, the spools 15 to 17 are connected to actuators such as travel, packet, and boom, respectively.

Modern construction machinery is sometimes used by adding a hydraulic breaker or the like as a special attachment to the standard vehicle consisting of the above-mentioned travel, packet, arm, and boom.

In this case, the usage conditions for the above attachment are that the main combined control valve and the attachment valve can be operated simultaneously with the actuator (for example, packet, boom) controlled by the main combined control valve, so the pump It is necessary to connect them in parallel to each other (see Figure 2).

For this reason, in the past, instead of the standard specification control valve (three valves shown in Figure 1), four valves were installed as standard, with one valve added as an attachment switching valve, and used only when an attachment was required. A method has been adopted to do so.

However, the requirements for attachments are only a few percent of the standard specification vehicles, so with this method, the overwhelming majority of standard specification vehicles always have attachment switching valves that are only used in a few percent. As a result, an increase in cost is unavoidable, and since the control valve becomes large, there are problems in that space is restricted.

Another method is to leave the standard specification control valve as a three-way valve and replace it with the four-way valve when an attachment is required.

However, although this method avoids the cost increase of the standard model, when changing to an attachment specification model midway through, it is necessary to discard the 3-unit valve that was used up until then and install a 4-unit valve in the tower. This not only increases the cost of modification such as replacing the control valve and removing the piping, but also poses a problem in that it is disadvantageous in terms of space.

Therefore, in order to solve the above-mentioned problem, a method has been adopted in which a single valve is added as an attachment to the composite control valve.

An example of this will be described with reference to FIG.

Note that parts equivalent to those in FIG. 1 are given the same reference numerals, and explanations thereof will be omitted.

In the valve body 12A of the composite control valve 11A, the inlet chamber 13A is disconnected from the side passages 20A and 21A due to the need for parallel connection with the attachment valve as described above.
The side lines 20A and 21A are connected to the pump 14 via the lines 31 to 33, which is connected to the aforementioned composite control valve 11.
different from.

In the newly added attachment valve 34, the inlet chamber 36 of the valve body 35 is connected to the pump 14, and the spool 3
7 is in the neutral state shown, the pressure oil flows through the bypass passage 38.
The spools 15 to 1 are guided from the central part of the spool 37 and through the conduit 39 to the cavity 13A of the composite control valve 11A.
7 is released into the tank 19 when it is in a neutral state.

When the spool] 6 of the composite control valve 11A is moved to the right, the pressure oil in the side passage 2OA flows from the hole 22, 23 and the chamber 24 to one side of the actuator (not shown), as in the previous example.
Oil on the other side of the actuator returns to tank 19 through chamber 25, holes 26 and 27 and passage 28.

Also, when the spool 37 of the valve 34 is moved to the right, the pressure oil in the cavity 36 is transferred from the side passage 40 to the holes 41 to 43 and to the chamber 4.
4 to one side of the actuator (not shown), and oil on the other side of the actuator flows from chamber 45 to hole 46 or 4.
8 and is discharged into tank 19 through return passage 49.

In such a configuration, the valve body 12A of the composite control valve 11A
Compared to the valve body 12 of a general composite control valve 11, the basic structure such as the internal passage is different, so it must be manufactured separately.
Furthermore, the discharge oil line of the pump 14 is branched at the pipe line 33, and further branched at the pipe lines 31 and 32 to connect the control valve. The need for main piping to connect to the main pipe increases assembly man-hours and costs, and complicates parts management during manufacturing.

The present invention eliminates such drawbacks, and its purpose is to use a generally widely used composite control valve and eliminate unnecessary piping from the pump, thereby reducing cost I and parts management and assembly. An object of the present invention is to provide a composite control valve to which a valve for easy attachment is added.

The details of the present invention will be explained below with reference to FIGS. 3 and 4 showing one embodiment.

Note that the same members as those in the conventional example shown in FIGS. 1 and 2 are given the same reference numerals, detailed explanations are omitted, and only the different parts will be explained.

A loading valve 51 for controlling loading and unloading by a pilot is installed downstream of the bypass passage 18 of the composite control valve 11.

This loading valve 51 has a spool 54 having a hole 53 at its tip inserted into a hollow valve body 52 which is fluid-tightly attached to the valve body 12.
is inserted, and the spool 54 is constantly pressed upward (in the figure) by a spring 56 whose one end is in contact with the lid 55, and a pilot chamber 57 is formed by the lower surface of the spool 54 and the valve body 52.

Further, the pilot chamber 57 is connected to a conduit 58 via a lid 55.

A Neulot switching valve 61 is attached to the right side of the valve body 35 of the attachment valve 34.

The pilot switching valve 61 has a cylinder 62 that is fluid-tightly attached to the valve body 35, and the spool 3 is disposed inside the cylinder 62.
A valve member 64 is inserted into the valve member 7 via a joint 63.

A chamber 66 is provided in the cylinder 62 so as to surround the land 65 of the valve member 64, and the chamber 66 communicates with the conduit 58.

Further, a passage 67 is provided on both sides of the chamber 66, and the passage 67 is connected to the return passage 49 of the valve body 35.

In the illustrated state, the chamber 66 and the passage 67 are in communication.

Next, the operation of the present invention will be explained.

When the spool 37 of the attachment valve 34 and the spools 15 to 17 of the composite control valve 11 are in the neutral state shown in the figure, the pressure oil from the pump 14 flows from the inlet chamber 36 of the attachment valve 34 to the bypass passage 38 and the pipeline. 39 into the inlet chamber 13 of the composite control valve 11, and this pressure oil flows into the bypass passage 18.

At this time, the loading valve 51 downstream of the bypass passage is connected to the tank 1 through the pilot chamber 57 via the pilot switching valve 61.
9, the spool 54 of the loading valve 51 is pressed downward against the spring 56 by the pressure on the upper surface and descends, thereby opening the bypass passage 18 and the return passage 28.
The pressure oil is connected to tank 1 in the unloading state.
It is discharged to 9.

When the spool 37 of the attachment valve 34 is placed in a neutral state and the spool 16 of the compound control valve 11 is moved to the right, pressure oil flows from the side passage 20 to the holes 22 and 23 and from the chamber 24 to one side of the actuator. Meanwhile, oil on the other side of the actuator returns to tank 19 through chambers 25 and 26 and 27 and return passage 28.

When the spool 37 of the attachment valve 34 is moved to the right, the valve member 64 is also moved to the right, and as a result, the communication between the chamber 66 and the passage 67 is cut off.

That is, the pilot chamber 57 of the loading valve 51 is connected to the tank 1.
9 is cut off, the pressure oil that has passed through the hole 53 of the spool 54 also acts on the downstream side of the spool 54.

Here, since the area of the upstream side of the spool 54 is smaller than the area of the downstream side, the spool 54 rises and cuts off communication between the bypass passage 18 and the return passage 28.

Therefore, the oil pressure in the inlet chamber 36 of the valve 34 increases, and this pressure oil flows from the side passages 40 (L41 to 43 and from the chamber 44 to one side of the actuator).

On the other hand, the oil on the other side of the actuator is in the chamber 45 and the hole 46 or 4.
8 and returns to the tank 19 through a return passage 49.

As described above, the compound control valve with an attachment valve according to the present invention is provided with a loading valve downstream of the bypass passage of a normal compound control valve, and when the attached attachment valve is in the neutral state, the 1 Δ - Open the Abung valve and maintain the un-do state,
When the attachment valve is activated, the pilot switching valve connected to the spool of the attachment light valve closes the loading valve and maintains the loading state, and the attachment actuator is operated via the attachment valve.

Therefore, ■ The standard specification composite control valve 11 can be created by simply modifying the conventionally used control valve 11 (Fig. 1) by making it possible to attach the loading valve 51 as a versatile control valve. Attachment valve 34 can be placed in any position without changing the standard specification control valve layout.
can be placed, and the pilot switching valve and loading valve 5
1. and can be handled by adding pilot piping 58. ■ Compared to the four-unit valve in which the aforementioned attachment switching valve is permanently installed, there is more freedom in space and the layout can be made more compact. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a general composite control valve, Fig. 2 is a sectional view of a conventional example, Fig. 3 is a sectional view of an embodiment of the present invention, and Fig. 4 is a hydraulic circuit diagram of the same embodiment. be. 11...Compound control valve, 13,36...
Inlet chamber, 14... Pump, 15. 16. 1
7. 37...Spool, 28.49...
...Return passage, 51...Spool valve, 52...
... Valve body, 54 ... Spool, 57 ...
... Pilot chamber, 61 ... Pilot switching valve, 62 ... Cylinder, 64 ... Valve member, 66 ... Chamber, 67 ... ··aisle.

Claims (1)

[Claims] 1. A composite control valve including an attachment valve having the following configuration. A) an inlet chamber connected to a hydraulic power source such as a pump, and a spool whose position is switched to selectively supply pressurized oil in the inlet chamber to the actuator and to pass return oil from the actuator to the tank; and a return passage connected to the tank. B) An inlet chamber connected to the hydraulic power source via the attachment valve, and a return passage connected to the same population chamber that passes through the center of the spools and downstream thereof when the plurality of spools are in a neutral state. and a bypass passageway connected to the composite control valve. C) The composite control valve is provided between the bypass passage and the return passage, and is composed of a hollow valve body, a spool slidably inserted into the valve body, one side of the spool, and the cylinder. a loading valve having a pilot chamber;
- D) A cylinder attached to the side surface of the attachment valve, a valve member fixed to the spool end of the attachment valve so as to slide in the cylinder, and a valve member attached to the spool end of the attachment valve; A pilot switching valve having a chamber connected to a pilot chamber of a loading valve, and a passage provided on a chamber side of the cylinder and connected to a return passage of the attachment valve.