JPS59194105A - Two-flow conflux circuit - Google Patents

Abstract

PURPOSE:To improve the operability by providing one hydraulic pump with a direction switching valve and providing the other hydraulic pump with a pilot- type two-port valve, so that two-port valve is opened with the switching operation of the direction switching valve to join pressurized oil of the hydraulic pumps to be supplied to an actuator. CONSTITUTION:A switch valve 15 for an arm is provided with a pilot port 41 which is connected to a tank 23 through a pilot path 40 when an arm cylinder 7 is located at an arm 3 switch position. A two-port valve 20 has the secondary side connected to the head side of the arm cylinder 7, so that the valve body 20a is seated and separated to permit and check the supply of a fluid from a hydraulic pump 11' to the arm cylinder 7. The valve body 20a is provided with a pilot path 20d formed for connecting the primary side and a spring chamber 20c, and a throttle 20c is interposed in the midway of the pilot path 20d.

Description

[Detailed description of the invention] The present invention (J, Combine the pressure oils of 7 hydraulic cylinders)
] Please forgive me regarding the two-stream suspension and merging circuit that I made.
This invention relates to a device in which seven flows can be merged by only switching operations of seven switching valves.

Conventionally, in this type of knee flow m-merging circuit, normally,
A main switching valve that switches the direction of oil supply from one hydraulic pump to the human passage actuator, and an auxiliary switching valve that switches the direction of pressure oil supply from the other hydraulic pump to the above-mentioned 77 mouths, Connect the auxiliary switching valve to the L2 switching valve and 1
By shallowly interlocking the two switching valves, the pressure oil from the seven hydraulic pumps is combined and supplied to the rapid actuator. For example, JP-A-5
7-74 /l /+ 2 Power excavator strength disclosed in Tan Official Gazette σ) Construction 1 In the first precept, 1, the 1-b cylinder and the ar\ cylinder of the power excavator are the main and auxiliary cylinders, respectively. A switching valve is installed. .

-9- However, in contrast to A1, the above conventional method requires an auxiliary switching valve, which increases the cost and reduces the operating force of the person who switches two switching valves at the same time. However, it had the disadvantage of being difficult to operate.

In view of the above, the present invention allows fluid supply from the other hydraulic pump to the acticoator, and makes it clear that
Two boat valves are provided, and the two boat valves are controlled to open and close by pilot operation according to the switching state of the main switching valve. It is an object of the present invention to provide a two-flow rate merging circuit which is inexpensive and requires a small operating force for a switching valve.

To achieve this objective, the present invention has a configuration of a two-flow merging circuit in which pressure oil from seven hydraulic pumps is combined and supplied to a large-capacity actuator. A directional control valve that switches the pressure oil supply direction and a V! pressure oil supply from the other hydraulic pump to the above actuator. The opening direction switching valve is provided with two valves 1 to 1 for holding and blocking valves, and the opening direction switching valve is closed when in the neutral position. At the same time, a pipe [1 to 1 is connected to the tank] is provided. A chamber and a diaphragm whose negative side communicates with the bar 7 and the chamber are provided,
When the directional control valve is in the neutral position, the primary pressure of the two-boat valve and the pressure acting on the spring chamber are used as tongue pressure to spring! While the 2-boat valve is closed by the spring pressure of +i,
When the switching valve is in the switching position, the springs in the bread chamber are set at 1" between the two boat valves to avoid creating a differential pressure between the two boat valves. It's Shino.

Both hands, glue of the present invention: An i+LD example will be explained in detail with reference to the drawings.

In the drawing, the structure of scale Z is l1iIi ul-1pe1no
The hydraulic control circuit for the bell (△) is handled by seven hydraulic circuits (,
(2>, Boo 1.. (3), each drive actuator for the bucket (/I) and the F section traveling body (not shown)]]-ta,
T-straw turning motion Z <5), boom silling (6)
, Boo 4-171 shilling (7), bucket 1 to cylinder (8), and left and right travel motors (9), (10). )~
(10) first and second movable lifting type hydraulic pumps (11) that supply pressure oil to the pumps (10);

(11'), and first and second switching valves (13) to (19) that switch the direction of fluid supply to each of the seven cuticoators (5) to (10). Valve block (a).

It consists of (b).

The first switching valve block (a) includes a right travel switching valve (13), a turning switching valve (14), and an A I\ switching valve (
15) and the auxiliary boom switching valve (1G);
7>, a switching valve (18) for the bucket, a switching valve (19) for the main zoo 11, and a two-boat valve (20) necessary for the construction of the present invention are provided. The seven switches *(13)-, -(19) are the aperture openings (1
3-5- a)"-(19a) is formed by a flow h) direction switching valve, and each of the switching valves (13)...-1
9), there is a load F [detection ball l-(13b), (13
c)-(19b), (19c) are formed, and the load pressure detection 111 baud 1-(131)), (13
0)-(19h).

< 19c) When in the neutral position, each switching valve block (31, communicating with each other and the same switching valve block 1) is in the neutral position ((1), and each switching valve block (
stomach).

(Installed inside the mouth)
22) is opened to the tank (23), and the two hydraulic pumps (11) and (11') of the above-mentioned pump 1 1 to (12) are The swash plates (11a) and (11a') are normally at the maximum inclination position, and the swash plate (11a) and (11a') are controlled in inclination according to the hydraulic pressure applied. Part (11b),
(111+') is on the right.

'', and a load sensing valve (2=1) that controls each hydraulic pump (11), (11') according to the load at the pump 1 (12). >, (2/I'
) is set (). Since the non-singing valves (24) and (211') are on the same side as each other, on the varnish, the sensing valve (24)
The force of C i'J2 will be explained, and the explanation of the other part will be omitted by using the same reference numerals and 1'1 for f;1. size l), [1-sensing valve (24) is rear)
When the constant horsepower control valve (31) is in the non-control position (31a), the discharge amount control section (11b) of the hydraulic pump (11) is opened to the tank (25) (2/1a), and the hydraulic pressure The discharge pressure of the pump (11) is controlled by the discharge amount control section (1i).
b) which control position (24b) to feed back to
The spring chamber (240) at one end has a spring (240) with a predetermined spring pressure (PS+) (for example, 6H/(hip)
4, tl) is disposed, and an eye t belonging to the spring chamber (2/I (on the side wall of 1) is a first switching valve 1).
f,: IT-ta's A1 The one with the highest FT b is selected by the Shahel 70, 71.72, and one end of the passage (26) is open.
, On the other hand, a hydraulic pump (11
) is used for a discharge pressure of 1'1. ",・), each switching valve (13) to (1 (U) of the first switching valve block (-)
When both are in the neutral position, each 0 pressure detection board f
−(13a >, (131)) −<16a), <16b
) is opened to the tank (23), the bread chamber (24(l) is released into the tank (23), and in this state, the hydraulic pump (11
) becomes higher than the spring pressure ([)St)J:, the discharge pressure is positioned at the control (I'/neck (24b)), and the discharge pressure is adjusted to the hydraulic pressure at the discharge 1 control section of the nozzle (11). (11
b), and by turning the swash plate (11a) in an upright direction,
? ! On the other hand, when any of the switching valves is switched to the switching position "J", the load pressure detection boat detects the IC load pressure and sends it to the spring chamber (24C) via the pyrower 1 passage (26). ), in this state, the discharge pressure acts on the spring chamber (24G) as the total force P (f' is the front pressure - 1 spring pressure (PS +)) 1.' By opening the discharge amount control section (11b) of the hydraulic pump (11) = 8 = to the tank (25), the swash plate is (11a) is positioned at the maximum inclination angle position to maximize the discharge amount. On the other hand, when the discharge pressure is higher than the total pressure P, the swash plate (11a) is positioned at the control position (24+1) by the discharge pressure and the swash plate (11a) is !By repeatedly controlling the inclination in one direction and decreasing the discharge amount,
The pressure difference before and after the throttle of the above switched switching valve is determined by the spring ff.
(PS1), and the discharge amount is controlled to a flow rate corresponding to the throttle condition of the switching valve.

On the other hand, a preferential expansion pressure compensation valve (27) is provided upstream of the first switching valve block (a). The priority expansion pressure compensation valve (27) is connected to the pump boat (27a), which is supplied with pressure oil from the hydraulic pump (11), and the other boat (2).
7b) and the non-priority boat (27c), and set the flow rate according to the throttle opening of the switching valve connected to the downstream side of the priority boat (271)) from the priority boat 1 to <27b). Distribute surplus oil internally to non-priority boat (27C)
-9- It is constructed so that the water is distributed downstream from -9-. Then, on the downstream side of the summer tip pressure compensation valve <27> 112711, there is a right-hand travel switching valve (13).
and a swing switching valve (14) are connected in parallel, and an arm switching valve (15) is connected downstream of the non-priority bow j- (27C).
) and the auxiliary frame switching valve (1G) are connected. In addition, the second switching valve block (b) is also provided with a priority pressure compensation valve (28), and the hydraulic pump (11'
) gives priority to the left travel switching valve (17), the switching valve for baffle 1 (18) a3, and the main boom switching valve (19), and supplies the excess oil to the above 2 bows 1. (2o)
It is designed to increase the supply capacity.

Therefore, the arm cylinder (7) is a large-capacity actuator that requires human flow for the pulling operation of the arm (3), that is, for supplying fluid to the head side, and is equipped with an arm switching valve (15). To (,1, above) 7-me (3) pulling motion 1'1
A ball ('I 1 ) is provided which communicates with the tank (23) via the pilot passage (40) at the upper switching position in the figure corresponding to . The pilot bow 1- (/11) is closed when in the neutral -10- position and the switching position shown on the lower side in the figure; ) is in any position, the above pie 1]
- It is configured as J: which communicates the passage (/IO).

In addition, the 2-boat valve (2) of the above-mentioned switching valve
0), its downstream side communicates with the non-priority boat (28C) of the priority expansion pressure compensation valve (28), its secondary side communicates with the head side of the arm cylinder (7), and the valve body (20a) is connected to the release seat of the valve body (20a). J: From the hydraulic pump (11') to the arm cylinder <7
), and is provided with a spring (2011) of a predetermined spring pressure (PS2) that urges the valve body (20a) in the seating direction. The pilot boat (41) of the arm switching valve (15) is connected to the chamber (20c) via the pilot passage (42).
is open. Further, the valve body (20a) is provided with a pilot passage (2) that communicates with and covers the downstream side and the spring chamber (20C).
0d> is formed, and a throttle (20o) is interposed in the middle of the pilot passage (20d).

-11- C'
13) OJ.

i'<4.4) f/i 1. /
-([i- The middle of the passage (2('+')) to the charging valve (2/l') is opened (), and the secondary side pressure <A-L <3> load pressure) and the other h of the switching valve block ([1)? 7j i, I: No. 1] High pressure load sensing valve <r'1') spring chamber (24'
c>)#to enter+=1. To go). In addition, the auxiliary boom switching valve (16) should pass through the piping passage (42)'i even if it is directly in front of it.
, the sea urchin is composed of PL-(and there are two poles l-jT(
The secondary side of 20) is connected to the tank (23) via the throttle (45).
When the valve body (20a) is in use, the secondary side is opened to the tank (23).

In addition, a hydraulic pump (11
), (11') with constant pressure nof control 1111 J constant horsepower secondary wheel lN? (:'11) , (11'l'
) is set up () 1'H (1), and each constant horsepower control valve (31
), <31') are respectively 1IllI'Tpon7'(
1-1), (11') 11 output control section (11h)
, (1111') to tank (2'5).

(25')l; Second open non-controlled Iza 71a (31a)
.

-12- (31a') and the discharge pressure control section (11b
), (1111') at the control position (
311]), (31b') and the swash plate (118) of the hydraulic pump <11>, <11'') against the discharge pressure.

A variable set pressure spring (31C) whose spring pressure is set to a high pressure in accordance with the tilt angle control of the spring (<118') in the upright direction;
31c'). Further, (32) is a driving force JgK that can drive the hydraulic pumps (11) and (11').

Next, the operation of the above embodiment will be explained. In this embodiment, the arm (3) is not limited to a single motion, but various compound motions are performed, so below, the arm (3) is pulled during the sole motion of the boot (2>), and the complex motion is described below. Let me explain what happens.

First, when the boom (2) 111 is operating independently, the main arm switching valve (15) is placed in the L position in the 11 and is closed. So, J'3, 2 balls l~The spring chamber (200) of the valve (20) is connected to the tank (
23) There is good communication with... Therefore, both the -1- spring distribution chamber (20c) and the -next side of the 2-port valve (20) have the -13- The hydraulic pressure acts equally, and the valve body (20a) is moved by the spring (
20b): The second variable displacement hydraulic cylinder J7 (11') is energized and seated, closing off the fluid supply to the cylinder (7). Main boom switching valve (?') is controlled by operation of (?').
19) Discharges a flow rate according to the throttle and polishing], the entire amount of pressure oil is transferred to the priority expansion pressure compensation valve (28> priority boat (28b)
) is supplied to the boom cylinder (6) via the main boom switch #, (19). At this time, the first variable displacement hydraulic pump (11) discharges a flow rate according to the throttle opening of the auxiliary boom switching valve (16) by controlling the load sensing valve (2/l). The pressure oil is transferred from the non-priority valve (27C) of the priority expansion pressure compensation valve (27) to the auxiliary boom switching valve (16) with a shuttle to the second hydraulic pump (1).
11') is supplied to the boom cylinder (6).

On the other hand, when the boom (2) and arm (3) are operated in combination, "-1-Drain cylinder * (24) bar 1
/l -- In the first room (24C), the load pressure of the boom (2) and the arm (3
) of the t1 load pressure, for example, Boo lx (2
) is selected and introduced into the shaft valves (7'), so that the first variable volume oil
] - The discharge pressure of the pump (11) is controlled by the load sensing valve (2
4) Load pressure of boom (2) - spring pressure (1) Sl
)], and the discharge amount (and the flow rate is controlled according to the discharge pressure.) Then, this pressure oil is controlled by the priority type pressure compensation valve (27).
From the non-priority bow i~ (27c) to the above arm switching valve
15) and the auxiliary boom switching valve (16), and are supplied to the arm cylinder (7) and boom cylinder (6), respectively. At that time, the arm switching valve (15) is in the upper switching position in the figure, and the pilot bow 1 (41) is in communication with the tank (23) via the pilot passage (40). 2 baud 1~valve (
20), a fluid flow occurs from the spring chamber (200) to the tank (23), and the pressure acting on the spring chamber (20C) from the primary side becomes the pressure reduced by the throttle (20e). Then, the differential pressure between the front and back of the throttle (20e) is reduced by the pressure reduction action at the throttle (20e>).
0e)'s spring (201))'s bread month IPs2)': Rintokikuee', the valve body (20, 1> is H-th, toshi, the primary side and the secondary side are in communication, 2 ports 1 -Valve (20) is an intercrop ¥
')J? I-3, therefore, the second variable volume suspended oil L
``During the discharge period of the pump (11'), the discharge pressure is maintained at the load indenter spring pressure (Ps+) of the boom (2) by the [1-drum pump ↑ (24')]. .The flow rate of the pressure oil from the second oil tank 7 (11') is determined by the priority type pressure compensator IIi valve (28 ) to the priority boat 1 (28b) to the boom cylinder (6). The first oil is supplied to the arm cylinder (7) through the first valve (20) and the pressure oil from the pump (11). 15), the pressure oil of the second hydraulic pump (11') is transferred to the first hydraulic pump (11') by the opening of the valves (20).
Since the pressure oil from 1) and -16-- are combined and supplied to the arm cylinder (7), the switching valve for merging the two small flows is the arm switching valve (15).
Not only can it be done independently and at a low cost, but also the switching operation force of the arm switching valve (15) can be significantly reduced.
The preferred operability is 19.

In addition, each switching valve (17) to (
With both arm switching valves (one) in the neutral position,
15) is positioned at the upper switching position in the figure, the second hydraulic pump <11') is initially in a 7J zaring state where the 1! Valve (20
), the secondary pressure increases from 1 to 71A.
> is selected and introduced into the spring chamber (2/IO') of the load sensing valve (24''), the J stiffness discharge amount is controlled by the load sensing valve (24''), so the two-flow suspension is activated as described above. A merger will take place.

J: In the above example (-11, arm shilling (3)
Although explanation 1 describes the case where the present invention is applied to the merging of two streams m to the boom cylinder (2), it can of course be similarly applied to the immediate merging of two streams to the boom cylinder (2). However, as shown in Fig. 2, instead of the auxiliary plume switching valve (16), the switching valve block (a) is equipped with a 1-=mu 2-boat valve (46) similar to the above embodiment. )
The two valves (46) allow pressure oil to be supplied from the first hydraulic pump (11) to the boom cylinder (6), and the soil boom switching valve ( 1
9) Connect the same pi[]ts 1 to ports (4) as in the embodiment described above.
7) 'as! +ノ, the pie [] hitbot 1-47
) is opened to the spring chamber fist (/16c) of the 2-bow 1-valve (46) for the 2-boom via the passage (/I8), and the Valve (46)
On the secondary side of
) If the middle of the pilot passage (26) of l\ is opened [1], there will be an opening for merging the second stream and supplying it to the boom cylinder (6) using only the soil boom switching valve (19). In addition, the same bow is attached to the main part of the same part as the closed figure 1.

Furthermore, in the above embodiment, the load sensing valve (2/I
), (2/l'), the discharge amount can be controlled -18
- Although a case has been described in which a hydraulic control circuit having variable displacement pumps (11), (11') and preferential expansion pressure compensation valves (27), (20) is used commercially, the present invention is not limited to this, but also uses two fixed pumps,
Of course, it is also possible to apply this method in the same way to the other stationary pumps, such as allowing the pressure oil (A) to flow into the other stationary pump when unloading one stationary pump. However, in the case of the above embodiment, the loss of power Jfi can be reduced while ensuring the independence of each actuator during compound operation, which is more preferable.

In addition, although the above embodiment describes the case where the present invention is applied to a hydraulic control circuit of a hydraulic excavator, it goes without saying that the present invention can be similarly applied to various other types of flow length merging circuits. .

As described above, the present invention includes a directional switching valve that switches the direction of pressure oil supply from one hydraulic pump to the large actuator, and a directional switching valve that switches the direction of pressure oil supply from one hydraulic pump to the above actuator. Allow oil supply
It is equipped with a pilot-operated 2-port valve.
〜Open the valve to merge the pressure oils of both hydraulic pumps and supply to the above AC-f1--)1;1-C1J
Therefore, it is possible to combine the T-2 flow with a single control valve, thereby providing a first-class suspension and merging circuit that is low in cost and easy to operate. There are things you can do.

Figure 1711 A of the raw drawings ``Explanatory drawings show an embodiment of the present invention, and Figure 1'' shows an example of hydraulic pressure in which the present invention is applied to a confluence circuit for knee flow m to the arm cylinder of an excavator. Fig. 2 is a hydraulic control circuit diagram of a hydraulic excavator in which the present invention is also applied to a two-flow suspension merging circuit for a boom cylinder of a hydraulic cylinder.

(11), <11')...Hydraulic pump, (6)...
・Boom cylinder (large capacity actuator) - "-ta", (7)
...Arm cylinder (large capacity acti I-[-ta)],
(15)... Arm switching valve ↑ (directional switching valve), (1
9)...Boom switching valve (directional switching valve), (20)
...2 bow 1~valve, (20a)...valve body, <20!1
)...=20-spring, (20C)...spring chamber, (20e)...diaphragm, (23)...tank, <41)...pi 1:1 1 he port.

21

Claims (1)

[Claims] (1) A double-flow merging circuit in which the pressure oil from one hydraulic pump (11), <11') is combined and supplied to a large-capacity 5-accuator, in which one hydraulic pump (11) From the above Akchi 1. , I - Directional switching valve 19 + valve (15) for switching the direction of pressure oil supply to the other hydraulic pump (<11'), and 2 bows [-5] for allowing and blocking the supply of pressure oil from the other hydraulic pump <11') ↑ (20), and the L-direction cut ↑ (15) is closed in the neutral position and communicated with the J tank (23) in the switching position that requires a large flow rate in the above-mentioned actuator position. pilot bow 1
- (/l 1) is installed (11) in the above two board f (20), and a spring chamber (200) which the above-mentioned pyrower 1-boat (41) has a frontage; (20C) and (20e) are connected to each other.