JP7360858B2 - Fluid control equipment and construction machinery - Google Patents

Description

The present invention relates to a fluid control device and a construction machine .

Construction machines such as hydraulic excavators are driven by various hydraulic actuators. The hydraulic actuator is driven by hydraulic fluid discharged from a pump (hydraulic pump). Drive control of the hydraulic actuator is performed by a fluid control device that adjusts the flow rate of hydraulic oil. The fluid control device includes a control valve and the like having a round bar-shaped spool. The spool includes a plurality of annular recesses (annular recesses), lands (ridges) formed between the recesses, and notches formed in the lands. In the control valve, the width of the flow path through which the hydraulic oil flows is adjusted by moving the position of the spool. As a result, the flow rate of hydraulic oil supplied to the hydraulic actuator is adjusted.

In recent years, there has been an increasing demand for improving the operating characteristics of hydraulic actuators by controlling the flow rate of hydraulic oil supplied to the hydraulic actuators with high precision. Since the concave portion and land of the spool move as a unit, there is a limit to the ability to control the flow rate of hydraulic oil with high precision only by adjusting the position of the spool. For this reason, the control valve may be provided with an adjustment valve that adjusts the flow rate of the hydraulic oil flowing into the spool. With this configuration, the flow rate of hydraulic oil supplied to the hydraulic actuator can be controlled with high precision by the regulating valve and the spool.

Japanese Unexamined Patent Publication No. 50-61734 Japanese Patent Application Publication No. 2004-360751

By the way, there are cases where a construction machine is provided with two pumps and the two pumps are used to supply hydraulic oil to each hydraulic actuator. In such a case, the hydraulic oil discharged from each pump is combined according to the load on the hydraulic actuator to increase the amount of hydraulic oil supplied to the desired hydraulic actuator. This improves the operability of construction machinery.

However, there is a problem in that it is difficult to precisely control the flow rate of the hydraulic oil supplied to each actuator by simply merging the hydraulic oil discharged from the two pumps.
Although it is conceivable to provide the above-mentioned conventional control valves in the hydraulic oil passages connected to the two pumps, there are problems in that the configuration of the fluid control device becomes complicated and the manufacturing cost increases.

The present invention provides a fluid control device and a construction machine that can control the confluence of fluid (hydraulic oil discharged from two pumps) with high precision through two passages, and that can reduce manufacturing costs with a simple structure. provide.

A fluid control device according to one aspect of the present invention includes : a valve body; a spool that is movably held in the valve body in an axial direction and controls driving of an actuator; a first fluid passage connected to the upstream side of the spool ; a second fluid passage formed in the valve body and connected to the upstream side of the spool ; and a second fluid passage formed in the valve body and connected to the first fluid passage and the A confluence passage leading to the spool and at least the first fluid passage are provided, and the fluid passing through the first fluid passage and the fluid passing through the second fluid passage communicate with each other separately. a flow rate adjustment valve that controls a merging amount based on an electric signal when merging in a merging passage ; the first fluid passage has a lighter load than the second fluid passage; Fluid is supplied to the spool .

With this configuration, the amount of merging of the fluid in the first fluid passage and the fluid in the second fluid passage can be controlled with high precision by the flow rate regulating valve. Further, the flow rate regulating valve is driven based on an electric signal. By using such a flow rate regulating valve, the amount of fluid flowing through the two passages can be controlled with high accuracy with a simple structure. The manufacturing cost of the fluid control device can also be reduced.

The above configuration may include another flow rate regulating valve that controls the drive of the spool based on an electric signal.

The above configuration may further include a regulating valve that controls the flow rate of the fluid discharged from the actuator.

A fluid control device according to another aspect of the present invention includes a valve body, a spool that is held movably in the axial direction by the valve body and controls the drive of an actuator, and is formed in the valve body, a first fluid passageway connected to the upstream side of the spool ; a second fluid passageway formed in the valve body and connected to the upstream side of the spool ; and a second fluid passageway formed in the valve body and connected to the upstream side of the spool. The second fluid passages communicate with each other separately, and a merging passage leading to the spool is provided at least in the first fluid passage, so that the fluid passing through the first fluid passage and the fluid passing through the second fluid passage are connected to each other. a flow rate adjustment valve that controls a merging amount based on an electric signal when the first fluid merges in the merging passage ; and another flow rate adjustment valve that controls driving of the spool based on the electric signal ; The passage has a light load compared to the second fluid passage, and the fluid in the merging passage is supplied to the spool .

With this configuration, the amount of merging of the fluid in the first fluid passage and the fluid in the second fluid passage can be controlled with high precision by the flow rate regulating valve. Further, the flow rate regulating valve is driven based on an electric signal. By using such a flow rate regulating valve, the amount of fluid flowing through the two passages can be controlled with high accuracy with a simple structure. The manufacturing cost of the fluid control device can also be reduced.

A construction machine according to another aspect of the present invention includes a vehicle body on which the fluid control device described above is mounted.

With this configuration, it is possible to provide a construction machine that can control the amount of fluid flowing through the two passages with high accuracy, and can reduce manufacturing costs with a simple structure.

The fluid control device, the construction machine, and the control method for the fluid control device described above can control the amount of fluid flowing through the two passages with high precision with a simple structure, and can reduce manufacturing costs with a simple structure.

1 is a schematic configuration diagram of a construction machine in an embodiment of the present invention. 1 is a schematic configuration diagram of a hydraulic control device, a hydraulic pump, and a hydraulic actuator in a first embodiment of the present invention. 1 is a sectional view of a control valve according to a first embodiment of the present invention. FIG. 3 is a sectional view of a control valve according to a second embodiment of the present invention.

Next, embodiments of the present invention will be described based on the drawings.

<Construction machinery>
FIG. 1 is a schematic configuration diagram of a construction machine 100.
As shown in FIG. 1, construction machine 100 is, for example, a hydraulic excavator. The construction machine 100 includes a revolving body (an example of a vehicle body in the claims) 101 and a running body (an example of a vehicle body in the claims) 102. The revolving body 101 is rotatably provided on the traveling body 102 . The revolving body 101 is provided with a hydraulic pump 110 and a hydraulic control device (an example of a fluid control device in the claims) 1 that controls the flow rate of hydraulic oil (an example of a fluid in the claims) discharged from the hydraulic pump 110. It is being

The revolving body 101 includes a cab 103 on which an operator can ride, a boom 104 whose one end is swingably connected to the cab 103, and a swinging structure at the other end (tip) of the boom 104 on the opposite side of the cab 103. An arm 105 that is freely connected at one end, a bucket 106 that is swingably connected to the other end (tip) of the arm 105 on the opposite side of the boom 104, and an operating section 107 provided on the cab 103. , is equipped with. The traveling body 102, the cab 103, the boom 104, the arm 105, and the bucket 106 are driven by various hydraulic actuators 111 (an example of an actuator in the claims). Hydraulic actuator 111 is driven by hydraulic oil from hydraulic pump 1110 supplied via hydraulic control device 1 .

FIG. 2 is a schematic configuration diagram of the hydraulic control device 1, the hydraulic pump 110, and the hydraulic actuator 111.
As shown in FIG. 2, the hydraulic actuator 111 includes, for example, a hydraulic motor 111a for driving the traveling body 102 and turning the cab 103, and a hydraulic cylinder for driving the boom 104, arm 105, and bucket 106. 111b.

Hydraulic pump 110 is driven by a prime mover (not shown). The hydraulic pump 110 is a so-called split flow type hydraulic piston pump. The hydraulic pump 110 has two discharge ports 110a and 110b (a first discharge port 110a and a second discharge port 110b) through which hydraulic oil is discharged. These two discharge ports 110a and 110b are connected to the hydraulic control device 1. The hydraulic pump 110 as described above varies the discharge amount of hydraulic oil based on an operation signal from an operation section 107 provided in the cab 103. Further, the hydraulic control device 1 is also drive-controlled based on the operation signal from the operation unit 107.

[First embodiment]
<Hydraulic control device>
The hydraulic control device 1 includes a first oil passage 2 connected to a first discharge port 110a, a second oil passage 3 (an example of a second fluid passage in the claims) connected to a second discharge port 110b, and a second oil passage 3 connected to a second discharge port 110b. 1 oil passage 2 (an example of the first fluid passage in the claims) 4, and a plurality of (six in the first embodiment) provided in the middle of each oil passage 2 to 4. The main components are a control valve 5 and electromagnetic proportional valves 6a and 6b. In the following description, the side of each of the oil passages 2 to 4 near the hydraulic pump 110 will be referred to as the upstream side, and the side opposite to the hydraulic pump 110 will be referred to as the downstream side.

The most downstream side of each oil passage 2 to 4 is connected to a tank T. A control valve 5 is connected to each oil passage 2 to 4 between the tank T and the hydraulic pump 110.
The control valve 5 is a so-called open center type control valve, and controls the flow rate of hydraulic oil supplied to the hydraulic actuator 111. The plurality of control valves 5 are connected in series to the first oil passage 2, which is a center passage. Further, each of the plurality of control valves 5 has a cylinder port 7, and a predetermined hydraulic actuator 111 is connected to this cylinder port 7. Note that the detailed configuration of the control valve 5 will be described later.

The first oil passage 2 is connected to all the control valves 5. A switching valve 8 is provided between the hydraulic pump 110 of the first oil passage 2 and the most upstream control valve 5.
The second oil passage 3 is branched on the upstream side of the switching valve 8 and includes a first branch passage 9 and a second branch passage 10 (an example of a second fluid passage in the claims). The first branch path 9 is connected to the second control valve 5 from the most upstream among the plurality of control valves 5 and all the control valves 5 downstream of this control valve 5 . The second branch 10 is connected to the third control valve 5 from the most upstream side and all the control valves 5 downstream of this control valve 5 via the switching valve 8 . That is, the positions between the second branch path 10, the switching valve 8, and the tank T, and corresponding to each predetermined control valve 5 in the second branch path 10, are branched and connected to the control valves 5, respectively. .

The third oil passage 4 is branched from the first oil passage 2 upstream of the switching valve 8 . The third oil passage 4 is connected to a fourth control valve 5 from the most upstream side and three control valves 5 downstream of this control valve 5. That is, the positions between the third oil passage 4 and the tank T and corresponding to each predetermined control valve 5 in the third oil passage 4 are branched and connected to the control valves 5, respectively.

In this way, the hydraulic oil flowing through the third oil passage 4 is mainly used to drive the hydraulic actuator 111 connected to the four control valves 5 on the downstream side. On the other hand, the hydraulic oil flowing through the second branch path 10 of the second oil passage 3 is supplied to the four control valves 5 on the downstream side in order to drive the hydraulic actuator 111 in a supplementary manner.
Note that the control valve 5 connected to the second branch road 10 is connected to a hydraulic motor 111a and the like for driving the construction machine 100. On the other hand, the control valve 5 connected to the third oil passage 4 is connected to a hydraulic cylinder 111b or the like having a relatively small load. Therefore, the load applied to the second branch passage 10 tends to be larger than the load applied to the third oil passage 4.

Among the four control valves 5 on the downstream side, the fourth control valve 5 from the most downstream is connected to the third oil passage 4 via the check valve 112. A first electromagnetic proportional valve (an example of a flow rate regulating valve in the claims) 6a is provided between the three most downstream control valves 5 (spools 13 to be described later) and the third oil passage 4. Further, between the three most downstream control valves 5 (spool 13 described below) and the second oil passage 3 (second branch path 10), a second electromagnetic proportional valve (an example of a flow rate adjustment valve in the claims) is provided. ) 6b is provided.

Each electromagnetic proportional valve 6a, 6b controls the amount of merging of the hydraulic oil in the second oil passage 3 and the hydraulic oil in the third oil passage 4. In the following description, the first solenoid proportional valve 6a and the second solenoid proportional valve 6b will be referred to as the first merging solenoid proportional valve 6a and the second merging solenoid proportional valve 6b in order to distinguish them from the later-described solenoid proportional valve 14. to be called. The details of the control valve 5 will be explained below.

<Control valve>
FIG. 3 is a sectional view of the control valve 5.
As shown in FIG. 3, the control valve 5 is slidable into the valve body 11, the sleeve hole 12 formed along one direction (the left-right direction in FIG. 3) of the valve body 11, and the sleeve hole 12. The main structure is a housed round bar-shaped spool 13. Hereinafter, the axial direction of the spool 13 will be simply referred to as the axial direction, the axial center side of the spool 13 will be simply referred to as the axial center side, and both end sides of the spool 13 in the axial direction will be referred to as the axial outer sides.

The valve body 11 is provided with an electromagnetic proportional valve 14 for driving the spool (an example of another flow rate regulating valve in the claims, hereinafter referred to as an electromagnetic proportional valve for spool) at a position corresponding to both ends of the spool 13 in the axial direction. It is being Further, the valve body 11 is formed with a pressure chamber 20 in which both ends of the spool 13 in the axial direction are accommodated. The spool electromagnetic proportional valve 14 receives an operation signal from the operation section 107 as an electric signal, and generates pressure in the pressure chamber 20 based on this signal. As a result, the spool 13 is slid within the sleeve hole 12. The spool 13 is positioned at three positions: a neutral position (center position) and positions to the left and right of the neutral position. Note that in FIG. 3, the spool 13 is in the neutral position.
A coil spring 32 is housed in the pressure chamber 20 in a compressed state. The coil spring 32 maintains the spool 13 in a neutral position under no load.

The valve body 11 is provided with cylinder ports 7 on both sides of the axial center thereof. A hydraulic actuator 111 is connected to this cylinder port 7.
A first pump passage 15 and a second pump passage 16 are provided around the sleeve hole 12 of the valve body 11 on the central side in the axial direction. The first pump passage 15 is connected to the second oil passage 3. The second pump passage 16 is connected to the third oil passage 4. A portion of each pump passage 15 , 16 communicates with the sleeve hole 12 .

Further, around the sleeve hole 12, a first bypass passage 17 and a second bypass passage 18 are provided on both axially outer sides of each pump passage 15, 16. Each bypass passage 17 , 18 also communicates with the sleeve bore 12 .
Further, around the sleeve hole 12, a first supply passage 21 and a second supply passage 22 are provided on both axially outer sides of each bypass passage 17, 18. The first supply passage 21 extends from the sleeve hole 12 to the periphery of the first pump passage 15 and communicates with the first pump passage 15 . The second supply passage 22 extends from the sleeve hole 12 to the periphery of the second pump passage 16 and communicates with the second pump passage 16 .

Further, the first supply passage 21 and the second supply passage 22 communicate with each other via a merging passage 23. A first merging electromagnetic proportional valve 6a is provided at the merging portion of the first pump passage 15, the first supply passage 21, and the merging passage 23. Further, a second merging electromagnetic proportional valve 6b is provided at the merging portion of the second pump passage 16, the second supply passage 22, and the merging passage 23.

Each merging electromagnetic proportional valve 6a, 6b is integrally provided in the valve body 11. Each of the merging electromagnetic proportional valves 6a and 6b receives an operation signal from the operating section 107 as an electric signal, and based on this signal, the corresponding supply passages 21 and 22 (merging passage 23 ) controls the flow rate of hydraulic oil flowing to Thereby, each merging electromagnetic proportional valve 6a, 6b controls the amount of merging of the hydraulic oil in the second oil passage 3 and the hydraulic oil in the third oil passage 4.

Around the sleeve hole 12, cylinder connection passages 24a and 24b (a first cylinder connection passage 24a and a second cylinder connection passage 24b) are provided on both axially outer sides of each supply passage 21 and 22. Each cylinder connection passage 24a, 24b communicates with the sleeve hole 12 and the corresponding cylinder port 7.
Furthermore, tank passages 25 are provided around the sleeve hole 12 on both axially outer sides of the cylinder connection passages 24a and 24b. The tank passage 25 allows the cylinder connection passages 24a, 24b to communicate with the tank T (see FIG. 2) through the sleeve hole 12.
Two relief valves (an example of a regulating valve in the claims) 26 are provided in the tank passage 25 so as to correspond to the two cylinder connection passages 24a and 24b, respectively. The relief valve 26 allows hydraulic oil to be returned to the tank T when excessively high pressure is applied to the cylinder connection passages 24a, 24b.

The spool 13 has a small diameter portion 31 formed at both ends in the axial direction with a small shaft diameter via a stepped surface 13a. A coil spring 32 housed in the pressure chamber 20 is compressed between the stepped surface 13a of the spool 13 and the wall surface of the pressure chamber 20 of the valve body 11. Further, the step surface 13a of the spool 13 and the end surface 31a of the small diameter portion 31 are pressure receiving surfaces on which the pressure of the pressure chamber 20 of the valve body 11 acts. When the pressure of the pressure chamber 20 is applied to the step surface 13a and the end surface 31a of the small diameter portion 31, the spool 13 is slid against the spring force of the coil spring 32.

The spool 13 has a central land portion 33 provided at an axially central position. First annular recesses 34a and 34b are provided on both axially outer sides of the central land portion 33. Further, the spool 13 is provided with first land portions 35a, 35b on both axially outer sides of the first annular recesses 34a, 34b. Further, the spool 13 is provided with second annular recesses 36a and 36b on both sides of the first land portions 35a and 35b in the axial direction.

Further, the spool 13 is provided with second land portions 37a, 37b on both sides of the second annular recesses 36a, 36b in the axial direction. Furthermore, the spool 13 is provided with a third annular recess 38 on the axially outer side of one of the two second land portions 27a, 27b.
Each land portion 33, 35a, 35b, 37a, 37b of the spool 13 has a notch (not shown) formed in the end face and corner (edge) on the corresponding annular recess 34a, 34b, 36a, 36b, 38 side. There is. These land portions 33, 35a, 35b, 37a, 37b, annular recesses 34a, 34b, 36a, 36b, 38, and notches (not shown) have the role of controlling the flow of hydraulic oil as the spool 13 moves. There is.

<Function of hydraulic control device>
Next, the operation of the hydraulic control device 1 will be explained.
As shown in FIG. 2, when the hydraulic pump 110 is driven by a prime mover (not shown), a predetermined flow rate of hydraulic oil is discharged from each discharge port 110a, 110b of the hydraulic pump 110. The hydraulic oil discharged from the first discharge port 110a flows into the third oil passage 4 and also flows into the second branch passage 10 of the first oil passage 2 or the second oil passage 3 via the switching valve 8. The hydraulic oil discharged from the second discharge port 110b flows into the first branch passage 9 of the second oil passage 3, and also flows into the second branch passage 10 or the first oil passage 2 via the switching valve 8. Hydraulic oil flowing through each oil passage 2 to 4 is supplied to a control valve 5.
Below, the operation of the control valve 5 provided with the merging electromagnetic proportional valves 6a and 6b among the plurality of control valves 5 will be explained. In addition, even in the control valve 5 in which the merging electromagnetic proportional valves 6a and 6b are not provided, the operation of the control valve 5 other than the merging electromagnetic proportional valves 6a and 6b is similar to the operation of the control valve 5 described below.

As shown in FIG. 3, when the spool 13 moves, the control valve 5 opens the first pump passage 15 and The second pump passage 16 communicates with or is blocked from the corresponding oil passages 3 and 4. Further, the first supply passage 21 and the first cylinder connection passage 24a are communicated with each other or are blocked by the first land portions 35a, 35b, notches (not shown) of the first land portions 35a, 35b, and second annular recesses 36a, 36b. At the same time, the second supply passage 22 and the second cylinder connection passage 24b are communicated with each other or are interrupted. Thereby, the flow direction and flow rate of the hydraulic oil in the second oil passage 3 and the third oil passage 4 that are merged via the merging passage 23 are controlled.

When the spool 13 is in the neutral position, the supplied hydraulic oil is returned to the tank T as it is.
In the following, for example, the spool 13 is moved leftward in FIG. 3 (see arrow Y1 in FIG. 3) with respect to the neutral position, and while the second supply passage 22 and the second cylinder connection passage 24b communicate with each other, the first The case where the supply passage 21 and the first cylinder connection passage 24a are cut off will be described in more detail.

In this case, the flow rate of the hydraulic oil flowing into the first pump passage 15 from the third oil passage 4 is controlled by the first merging electromagnetic proportional valve 6a that is driven based on the operation signal from the operation unit 107, and the hydraulic oil flows into the merging passage 23. . Further, the flow rate of the hydraulic oil flowing into the second pump passage 16 from the second oil passage 3 (second branch passage 10) is controlled by the second merging electromagnetic proportional valve 6b, which is driven based on an operation signal from the operation unit 107. , flows into the second supply passage 22. Then, the hydraulic oil that has flowed into the second supply passage 22 is merged with the hydraulic oil that has flowed into the merging passage 23 . In other words, each merging electromagnetic proportional valve 6a, 6b is driven based on the operation signal from the operation unit 107, thereby controlling the hydraulic oil in the third oil passage 4 (first pump passage 15) and the second oil passage 3 (first pump passage 15). The amount of merging of the two pump passages 16) with the hydraulic oil is controlled.

The combined working oil of the third oil passage 4 (first pump passage 15) and the second oil passage 3 (second pump passage 16) flows through the second supply passage 22, the second annular recess 36b of the spool 13, and the first It flows into the second cylinder connection passage 24b through a notch (not shown) of the land portion 35b and a notch (not shown) of the second land portion 37b (see arrow Y2 in FIG. 3). Thereafter, hydraulic oil is supplied to the hydraulic actuator 111 (see FIG. 2) via the cylinder port 7. As a result, the hydraulic actuator 111 is driven.
Here, if an excessively high pressure is applied to the second cylinder connection passage 24b due to a large load being applied to the hydraulic actuator 111, for example, the hydraulic oil in the second cylinder connection passage 24b is returned to the tank T by the relief valve 26. Ru. In this way, the relief valve 26 prevents excessively high pressure from being applied to the control valve 5.

The hydraulic oil supplied to the hydraulic actuator 111 is discharged to the first cylinder connection passage 24a via the cylinder port 7. This discharged hydraulic oil flows into the tank passage 25 (see arrow Y3 in FIG. 3) via the second annular recess 36a of the spool 13, and is returned to the tank T (see FIG. 2). That is, the hydraulic oil discharged from the hydraulic actuator 111 is returned to the tank T while the flow rate is controlled by the spool 13.

In this way, the hydraulic actuator 111 is driven by controlling the flow rate of hydraulic oil supplied to the hydraulic actuator 111 (meter-in control) and controlling the flow rate of hydraulic oil discharged from the hydraulic actuator 111 (meter-out control). control is in place. Since the spool 13 is driven and controlled by the spool electromagnetic proportional valve 14, it can be said that the flow rate of the hydraulic oil discharged from the hydraulic actuator 111 is controlled by the spool electromagnetic proportional valve 14.

In this manner, in the above-described hydraulic control device 1, the second branch passage 10 of the second oil passage 3, the third oil passage 4, and the combination of the hydraulic oil flowing through the second branch passage 10 and the third oil passage 4 are controlled. It includes merging electromagnetic proportional valves 6a and 6b that control the flow rate. In other words, for the hydraulic actuator 111 that is mainly driven by the hydraulic oil flowing through the third oil passage 4, the merging electromagnetic proportional Valves 6a and 6b are provided. Therefore, the amount of combined hydraulic oil flowing through the second branch path 10 and the third oil passage 4 can be controlled with high precision. Further, the flow rate of hydraulic oil can be easily changed, and the operating characteristics of the hydraulic actuator 111 can be improved.

Further, the merging electromagnetic proportional valves 6a and 6b are driven based on an operation signal (electrical signal) from the operation section 107. By using such merging electromagnetic proportional valves 6a and 6b, the merging amount of hydraulic oil discharged from the two discharge ports 110a and 110b of the hydraulic pump 110 can be controlled with a simple structure and with high precision. Therefore, the manufacturing cost of the hydraulic control device 1 can also be reduced.

Further, the merging electromagnetic proportional valves 6a and 6b are provided in each of the supply passages 21 and 22 of the control valve 5. That is, the merging electromagnetic proportional valves 6a and 6b are provided upstream of the spool 13 of the control valve 5. Therefore, the flow rate control (meter-in control) of the hydraulic oil supplied to the hydraulic actuator 111 can be performed by the merging electromagnetic proportional valves 6a and 6b.
The merging electromagnetic proportional valves 6a and 6b are integrally provided in the valve body 11 of the control valve 5. Therefore, in the entire hydraulic control device 1, the oil passage through which the hydraulic oil flows can be simplified.

A spool 13 that controls the flow rate of hydraulic oil discharged from a hydraulic actuator 111 is driven and controlled using a spool electromagnetic proportional valve 14. Therefore, the spool electromagnetic proportional valve 14 is driven based on an operation signal (electrical signal) from the operation section 107. By using such a spool electromagnetic proportional valve 14, the hydraulic control device 1 as a whole can further simplify the oil passage through which the hydraulic oil flows, compared to the case where the pilot pressure of the operation part 107 is directly introduced into the spool 13. can.

Further, the control valve 5 is provided at each of the merging portion between the first pump passage 15, the first supply passage 21, and the merging passage 23, and the merging portion between the second pump passage 16, the second supply passage 22, and the merging passage 23. It is provided with merging electromagnetic proportional valves 6a and 6b. That is, since the flow rate of both hydraulic oil discharged from the two discharge ports 110a and 110b of the hydraulic pump 110 is controlled on the upstream side of the spool 13, the amount of combined hydraulic oil can be controlled with higher precision. . Therefore, the operating characteristics of the hydraulic actuator 111 can be reliably improved. In particular, in the hydraulic actuator 111 which is mainly driven by the hydraulic oil flowing through the third oil passage 4, the desired hydraulic actuator 111 is controlled by controlling the flow rate of the hydraulic oil flowing through the third oil passage 4 on the upstream side of the spool 13. The responsiveness of the operation of the operation unit 107 can be improved.

[Second embodiment]
Next, a second embodiment of the present invention will be described based on FIG. 4.

<Control valve>
FIG. 4 is a sectional view of the control valve 205 in the second embodiment. FIG. 4 corresponds to FIG. 3 described above. Note that the same features as in the first embodiment described above are given the same reference numerals, and the description thereof will be omitted.
As shown in FIG. 4, the difference between the first embodiment and the second embodiment is that the control valve 5 in the first embodiment is provided with two merging electromagnetic proportional valves 6a and 6b. In contrast, the control valve 205 in the second embodiment is provided with a first merging electromagnetic proportional valve 6a. In other words, the control valve 205 operates between the first pump passage 15 (third oil passage 4), the first supply passage 21, and the confluence passage 23, which tend to have a smaller load than the second pump passage 16 (second oil passage 3). The first merging electromagnetic proportional valve 6a is provided at the merging portion with the first merging solenoid proportional valve 6a. The control valve 205 does not include the second merging electromagnetic proportional valve 6b in the first embodiment described above.

A check valve 40 is provided at the junction of the second pump passage 16, the second supply passage 22, and the merging passage 23. The check valve 40 allows the second pump passage 16 to communicate with the second supply passage 22 and the merging passage 23 when the hydraulic oil in the second pump passage 16 reaches a predetermined pressure.
The hydraulic oil flowing through the second branch 10 of the second oil passage 3 is supplied to the four control valves 5 on the downstream side in order to drive the hydraulic actuator 111 in a supplementary manner. Therefore, even if the check valve 40 is provided at the confluence of the second pump passage 16, the second supply passage 22, and the confluence passage 23, the same effects as in the first embodiment described above can be achieved. Further, by providing the check valve 40 in place of the second merging electromagnetic proportional valve 6b in the first embodiment described above, the configuration of the control valve 205 can be simplified and the manufacturing cost of the control valve 205 can be suppressed.

Note that the present invention is not limited to the above-described embodiments, and includes various modifications to the above-described embodiments without departing from the spirit of the present invention.
For example, in the above-described embodiment, the construction machine 100 is a hydraulic excavator. However, the present invention is not limited thereto, and the above-described hydraulic pump 110 can be employed in various construction machines.

Moreover, in the above-mentioned embodiment, the case where the hydraulic pump 110 is a so-called split flow type hydraulic piston pump has been described. However, the present invention is not limited to this, and two hydraulic pumps may be provided, one having the role of the first discharge port 110a and the other having the role of the second discharge port 110b.
Moreover, in the above-mentioned embodiment, the spool 13 of the control valve 5, 205 was driven by the electromagnetic proportional valve 14 for spool. However, the present invention is not limited to this, and the spool 13 may be configured to be directly driven by the pilot pressure output from the operating section 107.

Furthermore, in the above-described embodiment, hydraulic oil was used as an example of the fluid, and the hydraulic control device 1 was used as an example of the fluid control device. However, the present invention is not limited to this, and the configuration of the control valve 5 and the merging electromagnetic proportional valves 6a and 6b can be applied to, for example, a hydraulic motor or a control device using a fluid other than oil.
Further, in the above-described embodiment, in order to control the amount of the hydraulic oil flowing in the second oil passage 3 (second branch passage 10) and the hydraulic oil flowing in the third oil passage 4 flowing into the control valves 5, 205, The case where the merging electromagnetic proportional valves 6a and 6b are provided has been described. However, the invention is not limited to this, and instead of the merging electromagnetic proportional valves 6a and 6b, various valves that control the amount of merging of hydraulic oil based on electric signals can be applied.

Furthermore, in the above-described embodiment, a case has been described in which two relief valves 26 are provided in the tank passage 25 so as to correspond to the two cylinder connection passages 24a and 24b, respectively. However, the valve is not limited to this, and any valve that can control the flow rate of hydraulic oil discharged from the hydraulic actuator 111 may be used.

DESCRIPTION OF SYMBOLS 1... Hydraulic control device (fluid control device), 2... First oil passage, 3... Second oil passage (second fluid passage), 4... Third oil passage (first fluid passage), 5, 205... Control valve , 6a... First merging electromagnetic proportional valve (flow rate adjustment valve), 6b... Second merging electromagnetic proportional valve (flow rate adjustment valve), 10... Second branch path (second fluid passage), 11... Valve body, 13 ...Spool, 14...Spool electromagnetic proportional valve (other flow rate adjustment valve), 26...Relief valve (adjustment valve), 100...Construction machine, 101...Swivel body (vehicle body), 102...Traveling body (vehicle body), 110... Hydraulic pump (first pump, second pump), 110a...first discharge port (first pump), 110b...second discharge port (second pump), 111...hydraulic actuator (actuator)

Claims (5)

valve body and
a spool that is movably held in the valve body in an axial direction and that controls driving of an actuator;
a first fluid passage formed in the valve body and connected to the upstream side of the spool ;
a second fluid passage formed in the valve body and connected to the upstream side of the spool ;
a merging passage formed in the valve body, through which the first fluid passage and the second fluid passage communicate with each other separately, and which communicates with the spool;
A flow rate adjustment provided in at least the first fluid passage and controlling a merging amount based on an electric signal when the fluid passing through the first fluid passage and the fluid passing through the second fluid passage merge in the merging passage. valve and
Equipped with
The first fluid passage has a light load compared to the second fluid passage,
The fluid in the merging passage is supplied to the spool.
Fluid control device. 2. The fluid control device according to claim 1 , further comprising another flow rate regulating valve that controls the drive of the spool based on an electric signal. The fluid control device according to claim 1 or 2 , further comprising a regulating valve that controls the flow rate of the fluid discharged from the actuator. valve body and
a spool that is movably held in the valve body in an axial direction and that controls driving of an actuator;
a first fluid passage formed in the valve body and connected to the upstream side of the spool ;
a second fluid passage formed in the valve body and connected to the upstream side of the spool ;
a merging passage formed in the valve body, through which the first fluid passage and the second fluid passage communicate with each other separately, and which communicates with the spool;
A flow rate adjustment provided in at least the first fluid passage and controlling a merging amount based on an electric signal when the fluid passing through the first fluid passage and the fluid passing through the second fluid passage merge in the merging passage. valve and
another flow rate regulating valve that controls the drive of the spool based on an electrical signal;
Equipped with
The first fluid passage has a light load compared to the second fluid passage,
The fluid in the merging passage is supplied to the spool.
Fluid control device. A construction machine comprising a vehicle body on which the fluid control device according to any one of claims 1 to 4 is mounted.

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