JP7033463B2 - Spool valve device - Google Patents

Description

The present invention relates to a spool valve device that switches the connection state of the flow path according to the pilot pressure.

Conventionally, a spool valve device has been used in which the spool is moved according to the pilot pressure and the connection state of the flow path is switched according to the position of the spool to switch the supply of hydraulic oil. Further, as a spool valve device, a type having a configuration for detecting when the pilot pressure increases has been proposed. As such a spool valve device, for example, there is one disclosed in Patent Document 1. Patent Document 1 discloses a spool valve provided with a signal pressure flow path and capable of switching the supply of hydraulic oil from the pilot chamber to the signal pressure flow path according to the position of the spool. Since the spool valve device is provided with a configuration in which the supply of hydraulic oil from the pilot chamber to the signal pressure flow path is switched according to the position of the spool, it is possible to detect when the pilot pressure increases.

Japanese Patent No. 5602074

However, in the spool valve device disclosed in Patent Document 1, whether or not hydraulic oil is supplied from the pilot chamber to the signal pressure flow path is determined by the position of the spool that switches the connection state of the flow path. Therefore, whether or not the hydraulic oil is supplied to the signal pressure flow path is detected by whether or not the spool that switches the connection state of the flow path is moving. Whether or not the hydraulic oil is supplied from the pilot chamber to the signal pressure flow path is detected by the position of the spool that switches the connection state of the flow path, so that the hydraulic oil signals from the pilot chamber until this spool actually moves. It cannot be detected that the oil has been supplied to the pressure flow path.

Since the timing at which whether or not the hydraulic oil is supplied from the pilot chamber to the signal pressure flow path is detected is after the spool that actually switches the connection state of the flow path has moved, the hydraulic oil is transferred from the pilot chamber to the signal pressure flow path. The timing at which the supply is detected is determined by the timing of the movement of the spool that switches the connection state of the flow path.

It is detected that the hydraulic oil has been supplied from the pilot chamber to the signal pressure flow path after the spool that switches the connection state of the flow path has moved. Therefore, for example, the characteristics of the movement of the spool that switches the connection state of the flow path. Depending on the case, even if the hydraulic oil is supplied from the pilot chamber to the signal pressure flow path, it may not be possible to detect it immediately. Therefore, when the hydraulic oil is supplied from the pilot chamber to the signal pressure flow path, it may not be possible to accurately detect the timing.

Therefore, in view of the above circumstances, the present invention provides a spool valve device capable of detecting when the pilot pressure increases, regardless of whether or not the spool moves to switch the connection state of the flow path. The purpose is to do.

The spool valve device of the present invention communicates with a housing in which a plurality of flow paths including a signal pressure line having a signal pressure supply flow path and a signal pressure discharge flow path are formed, and the signal pressure supply flow path in a neutral state. It is provided with one flow path and a second flow path that communicates with the signal pressure discharge flow path in a neutral state, and the first spool valve chamber formed inside the housing is movably arranged and moved. The first spool for switching the connection state between the plurality of flow paths and the valve chamber for the second spool formed inside the first spool are movably arranged, and the first flow path and the first flow path are in a neutral state. A second spool having a third flow path communicating with the second flow path is provided, the first spool and the second spool move according to the pilot pressure, and the second spool is the second spool. When the spool is in the neutral state, the flow of hydraulic oil from the first flow path to the second flow path is allowed through the third flow path, and when the second spool moves from the neutral state, the flow is allowed. It is characterized in that the flow of hydraulic oil from the first flow path to the second flow path is blocked.

In the spool valve device having the above configuration, the second spool moves according to the pilot pressure separately from the first spool that switches the connection state between the plurality of flow paths, and when the second spool moves, it moves from the first flow path. Since the flow of hydraulic oil toward the second flow path is blocked, an increase in pilot pressure can be detected when the second spool moves, apart from the movement of the first spool.

Further, a first pilot chamber is defined on one end side of the valve chamber for the first spool, and a second pilot chamber is defined on the other end side of the valve chamber for the first spool. The second spool is configured to be movable inside the first spool valve chamber according to the pressure inside the first pilot chamber and the pressure inside the second pilot chamber. Depending on the pressure inside the pilot chamber and the pressure inside the second pilot chamber, the inside of the second spool valve chamber may be configured to be movable.

Since the first spool and the second spool are configured to be movable according to the pressure inside the first pilot chamber and the pressure inside the second pilot chamber, the first pilot chamber or the second pilot chamber can be moved. This can be reliably detected when the internal pressure increases.

Further, the third flow path may be a space formed between the first spool and the second spool.

Since the third flow path is a space formed between the first spool and the second spool, the third flow path can be easily formed.

Further, a first spring for urging the first spool in the axial direction and a second spring for urging the second spool in the axial direction are provided, and the spring constant of the second spring is the first spring. It may be smaller than the spring constant of the spring.

Since the spring constant of the second spring is smaller than the spring constant of the first spring, the second spool moves before the first spool when the pressure inside the pilot chamber increases. Therefore, when the pressure inside the pilot chamber increases, it can be detected immediately.

According to the present invention, it is possible to detect an increase in the pilot pressure regardless of the presence or absence of movement of the spool for switching the connection state of the flow path, so that this is detected when the pilot pressure increases. It is possible to improve the degree of freedom of the configuration for the purpose.

(A) is a cross-sectional view of the spool valve device according to the embodiment of the present invention, and (b) is an enlarged cross-sectional view of the second spool and the valve chamber for the second spool in (a). It is a hydraulic circuit diagram of the hydraulic pressure feeder provided with the spool valve device of FIG. 1 (a). FIG. 3 is an enlarged cross-sectional view of the second spool and the valve chamber for the second spool in the state where the second spool is moved to the other end side in the spool valve device of FIG. 1 (a). It is sectional drawing which showed the spool valve device in the state which the 1st spool moved to the other end side from the state of FIG. FIG. 3 is an enlarged cross-sectional view of the second spool and the valve chamber for the second spool in the state where the second spool is moved to one end side in the spool valve device of FIG. 1 (a). It is sectional drawing which showed the spool valve device in the state which the 1st spool moved to one end side from the state of FIG. It is sectional drawing about the spool valve device which concerns on other embodiment. It is sectional drawing about the spool valve device which concerns on another embodiment. It is sectional drawing about the spool valve device which concerns on still another Embodiment.

Hereinafter, the spool valve device according to the embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1A shows a cross-sectional view of the spool valve device 100 according to the embodiment, and FIG. 1B is an enlarged view of the second spool valve chamber 40 and the second spool 30 in FIG. 1A. A cross-sectional view is shown.

The spool valve device 100 is adopted, for example, in a hydraulic excavator. The hydraulic excavator is equipped with a bucket, which is an attachment, and also has a boom and an arm for moving the bucket.

Hydraulic actuators are attached to the boom, arm and bucket to move them, and the hydraulic actuator is composed of, for example, a hydraulic cylinder 2 as shown in FIG. The hydraulic actuator is not limited to the hydraulic cylinder, and may be a hydraulic motor or the like, as long as it can be driven by hydraulic oil.

As shown in FIGS. 1A and 1B, the spool valve device 100 includes a housing 10 and a first spool 20. The first spool 20 is formed in a substantially columnar shape extending in the axial direction. In the state shown in FIGS. 1 (a) and 1 (b), the first spool 20 is arranged in a neutral position.

Inside the housing 10, a first spool valve chamber 11 into which the first spool 20 can move is provided. The first spool 20 is movably housed inside the first spool valve chamber 11. The first spool 20 has a substantially cylindrical shape, and the first spool valve chamber 11 is also formed correspondingly to the substantially cylindrical shape. The first spool valve chamber 11 for accommodating the first spool 20 is formed so as to penetrate the housing 10 from one end side to the other end side. Further, a plurality of hydraulic oil flow paths 12 are formed in the housing 10.

The flow path 12 formed in the housing includes a pump flow path 12a through which hydraulic oil supplied from the pump flows, a rod side flow path 12b communicating with a cylinder that movably accommodates the rod, and a rod side flow in the cylinder. The bottom side flow path 12c communicating with the path 12b and the tank flow paths 12d and 12e communicating with the tank are formed inside the housing 10.

In the present embodiment, the pump flow path 12a from the pump is formed so as to penetrate the first spool 20 at a position substantially in the center of the housing 10 in the direction from one end side to the other end side. Further, the rod side flow path 12b is formed so as to penetrate the first spool 20 at a position on one end side of the pump flow path 12a in the housing 10. Further, the bottom side flow path 12c is formed so as to penetrate the first spool 20 at a position on the other end side of the pump flow path 12a in the housing 10. In this way, the flow paths 12a to 12e are connected to the first spool valve chamber 11 at different positions.

Pilot chambers 13 are provided on both extension lines of the first spool 20 in the length direction. Of the pilot chamber 13, the first pilot chamber 13a is formed by being connected to one end side of the first spool valve chamber 11. Further, of the pilot chamber 13, the second pilot chamber 13b is formed by being connected to the other end side of the first spool valve chamber 11. In this way, the first pilot chamber 13a is defined on one end side of the first spool valve chamber 11, and the second pilot chamber 13b is defined on the other end side of the first spool valve chamber 11. .. Further, a first pilot port 13c is formed in the first pilot chamber 13a, and hydraulic oil is circulated to the first pilot chamber 13a through the first pilot port 13c. Further, a second pilot port 13d is formed in the second pilot chamber 13b, and hydraulic oil is circulated to the second pilot chamber 13b through the second pilot port 13d.

Hereinafter, the side of the first pilot chamber 13a is referred to as one end side, and the side of the second pilot chamber 13b is referred to as the other end side.

In the present embodiment, the spring mechanism 50 is provided on one end side of the housing 10. The spring mechanism 50 has a spring-side casing 51, a first spring receiver 52, a second spring receiver 53, and a first spool spring 54. The spring-side casing 51 is a member having a substantially bottomed cylinder shape, and is fastened to the side surface of the housing 10 on one end side so as to cover the opening on one end side in the axial direction of the first spool 20. Further, the spring-side casing 51 accommodates the first spring receiver 52, the second spring receiver 53, and the first spool spring 54. The first spring receiver 52 and the second spring receiver 53 are formed in a substantially annular shape, and a through hole is formed in the axial center of each of the first spring receiver 52 and the second spring receiver 53. The first spring receiver 52 is attached to one end side of the first spool 20 with the end portion on one end side of the first spool 20 inserted into the through hole of the first spring receiver 52. Further, the first spool 20 is inserted into the through hole formed in the second spring receiver 53, and the second spring receiver 53 is attached to the first spool 20.

The first spring receiver 52 is arranged at a position on one end side of the second spring receiver 53. A first spool spring (first spring) 54 is arranged between the first spring receiver 52 and the second spring receiver 53. The first spool spring 54 urges the first spool 20 in the axial direction thereof. The first spool spring 54 includes a compression first spool spring 54a as a so-called compression coil spring and a tension first spool spring 54b as a tension coil spring. The compressed first spool spring 54a is interposed between the surfaces of the first spring receiver 52 and the second spring receiver 53 that face each other in a compressed state. As a result, the urging force in the expanding direction by the compressed first spool spring 54a acts on the first spool 20 via the second spring receiver 53. Further, the tension first spool spring 54b is interposed between the surfaces of the first spring receiver 52 and the second spring receiver 53 that face each other in a pulled state. As a result, the urging force in the compression direction by the tension first spool spring 54b acts on the first spool 20 via the second spring receiver 53. The first spool 20 is supported by the housing 10 inside the spring-side casing 51 via the first spool spring 54.

Since the first spool 20 is slidable inside the valve chamber 11 for the first spool, it is configured to be able to move according to the pressure of the hydraulic oil inside the first pilot chamber 13a and the second pilot chamber 13b. There is. The first spool 20 is formed with a groove 21 on the outer side surface in the radial direction. In the present embodiment, five grooves 21a to 21e are formed on the side surface of the first spool 20. Hereinafter, the pressure of the hydraulic oil inside the pilot chamber 13 is referred to as a pilot pressure.

In the state shown in FIGS. 1 (a) and 1 (b) (neutral state), among the grooves 21 formed in the first spool 20, the groove 21a is connected only to the tank flow path 12d, and the grooves 21b and 21c, The groove 21d is connected only to the pump flow path 12a, and the groove 21e is connected only to the tank flow path 12e.

When the first spool 20 moves inside the housing 10, the positions of the grooves 21a to 21e in the axial direction move inside the housing 10. As will be described later, by moving the first spool 20 in the housing 10, it is possible to switch the connection destination through which the plurality of flow paths 12 communicate with each other, and switch the connection state between the plurality of flow paths 12.

The spool valve device 100 of the present embodiment is configured to be movable to both one end side and the other end side according to the pressure of the hydraulic oil inside the first pilot chamber 13a and the second pilot chamber 13b, and is of a so-called three-function type. It is a spool valve.

Further, inside the first spool 20, a second spool valve chamber 40 and a second spool 30 slidable inside the second spool valve chamber 40 are provided.

The second spool 30 is movably arranged inside the second spool valve chamber 40 formed at the position of the other end of the first spool 20. In the states of FIGS. 1A and 1B, the second spool 30 is also arranged in a neutral position.

At the position of the center of the shaft in the first spool 20, a flow path 22 in the spool is provided so as to penetrate the first spool 20 along the axial direction. In the present embodiment, the flow path 22 in the spool penetrates the axial center of the first spool 20 from one end side to the other end side so as to communicate the first pilot chamber 13a and the second spool valve chamber 40. Is formed in.

The flow path 22 in the spool is formed so as to communicate with the first pilot chamber 13a on one end side. When the pilot pressure inside the first pilot chamber 13a changes, the change in pilot pressure is transmitted along the arrow P1 shown in FIG. 1 (a). Therefore, the change in the pilot pressure inside the first pilot chamber 13a is transmitted from the first pilot chamber 13a to the second spool valve chamber 40 via the in-spool flow path 22.

Further, in the first spool 20 that can move inside the first spool valve chamber 11, a flow path 24 that communicates the second spool valve chamber 40 and the radial outside of the first spool 20 is formed. There is. The flow path 24 extends along the radial direction of the first spool 20 from the valve chamber 40 for the second spool formed along the axial center of the first spool 20 to the radial outer region of the first spool 20. It is formed to extend. A plurality of flow paths 24 are formed in the first spool 20 along the direction from one end side to the other end side. In the present embodiment, two flow paths 24 are formed along the direction from one end side to the other end side. Of the two flow paths 24 formed along the direction from one end side to the other end side of the first spool 20, the flow path formed on one end side is defined as the first flow path 24a and is formed on the other end side. The flow path is referred to as a second flow path 24b.

In the neutral state shown in FIG. 1, a flow path 17 is formed at a position corresponding to the second spool 30 in the housing 10 with respect to the axial direction of the first spool 20. In the present embodiment, the flow paths 17 are formed at two positions with respect to the axial direction of the first spool 20. The flow path 17 is formed on the inner side surface of the first spool valve chamber 11 over the entire circumferential direction. The flow path 17 is formed at a position facing the first spool valve chamber 11 in the housing 10 so that the diameter of the first spool valve chamber 11 is partially expanded.

The first flow path 24a and the second flow path 24b are formed at positions corresponding to the flow paths 17a and 17b in the neutral first spool 20 shown in FIGS. 1A and 1B. The first flow path 24a and the second flow path 24b extend in a direction intersecting the axial direction of the first spool 20 and are formed inside the first spool 20. In the present embodiment, the first flow path 24a and the second flow path 24b each extend in a direction orthogonal to the axial direction of the first spool 20 and are formed so as to penetrate the first spool 20.

In the present embodiment, the second spool 30 is formed with a groove on the outer side surface in the radial direction, and the groove functions as the third flow path 31. That is, in the present embodiment, the third flow path 31 is a groove formed on the outer side surface of the second spool 30 in the radial direction. Since the third flow path 31 as a groove is formed on the outer side surface of the second spool 30, a space is formed between the first spool 20 and the second spool 30. Since a space is formed between the first spool 20 and the second spool 30, hydraulic oil can be circulated through the space. By circulating the hydraulic oil inside the space formed between the first spool 20 and the second spool 30, the space can function as the third flow path 31. The third flow path 31 is formed only partially in the axial direction of the second spool 30. In the present embodiment, the configuration in which the third flow path 31 is a groove formed on the outer side surface of the second spool 30 has been described, but the present invention is not limited to the above embodiment. If a space as a flow path is formed between the first spool 20 and the second spool 30, the space may have a configuration other than the groove formed in the second spool 30. For example, a convex portion may be formed on the outer side surface of the second spool 30, and a space as a flow path may be formed between the convex portions.

A spring receiver 32 is formed on the second spool 30. In the axial direction of the second spool 30, a second spool spring (second spring) 33 for the second spool 30 is provided between the spring receivers 32. The second spool spring 33 urges the second spool 30 in the axial direction thereof. The second spool 30 is supported by the first spool 20 via the second spool spring 33.

The second spool spring 33 includes a compression second spool spring as a compression coil spring and a tension second spool spring as a tension coil spring. Therefore, the urging force in the expanding direction by the compressed second spool spring acts on the second spool 30 via the spring receiver 32. Further, the urging force in the compression direction by the tension second spool spring acts on the second spool 30 via the spring receiver 32. The second spool 30 is supported by the first spool 20 via the second spool spring 33.

The spool valve device 100 is formed with a signal pressure line 70 for detecting whether or not the second spool 30 has moved. The signal pressure line 70 is a flow path of the hydraulic oil from the pump 60 for supplying the hydraulic oil to the drain portion 63 through the third flow path 31 of the second spool 30. The signal pressure line 70 includes a signal pressure supply flow path 61 for hydraulic oil from the pump 60 formed in the housing 10, and an inlet flow path 17a connected to the first spool valve chamber 11 in the signal pressure supply flow path 61. , A first flow path 24a formed in the first spool 20, a third flow path 31 formed in the second spool 30, a second flow path 24b formed in the first spool 20, and a signal. The pressure discharge flow path 64 includes a flow path 17b connected to the first spool valve chamber 11 and a signal pressure discharge flow path 64 formed in the housing 10 and through which hydraulic oil flows toward the drain portion 63.

Of the hydraulic oil flow paths 17 formed at two locations of the first spool 20 in the axial direction of the first spool 20, the flow path 17a formed on one end side is the signal pressure of the hydraulic oil from the pump 60. It is connected to the supply flow path 61. Therefore, while the pump 60 is being driven, the hydraulic oil continues to be supplied to the hydraulic oil flow path 17a on one end side by the pump 60. A pressure gauge 62 capable of measuring the pressure of the hydraulic oil inside the signal pressure supply flow path 61 is attached to the signal pressure supply flow path 61 from the pump 60 to the hydraulic oil flow path 17a on one end side. Further, of the flow path 17, the flow path 17b of the hydraulic oil formed on the other end side is connected to the signal pressure discharge flow path 64 that guides the hydraulic oil to the drain portion 63.

In the state shown in FIGS. 1 (a) and 1 (b) (neutral state), the flow paths 17a and 17b formed at the positions corresponding to the second spool 30 in the housing 10 are radially along the first spool 20. The first spool 20 and the second spool 30 are arranged so as to communicate with the first flow path 24a and the second flow path 24b formed in the above. In the present embodiment, the flow path 17a in the housing 10 and the first flow path 24a in the first spool 20 communicate with each other on one end side, and the flow path 17b in the housing 10 and the second flow path 24a in the first spool 20 on the other end side. It communicates with the flow path 24b.

Further, at the neutral positions shown in FIGS. 1 (a) and 1 (b), the first flow path 24a and the second flow path 24b formed along the radial direction in the first spool 20 are respectively the second spool 30. It communicates with a third flow path 31 formed along the axial direction on the outer periphery of the above. Therefore, the flow path 17a and the flow path 17b formed in the housing 10 are formed on the outer periphery of the first flow path 24a, the second flow path 24b, and the second spool 30 formed in the first spool 20. It communicates with the flow path 31. Therefore, the hydraulic oil supplied to the flow path 17a of the housing 10 is supplied to the first flow path 24a of the first spool 20, passes through the third flow path 31 formed on the outer periphery of the second spool 30, and is the first. It is supplied to the flow path 17b of the housing 10 through the second flow path 24b formed in the spool 20.

Since the flow path 17b is connected to the drain portion 63, the hydraulic oil supplied to the flow path 17a passes through the first flow path 24a, the third flow path 31, and the second flow path 24b, and is supplied to the flow path 17b. After that, it is discharged to the drain portion 63. Therefore, in the signal pressure supply flow path 61 from the pump 60, the hydraulic oil is connected to the drain portion 63, so that the pressure of the hydraulic oil in the signal pressure supply flow path 61 does not increase, and the pressure gauge 62 The pressure shown is kept constant.

As described above, the second spool 30 includes the signal pressure supply flow path 61, the flow path 17a, the first flow path 24a, the third flow path 31, the second flow path 24b, the flow path 17b, and the signal pressure discharge flow path 64. It can be located in a communication position that communicates with each other. On the other hand, the second spool 30 moves from the neutral state, and the signal pressure supply flow path 61, the flow path 17a, the first flow path 24a, the third flow path 31, the second flow path 24b, the flow path 17b, and the signal pressure. When the discharge flow paths 64 do not communicate with each other, the hydraulic oil is not discharged to the drain portion 63. Therefore, the pressure of the hydraulic oil in the signal pressure supply flow path 61 increases. By detecting whether or not the pressure of the hydraulic oil in the signal pressure supply flow path 61 at this time has increased, it is possible to detect whether or not the second spool 30 has moved.

As described above, the second spool 30 is formed with a third flow path 31 through which the hydraulic oil is circulated on the outer periphery of the second spool 30, and the first spool 20 is the third flow of the hydraulic oil in the neutral state. A first flow path 24a for guiding to the road 31 and a second flow path 24b for discharging hydraulic oil from the third flow path 31 in a neutral state are formed. Further, the housing 10 has a signal pressure supply flow path 61 and a flow path 17a for guiding the hydraulic oil to the first flow path 24a in the neutral state, and the hydraulic oil from the second flow path 24b in the neutral state. A flow path 17b for discharging and a signal pressure discharge flow path 64 are formed.

FIG. 2 shows a circuit diagram of a hydraulic circuit using the spool valve device 100 of the present embodiment.

The hydraulic cylinder 2 has a rod 2a, and advances and retreats the rod 2a according to the flow direction of the hydraulic oil supplied to the hydraulic cylinder 2. More specifically, the hydraulic cylinder 2 has two ports 2b and 2c, and when hydraulic oil is flowed through one port 2b, the rod 2a retracts in the D2 direction and the hydraulic oil is flowed through the other port 2c. And the rod 2a move forward in the D1 direction. A hydraulic pressure supply device 3 is connected to the hydraulic cylinder 2 configured in this way.

Although the present embodiment describes a mode in which the spool valve device 100 of the present invention is used for the hydraulic excavator, the present invention is not limited to the above embodiment. The spool valve device 100 of the present invention may be used for other configurations. It may be used for other construction machinery driven hydraulically. Further, the spool valve device 100 of the present invention may be used for industrial machines other than construction machines.

The hydraulic pressure supply device 3 is configured to be able to supply hydraulic oil to the two ports 2b and 2c, and includes two hydraulic pumps 4. In the present embodiment, the hydraulic pressure supply device 3 includes one spool valve device 100 having a first spool 20 and a second spool 30, and one first spool 20 having no second spool 30. ing. The hydraulic pump 4 is, for example, a swash plate pump, and sucks and discharges the hydraulic fluid from the tank 5. Further, the hydraulic pump 4 is connected to one of the spool valve devices 100, and hydraulic oil from the hydraulic pump 4 is supplied to the spool valve device 100.

In the present embodiment, the flow path 8 extending from the hydraulic pump 4 is connected to the tank 7. The flow path 8 extending from the hydraulic pump 4 toward the tank 7 branches in the middle and is connected to the pump flow path 12a formed in the housing 10. Therefore, of the hydraulic oil supplied from the hydraulic pump 4 toward the tank 7, a part of the hydraulic oil is supplied to the hydraulic cylinder 2 via the pump flow path 12a and the first spool 20. Of the hydraulic oil supplied from the hydraulic pump 4 toward the tank 7, the hydraulic oil that is not supplied to the pump flow path 12a is discharged to the tank 7 as it is through the flow path 8.

In this embodiment, two hydraulic pumps 4 are connected to one hydraulic cylinder 2. Further, two first spools 20 for distributing the hydraulic oil supplied from the hydraulic pump 4 are provided. Further, a flow path in which the two bottom-side flow paths 12c merge is connected to the port 2b. Similarly, a flow path in which the two rod-side flow paths 12b merge is connected to the port 2c.

In the hydraulic pressure supply device 3 of the present embodiment, two hydraulic pumps 4 are connected to one hydraulic cylinder 2, but one hydraulic pump 4 is connected to one hydraulic cylinder 2. You may. Further, three or more hydraulic pumps 4 may be connected to one hydraulic cylinder 2.

The first spool 20 in the spool valve device 100 is a valve device provided with a so-called direction switching valve, and the hydraulic oil is selectively flowed to the two ports 2b and 2c by switching the flow direction of the hydraulic oil and flows to the hydraulic cylinder 2. Adjust the flow rate of hydraulic oil.

The first spool 20 is configured to switch the connection state of each flow path 12a to 12e according to its position.

The hydraulic pressure supply device 3 includes an operation rod 80. When the operating rod 80 is tilted by the operator of the hydraulic pressure supply device 3, the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b increases accordingly. The second spool 30 and the first spool 20 move according to the increase in the pilot pressure of the first pilot chamber 13a or the second pilot chamber 13b. That is, the second spool 30 and the first spool 20 can be moved according to the operation of the operating rod 80, and the rod 2a can be driven in the D1 direction or the D2 direction in the hydraulic cylinder 2. In this way, the hydraulic pressure supply device 3 can be operated by operating the operating rod 80.

Next, the time when the first spool 20 moves from the neutral state shown in FIG. 1 will be described. First, a case where the pilot pressure of the first pilot chamber 13a increases and the second spool 30 and the first spool 20 move from one end side to the other end side will be described. When the first spool 20 moves, in the present embodiment, the second spool 30 moves inside the second spool valve chamber 40 before the first spool 20 slides and moves inside the passage 11. It slides and moves.

In FIG. 3, from the neutral state of FIGS. 1 (a) and 1 (b), the second spool 30 enters the inside of the second spool valve chamber 40 by increasing the pilot pressure of the first pilot chamber 13a on one end side. A cross-sectional view of the spool valve device 100 when the first spool 20 moves inside the passage 11 while moving is shown.

In FIG. 3, for the second spool 30 and the second spool when the second spool 30 moves to the other end side inside the valve chamber 40 for the second spool due to the increase in the pilot pressure of the first pilot chamber 13a. An enlarged cross-sectional view of the interior of the valve chamber 40 is shown. In the state shown in FIG. 3, the first spool 20 has not moved.

When the pilot pressure inside the first pilot chamber 13a increases, the increase in the pressure inside the first pilot chamber 13a increases on one end side of the valve chamber 40 for the second spool via the flow path 22 in the spool inside the first spool 20. Is transmitted to the part of. When the pressure of the hydraulic oil in the one end side portion of the second spool valve chamber 40 increases, the second spool 30 arranged inside the second spool valve chamber 40 moves.

In the present embodiment, the second spool spring 33 and the first spool spring 54 are moved so that the second spool 30 moves before the first spool 20 when the pilot pressure inside the first pilot chamber 13a increases. Is set. That is, the spring constant of the second spool spring 33 is smaller than the spring constant of the first spool spring 54.

Since the second spool 30 moves to the other end side due to the increase in the pilot pressure inside the first pilot chamber 13a, the position of the third flow path 31 formed on the outer periphery of the second spool 30 is along the axial direction. Moving. Therefore, as shown in FIG. 3, the communication state between the first flow path 24a of the first spool 20 and the third flow path 31 of the second spool 30 is released.

Since the hydraulic oil continues to be supplied from the pump 60 to the signal pressure supply flow path 61 in a state where the first flow path 24a and the third flow path 31 do not communicate with each other, the hydraulic oil in the signal pressure supply flow path 61 The pressure increases. As the pressure of the hydraulic oil in the signal pressure supply flow path 61 increases, the value of the pressure indicated by the pressure gauge 62 increases. By detecting the increase in pressure indicated by the pressure gauge 62 at this time, it is possible to detect that the second spool 30 has moved to the other end side, and that the pressure inside the first pilot chamber 13a has increased. Can be detected.

As described above, the second spool 30 includes the signal pressure supply flow path 61, the flow path 17a, the first flow path 24a, the third flow path 31, the second flow path 24b, the flow path 17b, and the signal pressure discharge flow path 64. It can be located in a non-communication position that does not communicate.

When the second spool 30 is in the neutral state, the flow of hydraulic oil from the first flow path 24a to the second flow path 24b via the third flow path 31 is allowed. On the other hand, when the second spool 30 moves, the flow of hydraulic oil from the first flow path 24a to the second flow path 24b is blocked.

When the pressure gauge 62 detects that the pressure in the signal pressure supply flow path 61 has increased and the second spool 30 has moved, it is detected that the pilot pressure has increased inside the first pilot chamber 13a. .. Therefore, it is possible to detect that the operation of the operation rod 80 has been performed. Further, when it is detected that the second spool 30 has moved in one of the first spools 20 and the pilot pressure inside the first pilot chamber 13a is detected, the other first spool 20 also receives. It is determined that the pilot pressure inside the first pilot chamber 13a has increased.

When the pilot pressure inside the first pilot chamber 13a further increases from the state shown in FIG. 3, the first spool 20 moves toward the other end side.

FIG. 4 shows a cross-sectional view of the spool valve device 100 when the first spool 20 moves to the other end side.

When the first spool 20 moves to the other end side due to an increase in the pilot pressure inside the first pilot chamber 13a, the positions of the grooves 21a to 21e formed on the outer periphery of the first spool 20 along the axial direction move. In the state shown in FIG. 4, among the grooves 21 formed in the first spool 20, the groove 21a is connected between the tank flow path 12d and the rod side flow path 12b, and the groove 21b and the groove 21c are pumps. It is connected only to the flow path 12a, the groove 21d is connected between the pump flow path 12a and the bottom side flow path 12c, and the groove 21e is connected only to the tank flow path 12e. Therefore, the tank flow path 12d and the rod side flow path 12b are connected via the groove 21a, and the pump flow path 12a and the bottom side flow path 12c are connected via the groove 21d. In this way, since the pump flow path 12a and the bottom side flow path 12c are connected via the groove 21d, the hydraulic oil from the hydraulic pump 4 can be supplied toward the bottom side flow path 12c.

On the other hand, since the tank flow path 12d and the rod side flow path 12b are connected via the groove 21a, the hydraulic oil inside the cylinder on the side where the rod is arranged can be discharged to the tank 5. Therefore, the pressure on the rod side portion inside the cylinder can be reduced and the pressure on the bottom side portion inside the cylinder can be increased. As a result, the rod 2a can be moved toward the extending direction D1 of the rod 2a shown in FIG.

Next, a case where the pilot pressure in the second pilot chamber 13b increases and the second spool 30 and the first spool 20 move from the other end side toward one end side will be described.

5A and 5B show that the second spool 30 is inside the second spool valve chamber 40 due to an increase in the pilot pressure of the second pilot chamber 13b on the other end side from the neutral state of FIGS. 1A and 1B. The inside of the 2nd spool 30 and the 2nd spool valve chamber 40 when moved is shown is the enlarged sectional view. In the state shown in FIG. 5, the first spool 20 has not moved.

When the pressure of the hydraulic oil in the other end side portion of the second spool valve chamber 40 increases, the second spool 30 arranged inside the second spool valve chamber 40 moves from the other end side toward one end side. do. In the present embodiment, the second spool spring 33 and the first spool spring 54 are moved so that the second spool 30 moves before the first spool 20 when the pilot pressure inside the second pilot chamber 13b increases. Is set. Since the second spool 30 moves to one end side due to the increase in the pilot pressure inside the second pilot chamber 13b, the position of the third flow path 31 formed on the outer circumference of the second spool 30 moves along the axial direction. do.

Therefore, as shown in FIG. 5, the first flow path 24a of the first spool 20 and the third flow path 31 of the second spool 30 communicate with each other, but with the third flow path 31 of the second spool 30. The second flow path 24b of the first spool 20 is not in communication with the second flow path 24b. Therefore, the communication state between the third flow path 31 of the second spool 30 and the second flow path 24b of the first spool 20 is released.

Since the hydraulic oil continues to be supplied from the pump 60 to the signal pressure supply flow path 61 in a state where the third flow path 31 and the second flow path 24b do not communicate with each other, the pressure of the hydraulic oil in the signal pressure supply flow path 61 Will increase. As the pressure of the hydraulic oil in the signal pressure supply flow path 61 increases, the value of the pressure indicated by the pressure gauge 62 increases. By detecting the increase in pressure indicated by the pressure gauge 62 at this time, it is possible to detect that the second spool 30 has moved to one end side, and it is possible to detect that the pressure inside the second pilot chamber 13b has increased. can do.

When the pressure gauge 62 detects that the pressure in the signal pressure supply flow path 61 has increased and the second spool 30 has moved, it is detected that the pilot pressure has increased inside the second pilot chamber 13b. .. Therefore, it is possible to detect that the operation of the operation rod 80 has been performed. Further, when it is detected that the second spool 30 has moved in one of the first spools 20 and the pilot pressure inside the second pilot chamber 13b is detected, the other first spool 20 also also receives. It is determined that the pilot pressure inside the second pilot chamber 13b has increased.

When the pilot pressure inside the second pilot chamber 13b further increases from the state shown in FIG. 5, the first spool 20 moves toward one end.

FIG. 6 shows a cross-sectional view of the spool valve device 100 when the first spool 20 is moved to one end side.

When the first spool 20 moves to one end side due to an increase in the pilot pressure inside the first pilot chamber 13b, the positions of the grooves 21a to 21e formed on the outer periphery of the first spool 20 move along the axial direction.

In the state shown in FIG. 6, of the grooves 21 formed in the first spool 20, the groove 21a is connected only to the tank flow path 12d, and the groove 21b is a rod-side flow path 12b and a pump flow path 12a. The groove 21c and the groove 21d are connected only to the pump flow path 12a, and the groove 21e is connected between the bottom side flow path 12c and the tank flow path 12e. Therefore, the rod side flow path 12b and the pump flow path 12a are connected via the groove 21b, and the bottom side flow path 12c and the tank flow path 12e are connected via the groove 21e.

Since the rod-side flow path 12b and the pump flow path 12a are connected via the groove 21b in this way, the hydraulic oil from the hydraulic pump 4 can be supplied toward the rod-side flow path 12b. On the other hand, since the bottom side flow path 12c and the tank flow path 12e are connected via the groove 21e, the hydraulic oil inside the cylinder on the bottom side can be discharged to the tank 5.

Therefore, it is possible to increase the pressure of the rod-side portion inside the cylinder and decrease the pressure of the bottom-side portion inside the cylinder. As a result, the rod 2a can be moved toward D2 on the side opposite to the extending direction of the rod 2a shown in FIG.

According to the spool valve device 100 of the present embodiment, the spool valve device 100 is slidable inside the first spool 20 and the second spool valve chamber 40 slidably arranged inside the passage 11. Since the second spool 30 is provided, whether or not the pilot pressure of the first pilot chamber 13a or the second pilot chamber 13b is increased by the second spool 30 separately from the movement of the first spool 20. Can be detected. Therefore, it is possible to detect that the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 13b has increased regardless of the timing of movement of the first spool 20. Therefore, it is possible to detect that the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 13b has increased without being limited by the movement characteristics of the first spool 20.

For example, by making the spring constant of the second spool spring 33 in the second spool 30 smaller than the spring constant of the first spool spring 54 in the first spool 20, the inside of the first pilot chamber 13a or the second pilot chamber 13b The timing of movement of the second spool 30 when the pilot pressure increases can be accelerated. In this way, by appropriately setting the spring constant of the second spool spring 33 in the second spool 30 and the spring constant of the first spool spring 54 in the first spool 20, the inside of the first pilot chamber 13a or the second pilot chamber 13b The timing of movement of the second spool 30 when the pilot pressure of the second spool 30 increases can be accelerated. Thereby, when the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 13b increases, it is possible to immediately detect that the pilot pressure has increased without delay. Therefore, when the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 13b increases, the timing can be detected more accurately.

When the second spool 30 moves, the communication between the signal pressure supply flow path 61 and the signal pressure discharge flow path 64 is released even though the pump 60 is driven, so that the signal pressure supply flow path 61 is released. The pressure of the hydraulic oil inside increases. Further, when the pressure of the hydraulic oil inside the signal pressure supply flow path 61 increases, it can be detected by the pressure indicated by the pressure gauge 62. Therefore, when the second spool 30 moves due to an increase in the pressure in the first pilot chamber 13a or the second pilot chamber 13b, it can be detected by the pressure indicated by the pressure gauge 62. As a result, when the pressure in the first pilot chamber 13a or the second pilot chamber 13b increases, it can be reliably detected.

Further, in the present embodiment, when the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b increases, this can be detected by the movement of the second spool 30, so that the movement of the first spool 20 and the movement of the first spool 20 Can detect that regardless. Regardless of the movement characteristics of the first spool 20, when the second spool 30 moves, the movement of the second spool 30 is detected to increase the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b. Can be detected. By detecting the movement of the second spool 30, the increase in the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b is detected, so that the increase in the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b is detected. It is possible to improve the degree of freedom of the configuration for the purpose. Without being limited by the movement characteristics of the first spool 20, a configuration for detecting an increase in pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b can be freely designed.

In this way, it is possible to detect that the pilot pressure in the first pilot chamber 13a or the second pilot chamber 13b has increased when the movement of the second spool 30 is detected regardless of the movement of the first spool 20. Therefore, the configuration for detecting the increase in pilot pressure can be freely set. That is, the characteristics of the second spool spring 33 that slidably supports the second spool 30 and the characteristics of the first spool spring 54 that slidably supports the first spool 20 are set in any combination. be able to. This makes it possible to improve the degree of freedom in designing the spool valve device 100.

As shown in FIG. 2, when two hydraulic pumps 4 are connected to one hydraulic cylinder 2, two hydraulic pumps 4 are driven by different timings between the two hydraulic pumps 4. The flow rate of the hydraulic oil supplied to the hydraulic cylinder 2 by the hydraulic pump 4 can be adjusted. Since it is possible to detect that the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 31b has increased regardless of the timing of movement of the first spool 20, it is possible to detect that the pilot pressure has increased between the two first spools 20. , The timing at which the first spool 20 starts moving can be changed. Specifically, when it is detected that the second spool 30 has moved, it is possible to make a difference in the timing of movement between the one first spool 20 and the other first spool 20 thereafter. can. The hydraulic cylinder 2 is made to move the hydraulic oil by making a difference in the timing of movement between the two first spools 20 so that one first spool 20 moves and then the other first spool 20 moves. Can be supplied gradually. Since there is a difference in the timing of movement between the two first spools 20, it is possible to make time for supplying hydraulic oil to the hydraulic cylinder 2 only by one of the hydraulic pumps 4. Therefore, first, hydraulic oil is supplied to the hydraulic cylinder 2 only by one hydraulic pump 4, and then hydraulic oil is supplied to the hydraulic cylinder 2 of the other hydraulic pump 4, and both hydraulic pumps 4 supply the hydraulic oil to the hydraulic cylinder 2. Hydraulic oil will be supplied. Therefore, the hydraulic oil can be gradually supplied to the hydraulic cylinder 2.

In this way, for example, in the process of increasing the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 31b, one first spool 20 is first moved, and then the other first spool 20 is moved. Can be made to. In this case, by making a difference in the spring constant of the first spool spring 54 between the two first spools 20, it is possible to make a difference in the timing of movement between the two first spools 20. Therefore, when increasing the supply amount of the hydraulic oil to the hydraulic cylinder 2, the hydraulic oil is first supplied from one of the hydraulic pumps 4, and then the hydraulic oil is supplied from both hydraulic pumps 4. The flow rate of the hydraulic oil supplied to the cylinder 2 can be gradually increased.

Further, in the case of a delicate operation area by the operating rod 80, the hydraulic oil is supplied by only one of the hydraulic pumps 4, and when the operation rod 80 is largely operated, the hydraulic oil is supplied by both hydraulic pumps 4. The amount of hydraulic oil supplied can be controlled so as to perform the above.

In the conventional configuration, it is detected that the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 13b increases when the first spool 20 moves. At this time, since it was necessary to reliably move the first spool 20 when the operation was performed by the operating rod 80, it was difficult to make a difference in the timing of movement between the two first spools 20. Therefore, it is difficult to make a difference in the timing of increasing the supply of hydraulic oil between the two hydraulic pumps 4. As a result, when the operating rod 80 was operated, the supply of hydraulic oil was increased at one time, and it was not possible to make fine adjustments in the supply of hydraulic oil from the hydraulic pump 4.

On the other hand, in the present invention, it is possible to detect that the pilot pressure inside the first pilot chamber 13a or the second pilot chamber 31b has increased regardless of the timing of movement of the first spool 20. The timing at which the first spool 20 starts moving can be changed between the two first spools 20. Therefore, it is possible to make a difference in the timing of increasing the supply of the hydraulic oil, and in the supply of the hydraulic oil, it is possible to finely adjust the flow rate in the step of increasing the supply amount of the hydraulic oil.

The spring coefficient of the second spool spring 33 that slidably supports the second spool 30 is not necessarily smaller than the spring coefficient of the first spool spring 54 that slidably supports the first spool 20. You may. The spring coefficient of the second spool spring 33 that slidably supports the second spool 30 may be set to be larger than the spring coefficient of the first spool spring 54 that slidably supports the first spool 20.

Further, in the present embodiment, the valve chamber 40 for the second spool and the second spool 30 are provided inside the first spool 20. Therefore, a configuration for detecting an increase in the pilot pressure of the first pilot chamber 13a or the second pilot chamber 13b is provided separately from the first spool 20, and the configuration can be miniaturized.

In the present embodiment, a configuration for detecting an increase in the pilot pressure inside the pilot chamber is provided inside the first spool 20. Therefore, the space for the first spool 20 and the space for the configuration for detecting the increase in the pilot pressure inside the pilot chamber are commonly used. Therefore, the required space can be saved as compared with the case where each is configured separately. This saves space in the configuration of the spool valve device 100, so that the spool valve device 100 can be miniaturized.

Further, when the present invention is applied to a work machine having a swivel body such as a hydraulic excavator, the signal of the pressure gauge 62 can be used as a signal for releasing the parking brake of the swivel actuator. When the swivel actuator is not operated and other actuators (boom, arm, bucket) are being operated, the shovel unexpectedly swivels due to external force, and the brake Friction plate may be burned. Even in this case, if the parking brake of the swivel actuator is released by quickly detecting the lever operation of the other actuators, the seizure of the brake can be prevented.

In the above embodiment, the configuration in which the second spool 30 is movably supported by the second spool spring 33 provided on the other end side of the second spool 30 with respect to the first spool 20 has been described. However, the present invention is not limited to the above embodiment. The configuration for movably supporting the second spool 30 with respect to the first spool 20 may be another configuration.

For example, as in the spool valve device 100a shown in FIG. 7, a second spool spring 33 provided on the other end side of the second spool 30 is provided, and a second spool spring is provided on one end side of the second spool 30. A spring 34 different from the 33 may be provided.

Further, in the above embodiment, the second spool 30 and the first spool 20 face the first pilot chamber and the second pilot chamber, and the second spool responds to an increase in the pilot pressure in the first pilot chamber or the second pilot chamber. The configuration of the spool valve to which the 30 and the first spool 20 move has been described. However, the above embodiment is not limited to this. The second spool 30 and the first spool 20 are configured to face only one pilot chamber, and the second spool 30 and the first spool 20 move according to an increase in pilot pressure inside one pilot chamber. It may be configured to be used. As described above, the spool valve may be of a so-called two-function type.

FIG. 8 shows a spool having only the second pilot chamber 13b provided on the other end side, and the second spool 30 and the first spool 20 move according to an increase in the pilot pressure inside the second pilot chamber 13b. A cross-sectional view of the valve device 100b is shown. In the spool valve device 100b shown in FIG. 8, the first pilot chamber 13a does not exist on one end side of the first spool 20, and only the second pilot chamber 13b on the other end side of the first spool 20 is formed. A first spool spring 54 that movably supports the first spool 20 with respect to the housing 10 is attached to the inner wall surface of the spring-side casing 51. Therefore, when the pilot pressure of the second pilot chamber 13b increases, the second spool 30 moves to one end side. Further, when the pilot pressure of the second pilot chamber 13b further increases, the first spool 20 moves to one end side. As described above, the spool valve device 100b may be configured to have only one pilot chamber.

Further, in the configuration of the spool valve device 100 shown in FIGS. 1 to 6, a second spool spring 33 for movably supporting the second spool 30 is provided only on the other end side of the second spool 30, and FIG. 7 In the configuration of the spool valve device 100a shown in the above, a configuration in which springs for movably supporting the second spool 30 are provided on both one end side and the other end side of the second spool 30 has been described. However, the configuration of the spring for movably supporting the second spool 30 is not limited to the above embodiment. The spring for movably supporting the second spool 30 may be provided only on one end side of the second spool 30.

FIG. 9 shows a cross-sectional view of the configuration of the spool valve device 100c in which the spring 35 for movably supporting the second spool 30 is provided only on one end side of the second spool 30. In the spool valve device 100c shown in FIG. 9, the second spool 30 and the first spool 20 face only the second pilot chamber 13b, and the second spool 30 and the first spool 20 are inside the second pilot chamber 13b. It is configured to move as the pilot pressure increases.

As described above, the spring for movably supporting the second spool 30 may be provided only on one end side of the small spool, may be provided only on the other end side, or may be provided only on one end side and the other end. It may be provided on both sides. As long as the second spool 30 can be movably supported, the spring for movably supporting the second spool 30 may be configured in any way.

Further, the second spool 30 and the first spool 20 may be configured to face only one pilot chamber, or may be configured to be arranged between the two pilot chambers.

Further, the combination of the configuration of the spring for movably supporting the second spool 30 and the number of pilot chambers may be any configuration. If the second spool 30 and the first spool 20 can be moved according to the increase in the pilot pressure in the pilot chamber, the configuration of the spring for movably supporting the second spool 30 and the configuration of the pilot chamber. The combination with the configuration may be combined in any way.

11 Valve chamber for 1st spool 13a 1st pilot chamber 13b 2nd pilot chamber 20 1st spool 24a 1st flow path 24b 2nd flow path 30 2nd spool 31 3rd flow path 33 2nd spool spring (2nd spring)
40 Valve chamber for 2nd spool 54 1st spool spring (1st spring)
61 Signal pressure supply flow path 64 Signal pressure discharge flow path 100 Spool valve device

Claims (4)

A housing in which a plurality of flow paths including a signal pressure line having a signal pressure supply flow path and a signal pressure discharge flow path are formed, and a housing.
A first spool that communicates with the signal pressure supply flow path in a neutral state and a second flow path that communicates with the signal pressure discharge flow path in a neutral state are provided, and a first spool formed inside the housing. A first spool in which the valve chamber is movably arranged and the connection state between the plurality of flow paths is switched by moving the valve chamber,
A second spool having a second spool valve chamber formed inside the first spool so as to be movable and having a third flow path communicating with the first flow path and the second flow path in a neutral state. And with
The first spool and the second spool move according to the pilot pressure,
The second spool allows the flow of hydraulic oil from the first flow path to the second flow path via the third flow path when the second spool is in the neutral state, and the second spool allows the flow of hydraulic oil. A spool valve device characterized in that when the oil moves from the neutral state, the flow of hydraulic oil from the first flow path to the second flow path is blocked. A first pilot chamber is defined on one end side of the first spool valve chamber, and a second pilot chamber is defined on the other end side of the first spool valve chamber.
The first spool is configured to be movable inside the valve chamber for the first spool according to the pressure inside the first pilot chamber and the pressure inside the second pilot chamber.
The second spool is configured to be movable inside the second spool valve chamber according to the pressure inside the first pilot chamber and the pressure inside the second pilot chamber. The spool valve device according to claim 1. The spool valve device according to claim 1 or 2, wherein the third flow path is a space formed between the first spool and the second spool. A first spring that urges the first spool in its axial direction,
A second spring for urging the second spool in its axial direction is provided.
The spool valve device according to any one of claims 1 to 3, wherein the spring constant of the second spring is smaller than the spring constant of the first spring.

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