Directional control valve device

Abstract

To provide a directional control valve device that suppresses an increase in size caused by providing a second signal passage.SOLUTION: A directional control valve device 1 has: a plurality of spool valves 3; a first signal passage 11 connected to the plurality of spool valves 3; and a second signal passage 12 merging into the first signal passage 11 at a site upstream from the spool valve 3 for which shifting is to be detected of the plurality of spool valves 3 and sharing the passage extending downstream from the merging site 16 with the first signal passage 11, where the part of the second signal passage 12 that extends upstream from the merging site 16 is not connected to the spool valve 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a directional control valve device. [Background technology]

[0002] The directional control valve device described in Patent Document 1 has multiple valve blocks stacked on top of each other. The valve blocks have a valve body with a spool hole and a spool that is movably mounted in the spool hole. The directional control valve device switches between supplying and cutting off hydraulic oil by moving these spools. The directional control valve device is equipped with a signal passage that detects the switching status of the spool. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-221357 Summary of the Invention [Problem to be solved by the invention]

[0004] The directional control valve device described in Patent Document 1 above is equipped with a first signal passage that generates pressure when any of the multiple spools is switched. In addition to this first signal passage, a second signal passage that generates pressure when any of the multiple spools is switched may be provided. If a second signal passage is provided, two signal passages must be routed above the spools, which increases the size of the directional control valve device. [Means for solving the problem]

[0005] A directional control valve device that solves the above problem includes a plurality of spool valves, a first signal passage connected to the plurality of spool valves, and a second signal passage that merges with the first signal passage upstream of a spool valve among the plurality of spool valves whose switching status is to be detected, shares a passage downstream from the merging position with the first signal passage, and has a passage upstream from the merging position that is not connected to the spool valves.

[0006] According to the above configuration, the second signal passage shares the passage downstream of the junction with the first signal passage with the first signal passage. Therefore, it is sufficient to provide only the first signal passage downstream of the junction with the first signal passage. Furthermore, the passage upstream of the junction with the first signal passage is not connected to the spool valve. Therefore, it is not necessary to provide the second signal passage at the position where the spool valve is provided. Therefore, it is possible to prevent the directional control valve device from becoming larger due to the provision of the second signal passage.

[0007] In the above-described directional control valve device, it is preferable that the second signal passage be branched off from the first signal passage and include a first throttle provided between a branching position of the first signal passage and a first spool valve, and a second throttle provided between the branching position of the second signal passage and the joining position.

[0008] The above-mentioned directional control valve device preferably includes a switching valve that is provided between the first orifice and the first spool valve in the first signal passage and switches when a predetermined pressure is generated, and a pressure sensor that is provided between the second orifice and the junction position in the second signal passage and detects and outputs a signal when a predetermined pressure is generated.

[0009] In the above-described directional control valve device, it is preferable that the plurality of spool valves are provided in respective valve blocks, and the joining position is formed on a mating surface between the valve blocks. In the above-described directional control valve device, it is preferable that the first signal passage and the second signal passage are provided on the same plane perpendicular to the axial direction of the spool valve. [Effects of the Invention]

[0010] According to the present invention, it is possible to prevent the directional control valve device from becoming large while providing two signal passages. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a hydraulic circuit diagram showing a configuration of a directional control valve device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of the directional control valve device of the embodiment. [Figure 3] FIG. 10 is a vertical cross-sectional view showing the configuration of a modified example of the directional control valve device. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Present embodiment) An embodiment of a directional control valve device will be described below with reference to Figures 1 and 2. The directional control valve device is a valve that controls the flow of hydraulic oil supplied from a pump to a hydraulic actuator and the flow of hydraulic oil discharged from the hydraulic actuator to a tank. For example, the hydraulic actuator is a hydraulic cylinder for operating an arm or boom of a construction machine. The hydraulic actuator may also be a hydraulic motor or the like.

[0013] (Directional switching valve device 1) 1, the directional control valve device 1 includes four hydraulic actuators 2 and four spool valves 3. The hydraulic actuators 2 are connected to the corresponding spool valves 3, respectively.

[0014] The spool valve 3 is supplied with pressure oil from the first pump 4 and controls the supply of pressure oil supplied from the first pump 4 to the hydraulic actuator 2. The spool valve 3 is supplied with pressure oil from the second pump 5 and the switching of the spool valve 3 is detected by the supplied pressure oil. The spool valve 3 controls the supply of pressure oil to the hydraulic actuator 2 by switching the position of the spool using control pressure output from an electromagnetic proportional valve (not shown). The pressure oil supplied to the spool valve 3 and the hydraulic actuator 2 is discharged to a tank 6.

[0015] The supply of pressure oil to the first hydraulic actuator 2A is controlled by a first spool valve 3A. The supply of pressure oil to the second hydraulic actuator 2B is controlled by a second spool valve 3B. The supply of pressure oil to the third hydraulic actuator 2C is controlled by a third spool valve 3C. The supply of pressure oil to the fourth hydraulic actuator 2D is controlled by a fourth spool valve 3D.

[0016] The directional control valve device 1 includes a first signal passage 11 and a second signal passage 12. Pressure oil is supplied to the first signal passage 11 and the second signal passage 12 from the second pump 5. The pressure oil supplied to the first signal passage 11 and the second signal passage 12 is discharged to the tank 6. The first signal passage 11 is connected in series to the four spool valves 3, and generates pressure when at least one of the four spool valves 3 is switched. In other words, when any of the four spool valves 3 is switched, the first signal passage 11 is blocked and pressure is generated.

[0017] The second signal passage 12 generates pressure when at least one of the third spool valve 3C and the fourth spool valve 3D is switched. The third spool valve 3C and the fourth spool valve 3D are the spool valves 3 whose switching status is to be detected among the multiple spool valves 3. The second signal passage 12 branches off from the first signal passage 11 upstream of the first spool valve 3A. The second signal passage 12 merges with the first signal passage 11 upstream of the third spool valve 3C. The second signal passage 12 merges with the first signal passage 11 downstream of the second spool valve 3B. The second signal passage 12 shares a passage downstream from the junction position 16 with the first signal passage 11, but the passage upstream from the junction position 16 is not connected to the first spool valve 3A or the second spool valve 3B. In other words, the second signal passage 12 is not blocked by the first spool valve 3A or the second spool valve 3B.

[0018] The directional control valve device 1 includes a first orifice 17 and a second orifice 18. The first orifice 17 is provided between the branching position 15 of the first signal passage 11 and the first spool valve 3A. The second orifice 18 is provided between the branching position 15 of the second signal passage 12 and the merging position 16.

[0019] The directional control valve device 1 includes a switching valve 13 and a pressure sensor 14. The switching valve 13 is provided between the first orifice 17 of the first signal passage 11 and the first spool valve 3A, and switches when a predetermined pressure is generated. The pressure sensor 14 is provided between the second orifice 18 of the second signal passage 12 and the confluence position 16, and detects the generation of the predetermined pressure and outputs a detection signal.

[0020] (Valve block 30) As shown in FIG. 2, each spool valve 3 is provided in a rectangular parallelepiped valve block 30. The spool valve 3 has a spool hole 31 and a spool 32. The spool hole 31 is provided in the valve block 30. The spool 32 slides within the spool hole 31. A first hydraulic chamber 33 is provided at the left end of the valve block 30. A first biasing spring 35 that biases the spool 32 is provided within the first hydraulic chamber 33. A second hydraulic chamber 34 is provided at the right end of the valve block 30. A second biasing spring 36 that biases the spool 32 is provided within the second hydraulic chamber 34. The spool 32 is driven rightward when pressure oil is supplied to the first hydraulic chamber 33, and driven leftward when pressure oil is supplied to the second hydraulic chamber 34.

[0021] The first spool valve 3A is provided in the first valve block 30A. The second spool valve 3B is provided in the second valve block 30B. The third spool valve 3C is provided in the third valve block 30C. The fourth spool valve 3D is provided in the fourth valve block 30D. The first valve block 30A, the second valve block 30B, the third valve block 30C, and the fourth valve block 30D are stacked.

[0022] The first signal passage 11 and the second signal passage 12 are provided at different positions in the axial direction of the spool valve 3. A junction position 16 is formed on the mating surface between the second valve block 30B and the third valve block 30C. The passage at the junction position 16 is a groove formed on the outer surface of at least one of the second valve block 30B and the third valve block 30C.

[0023] (Action of this embodiment) Next, detection by the first signal passage 11 and the second signal passage 12 during the operation of the directional control valve device 1 will be described with reference to FIG.

[0024] (When the first spool valve 3A is switched) When the first spool valve 3A switches, the first signal passage 11 is blocked. As a result, a predetermined pressure is generated in the first signal passage 11 upstream of the first spool valve 3A. Then, the switching valve 13 switches. The second signal passage 12 merges with the first signal passage 11 at a junction position 16 and is connected to the third spool valve 3C and the fourth spool valve 3D, which are located downstream of the first spool valve 3A. As a result, the predetermined pressure is not generated in the second signal passage 12 even when the first spool valve 3A switches.

[0025] (When the third spool valve 3C is switched) When the third spool valve 3C switches, the first signal passage 11 is blocked. As a result, a predetermined pressure is generated in the first signal passage 11 upstream of the third spool valve 3C. Then, the switching valve 13 switches. The second signal passage 12 merges with the first signal passage 11 at a junction position 16 and is connected to the third spool valve 3C and the fourth spool valve 3D. When the third spool valve 3C switches, the second signal passage 12 is blocked. As a result, a predetermined pressure is generated in the second signal passage 12 upstream of the third spool valve 3C.

[0026] (When the first spool valve 3A and the third spool valve 3C are switched) As a result of the first spool valve 3A switching, the first signal passage 11 is blocked. As a result, a predetermined pressure is generated upstream of the first spool valve 3A in the first signal passage 11. Then, the switching valve 13 switches. As a result of the third spool valve 3C switching, the second signal passage 12 is blocked. As a result, a predetermined pressure is generated upstream of the third spool valve 3C in the second signal passage 12. Then, the pressure sensor 14 outputs a detection signal.

[0027] Therefore, the first signal passage 11 can detect that any one of the first spool valve 3A, second spool valve 3B, third spool valve 3C, and fourth spool valve 3D has been switched, while the second signal passage 12 can detect that any one of the third spool valve 3C and fourth spool valve 3D has been switched.

[0028] (Effects of this embodiment) Next, the effects of this embodiment will be described. (1) The second signal passage 12 shares the passage downstream of the junction 16 with the first signal passage 11. Therefore, it is sufficient to provide only the first signal passage 11 downstream of the junction 16 with the first signal passage 11. Furthermore, the passage upstream of the junction 16 with the first signal passage 11 with the second signal passage 12 is not connected to the spool valve 3. Therefore, it is not necessary to provide the second signal passage 12 at the position where the spool valve 3 is provided. Therefore, it is possible to prevent the directional control valve device 1 from becoming larger due to the provision of the second signal passage 12.

[0029] (2) A first orifice 17 is provided downstream of the branching position 15 of the first signal passage 11, and a second orifice 18 is provided downstream of the branching position 15 of the second signal passage 12. Therefore, the pressures generated in the first signal passage 11 and the second signal passage 12 do not interfere with each other, and can be extracted separately.

[0030] (3) When a predetermined pressure is generated in the first signal passage 11, the switching valve 13 switches, and when a predetermined pressure is generated in the second signal passage 12, the pressure sensor 14 detects it and outputs a signal. Therefore, when any of the multiple spool valves 3 switches, switching is performed by the first signal passage 11, and when the spool valve 3 to be detected switches, a signal is output by the second signal passage 12.

[0031] (4) The confluence 16 of the first signal passage 11 and the second signal passage 12 is provided on the mating surface between the second valve block 30B and the third valve block 30C. This makes it easy to process the confluence 16.

[0032] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0033] In the above embodiment, the first signal passage 11 and the second signal passage 12 are provided on different surfaces in the axial direction of the spool valve 3. However, as shown in Fig. 3, the first signal passage 11 and the second signal passage 12 may be provided on the same surface perpendicular to the axial direction of the spool valve 3. In this way, the directional control valve device can be made smaller in size in the axial direction of the spool valve 3.

[0034] In the above embodiment, the confluence 16 of the first signal passage 11 and the second signal passage 12 is provided on the mating surface of the valve block 30. However, the confluence 16 of the first signal passage 11 and the second signal passage 12 may be provided inside the valve block 30.

[0035] In the above embodiment, the switching valve 13 switches when a predetermined pressure is generated in the first signal passage 11, and the pressure sensor 14 detects and outputs a signal when a predetermined pressure is generated in the second signal passage 12. However, the pressure sensor may detect and output a signal when a predetermined pressure is generated in the first signal passage 11. Also, the switching valve may switch when a predetermined pressure is generated in the second signal passage 12. Note that the switching valve 13 may switch when a predetermined pressure is generated in the first signal passage 11, and the switching valve may switch when a predetermined pressure is generated in the second signal passage 12. Also, the pressure sensor may detect and output a signal when a predetermined pressure is generated in the first signal passage 11, and the pressure sensor 14 may detect and output a signal when a predetermined pressure is generated in the second signal passage 12.

[0036] In the above embodiment, pressure oil is supplied to the first signal passage 11 and the second signal passage 12 from the second pump 5. However, the pump that supplies pressure oil to the first signal passage 11 and the pump that supplies pressure oil to the second signal passage 12 may be different.

[0037] In the above embodiment, the second signal passage 12 detects the switching of the third spool valve 3C and the fourth spool valve 3D. However, depending on the spool valve 3 whose switching is to be detected, the confluence position 16 may be provided upstream of the spool valve 3 whose switching is to be detected. When it is desired to detect the switching of only the fourth spool valve 3D, the confluence position 16 is provided upstream of the fourth spool valve 3D and downstream of the third spool valve 3C. When it is desired to detect the switching of the second spool valve 3B, the third spool valve 3C, and the fourth spool valve 3D, the confluence position 16 is provided upstream of the second spool valve 3B and downstream of the first spool valve 3A.

[0038] In the above embodiment, four spool valves 3 are provided in the directional control valve device 1. However, the number is not limited to four, and two, three, or five or more spool valves 3 may be provided in the directional control valve device. In this case, the spool valve 3 whose switching status is to be detected by the second signal passage 12 is provided downstream of the confluence position.

[0039] In the above embodiments, if an object is made up of multiple objects, the multiple objects may be integrated, and conversely, if an object is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the object of the invention can be achieved. [Explanation of symbols]

[0040] 1...Directional switching valve device 2...Hydraulic actuator 2A...First hydraulic actuator 2B...Second hydraulic actuator 2C...Third hydraulic actuator 2D...4th hydraulic actuator 3...Spool valve 3A...First spool valve 3B...Second spool valve 3C...Third spool valve 3D...4th spool valve 4...First pump 5...Second pump 6. Tank 11...First signal passage 12...Second signal passage 13...Switching valve 14...Pressure sensor 15...Branch position 16…merging position 17...First aperture 18...Second aperture 30...Valve block 30A...First valve block 30B...Second valve block 30C...Third valve block 30D...4th valve block 31...Spool hole 32...Spool 33...First hydraulic chamber 34...Second hydraulic chamber 35...First biasing spring 36...Second biasing spring

Claims

1. a plurality of spool valves; a first signal passage connected to the plurality of spool valves; a second signal passage that merges with the first signal passage upstream of a spool valve of the plurality of spool valves whose switching state is to be detected, shares a passage downstream from the merging position with the first signal passage, and has a passage upstream from the merging position that is not connected to the spool valve; Directional switching valve device.

2. the second signal path is branched from the first signal path, a first throttle provided between a branching position of the first signal passage and a first spool valve; a second throttle provided in the second signal passage between the branching position and the joining position. The directional control valve device according to claim 1 .

3. a switching valve provided in the first signal passage between the first throttle and the first spool valve, the switching valve being switched when a predetermined pressure is generated; a pressure sensor that is provided in the second signal passage between the second throttle and the joining position and that detects and outputs an output when a predetermined pressure is generated. The directional control valve device according to claim 2 .

4. The plurality of spool valves are each provided in a valve block, The joining position is formed on the mating surfaces of the valve blocks. The directional control valve device according to any one of claims 1 to 3.

5. The first signal passage and the second signal passage are provided on the same plane perpendicular to the axial direction of the spool valve. The directional control valve device according to claim 1 .

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