JPH0662203U - Directional control valve for series circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a series circuit directional control valve that can fully achieve the series circuit function and at the same time secure a sufficient unload passage area. [Structure] Auxiliary annular oil passages 52a and 52b are provided adjacent to the tank cores 32a and 32b.
a and 52b are the oil supply and drain passages 30a and 3 adjacent to the inside.
The unloading passages 50a, 50b are provided by providing branch passages 54a, 54b connected to 0b and outer peripheral grooves 56a, 56b provided on the spool 16 so as to connect the auxiliary annular oil passages 52a, 52b and the tank cores 32a, 32b.
Make up.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a directional control valve in a series circuit including, for example, a plurality of directional control valves.

[0002]

[Prior art]

 For example, as shown in FIG. 2, a directional control valve in a series circuit composed of two directional control valves, that is, an upstream side directional control valve 10 and a downstream side directional control valve 12, is shown in FIG. In this case, the upstream direction control valve 10 is shown), and the supply oil passages 18, 20a, 20b and 20c (here, the oil passages) of the pump 15 are provided to the switching spool 16 slidably arranged in the casing 14. 20c forms a bypass passage), and oil supply / discharge passages 30a, 30b communicating with supply / discharge ports 28a, 28b connected to the actuator 36, tank cores 32a, 32b, and supply of the downstream side direction control valve 12. It is configured by providing oil passages 34a, 34b and connection passages 26a, 26b for communicating the tank cores 32a, 32b with the oil supply / discharge passages 30a, 30b. . Note that, in FIG. 2, the downstream side directional control valve 12 that drives the actuator 38 is also configured in the same manner as the upstream side directional control valve 10 shown in FIG.

In the directional control valve having such a configuration, when the spool 16 moves, for example, in the direction of the arrow (right side) shown, the supply oil passage 20a is opened. On the other hand, while the other supply oil passages 20b and 20c and the connection passages 26a and 26b are closed, the hydraulic pressure (pressure oil) from the pump 15 is changed from the supply oil passage 20a to the supply / discharge oil passage 30a and the supply / discharge port. After driving the actuator 36 through the port 28a, it is further returned to the supply / discharge port 28b and the supply / discharge oil passage 30b.

However, at this time, in this return oil, since the supply / discharge oil passage 30b and the supply oil passage 34b communicate with each other by the movement of the spool 16, the return oil passes through the supply oil passage 34b and is controlled in the downstream direction. It is supplied to the valve 12. That is, the series circuit function of the bidirectional control valves 10 and 12 is achieved.

[0005]

[Problems to be solved by the device]

 However, the directional control valve for series circuits described above (hereinafter simply referred to as directional control valve) has the following drawbacks.

That is, in the upstream side directional control valve 10, when the actuator 36 is not operated, the spool 16 is moved to the neutral position (the position shown in the drawing), the bypass oil passage 20c is opened, and the supply oil passages 20a and 20b are opened. By closing, the hydraulic pressure (pressure oil) from the pump 15 is supplied to the downstream side direction control valve 12 via the bypass oil passage 20c and the supply oil passages 34a, 34b. Then, in this case, the supply / discharge ports 28a, 28b connected to the actuator 36 communicate with the tank cores 32a, 32b via the connection passages 26a, 26b to unload the actuator 36.

However, in the passages for unloading the actuator 36, that is, the connection passages 26a, 26b, the communication of these passages is determined by the supply / discharge ports 28a, 28b and the supply oil passages 20a, 20b and the supply oil passages 34a, 34b. It is configured with a small-diameter drilled hole provided inside the casing 14 and the spool 16 so that it can be reliably unloaded even if it is disconnected before being connected to. Therefore, in the conventional directional control valve, it was not only difficult to secure the unload passage area, but also the workability was poor. Further, accessory valves such as relief or anti-cavitation are usually arranged around the connection passages 26a, 26b and the tank cores 32a, 32b, but the passages are complicatedly crossed as described above. Therefore, the processing position of the new additional passage is restricted, and the mounting of the valve is also restricted.

Therefore, an object of the present invention is to provide a series circuit direction in which an unload passage area can be sufficiently secured, this can be easily processed, and an accessory valve or the like can be easily mounted. To provide a control valve.

[0009]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the series circuit directional control valve according to the present invention is provided with a supply oil passage for a downstream side directional control valve on both sides of a central bypass passage with respect to a switching spool, and supplies the oil on both sides thereof. An oil supply / drain passage connected to the drain port is further provided, auxiliary annular oil passages connected to the oil supply / drain passage are provided on both sides of the oil supply port, and tank cores are provided on both sides of the auxiliary annular oil passage. It is characterized in that they communicate with each other via an annular oil passage and an outer peripheral groove provided on the spool.

[0010]

[Action]

 The unload passage, that is, the passage between the supply / discharge port and the tank core, communicates via an auxiliary annular oil passage that cooperates with the tank core. Therefore, the structure of the unload passage is simple and enlarged, and as a result, the unload passage has a sufficient passage area and can be easily processed. Also, it is possible to easily attach accessory valves and the like.

[0011]

【Example】

 Next, an embodiment of a directional control valve for a series circuit according to the present invention will be described in detail below with reference to the accompanying drawings. For convenience of explanation, the same components as those of the conventional structure shown in FIGS. 2 and 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, the upstream side directional control valve 48 of the present invention is basically the same as the conventional one shown in FIG. That is, the directional control valve 48 is basically arranged on both sides of the central bypass passage 20c with respect to the switching spool 16 slidably arranged in the casing 14 (see FIG. 2). In FIG. 3, supply oil passages 34a, 34b of the directional control valve corresponding to the reference numeral 12 are provided, and supply / discharge oil passages 30a, 30b connected to supply / discharge ports 28a, 28b for connecting to the actuator 36 are provided on both sides thereof. Is provided, auxiliary annular oil passages 52a and 52b connected to the oil supply and discharge passages 30a and 30b are provided on both sides thereof, and tank cores 32a and 32b are provided on both sides thereof.

However, in the present invention, the auxiliary annular oil passages 52a and 52b described above include the branch passages 54a and 54b connected to the supply / discharge oil passages 30a and 30b adjacent to the insides thereof, and the tank core 32a adjacent to the outside thereof. , 32b are provided side by side with outer circumferential grooves 56a, 56b provided on the spool 16 to form unload passages 50a, 50b.

In the present invention, it is needless to say that the downstream directional control valve 49 for driving the actuator 38 in FIG. 2 has the same configuration as the upstream directional control valve 48 shown in FIG.

In the present invention, the above-mentioned respective oil passages or passages are connected or closed by a shoulder portion or a notch provided on the spool 16 as will be apparent from the explanation of the operation described below. Is configured.

Therefore, the operation of the present invention having such a configuration will be described. However, as described above, the present invention ensures a sufficient unload passage area at the time of neutrality of the spool (reliable unload function is ensured). It will be achieved), so this will be explained first below. It is needless to say that the basic operation is the same as that of the conventional example described above.

When the spool 16 is in the neutral position (the position shown in the drawing), the bypass oil passage 20c is opened as in the conventional example described above. On the other hand, since the supply oil passages 20a and 20b are closed, the hydraulic pressure (pressure oil) from the pump 15 is passed through the bypass oil passage 20c and the supply oil passages 34a and 34b to the downstream direction control valve 49. Supplied. At this time, when the spool of the downstream side direction control valve 49 is also in the neutral state, the pressure oil flows out to the tank through the same route as in the downstream side direction control valve 49.

On the other hand, the supply / discharge ports 28a, 28b connected to the actuator 36 are closed (blocked) as described above with respect to the supply / discharge oil passages 30a, 30b. By way of auxiliary annular oil passages 52a, 52b communicating with the passages 30a, 30b, they are communicated with the tank cores 32a, 32b in a bypass manner. Moreover, the communicating portion (unloading passage) is constituted by wide outer peripheral grooves 56a and 56b. Therefore, in this case, even if the communication of the unload passage is disconnected before the connection between the supply / discharge ports 28a, 28b and the supply oil passages 20a, 20b and the supply oil passages 34a, 34b, it is ensured. Can be unloaded.

As described above, according to the present invention, the unloading is surely achieved. Moreover, the workability of this unloading passage is also greatly improved compared to the conventional crossed and complicated drilled hole structure. Moreover, since the structure around the unloading passage can be enlarged in this way, it is possible to easily install the necessary accessory valves and the like.

Next, when the spool 16 is moved, for example, in the direction of the arrow (right side) shown in the figure, it is the same as the above-mentioned conventional example, but more detailed description will be made. The passage of 20c is gradually closed by the shoulder 58 and notch 60 of the spool 16.

On the other hand, the supply oil passage 20a is gradually opened by the notch 62, whereby the hydraulic pressure (pressure oil) from the pump 15 flows from the supply oil passage 20a to the supply / discharge oil passage 30a and the supply / discharge port 28a. And is supplied to the actuator 36. At this time, since the passage between the auxiliary annular oil passage 52a and the tank core 32a is closed by the shoulder 64 before the notch 62 is connected to the supply oil passage 20a, the pressure oil from the pump 15 is stored in the tank. It will not leak to 22. Then, the return oil from the actuator 36 passes through the supply / discharge port 28b, the supply / discharge oil passage 30b, and the notch 66, and is supplied from the supply oil passage 34b to the downstream direction control valve 49. At this time, when the spool of the downstream side direction control valve 49 is in the neutral state, the pressure oil flows out to the tank through a predetermined path of the downstream side direction control valve 49.

In this way, since the return oil from the supply / discharge port 28b is closed at this time by the shoulder portion 68 between the auxiliary annular oil passage 52b and the tank core 32b, the entire amount of the return oil is controlled in the downstream direction. The oil is supplied to the oil supply passage 34b of the valve 49. That is, the series circuit function of the bidirectional control valve is completely achieved.

Next, when the spool 16 moves in the opposite direction (leftward in the figure) to the above, the hydraulic pressure (pressure oil) from the pump 15 is in the opposite direction to the above, that is, the supply oil. The oil is supplied from the passage 20b to the actuator 36 through the oil supply / drain passage 30b and the oil supply / discharge port 28b. Then, the return oil is supplied from the supply / discharge port 28a through the supply / discharge oil passage 30a and the supply oil passage 34a to the downstream side directional control valve 49, the operation of which is easily inferred from the above-mentioned operation. is there.

As described above, according to the present invention, the series circuit function can be completely achieved, and at the same time, the unload function can be sufficiently ensured. Furthermore, the workability of the unload passage is improved, and the accessory valves required around the unload passage can be easily installed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and many improvements and modifications can be made without departing from the spirit thereof. For example, depending on the type of actuator, the unloading function may be provided only for one of the supply and discharge ports, and the unloading passage area may also be composed of a drill hole or the like of a necessary and sufficient size. May be.

[0026]

[Effect of device]

 As described above, the series circuit directional control valve according to the present invention is provided with the supply oil passages of the downstream side directional control valve on both sides of the central bypass passage with respect to the switching spool, and the supply / discharge ports on both sides thereof. By providing an auxiliary annular oil passage that is connected to the tank, and tank cores on both sides of the auxiliary annular oil passage, the auxiliary annular oil passage and the tank core are configured to communicate with each other via an outer peripheral groove provided on the spool. It is possible to secure a sufficient passage area of the passage (unload passage) between the passage and the tank core.

Therefore, according to the present invention, it is possible to fully achieve the series circuit function and at the same time sufficiently secure the unload function. Further, since the unload passage is constructed in a simple and enlarged structure, workability is improved, and at the same time, an advantage that the necessary accessory valves can be easily attached to the periphery thereof can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a directional control valve for series circuits according to the present invention.

FIG. 2 is a circuit diagram showing a configuration of a series circuit.

FIG. 3 is a cross-sectional view showing a conventional series circuit directional control valve.

[Explanation of symbols]

 14 casing 15 pump 16 spool 18 supply oil passage 20a, 20b supply oil passage 20c bypass passage (supply oil passage) 22 tank 28a, 28b supply / discharge port 30a, 30b supply / discharge oil passage 32a, 32b tank core 34a, 34b supply oil passage 36 Actuator 48 Upstream side directional control valve 49 Downstream side directional control valve 50a, 50b Unload passage 52a, 52b Auxiliary annular oil passage 54a, 54b Branch passage 56a, 56b Outer peripheral groove 58, 64, 68 Shoulder portion 60, 62, 66 Notch

Claims (1)

[Scope of utility model registration request] 1. A supply oil passage for a downstream side directional control valve is provided on both sides of a central bypass passage with respect to a switching spool, and a supply / exhaust oil passage connected to a supply / discharge port is provided on both sides of the supply oil passage. An auxiliary annular oil passage connected to the oil discharge passage is provided, and tank cores are provided on both sides of the auxiliary annular oil passage so that the supply and discharge oil passage and the tank core are communicated with each other through the auxiliary annular oil passage and the outer peripheral groove provided on the spool. A directional control valve for series circuits characterized by being configured.