JP2004076792A - Valve device having regenerative function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device having a regenerative function, which valve device can achieve a required regenerative operation and a required regeneration releasing operation. <P>SOLUTION: The valve device is provided on a hydraulic shovel and has a directional control valve 1 for controlling the drive of an arm cylinder 6, and a regenerative valve 30 which can supply the return oil from the arm cylinder 6 to the arm cylinder 6 via the directional control valve 1 by regenerating the oil returned from the arm cylinder 6. A spool 32 of this regenerative valve 30 is set so as to have a stepped shape including a large diameter part 32a and a small diameter part 32b continued to the large diameter part 32a. In addition, a control chamber, that is a first oil camber 35, into which a control pressure for sliding the spool 32 against the energizing force of a spring 37 for energizing the spool 32 of this regenerative valve 30, for example, the load pressure of a bottom side chamber 6a of the arm cylinder 6 is introduced, is provided in the neighborhood of the small diameter part 32b, for example, so as to face the outer peripheral surface of the small diameter part 32b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a valve device having a regeneration function provided in a work machine such as a hydraulic shovel or the like, which includes a direction switching valve for controlling driving of a hydraulic actuator and a regeneration valve capable of supplying return oil to the hydraulic actuator.
[0002]
[Prior art]
As this kind of conventional technology, for example, there is a valve device described in Japanese Patent Application Laid-Open No. 8-35502. This prior art regenerates return oil from a rod-side chamber of a hydraulic cylinder as pressure-increasing oil inside a directional switching valve that performs drive control of a hydraulic cylinder, and a regeneration valve that can supply the oil to a bottom-side chamber of the hydraulic cylinder. It is provided with.
[0003]
The regeneration valve includes a slidable spool, a piston that abuts on an end of the spool, a spring that biases the piston in the above-described spool direction, a support device that movably supports the piston, and the like. I have.
[0004]
When the load pressure of the bottom side chamber of the hydraulic cylinder is lower than the predetermined pressure and the piston is urged toward the spool side of the regeneration valve by the above-mentioned spring force, the return oil from the rod side chamber of the hydraulic cylinder is regenerated. The pressure oil of the main hydraulic pump supplied from the direction switching valve to the bottom chamber of the hydraulic cylinder is supplied to the bottom chamber of the hydraulic cylinder via the regeneration valve. That is, a reproducing operation is performed. As a result, the speed is increased when the rod of the hydraulic cylinder is extended.
[0005]
Also, when the load pressure of the bottom chamber of the hydraulic cylinder becomes higher than a predetermined pressure, the piston moves against the force of the above-described spring, and the spool of the regeneration valve follows the piston and slides toward the piston. The regeneration valve is in the regeneration release mode, and part or all of the return oil from the rod side chamber of the hydraulic cylinder is discharged to the tank via the regeneration valve, and the above-described regeneration operation is partially released or completely released. .
[0006]
Here, for example, when the above-mentioned hydraulic cylinder is an arm cylinder provided in a hydraulic shovel, and an arm cloud for rotating the arm downward is performed, a bucket abutting on the tip of the arm is in the air. In order to move the arm quickly, the above-described reproducing operation is performed. At this time, the load pressure in the bottom chamber of the arm cylinder is relatively low. When the bucket hits hard rock or the like in the middle of the arm cloud and the load pressure in the bottom chamber of the arm cylinder instantaneously increases, the above-described regeneration canceling operation is performed, and the speed of the arm is reduced. By such a reproducing operation and a reproduction canceling operation, work efficiency is improved and damage to the front working machine such as a boom and an arm, or various parts and the like due to a large shock is realized.
[0007]
It should be noted that another known technique of this type is disclosed in, for example, Japanese Patent Publication No. 4-57881. In this prior art, the regeneration valve also includes a piston similar to that described above.
[0008]
[Problems to be solved by the invention]
In each of the above-described prior arts, the regeneration valve includes small parts such as a piston, a spring for biasing the piston, and a supporting device for movably supporting the piston, and there are problems associated with these small parts. . That is,
(1) These small parts complicate the structure and increase the number of parts, which tends to increase the manufacturing cost.
[0009]
(2) In addition, since these small parts are incorporated in a very narrow space, the assembling work is complicated, and the number of manufacturing steps is increased. This also tends to increase production costs.
[0010]
(3) Further, when these small parts are erroneously dropped into the directional control valve when these small parts are incorporated into the directional control valve, and are left as they are even after manufacturing, the spool of the regeneration valve, Alternatively, there is a concern that the above-mentioned dropped parts may be caught when the sliding member such as the spool of the direction switching valve slides. In such a case, operation failure of the valve device occurs.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described state of the art, and an object of the present invention is to provide a valve device with a regeneration function capable of realizing desired regeneration and regeneration release operations without providing a piston in a regeneration valve. .
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a directional control valve provided in a work machine, which controls driving of a hydraulic actuator, and regenerates return oil from the hydraulic actuator through the directional control valve to reduce the hydraulic pressure. In a valve device with a regeneration function provided with a regeneration valve that can be supplied to an actuator, a spool of the regeneration valve is set to a stepped shape including a large diameter portion and a small diameter portion connected to the large diameter portion. A control chamber is provided near the small-diameter portion, into which a control pressure for sliding the spool of the regeneration valve against the force of a spring for urging the spool is introduced.
[0013]
The present invention thus configured enables the spool of the regeneration valve to perform a regeneration operation when the force due to the control pressure guided to the control chamber provided near the small diameter portion of the regeneration valve spool is smaller than the force of the spring. It is kept in the playback mode. As a result, return oil from the hydraulic actuator is supplied to the hydraulic actuator as the speed increasing pressure oil via the direction switching valve. Further, when the force due to the control pressure guided to the control chamber becomes larger than the force of the spring, the spool of the regeneration valve slides so as to be in a regeneration canceling mode that allows the regeneration to be canceled. As a result, part or all of the return oil from the hydraulic actuator is not supplied to the hydraulic actuator, and the speed of the hydraulic actuator becomes lower than before.
[0014]
According to the present invention, the sliding of the spool of the regeneration valve can be realized without the intervention of the piston.
[0015]
The present invention is also characterized in that, in the above invention, the control chamber comprises an oil chamber formed so as to face the outer peripheral surface of the small diameter portion of the spool of the regeneration valve.
[0016]
In the present invention configured as described above, at the time of regeneration release, the control pressure is guided to the oil chamber formed so as to face the outer peripheral surface of the small diameter portion of the regeneration valve spool. Slide to be.
[0017]
Further, the present invention is characterized in that, in the above invention, the control chamber comprises an oil chamber formed so as to face an end surface of the small diameter portion of the spool of the regeneration valve.
[0018]
In the present invention thus configured, at the time of release of the regeneration, the control pressure is guided to the oil chamber formed so as to face the end surface of the spool of the regeneration valve, and thereby the spool of the regeneration valve is brought into the regeneration release mode. Move.
[0019]
Further, the present invention is characterized in that, in the above invention, a passage for guiding the load pressure of the bottom side chamber of the hydraulic actuator to the control chamber is provided.
[0020]
In the present invention thus configured, when the force due to the load pressure of the bottom chamber of the hydraulic actuator guided to the control chamber via the passage is smaller than the force of the spring, the spool of the regeneration valve is held in the regeneration mode. Further, when the force due to the load pressure of the bottom chamber of the hydraulic actuator guided to the control chamber becomes larger than the force of the spring, the spool of the regeneration valve slides so as to be in the regeneration release mode.
[0021]
Further, the present invention is characterized in that, in the above invention, a passage for guiding return oil from the hydraulic actuator is provided in a spool of the directional control valve.
[0022]
According to the present invention configured as described above, when the spool of the regeneration valve is held in the regeneration mode, the return oil from the hydraulic actuator passes through the passage provided in the spool of the directional control valve, and is used as hydraulic oil for speed increase. Supplied to the actuator.
[0023]
Further, the present invention is characterized in that, in the above invention, the regeneration valve is provided outside the direction switching valve.
[0024]
The present invention configured as described above can suppress the complexity of the structure of the directional control valve.
[0025]
The present invention is also characterized in that, in the above invention, the work machine comprises a hydraulic shovel.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a valve device with a regeneration function according to the present invention will be described with reference to the drawings.
[0027]
FIG. 1 is a sectional view showing a first embodiment of a valve device with a regeneration function of the present invention, and FIG. 2 is an enlarged view of a regeneration valve portion of FIG.
[0028]
As shown in FIGS. 1 and 2, the first embodiment of the present invention is provided in a work machine, for example, a hydraulic shovel, and includes a directional control valve 1 for controlling the driving of a hydraulic actuator, for example, an arm cylinder 6. And a regeneration valve 30 capable of regenerating the return oil from the arm cylinder 6 via the switching valve 1 and supplying the oil to the arm cylinder 6 again.
[0029]
As shown in FIG. 1, the direction switching valve 1 has a direction switching valve spool 3 slidable in a casing 2. The directional control valve spool 3 slides leftward in FIG. 1 by the pilot pressure applied to the pilot port 4, and slides rightward in FIG. 1 by the pilot pressure applied to the pilot port 5. When the pilot pressure is no longer guided to the pilot ports 4 and 5, the spring returns to the neutral position by the force of the spring 24.
[0030]
A cylinder port 8 connected to the bottom chamber 6a of the arm cylinder 6 via the main pipe 7 and a rod port 6b of the arm cylinder 6 connected via the main pipe 9 inside the casing 2 of the direction switching valve 1. And a cylinder port 10.
[0031]
Further, there are bridge passages 11 and 16 for guiding the pressure oil from a main hydraulic pump 25 that supplies the pressure oil for driving the arm cylinder 6. Check valves 13 and 17 are arranged in these bridge passages 11 and 16, respectively.
[0032]
When the directional control valve spool 3 slides leftward in FIG. 1, the directional control valve spool 3 allows communication between the bridge passage 11 of the casing 2 and the passage 14 communicating with the cylinder port 8. A notch 18 is provided. A notch 18a is provided to allow the bridge passage 16 of the casing 2 to communicate with the passage 14a communicating with the cylinder port 10 when the directional control valve spool 3 slides rightward in FIG. .
[0033]
Further, the directional control valve spool 3 has a hole 20 opened on the outer peripheral surface and communicating with the passage 15 of the casing 2. The hole 20 communicates with the hole 20 and extends along the axis of the directional control valve spool 3. A passage 21 capable of guiding return oil from the rod side chamber 6b of the arm cylinder 6, a check valve 22 provided in the passage 21, a passage 21 and a bridge passage 11 when the check valve 22 is operated. And a hole 23 for communicating the same. In addition, a notch 19 is provided to enable communication between the passage 14a and the passage 15 of the casing 2 when the direction switching valve spool 3 slides leftward in FIG.
[0034]
The regeneration valve 30 is provided, for example, outside the direction switching valve 1. That is, the casing 31 of the regeneration valve 30 is provided so as to be connected to the casing 2 of the direction switching valve 1.
[0035]
The casing 31 of the regeneration valve 30 is provided with a passage 34 that communicates with the bridge passage 16 of the casing 2 of the direction switching valve 1 in addition to the passage 15 described above.
[0036]
As shown in FIG. 2, the regeneration valve 30 has a regeneration valve spool 32 set in a stepped shape including a large-diameter portion 32a and a small-diameter portion 32b connected to the large-diameter portion 32a. A step portion 32c is formed at a connection portion between the large diameter portion 32a and the small diameter portion 32b.
[0037]
The regeneration valve spool 32 is urged leftward in FIG. 2 by a spring 37 housed in a spring chamber 36. The spring chamber 36 communicates with the tank 12 via a drain circuit 44.
[0038]
In the casing 31 near the small diameter portion 32b of the regeneration valve spool 32, a control chamber communicating with the above-described passage 34, that is, a first oil chamber 35 is provided so as to face, for example, the outer peripheral surface of the small diameter portion 32b. is there. A second oil chamber 39 is provided near the end of the small diameter portion 32b.
[0039]
When the force by the control pressure guided to the first oil chamber 35 described above becomes larger than the combined force of the force by the spring 37 and the force by the resistance applying means described later, the regeneration valve spool 32 moves to the right in FIG. To slide. As the control pressure at this time, for example, the load pressure of the bottom chamber 6a of the arm cylinder 6 (strictly, the pressure of the bridge passage 16) is used.
[0040]
Further, the regeneration valve spool 32 is provided with a passage 40 extending along the axis thereof and communicating the second oil chamber 39 and the spring chamber 36. The passage 40 communicates with the spring chamber 36 and communicates with a conduit 40 a formed in the casing 31. The conduit 40 b extends perpendicularly to the sliding direction of the regeneration valve spool 32, and communicates with the conduit 40 b. The configuration includes a pipe 40c provided in the sliding direction of the valve spool 32, and a pipe 40d communicating with the pipe 40c and the second oil chamber 39 and provided perpendicularly to the regeneration valve spool 32.
[0041]
The regeneration valve spool 32 has a notch 38 that allows the passage 15 to communicate with the discharge passage 33 provided in the casing 31 when the regeneration valve spool 32 slides rightward in FIG. Is provided.
[0042]
Further, in the first embodiment, the above-described resistance applying means for giving resistance when the regeneration valve spool 32 slides, for example, the seal member 41 is provided with a small diameter located between the first oil chamber 35 and the second oil chamber 39. At least one of the outer peripheral surface of the portion 32b and the inner peripheral surface of the casing 31 facing the outer peripheral surface, for example, is mounted on the outer peripheral surface of the small diameter portion 32b.
[0043]
The operation of the first embodiment thus configured is as follows.
[0044]
[Complete playback]
When the arm cloud is performed by extending the rod of the arm cylinder 6, when an operating device (not shown) of the arm cylinder 6 is operated, a pilot pressure is applied to the pilot port 4 shown in FIG. Thereby, the directional control valve spool 3 slides to the left in FIG. 1, the bridge passage 11 and the passage 14 communicate with each other through the notch 18, and the passage 14 a and the passage 15 communicate with each other through the notch 19. Communicate.
[0045]
Thereby, the pressure oil of the main hydraulic pump 25 is guided to the main pipeline 7 via the check valve 13, the bridge passage 11, the notch 18, the passage 14, and the cylinder port 8, and is supplied to the bottom chamber 6 a of the arm cylinder 6. . At this time, the pressure oil of the main hydraulic pump 25 described above is guided to the first oil chamber 35 of the regeneration valve 30 via the check valve 17, the bridge passage 16, and the passage 34.
[0046]
Assuming that the pressure of the pressure oil guided to the first oil chamber 35, that is, the control pressure which is the pressure of the bridge passage 16 is lower than a predetermined pressure, the spring force is smaller than the force due to the pressure applied to the first oil chamber 35. The force obtained by combining the force of 37 and the frictional force of the sealing material 41 becomes larger, and the regeneration valve spool 32 is held in the state shown in FIGS. At this time, the notch 38 and the discharge passage 33 shown in FIG. 2 are, for example, in a disconnected state.
[0047]
The return oil from the rod side chamber 6b of the arm cylinder 6 is guided from the main pipe line 9 to the cylinder port 10, and further passes through the passage 14a, the notch 19 of the direction switching valve spool 3, and the passage 15 to cut the regeneration valve spool 32. The notch is given to 38 parts. As described above, since the notch 38 and the discharge passage 33 are now shut off, the return oil guided to the passage 15 is checked via the hole 20 and the passage 21 of the directional control valve spool 3. The valve 22 is pushed open and guided into the bridge passage 11 via the hole 23.
[0048]
That is, the return oil from the rod-side chamber 6b of the arm cylinder 6 is regenerated as speed-increasing pressure oil and joins the pressure oil supplied from the main hydraulic pump 25. The combined pressure oil is supplied to the bottom chamber 6a of the arm cylinder 6 as described above. Therefore, the speed of the arm cylinder 6 is increased, and an arm cloud of a relatively fast operation is performed.
[0049]
[Release complete release]
For some reason, the pressure in the bridge passage 16 becomes higher than a predetermined pressure and becomes sufficiently high, and the force due to the control pressure applied to the first oil chamber 35 of the regeneration valve 30 via the bridge passage 16 and the passage 34 is reduced by the force of the spring 37. And the frictional force of the sealing material 41, the regeneration valve spool 32 slides rightward in FIGS. Thereby, the passage 15 and the discharge passage 33 communicate with each other through the notch 38 that forms a large opening of the regeneration valve spool 32 shown in FIGS.
[0050]
When the regeneration valve spool 32 is slid at this time, oil in the spring chamber 36 is guided to the tank 12 via the drain circuit 44, and is also passed through the passage 40 of the regeneration valve spool 32, that is, the pipes 40a and 40b. , 40c, 40d, the oil in the spring chamber 36 is guided to the second oil chamber 39.
[0051]
As described above, the communication between the passage 15 and the discharge passage 33 through the notch 38 of the regeneration valve spool 32 allows return oil from the rod side chamber 6b of the arm cylinder 6 to flow through the main pipeline 9, the cylinder port 10, The fluid is returned to the tank 12 through the passage 14a, the notch 19 of the direction switching valve spool 3, the passage 15, the notch 38 of the regeneration valve spool 32, and the discharge passage 33. Therefore, for example, the return oil described above is not guided to the passage 21 side of the direction switching valve spool 3, and the regeneration is completely released. As a result, the operating speed of the arm cylinder 6 becomes lower than before.
[0052]
[Partial playback]
Although the control pressure applied to the first oil chamber 35 of the regeneration valve spool 32 is equal to or higher than a predetermined pressure, it is not relatively high. Therefore, the opening when the notch 38 of the regeneration valve spool 32 opens to the discharge passage 32 is opened. When the amount is small, a part of the return oil guided to the passage 15 is regenerated as the pressure increasing oil via the passage 21 of the direction switching valve spool 3 and the check valve 22. The remaining return oil is returned to the tank 12 through the notch 38 of the regeneration valve spool 32 and the discharge passage 33.
[0053]
Therefore, in this case, although the operating speed of the arm cylinder 6 is slower than that in the above-described complete regeneration, a part of the return oil from the arm cylinder 6 is regenerated, thereby increasing the speed of the arm cloud. it can. That is, at the time of increasing the speed of the arm cloud, it is possible to control the operating speed to change according to the magnitude of the pressure in the bridge passage 16.
[0054]
[From complete playback to playback]
Further, from the state in which the regeneration is completely released as described above, the pressure in the bridge passage 16 becomes lower than the predetermined pressure, and the combined force of the force of the spring 37 and the frictional force of the sealing material 41 increases. The regeneration valve spool 32, which has slid rightward, now slides leftward. As a result, the opening amount of the notch 38 of the regeneration valve spool 32 with respect to the discharge passage 33 is reduced, and the process shifts to the partial regeneration described above. Alternatively, the notch 38 and the discharge passage 33 are shut off, and the process shifts to the complete regeneration described above.
[0055]
When the regeneration valve spool 32 slides at this time, the oil in the second oil chamber 39 is returned to the tank 12 via the passage 40, the spring chamber 36, and the drain circuit 44.
[0056]
[Operation of Regeneration Valve Spool 32 Related to Seal Material 41]
FIG. 3 is a diagram showing a comparison between the operating characteristics of the regeneration valve 30 shown in FIG. 2 having the sealing material 41 and the operating characteristics of the regeneration valve 30 not having the sealing material 41. FIG. 16A and 16B show a sliding start point and a sliding end point of the regenerative valve spool 32 in accordance with a change in the pressure of 16; FIG. 12B shows a sliding start point and a sliding end point of the regenerative valve spool 32 shown in FIG. (C) is a diagram showing the displacement of the regeneration valve spool 32 with respect to the passage of time, and FIG. (A) shows the relationship between the change in the pressure of the bridge passage 16 and the displacement of the regeneration valve spool 32 shown in FIG. FIG.
[0057]
If the seal member 41 is not provided, the pressure P of the bridge passage 16 is set by the spring 37 when the regeneration is released, as shown at the regeneration releasing / sliding start point F1 in FIG. At a relatively low P1 corresponding to the force, the regenerative valve spool 32 shown in FIG. 2 starts sliding to the right in FIG. When the pressure P in the bridge passage 16 increases to P2, the regeneration valve spool 32 ends sliding rightward in FIG. 2 as indicated by a regeneration release / sliding end point F2.
[0058]
At, for example, an intermediate position between the reproduction release / sliding start point F1 and the reproduction release / sliding end point F2, the above-described partial release of the reproduction, that is, the partial reproduction is performed, and the reproduction release / sliding end point. When near F2, complete reproduction is released.
[0059]
Further, at the time of regeneration, when the pressure P in the bridge passage 16 is P2 as described above, the regeneration valve spool 32 shown in FIG. 2 starts sliding leftward as shown at the regeneration / slide start point F3. . When the pressure P in the bridge passage 16 decreases to P1, the sliding of the regeneration valve spool 32 in the left direction ends as indicated by the regeneration / slide end point F4.
[0060]
At this time, at the intermediate position between the reproduction / sliding start point F3 and the reproduction / sliding end point F4, for example, the above-described partial reproduction is performed. Move to playback.
[0061]
The displacement x of the regeneration valve spool 32 in the sliding operation described above is indicated by a broken line in FIG. 3B.
[0062]
The displacement x of the regeneration valve spool 32 with respect to the change in the pressure P in the bridge passage 16 is indicated by the broken line in FIG. 3C.
[0063]
As shown by the dashed line in FIG. 3C, when the seal member 41 is not provided, the displacement x of the regeneration valve spool 41 fluctuates according to the change in the pressure P in the bridge passage 16. That is, the displacement x of the regeneration valve spool 32 depends only on the force of the spring 37, and it is difficult to obtain dynamic stability of the regeneration valve spool 41 with respect to a change in the pressure P of the bridge passage 16. In the arm cloud operation, a slight change in the pressure P in the bridge passage 16 can frequently occur. Therefore, even if the pressure P in the bridge passage 16 slightly changes, the regenerative valve spool 41 always moves, and the operating speed of the arm cylinder 6 is liable to fluctuate unexpectedly.
[0064]
In the first embodiment of the present invention, the provision of the seal material 41 prevents the regeneration valve spool 41 from being displaced by a slight change in the pressure P in the bridge passage 16, thereby providing the bottom side chamber at the time of arm clouding. The operation speed of the arm cylinder 6 can be stably maintained with respect to a minute change in the load pressure of the arm 6a. That is, the dynamic stability of the regeneration valve spool 41 with respect to the change in the pressure P of the bridge passage 16 can be ensured.
[0065]
As shown in FIG. 2, in the first embodiment having the seal material 41, the seal material 41 becomes a resistance when the regeneration valve spool 32 slides. As shown in the figure, when the pressure P in the bridge passage 16 is P3 higher than P1, the regeneration release / sliding start point F5 is formed, and when the pressure P is higher than P2, the regeneration release / slide end point F6 is formed. Is done.
[0066]
During regeneration, a regeneration / sliding start point F7 is formed when the pressure P of the bridge passage 16 is P5 lower than P2, and a regeneration / slide end point F8 is formed when the pressure P is lower than P1. You.
[0067]
At this time, the displacement x of the regeneration valve spool 32 in the first embodiment is shown by a solid line in FIG. 3B. That is, the regeneration valve spool 32 slides with a delay of time t1, t2 in both the regeneration and the regeneration release, as compared with the case where the sealing material 41 is not provided.
[0068]
As a result, the displacement x of the regeneration valve spool 32 with respect to the change in the pressure P of the bridge passage 16 is as shown by the solid line in FIG. 3C.
[0069]
As shown in FIG. 3C, the pressure P4 of the bridge passage 16 at which the regeneration is completely released and the pressure P5 of the bridge passage 16 at the time when the regeneration is started after the regeneration is completely released. In between, there can be a pressure zone PS forming a dead zone. Therefore, as long as the load pressure of the bottom chamber 6a of the arm cylinder 6 fluctuates between P4 and P5, the load pressure of the bottom chamber 6a of the arm cylinder 6 fluctuates between P6 and P3. As far as the regeneration valve spool 32 does not slide, dynamic stability of the regeneration valve spool 32 can be realized. That is, it is possible to stably maintain the operating speed of the arm cylinder 6 with respect to the minute fluctuation of the pressure P in the bridge passage 16.
[0070]
In the first embodiment configured as described above, the regenerative valve 30 does not require small parts such as a piston, a spring for biasing the piston, and a piston support device. Desired reproduction and reproduction release can be realized in accordance with the magnitude of the control pressure applied to the small diameter portion 32b, the structure is simple, and the number of parts can be reduced. As a result, manufacturing costs can be reduced. Further, the assembling work is simplified, and the number of manufacturing steps can be reduced. Therefore, this can also reduce the manufacturing cost. Further, there is no concern that the piston or the like may become jammed in the regeneration valve spool 32 due to dropping off, and no malfunction occurs due to such jamming.
[0071]
Further, the provision of the seal member 41 can realize dynamic stability of the regeneration valve spool 32 with respect to a minute change in the pressure P of the bridge passage 16. As a result, excellent reproduction performance and reproduction release performance can be obtained, and highly accurate arm cloud control can be realized, which contributes to improvement in work efficiency.
[0072]
Further, the sealing member 41 can suppress oil leakage from the high-pressure first oil chamber 35 to the low-pressure second oil chamber 39, and reduce energy loss due to such oil leakage. it can. Further, when there is a large amount of oil leakage from the first oil chamber 35 to the second oil chamber 39, an intermediate pressure in the second oil chamber 39 may be trapped due to the dimensions of the passage 40 and the drain circuit 44. . If an intermediate pressure is retained, the regeneration valve spool 32 tends to move in the regeneration canceling direction, and the intended regeneration flow rate cannot be obtained, so that accurate arm cloud control may not be realized. By providing the sealing material 41, such a problem due to such leakage can be avoided.
[0073]
Further, since the regeneration valve 30 is provided outside the directional control valve 1, that is, inside the casing 31 separate from the casing 2, the structure of the directional control valve 1 can be suppressed from being complicated, and the manufacture is easy.
[0074]
FIG. 4 is a sectional view showing a second embodiment of the present invention, and FIG. 5 is an enlarged view of a regeneration valve portion in FIG.
[0075]
In the second embodiment, a passage 45 communicating with a passage 14a to which the bridge passage 11 provided in the casing 2 of the direction switching valve 1 can communicate is provided in the casing 31 of the regeneration valve 30, and this passage 45 is connected to the regeneration valve spool. The first oil chamber 35 communicates with the first oil chamber 35 near the small diameter portion 32b.
[0076]
Other configurations are the same as, for example, the above-described first embodiment.
[0077]
In the case of the second embodiment configured as described above, the load pressure of the bottom side chamber 6a of the arm cylinder 6 is supplied as a control pressure to the first oil chamber 35 of the regeneration valve 30 via the passage 45, and the control pressure is applied. When the force is smaller than the combined force of the spring 37 and the frictional force of the sealing material 41, the regeneration valve spool 32 is held in the regeneration state, and the force due to the control pressure is the force of the spring 37 and the force of the sealing material 41. When the force becomes larger than the combined force with the frictional force, the regeneration valve spool 32 slides to enter a partially regenerated state or a completely regenerated release state. Further, since the seal member 41 for providing a frictional force, that is, resistance, is provided between the first oil chamber 35 and the second oil chamber 39, regeneration with respect to a minute change in the load pressure P of the bottom chamber 6a of the arm cylinder 6 is performed. The dynamic stability of the valve spool 32 can be realized, and the same operation and effects as those of the first embodiment can be obtained.
[0078]
In each of the above embodiments, the first oil chamber 35 for guiding the control pressure is provided so as to face the outer peripheral surface of the small diameter portion 32b of the regeneration valve spool 32, and a drain circuit is provided near the end of the small diameter portion 32b. Although the second oil chamber 39 communicating with 44 is provided, the present invention is not limited to such a configuration, and the control pressure is controlled so as to face the end face of the small diameter portion 32b of the regeneration valve spool 32. May be provided, and the second oil chamber 39 communicating with the drain circuit 44 may be provided so as to face the outer peripheral surface of the small diameter portion 32b.
[0079]
Further, in the above description, the regeneration valve 30 is provided outside the direction switching valve 1, that is, inside the casing 31 separate from the casing 2, but unless the production complexity is taken into consideration, the regeneration valve 30 is replaced with the direction switching valve 1. The configuration may be such that it is incorporated in the inside.
[0080]
In the above description, the resistance applying means for applying resistance to the sliding of the regeneration valve spool 32 to the small diameter portion 32b of the regeneration valve spool 32 located between the first oil chamber 35 and the second oil chamber 39 of the regeneration valve 30. Is provided, but the position where the seal material 41 is provided is not limited to the above-described position. For example, the seal member 41 may be provided in the portion 42 of the large diameter portion 32a of the regeneration valve spool 32 located between the first oil chamber 35 and the passage 15 in FIGS. The seal member 41 may be provided at a portion 43 of the regeneration valve spool 32 located between the spring chamber 36 and the spring valve 36.
[0081]
Further, the sealing member 41 may be an elastic member or a synthetic resin member.
[0082]
In the above description, the seal material 41 is mounted on the outer peripheral surface of the regeneration valve spool 32. However, the seal material 41 may be mounted on the inner peripheral surface of the casing 31 facing the outer peripheral surface of the regeneration valve spool 32.
[0083]
In a case where there is little concern about oil leakage or the like, a configuration may be adopted in which a resistor that allows the passage of oil is provided as a resistance applying unit that applies resistance when the regeneration valve spool 32 slides, instead of the sealing material 41. Good.
[0084]
Further, when performing an operation that does not need to consider the movement of the regeneration valve spool 32 with respect to the load pressure of the bottom side chamber 6a of the arm cylinder 6 or the minute fluctuation of the pressure P of the bridge passage 16, etc., a resistance applying means, that is, A configuration without the sealing material 41 may be adopted.
[0085]
The working machine to which the present invention is applied is not limited to the above-described hydraulic shovel. It may be a crane working machine or the like.
[0086]
In addition, even when the hydraulic excavator is provided, the hydraulic actuator applied is not limited to the above-described arm cylinder 6, and may be a bucket cylinder, a boom cylinder, or the like.
[0087]
【The invention's effect】
According to the present invention, the spool of the regeneration valve is formed in a stepped shape having a large-diameter portion and a small-diameter portion, and a control chamber in which a control pressure for sliding the regeneration valve spool is guided is provided near the small-diameter portion. Therefore, desired regeneration and regeneration cancellation can be realized without providing a piston in the regeneration valve, the structure is simple, and the number of parts can be reduced as compared with the conventional case. As a result, manufacturing costs can be reduced. Further, the assembling work is simplified, and the number of manufacturing steps can be reduced. Therefore, this also makes it possible to reduce the manufacturing cost as compared with the related art. In addition, there is no concern that the piston or the like may become jammed in the regeneration valve spool due to falling off, and therefore, there is no occurrence of such a malfunction that has conventionally occurred due to such jamming.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of a valve device with a regeneration function of the present invention.
FIG. 2 is an enlarged view of a regeneration valve portion of FIG.
3A and 3B are diagrams showing a comparison between the operation characteristics of the regeneration valve shown in FIG. 2 having a seal material and the operation characteristics of the regeneration valve without a seal material, and FIG. 3A is a diagram showing a bottom side chamber of an arm cylinder; (A) shows the sliding start point and the sliding end point of the regeneration valve spool in accordance with the change of the load pressure (pressure in the bridge passage) of FIG. FIG. 7C is a diagram showing displacement of the regeneration valve spool with respect to the passage of time drawn in relation to the sliding end point, and FIG. 9C is a diagram showing a change in load pressure (pressure in the bridge passage) of the bottom chamber of the arm cylinder shown in FIG. FIG. 4 is a diagram showing a relationship between the displacement of the regeneration valve spool and the displacement of the regeneration valve spool.
FIG. 4 is a sectional view showing a second embodiment of the present invention.
FIG. 5 is an enlarged view of a regeneration valve portion of FIG.
[Explanation of symbols]
One-way switching valve
2 casing
3-way switching valve spool
4 Pilot port
5 Pilot port
6. Arm cylinder (hydraulic actuator)
6a Bottom side room
6b Rod side chamber
7 Main pipeline
8 Cylinder port
9 Main pipeline
10 Cylinder port
11 Bridge passage
12 tanks
14 passage
14a passage
15 passage
16 Bridge passage
18 Notch
19 Notch
20 holes
21 passage
22 Check valve
23 holes
25 Main hydraulic pump
30 regeneration valve
31 Casing
32 Regeneration valve spool
32a Large diameter part
32b small diameter part
32c step
33 discharge passage
34 passage
35 1st oil chamber (control room)
36 Spring Chamber
37 spring
38 Notch
39 2nd oil chamber
40 passage
41 Sealing material (resistance applying means)
44 Drain circuit
45 passage

Claims (7)

A regeneration device provided in a work machine, comprising: a direction switching valve for controlling driving of a hydraulic actuator, and a regeneration valve capable of regenerating oil returned from the hydraulic actuator via the direction switching valve and supplying the oil to the hydraulic actuator. In a valve device with a function,
While setting the spool of the regeneration valve to a stepped shape including a large diameter portion and a small diameter portion connected to the large diameter portion,
A valve device with a regeneration function, wherein a control chamber is provided in the vicinity of the small diameter portion, to which a control pressure for sliding the spool of the regeneration valve against the force of a spring for urging the spool is provided. The valve device with a regeneration function according to claim 1, wherein the control chamber comprises an oil chamber formed so as to face an outer peripheral surface of the small diameter portion of a spool of the regeneration valve. The valve device with a regeneration function according to claim 1, wherein the control chamber comprises an oil chamber formed so as to face an end surface of the small diameter portion of the spool of the regeneration valve. The valve device with a regeneration function according to any one of claims 1 to 3, wherein a passage for guiding a load pressure of a bottom side chamber of the hydraulic actuator to the control chamber is provided. 2. The valve device with a regeneration function according to claim 1, wherein a passage for guiding return oil from the hydraulic actuator is provided in a spool of the direction switching valve. 2. The valve device with a regeneration function according to claim 1, wherein the regeneration valve is provided outside the direction switching valve. The valve device with a regeneration function according to claim 1, wherein the work machine is a hydraulic shovel.

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