JP2006017257A - Valve device with regenerating function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device with regenerating function capable of permanently holding the dynamic stability of the spool of a regenerating valve against a change in load pressure of a hydraulic actuator. <P>SOLUTION: This valve device comprises a directional control valve 1 installed in a hydraulic shovel and controlling the driving of an arm cylinder 6 and the regenerating valve 30 regenerating a return oil from the arm cylinder 6 and supplying it to the arm cylinder 6 through the directional control valve 1. Also, a first hydraulic oil chamber 35 to which a control pressure to slide the spool 32 of the regenerating valve 30 against the force of a spring 37 energizing the spool 32, for example, a load pressure in the bottom side chamber 6a of the arm cylinder 6 is led is formed in the valve device so as to be opposed to the outer peripheral surface of the small diameter part 32b of the spool 32 of the regenerating valve 30, and an internal passage 40 in which a restrictor 41 is disposed is formed in the spool 32 of the regenerating valve. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a valve device with a regeneration function that is provided in a work machine such as a hydraulic excavator and includes a direction switching valve that controls driving of a hydraulic actuator and a regeneration valve that can supply return oil to the hydraulic actuator.

  As this type of conventional technology, for example, there is a technology described in Patent Document 1. In the technique described in Patent Document 1, a passage for regenerating and supplying return oil from the rod side chamber of the hydraulic cylinder to the bottom side chamber as pressure-accelerating oil in the spool of a direction switching valve that performs drive control of the hydraulic cylinder is provided. In addition, a regeneration valve for controlling regeneration and regeneration cancellation is provided outside the direction switching valve.

  The regenerative valve has a slidable spool, a spring that urges the spool against the spool, and a first oil chamber into which the load pressure of the hydraulic cylinder is guided as a control pressure for sliding the spool. The return oil from the rod side chamber of the hydraulic cylinder communicates with or shuts off the tank according to the spool position. Further, a sealing material that provides resistance when the spool slides is provided on the outer peripheral surface of the spool or the inner peripheral surface of the casing facing the outer peripheral surface.

  When the load pressure in the bottom chamber of the hydraulic cylinder is lower than a predetermined pressure and the spool position of the regeneration valve is biased to the initial position by the above-described spring force, the rod side chamber of the hydraulic cylinder and the tank are connected. The return oil from the rod side chamber of the hydraulic cylinder is cut off and joined to the pressure oil supplied from the main hydraulic pump through the passage provided in the spool of the direction switching valve, and supplied to the bottom side chamber of the hydraulic cylinder. That is, the reproduction operation is performed. As a result, the speed is increased when the rod of the hydraulic cylinder is extended.

  In addition, the load pressure in the bottom side chamber of the hydraulic cylinder becomes higher than a predetermined pressure, and the spool pressing force due to the control pressure applied to the first oil chamber of the regenerative valve is greater than the resultant force of the spring force and the frictional force due to the sealing material. Becomes larger, the spool slides, and part or all of the return oil from the rod side chamber of the hydraulic cylinder is led to the tank through the regeneration valve, and the regeneration operation is partially canceled or completely released. .

  Here, for example, the hydraulic cylinder described above is an arm cylinder provided in a hydraulic excavator, and when an arm cloud for rotating the arm downward is performed, when a bucket provided at the tip of the arm is in the air, The above-described reproduction operation is performed in order to move the arm quickly. At this time, the load pressure in the bottom side chamber of the arm cylinder is relatively low. For example, when the bucket hits a hard rock or the like in the middle of the arm cloud, the load pressure in the bottom side chamber of the arm cylinder increases momentarily. In such a case, if the regeneration release operation and the regeneration operation described above are continuously performed, the operation speed of the arm changes rapidly, resulting in poor operability and a decrease in work efficiency.

In order to eliminate such problems, in the technique described in Patent Document 1, a seal material is provided on the outer peripheral surface of the regeneration valve spool or the inner peripheral surface of the casing facing the outer peripheral surface. The spool is not displaced by a slight change in the control pressure for sliding the spool due to the frictional resistance of the seal material, that is, the hydraulic cylinder load pressure, and the hydraulic cylinder operating speed is stably maintained with respect to minute changes in the load pressure. be able to. As a result, deterioration of operability can be prevented and the suspension efficiency can be improved, and damage to the front working machine such as a boom and an arm or various parts due to a large shock can be prevented.
JP 2004-76793 A

  In the technique described in Patent Document 1 described above, the friction resistance of the sealing material delays the response of the regenerative valve spool to the change in the load pressure of the hydraulic cylinder, and the wear of the sealing material due to the number of sliding times or aging changes. Or the deformation of the hydraulic cylinder may fail to maintain a stable operating speed. Further, when the sealing material is damaged and flows out as a foreign substance in the hydraulic circuit, there is a concern that it may adversely affect the sliding of the spool of the regeneration valve or the direction switching valve and the operation of the hydraulic equipment.

  The present invention has been made based on the above-described situation in the prior art, and its object is to dynamically change the spool of the regenerative valve with respect to changes in the load pressure of the hydraulic actuator without being affected by the sliding of the spool or the service life. An object of the present invention is to provide a valve device with a regenerative function that can realize stability.

  In order to achieve the above object, the present invention provides a directional switching valve that is provided in a work machine and controls the driving of a hydraulic actuator, and regenerates return oil from the hydraulic actuator via the directional switching valve to regenerate the hydraulic pressure. In a valve device with a regeneration function including a regeneration valve that can be supplied to an actuator, the regeneration valve is provided with a spool, a spring that is provided on one end side of the spool and biases the spool, and resists the spring force. A first oil chamber to which a control pressure for sliding the spool is guided; an internal passage provided in the spool and communicating with a drain circuit; and a first oil chamber provided on the other end side of the spool and connected to the internal passage. And a throttle means provided in the internal passage for providing resistance against sliding of the spool.

  In the present invention configured as described above, the internal passage of the regeneration valve spool is filled with hydraulic oil, and the transition from the regeneration state to the regeneration cancellation, or the transition from the regeneration cancellation state to the regeneration, that is, the sliding of the spool. At this time, the throttle means provided in the internal passage becomes a resistance, and the sliding of the regenerative valve spool can be restricted. As a result, in the regenerated state, unless an extra force corresponding to the sliding restriction force by the throttle means is applied to the regeneration valve spool, and in the regenerative release state, only a force corresponding to the sliding restriction force is applied to the regeneration valve spool. The regeneration valve spool will not move unless it is subtracted from the applied force. Here, the throttle means receives a fluid force due to the viscosity of the hydraulic oil, the sliding speed, the pipe shape, etc. as the spool slides from the hydraulic oil in the internal passage. There is no deformation.

  Accordingly, the dynamic stability of the spool of the regenerative valve with respect to the change in the load pressure of the hydraulic actuator can be realized without being affected by the sliding of the spool and the age of use.

  According to a second aspect of the present invention, the throttle means is at least one of the vicinity of the opening on one end side of the internal passage provided in the regeneration valve spool, or the vicinity of the opening on the other end side of the internal passage. It is characterized by being provided in.

  When the throttle means is provided in the internal passage of the spool, it can be formed by first forming the internal passage by drilling and then press-fitting the throttle member into the passage. In this case, the press-fitting operation can be efficiently performed by providing the internal passage in the vicinity of the opening. Further, the narrowed portion can be easily formed by drilling in the spool axial direction and providing a small diameter hole communicating with the axial hole in the spool radial direction.

  According to the present invention, since the throttle means for giving resistance when the spool of the regenerative valve slides is provided, wear or deformation does not occur due to sliding or years of use, and the load pressure of the hydraulic actuator can be reduced. The dynamic stability of the regenerative valve spool against changes can be realized permanently, and excellent regenerative performance and regenerative release performance can be maintained.

  Embodiments of a valve device with a regeneration function according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-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.

  As shown in FIGS. 1 and 2, the first embodiment of the present invention is provided in a work machine such as a hydraulic excavator, and includes a direction switching valve 1 that controls driving of a hydraulic actuator such as an arm cylinder 6, and this direction. A regenerative valve 30 that regenerates the return oil from the arm cylinder 6 through the switching valve 1 and can supply it again to the arm cylinder 6 is included.

  As shown in FIG. 1, the direction switching valve 1 has a direction switching valve spool 3 slidable in a casing 2. The direction switching valve spool 3 slides in the left direction in FIG. 1 due to the pilot pressure applied to the pilot port 4, and slides in the right direction in FIG. 1 due to 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 24 returns to the neutral position.

  In the casing 2 of the direction switching valve 1, a cylinder port 8 connected to the bottom side chamber 6 a of the arm cylinder 6 via the main pipe line 7 and a rod side chamber 6 b of the arm cylinder 6 are connected via the main pipe line 9. Cylinder port 10.

  In addition, bridge passages 11 and 16 are provided for guiding pressure oil from a main hydraulic pump 25 that supplies pressure oil for driving the arm cylinder 6. In these bridge passages 11 and 16, check valves 13 and 17 are arranged, respectively.

  The direction switching valve spool 3 allows the bridge passage 11 of the casing 2 and the passage 14 communicating with the cylinder port 8 to communicate with each other when the direction switching valve spool 3 slides leftward in FIG. A notch 18 is provided. Further, when the direction switching valve spool 3 slides in the right direction in FIG. 1, a notch 18 a is provided that allows the bridge passage 16 of the casing 2 and the passage 14 a communicating with the cylinder port 10 to communicate with each other. .

  Further, the direction switching valve spool 3 opens to the outer peripheral surface and communicates with the hole 20 communicating with the passage 15 of the casing 2 and extends along the axis of the direction switching 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, and the passage 21 and the bridge passage 11 when the check valve 22 is operated. And a hole 23 for communicating with each other.

  Further, a notch 19 is provided to allow the passage 14a and the passage 15 of the casing 2 to communicate with each other when the direction switching valve spool 3 slides in the left direction in FIG.

  The regeneration valve 30 is provided outside the direction switching valve 1, for example. That is, the casing 31 of the regenerative valve 30 is provided continuously with the casing 2 of the direction switching valve 1.

  In addition to the above-described passage 15, a passage 34 communicating with the bridge passage 16 of the casing 2 of the direction switching valve 1 is provided in the casing 31 of the regeneration valve 30.

  As shown in FIG. 2, the regenerative valve 30 has a regenerative 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 stepped portion 32c is formed at a connection portion between the large diameter portion 32a and the small diameter portion 32b.

  The regeneration valve spool 32 is urged toward the left in FIG. 2 by a spring 37 housed in the spring chamber 36. The spring chamber 36 is communicated with the tank 12 via the drain circuit 44.

  A control chamber, that is, a first oil chamber 35 communicating with the above-described passage 34 is provided in a portion of the casing 31 near the small diameter portion 32b of the regeneration valve spool 32 so as to face, for example, the outer peripheral surface of the small diameter portion 32b. Yes. A second oil chamber 39 is provided near the end of the small diameter portion 32b.

  When the force by the control pressure guided to the first oil chamber 35 described above becomes larger than the force by the spring 37, the regeneration valve spool 32 slides in the right direction in FIG. As the control pressure at this time, for example, the load pressure of the bottom side chamber 6a of the arm cylinder 6 (strictly, the pressure of the bridge passage 16) is used.

  Further, the regeneration valve spool 32 is provided with an internal passage 40 that extends along the axial center thereof and communicates the second oil chamber 39 and the spring chamber 36. This internal passage 40 communicates with the spring chamber 36, communicates with a passage 40a formed in the casing 31, communicates with the passage 40b provided perpendicular to the sliding direction of the regeneration valve spool 32, and the regeneration valve spool. 32 includes a passage 40c provided in the sliding direction of 32, and a passage 40d provided in communication with the passage 40c and the second oil chamber 39 and provided perpendicularly to the regeneration valve spool 32.

  Further, the regeneration valve spool 32 has a notch 38 for communicating the passage 15 and the discharge passage 33 provided in the casing 31 when the regeneration valve spool 32 slides in the right direction of FIG. Is provided.

  In the first embodiment, a throttle 41 as a throttle means that provides resistance when the regeneration valve spool 32 slides is provided in the vicinity of the second oil chamber 39 side opening of the internal passage 40. The throttle 41 is formed by press-fitting a throttle 41 member after providing a passage 40c having a relatively large hole diameter.

  The configuration of the first embodiment according to the present invention is as described above. The technique described in Patent Document 1 is different from the technique described in Patent Document 1 in Patent Document 1 as means for imparting resistance to sliding of the regenerative valve spool 32. The first embodiment is different from the first embodiment in that a diaphragm 41 is provided.

  The operation of the first embodiment configured as described above is as follows in substantially the same manner as in Patent Document 1.

[Complete playback]
When carrying out the arm cloud performed by extending the rod of the arm cylinder 6, if 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. 1. As a result, the direction switching valve spool 3 slides leftward 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.

  Thereby, the pressure oil of the main hydraulic pump 25 is guided to the main pipe line 7 through 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 side 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.

  If the pressure of the pressure oil introduced into 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 is more than the force due to the pressure applied to the first oil chamber 35. The force by 37 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 in a blocked state, for example.

  The return oil from the rod side chamber 6b of the arm cylinder 6 is guided from the main pipe 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 off the regeneration valve spool 32. It is given to the notch 38 part.

  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 non-returned through the hole 20 and the passage 21 of the direction switching valve spool 3. The valve 22 is pushed open and guided to the bridge passage 11 through the hole 23.

  That is, the return oil from the rod side chamber 6 b of the arm cylinder 6 is regenerated as the speed increasing pressure oil and merges with the pressure oil supplied from the main hydraulic pump 25. The joined 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 that operates relatively quickly is implemented.

[Complete playback release]
For some reason, when the pressure in the bridge passage 16 becomes higher than a predetermined pressure, 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 becomes larger than the force of the spring 37. The regeneration valve spool 32 slides in the right direction in FIGS. When the regenerative valve spool 32 slides, the internal passage 40 is filled with hydraulic oil having a pressure substantially equal to the tank pressure, so that the throttle 41 provided in the vicinity of the opening on the second oil chamber 39 side resists. Accordingly, the amount of displacement of the regenerative valve spool 32 with respect to the magnitude of the control pressure applied to the first oil chamber 35 is smaller than when the throttle 41 is not provided. In particular, the resistance force increases immediately after the start of sliding, the displacement speed of the regenerative valve 32 decreases, and gradually approaches a constant speed.

  As a result, the passage 15 and the discharge passage 33 gradually communicate with each other through the notch 38 that forms a large opening of the regeneration valve spool 32 shown in FIGS.

  At this time, when the regeneration valve spool 32 slides, the oil in the spring chamber 36 is guided to the tank 12 through the drain circuit 44, and also through the passage 40 of the regeneration valve spool 32, that is, the passages 40a, 40b, The oil in the spring chamber 36 is guided to the second oil chamber 39 through 40c, the throttle 41, and the passage 40d.

  As described above, the passage 15 and the discharge passage 33 communicate with each other via the notch 38 of the regenerative valve spool 32, so that the return oil from the rod side chamber 6b of the arm cylinder 6 flows into the main pipeline 9, the cylinder port 10, It is returned to the tank 12 through the passage 14 a, 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 is not guided to the passage 21 side of the direction switching valve spool 3, and the regeneration is completely canceled. As a result, the operating speed of the arm cylinder 6 becomes lower than before.

[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 into the discharge passage 32. When the amount is small, a part of the return oil guided to the passage 15 is regenerated as the speed increasing pressure oil through the passage 21 and the check valve 22 of the direction switching valve spool 3. The remaining return oil is returned to the tank 12 through the notch 38 and the discharge passage 33 of the regeneration valve spool 32.

  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, so that the arm cloud can be accelerated. it can. That is, when the arm cloud is accelerated, it can be controlled to an operating speed that changes in accordance with the pressure of the bridge passage 16.

[From complete playback to playback]
Further, when the pressure in the bridge passage 16 is lower than a predetermined pressure and the force by the spring 37 is increased from the state where the regeneration is completely released as described above, the regeneration valve that has been slid in the right direction. The spool 32 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 partial regeneration described above is started. Alternatively, the notch 38 and the discharge passage 33 are blocked and the full regeneration described above is performed.

  At this time, when the regeneration valve spool 32 slides, the oil in the second oil chamber 39 passes through the conduit 40 d, the throttle 41, the conduits 40 c, 40 b, 40 a, the spring chamber 36, and the drain circuit 44. Returned to

  Also in this case, the restrictor 41 becomes a resistance, and in particular, the resistance force increases immediately after the start of sliding, and the displacement speed of the regenerative valve 32 becomes slow and gradually approaches a constant speed.

[Operation of the regeneration valve spool 32 related to the throttle 41]
FIG. 3 is a diagram comparing the operating characteristics of the regenerative valve 30 shown in FIG. 2 with the throttle 41 and the operating characteristics of the regenerative valve 30 without the throttle 41. FIG. FIG. 3B is a diagram showing a sliding start point and a sliding end point of the regenerative valve spool 32 according to a change in pressure, and FIG. 3B is a sliding start point and a sliding end of the regenerative valve spool 32 shown in FIG. FIG. 3C is a diagram showing the displacement of the regenerative valve spool 32 drawn with respect to time, and FIG. 3C shows the change in the pressure of the bridge passage 16 shown in FIG. It is a figure which shows the relationship.

  If the throttle 41 is not provided, as shown in the regeneration release / sliding start point F1 in FIG. 3A, when the regeneration is canceled, the pressure P of the bridge passage 16 is compared with the set force of the spring 37. When the target P1 is low, the regenerative valve spool 32 shown in FIG. 2 starts to slide in the right direction in FIG. When the pressure P of the bridge passage 16 increases to P2, as shown by the regeneration release / sliding end point F2, sliding of the regeneration valve spool 32 in the right direction in FIG.

  For example, at an intermediate position from the playback release / sliding start point F1 to the playback release / sliding end point F2, the above-mentioned partial playback release, that is, partial playback is performed, and the playback release / slide end point. When it reaches the vicinity of F2, it shifts to the cancellation of complete reproduction.

  Further, at the time of regeneration, when the pressure P of the bridge passage 16 is P2 described above, the regeneration valve spool 32 shown in FIG. 2 starts sliding leftward as indicated by the regeneration / sliding start point F3. . When the pressure P of the bridge passage 16 is lowered to P1, the sliding of the regeneration valve spool 32 in the left direction is completed as indicated by the regeneration / sliding end point F4.

  Also at this time, for example, at the intermediate position from the reproduction / sliding start point F3 to the reproduction / sliding end point F4, the above-mentioned partial reproduction is performed, and when the vicinity of the reproduction / sliding end point F4 is reached, the complete reproduction is performed. Transition to playback.

  The displacement x of the regenerative valve spool 32 in the sliding operation described above is shown by the broken line in FIG.

  Further, the displacement x of the regenerative valve spool 32 with respect to the change in the pressure P in the bridge passage 16 is indicated by a broken line in FIG.

  As indicated by the broken line in FIG. 3C, when the throttle 41 is not provided, the displacement x of the regeneration valve spool 32 varies 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 the dynamic stability of the regeneration valve spool 32 with respect to the change in the pressure P of the bridge passage 16. In arm cloud operation, slight changes in the pressure P in the bridge passage 16 can occur frequently. Therefore, even if the pressure P in the bridge passage 16 slightly changes, the regeneration valve spool 32 always moves, and the operating speed of the arm cylinder 6 tends to fluctuate unintentionally.

  In the first embodiment of the present invention, since the throttle 41 is provided, the regenerative valve spool 32 is hardly displaced with respect to a slight change in the pressure P of the bridge passage 16, particularly an instantaneous change. It is possible to achieve stable maintenance of the operating speed of the arm cylinder 6 against a minute change in the load pressure of the bottom side chamber 6a during the arm cloud. That is, the dynamic stability of the regeneration valve spool 32 with respect to changes in the pressure P of the bridge passage 16 can be ensured.

  As shown in FIG. 2, in the first embodiment provided with the throttle 41, the throttle 41 becomes a resistance when the regeneration valve spool 32 slides. Thus, although the regeneration release / sliding start point F1 is formed when the pressure P of the bridge passage 16 is P1, the displacement speed is extremely slow immediately after the start of sliding. On the other hand, the regeneration release / sliding end point F5 is P3 higher than the pressure P2 at the end point when the throttle 41 is not provided.

  Further, at the time of regeneration, although the regeneration / sliding start point F3 is formed when the pressure P of the bridge passage 16 is P2, the displacement speed becomes extremely slow immediately after the start of sliding. On the other hand, the regeneration / sliding end point F6 is P4 lower than the pressure P1 at the end point when there is no throttle 41.

  As a result, the displacement x of the regeneration valve spool 32 with respect to the change in the pressure P in the bridge passage 16 is as shown by the solid line in FIG.

  As shown in FIG. 3C, between the pressure P3 of the bridge passage 16 where the regeneration is completely released and the pressure P2 of the bridge passage 16 when the regeneration starts from the state where the regeneration is completely released. There can be a region PS of pressure forming a dead zone. Further, the displacement speed of the regenerative valve spool 32 becomes extremely slow while the pressure is slightly lower than the pressure P2. Therefore, as long as the load pressure in the bottom side chamber 6a of the arm cylinder 6 varies slightly between P3 and P2, the load pressure in the bottom side chamber 6a of the arm cylinder 6 is in the vicinity of P1. As long as it fluctuates, the regenerative valve spool 32 hardly slides, whereby the dynamic stability of the regenerative valve spool 32 can be realized. In other words, it is possible to achieve stable maintenance of the operating speed of the arm cylinder 6 against minute fluctuations in the pressure P of the bridge passage 16.

  Thus, the operation according to the present embodiment is almost equivalent to the technique described in Patent Document 1 described above. However, as described above, in the present embodiment, the throttle 41 is used as a means for giving resistance when the regenerative valve spool 32 slides, and therefore, as the spool slides from the hydraulic oil in the internal passage. Although the fluid force is caused by the viscosity of the hydraulic oil, the sliding speed, the tube shape, etc., the throttle 41 is not worn or deformed by this.

  Therefore, the dynamic stability of the regeneration valve spool with respect to the change in the load pressure of the hydraulic actuator can be realized without being affected by the sliding of the regeneration valve spool 32 and the years of use.

In addition, since the throttle member is press-fitted near the opening of the regeneration valve spool 32 on the second oil chamber 39 side, the throttle 41 can be easily formed.

  FIG. 4 is a cross-sectional view of a regenerative valve portion showing a second embodiment of the present invention.

  In the second embodiment, the diameter of the passage 41A provided in the radial direction of the regenerative valve spool 32 in communication with the internal passage 40 on the spring chamber 36 side is reduced, and this is the throttle 41 provided in the first embodiment. Is used instead of. Other configurations are the same as those of the first embodiment described above, and the operations thereof are also the same.

  Therefore, according to the second embodiment, the same effect as that of the first embodiment can be obtained. In addition, since it is not necessary to use a special member when forming the diaphragm 41A, the diaphragm can be formed more easily.

  The work machine to be applied is not limited to the hydraulic excavator described above, and may be a crane work machine or the like.

  Even when the hydraulic excavator is provided, the applied hydraulic actuator is not limited to the arm cylinder 6 described above, and may be a bucket cylinder, a boom cylinder, or the like.

It is sectional drawing which shows 1st Embodiment of the valve apparatus with a regeneration function of this invention. It is an enlarged view of the regeneration valve part of FIG. 2 is a diagram showing a comparison of operating characteristics of the regenerative valve shown in FIG. 2 with a sealing material and operating characteristics of the regenerative valve without a throttle, in which (a) shows the load pressure (bridge path) in the bottom side chamber of the arm cylinder; (B) is related to the slide start point and slide end point of the regeneration valve spool shown in (a). The figure which shows the displacement with respect to passage of time of the drawn regeneration valve spool, (c) is the relationship between the change of the load pressure (bridge passage pressure) of the bottom side chamber of the arm cylinder shown in (a) and the displacement of the regeneration valve spool. FIG. It is sectional drawing of the regeneration valve in 2nd Embodiment of this invention.

Explanation of symbols

1 direction switching valve 2 casing 3 direction switching valve spool 4 pilot port 5 pilot port 6 arm cylinder (hydraulic actuator)
6a Bottom side chamber 6b Rod side chamber 7 Main conduit 8 Cylinder port 9 Main conduit 10 Cylinder port 11 Bridge passage 12 Tank 14 passage 14a passage 15 passage 16 Bridge passage 18 Notch 19 Notch 20 Hole 21 Passage 22 Check valve 23 Hole 25 Main Hydraulic pump 30 Regeneration valve 31 Casing 32 Regeneration valve spool 32a Large diameter portion 32b Small diameter portion 32c Stepped portion 33 Discharge passage 34 Passage 35 First oil chamber (control chamber)
36 Spring chamber 37 Spring 38 Notch 39 Second oil chamber 40 Internal passage 41 Restriction (throttle means)
44 Drain circuit

Claims (2)

A regeneration valve that is provided in the work machine and that controls the drive of the hydraulic actuator, and a regeneration valve that regenerates the return oil from the hydraulic actuator through the direction switch valve and can supply the oil to the hydraulic actuator. In the valve device with function,
The regeneration valve includes a spool, a spring provided on one end of the spool and biasing the spool, a first oil chamber to which a control pressure for sliding the spool against the spring force is guided, An internal passage provided inside the spool and communicating with the drain circuit, a second oil chamber provided on the other end of the spool and connected to the internal passage, and a resistance against sliding of the spool provided in the internal passage. A valve device with a regenerating function, characterized by comprising a throttle means for giving.   The said throttle means is provided in at least any one of the vicinity of the opening part of the one end side of the internal passage provided in the said spool, or the opening part vicinity of the other end side of the said internal passage. The valve device with a regeneration function as described.

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