JP2006329241A - Composite valve and hydraulic driven unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite valve consisting of an emergency manual valve and a relief valve unitized therewith in a general hydraulic circuit, particularly, a hydraulic driven unit and having inexpensive and compact construction for saving space. <P>SOLUTION: In the hydraulic driven unit 10, the composite valve 7 is provided which consists of the relief valve (7r) to be used between a hydraulic cylinder 2 and a hydraulic pump 1 and the emergency manual valve (7h) unitized coaxially therewith for escaping operating fluid between the hydraulic pump 1 and the hydraulic cylinder 2 into a tank 3 during stopping the hydraulic pump 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used in a hydraulic circuit, and is interposed between a hydraulic pump that pumps a working fluid and a hydraulic actuator that is operated by the working fluid, and the working fluid between the hydraulic pump and the hydraulic actuator exceeds a predetermined level. A relief valve that allows the working fluid to escape to the tank when the pressure becomes high, and an emergency that allows the working fluid between the hydraulic pump and the hydraulic actuator to escape to the tank when the hydraulic pump is stopped. The present invention relates to a composite valve that performs both functions of a manual valve.

  Further, the present invention provides a hydraulic pump that includes an electric motor and pumps hydraulic oil in both forward and reverse directions, a hydraulic actuator that operates by the hydraulic oil, and an operation that controls the forward and reverse bidirectional flow of hydraulic oil between the two. This hydraulic drive unit is equipped with a check valve, a tank for storing hydraulic oil, a switching valve for controlling the forward and reverse bidirectional flow between the tank and the hydraulic pump, and the like. The present invention relates to the composite valve used and a hydraulic drive unit including the composite valve.

  A hydraulic drive unit that easily provides hydraulic drive force as long as there is a power supply without using hydraulic piping is used, for example, for lifting and lowering work equipment with respect to the cultivated ground of special agricultural vehicles. The above application fields are expected and expanded.

  FIG. 10 is a hydraulic circuit diagram showing a basic configuration of the hydraulic drive unit.

  The hydraulic drive unit OU pumps the hydraulic oil in both forward and reverse directions by the forward / reverse rotating motor M in order to apply the hydraulic drive force to the driven body W independently, that is, while circulating the hydraulic oil in a closed system. A hydraulic pump OP, a hydraulic actuator OA (here, a hydraulic cylinder) that operates by the hydraulic oil and generates the driving force, a tank OT that stores hydraulic oil in a closed space, and between the hydraulic pump OP and the hydraulic actuator OA The operation check valve OC for controlling the forward / reverse bidirectional flow of the hydraulic oil and the switching valve OI for controlling the forward / reverse bidirectional hydraulic oil flow between the hydraulic pump OP and the tank OT are provided as basic components. Yes.

  The operating check valve OC basically pilots the hydraulic pressure to the check valve OCa to a pair of check valves OCa that allow only the flow of hydraulic oil from the hydraulic pump OP to the hydraulic actuator OA. And a pair of pilot lines OCb.

  The pair of check valves OCa includes a pipe line connecting one port of the hydraulic pump OP and the bottom side oil chamber OAa of the hydraulic actuator OA, the other port of the hydraulic pump OP and the rod side oil chamber OAb of the hydraulic actuator OA. And a pipe line connecting the two.

  The switching valve OI switches and connects between the tank OT and any pipe line between the hydraulic pump OP and the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA.

  In the following description, the left side in the figure, such as the check valve OCa arranged in a pair of left and right, the one on the bottom side and the right side as the hydraulic oil entering and leaving the bottom side oil chamber OAa of the hydraulic actuator OA, The rod-side oil chamber OAb may be referred to as the rod side as it relates to the hydraulic oil entering and leaving the rod-side oil chamber OAb. Similarly, in the port of the hydraulic pump OP, the left side may be referred to as the bottom side and the right side may be referred to as the rod side.

  With such a configuration, according to the hydraulic drive unit OU, in a state where the hydraulic pump OP is stopped, the operation check valve OC allows any one of the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA. The hydraulic oil is prevented from flowing out from the side, the current stationary state of the hydraulic actuator OA is maintained against a predetermined external force, and the driven body W can be held at a fixed stationary position.

  When the hydraulic pump OP rotates so as to discharge the hydraulic oil to the bottom side port, the hydraulic oil is supplied from the hydraulic pump OP to the bottom side oil chamber OAa through the bottom side check valve OCa, and at the same time, the bottom side pilot line OCb The hydraulic oil that pushes and opens the rod side check valve OCa by the hydraulic pressure, allows the hydraulic oil to flow from the rod side oil chamber OAb to the hydraulic pump OP, and circulates clockwise between the hydraulic pump OP and the hydraulic actuator OA. As a result, a driving force in the extending direction is generated in the hydraulic actuator OA, and the driven body W is moved to the rod side.

  At this time, considering the case where the hydraulic actuator OA is a single rod hydraulic cylinder as shown in the drawing, the rod side oil is compared to the amount of hydraulic oil flowing into the bottom side oil chamber OAa with respect to the movement amount of the piston of the hydraulic cylinder. The amount of hydraulic oil flowing out from the chamber OAb is reduced by the amount of this rod, but the switching valve OI is pushed by the hydraulic oil at the bottom side with higher hydraulic pressure so that the switching valve OI is connected to the rod side oil chamber OAb and the tank OT. The shortage of hydraulic oil is supplied from the tank OT to the rod side of the hydraulic pump OP.

  On the other hand, when the hydraulic pump OP rotates so as to discharge the hydraulic oil to the rod side port, the reverse flow of the hydraulic oil occurs, and a driving force in the contracting direction is generated in the hydraulic actuator OA, and the bottom side oil is generated. The hydraulic fluid flowing into the hydraulic pump OP from the chamber OAa becomes redundant, but the excess hydraulic fluid is connected to the tank OT and the pipe line to the bottom side oil chamber OAa by the action of the switching valve OI opposite to the above. , It is returned to the tank OT.

  Note that the amount of hydraulic oil in the sealed tank OT increases or decreases depending on the position of the piston of the hydraulic cylinder that is the hydraulic actuator OA, and the gas pressure sealed in the tank OT varies. Therefore, the fluctuation of the gas pressure does not affect the operation of the hydraulic drive unit OU.

  Thus, the function of the hydraulic drive unit OU is exhibited and maintained while using the hydraulic actuator OA which is a closed system and has a difference in the amount of hydraulic oil entering and exiting due to its operation.

  The hydraulic drive unit OU includes the following additional elements in addition to the basic components described above.

  In the pipelines between the bottom side oil chamber OAa of the hydraulic actuator OA, the rod side oil chamber OAb and the respective check valves OCa of the operating check valve OC, hydraulic oil from the respective oil chambers OAa, OAb to the check valve OCa is provided. Slow return valves SR for restricting only the flow are provided respectively.

  The slow return valve SR is for preventing hunting that occurs when an external force is generated from the driven body W during operation of the hydraulic pump OP.

  From the pipelines between the slow return valves SR and the check valves OCa, pipelines provided with relief valves RV1 respectively branch to the tank OT. Similarly, from the pipe line between the hydraulic pump OP and the check valve OCa on the bottom side and the rod side, pipe lines each provided with a relief valve RV2 branch to the tank OT.

  These relief valves RV1 and RV2 allow excess hydraulic oil to escape to the tank OT when an abnormal pressure occurs in the branch source pipe.

  Furthermore, from the pipe line between the rod side and bottom side slow return valve SR and the check valve OCa, the pipe line provided with the emergency manual valve MV branches to the tank OT, and the hydraulic pump OP is powered. When the emergency manual valve MV is used, the hydraulic actuator OA can be manually operated by releasing the pipelines of the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA to the tank OT. I am doing so.

  With such a configuration, this hydraulic drive unit OU achieves its basic functions well, and even if an abnormal situation occurs, it does not lead to damage of the unit OU, thus ensuring safety and reliability. Accident avoidance is ensured.

  However, in the hydraulic drive unit OU, the emergency manual valve MV and the relief valve RV1 are provided separately and independently, so that more space is required and a pipe line connecting the two is required. Could not achieve compactness. This demand for compactness has become more important as a hydraulic drive unit that should provide hydraulic driving force at a required location in a simple and inexpensive manner.

  This problem is common not only as a component of the hydraulic drive unit as described above but also in an emergency manual valve and a relief valve used in combination with the hydraulic pump OP, the hydraulic actuator OA, and the tank OT. .

Further, specific examples of the hydraulic drive unit include those described in Patent Document 1 and Patent Document 2, but none of them solves the above problem.
Japanese Patent No. 2824659 (FIG. 1) Japanese Patent Laying-Open No. 2003-172307 (FIG. 1)

  The present invention is intended to improve the above problem, and in an ordinary hydraulic circuit and particularly a hydraulic drive unit, an emergency manual valve and a relief valve are integrated into a single unit, thereby realizing space saving, cost reduction, and compactness. An object of the present invention is to provide a composite valve and a hydraulic drive unit including the composite valve.

  The composite valve of the present invention is used in a hydraulic circuit, and is interposed between a hydraulic pump that pumps a working fluid and a hydraulic actuator that is operated by the working fluid, and the working fluid between the hydraulic pump and the hydraulic actuator. A relief valve that allows the working fluid to escape to the tank when the pressure exceeds a predetermined pressure, and allows the working fluid between the hydraulic pump and the hydraulic actuator to escape to the tank when the hydraulic pump is stopped. The emergency manual valve is integrated into one unit on the same axis.

  In addition, the hydraulic drive unit of the present invention includes a composite valve having such characteristics.

  According to the composite valve of the present invention, the relief valve and the emergency manual valve are integrated into one unit, so that space saving, cost reduction, and downsizing can be realized in a general hydraulic circuit, particularly a hydraulic drive unit. Moreover, the same effect is demonstrated also as a hydraulic drive unit provided with this compound valve.

  Embodiments (examples) of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram conceptually showing an example of a hydraulic drive unit equipped with a composite valve of the present invention, and FIG. 2 (a) is a diagram showing the operation of an emergency manual valve of the composite valve in the hydraulic drive unit of FIG. FIG. 2B is a front view showing a stop ring used in the emergency operation valve of FIG. 1.

  The hydraulic drive unit 10 is used for, for example, raising and lowering work equipment with respect to the cultivated ground of an agricultural special vehicle, which requires a simple and independent hydraulic drive force, and is also included in the hydraulic drive unit 10. The combined valve 7 is used not only in such a hydraulic drive unit but also in a general hydraulic circuit, in combination with a hydraulic pump, a hydraulic actuator, and a tank, and functions as both an emergency manual valve and a relief valve. It is also used as a composite valve.

  The unit 10 includes an electric motor M and a hydraulic pump 1 that pumps hydraulic oil in both forward and reverse directions, and a hydraulic cylinder that is operated by the hydraulic oil and generates a driving force to the driven body W. 2, a tank 3 for storing hydraulic oil in a closed space, an operation check valve 4 for controlling the forward and reverse bidirectional flow of hydraulic oil between the hydraulic pump 1 and the hydraulic cylinder 2, and the hydraulic pump 1 and the tank 3 The composite valve 7 is basically composed of the switching valve 5 for controlling the flow of hydraulic oil in the forward and reverse directions and the composite valve 7 described above. The composite valve 7 is an emergency manual valve (reference numeral MV in FIG. 10) and the operation check valve 4. And a relief valve (reference symbol RV1 in FIG. 10) provided between the hydraulic cylinder 2 and the hydraulic cylinder 2 is formed as one unit on the same axis.

  The basic functions and interrelationships of these hydraulic pump 1, hydraulic cylinder 2, tank 3, operation check valve 4, and switching valve 5 are the hydraulic pump OP, hydraulic actuator OA, and tank constituting the conventional hydraulic drive unit OU. Since it is the same as OT, the operation check valve OC, and the switching valve OI, redundant description is omitted. In addition, the code | symbol 2a of the hydraulic cylinder 2 is a bottom side oil chamber, and the code | symbol 2b is a rod side oil chamber.

  Here, the slow return valve SR and the relief valve RV2 shown in the hydraulic circuit diagram of FIG. 10 are not shown, but these are provided as necessary. In this figure, the operation check valve 4 and the switching valve 5 constituting the hydraulic drive unit 10 are indicated by hydraulic symbols here, but their configuration, operation and effect will be described with reference to FIG.

  The composite valve 7 includes an emergency manual valve, a valve accommodating portion 7a that coaxially accommodates a portion that functions as a relief valve, a manual valve portion 7h that mainly shares the function as an emergency manual valve, and this manual valve portion. A relief valve element 7r that slides relative to 7h to open and close the valve and a spring 7t that urges the relief valve element 7r relative to the manual valve portion 7h in the direction of closing the valve are provided.

  Among the above-described components, the manual valve portion 7h, the relief valve body 7r, and the spring 7t are accommodated in the valve accommodating portion 7a so as to be coaxially opposed to each other, and the same one is accommodated. The accommodating portions provided in the valve accommodating portion 7a are also provided so as to face each other except for the central portion.

  The single composite valve 7 has such a structure in which a pair of two relief valves RV1 on the rod side and bottom side constituting the hydraulic drive unit OU in FIG. 10 and an emergency manual valve MV are integrated. This is because these functions are realized. More precisely, the emergency manual valve in the composite valve 7 is a pair provided on the rod-side and bottom-side conduits as compared to the emergency manual valve MV of the hydraulic drive unit OU in FIG. It has become.

  Therefore, if necessary, it is possible to make a simpler configuration excluding one or both of the relief valve and the emergency manual valve constituting the composite valve 7.

  In this example, the valve accommodating portion 7a is assumed to be entirely cylindrical, and a plurality of stepped holes penetrating from the end surface to the other end surface facing each other are formed in the center facing.

  In order to make the explanation easier to understand, the valve accommodating portion 7a is shown as a cylindrical separate independent part. However, in an actual hydraulic drive unit or the like, the structure is a part of the structure of the entire unit. Incorporated into the inside, and the stepped hole is formed in the inside thereof. When the composite valve 7 is used as a single body, it is desirable to use such a valve accommodating portion 7a.

  This stepped hole is formed from the opposite end face of the valve accommodating portion 7a toward the center of the both end faces, and has a maximum diameter opening hole 7b, followed by a female screw hole provided with a female screw having a smaller diameter. 7c, a passage hole 7d having a smaller diameter than the female screw hole 7c and a communication hole 7e having a smaller diameter than the passage hole 7d and communicating both the passage holes 7d.

  The valve accommodating portion 7a is further provided with a pair of hydraulic oil passages 7f penetrating from the one side of the cylindrical outer periphery to the other side through the passage hole 7e. These hydraulic oil passages 7f are respectively hydraulic cylinders. 2 is connected to the bottom oil chamber 2a and the bottom side of the operation check valve 4, and the rod side oil chamber 2b of the hydraulic cylinder 2 and the rod side of the operation check valve 4 are connected.

  Further, the valve accommodating portion 7 a is provided with a hydraulic oil passage 7 g that guides the hydraulic oil to the outside from the communication hole 7 e, and the hydraulic oil passage 7 g is connected to the tank 3.

  The pair of manual valve portions 7h are accommodated from the opening hole 7b of the valve accommodating portion 7a to the communication hole 7e. The male screw portion 7i is screwed into the female screw hole 7c, and the passage hole 7d is continuous therewith. An oil-tight slidable intermediate portion 7j, a passage portion 7k having a gap that permits the flow of hydraulic oil to the passage hole 7d, and a passage hole 7d and a communication hole 7e of the valve housing portion 7a. A valve portion 7m that opens and closes the flow of the hydraulic oil between the passage hole 7d and the communication hole 7e, and permits the flow of the hydraulic oil to the communication hole 7e that follows this. It has an external shape composed of a small-diameter portion 7n having a gap.

  A hydraulic fluid passage 7v that allows hydraulic fluid to flow through the hydraulic fluid passages 7f on the bottom side and the rod side of the valve accommodating portion 7a is provided at an appropriate position of the passage portion 7k.

  On the inner side of the manual valve portion 7h, a bottomed valve accommodating hole 7o having a predetermined depth from the end surface of the small diameter portion 7n and a relief valve hole 7q penetrating from the center of the bottom surface to the hydraulic oil passage 7v are formed. .

  A hydraulic oil passage hole 7p through which hydraulic oil can flow between the small diameter portion 7n and the valve accommodating hole 7o is provided at an appropriate position on the peripheral wall between the valve accommodating hole 7o and the small diameter portion 7n outside the valve accommodating hole 7o. .

  The valve accommodating hole 7o accommodates a relief valve element 7r and a spring 7t that urges the relief valve element 7r in the valve closing direction, and is closed by an accommodating hole lid 7u.

  The relief valve body 7r is slidably accommodated in the valve accommodation hole 7o, and includes a valve portion 7s that opens and closes the relief valve hole 7q in an oil-tight manner. The spring 7t is interposed between the relief valve body 7r and the accommodation hole lid 7u, and urges the valve portion 7s of the relief valve body 7r to close the relief valve hole 7q with a predetermined pressure.

  When the relief valve body 7r opens the relief valve hole 7q, the hydraulic oil that has flowed into the valve accommodating hole 7o from the relief valve hole 7q passes through the hydraulic oil passage hole 7p and is outside the small diameter portion 7n of the manual valve portion 7h. The valve accommodating portion 7a can flow out to the inside of the communication hole 7e.

  A hexagon hole 7w for manually rotating the manual valve portion 7h is formed on the end surface of the male screw portion 7i of the manual valve portion 7h.

  A concave groove 72 is provided at an appropriate position of the opening hole 7b of the valve accommodating portion 7a. In this concave groove 72, the stop ring 71 is reduced in diameter against an elastic force to be further expanded. The inner diameter of the accommodated state is smaller than the outer diameter of the male screw portion 7i of the manual valve portion 7h.

  The retaining ring 71 and the recessed groove 72 are threadedly engaged with the male threaded portion 7i of the manual valve portion 7h and the female threaded hole 7c of the valve accommodating portion 7a. The slide is regulated so as not to go further outside.

  That is, the manual valve portion 7h can be opened and closed by inserting a tool such as a hexagon wrench into the hexagonal hole 7w and sliding the manual valve portion 7h, but the stop ring 71 and the groove 72 Constitutes a valve body drop prevention means 73 that prevents the manual valve portion 7h from falling off by manually turning it more than necessary.

  The stop ring 71 used in the valve body drop prevention means 73 is as shown in FIG. 2B, and is an elastic rigid body with a simple structure in which a wire having a circular cross section is bent into a C shape. Thus, the valve body drop prevention means 73 can be constructed at a low cost.

  Instead of such a retaining ring 71, a C-type retaining ring for holes or an E-shaped retaining ring for holes (JIS B 2804 2001) that is generally standardized and commercially available may be used. The concave groove also corresponds to it.

  As can be seen from FIG. 1, for example, when a high pressure exceeding a predetermined level is generated in the hydraulic fluid passage 7f on the rod side, the relief valve body 7r opens against the urging force of the spring 7t. Excess hydraulic oil is released to the tank 3 through the hydraulic oil passage 7v, the relief valve hole 7q, the valve accommodating hole 7o, the hydraulic oil passage hole 7p, the communication hole 7e, and the hydraulic oil passage 7g.

  The same applies to the bottom side, and this composite valve 7 exhibits the function of a relief valve for each of the rod side and the bottom side.

  On the other hand, when viewing FIG. 2 (a), the manual valve portion 7h on both the rod side and the bottom side is manually operated, and the axial center of the valve accommodating portion 7a is maximally within the restriction range by the valve body drop prevention means 73. The valve portion 7m is in a state of permitting the flow of hydraulic oil between the passage hole 7d and the communication hole 7e.

  In this state, passages are formed in the tank 3 through the respective hydraulic oil passages 7f, passage holes 7d, communication holes 7e, and hydraulic oil passages 7g, and the hydraulic oil on the rod side and bottom side of the hydraulic cylinder 2 is released. The hydraulic cylinder 2 can be moved manually, and the function of an emergency manual valve is exhibited.

  Even when only the manual valve portion 7h on one side is operated, the hydraulic cylinder 2 can be moved manually because the other side is in a state where the hydraulic oil can be sucked.

  Further, as described above, the manual valve portion 7h is regulated by the valve body drop prevention means 73 so as not to drop from the valve housing portion 7a.

  Therefore, it is necessary to consider contamination (intrusion of foreign matter) at the time of reassembly, preventing the omission of the manual valve part, which is a built-in component, preventing omissions from being detected, and eliminating the need for reassembly. Demonstrates the effect of being unnecessary. This means that an emergency manual valve function can be handled by an amateur on site, and foolproofing is achieved.

  Further, the manual valve portion 7h having such a configuration can be manually returned to the normal closed state even after being opened as an emergency manual valve, and can be used repeatedly.

  Further, the manual valve portion 7h having such a structure is a unit in which the relief valve is completely accommodated therein, and when this is assembled to the valve accommodating portion a, the manual valve portion 7h It is only necessary to accommodate the relief valve element 7r and the spring 7t in 7h and screw the unit covered with the accommodation hole lid 7u, so that the assembly at the site is improved. In addition, handling and repair are facilitated.

  Further, since the performance of the relief valve in the manual valve portion 7h can be inspected as a single unit and only good products after the inspection can be incorporated, the inspection after the assembly becomes unnecessary, and the assemblability is improved in this respect.

  Thus, according to this composite valve 7, in the hydraulic drive unit, the emergency manual valve and the relief valve can be integrated into one unit, and space saving, cost reduction, and downsizing can be realized. It is also demonstrated in a hydraulic circuit. Moreover, the hydraulic drive unit 10 provided with this composite valve exhibits the effect of the composite valve as a unit.

  FIG. 3 is a configuration diagram conceptually showing the detailed configuration of the operation check valve in the hydraulic drive unit of FIG. 1. Accordingly, the same parts as those already described are denoted by the same reference numerals and redundant description is omitted. In addition, in the case where there is a separate code for the aggregate of each part, only the code of the aggregate may be shown to avoid complication.

  In FIG. 3, features of the operation check valve that could not be explained in FIG. 1 will be explained. This characteristic is another characteristic point of the hydraulic drive unit 10 including the composite valve 7 of the present invention.

  The operated check valve 4 includes a valve accommodating portion 4a, a switching valve 5 accommodated in the central portion of the valve accommodating portion 4a, and a pair of check valves 4b accommodated so as to face each other with the switching valve 5 interposed therebetween. And the switching valve 5 shown in FIG. 1 is housed and integrated.

  In this example, the valve accommodating portion 4a includes a cylindrical accommodating cylinder 4aa and an accommodating cylinder lid 4ab that closes both end openings in an oil-tight manner.

  In order to make the explanation easy to understand, the valve accommodating portion 4a is shown as a cylindrical separate independent part. However, in an actual hydraulic drive unit, the structure body is a part of the structure of the entire unit. It is incorporated therein and includes an internal housing space for the valve housing portion 4a. When the operation check valve 4 is used as a single unit, it is desirable to use such a valve accommodating portion 4a.

  The switching valve 5 and the pair of check valves 4b are oil-tightly housed in the internal housing space of the housing cylinder 4aa of the valve housing portion 4a.

  The switching valve 5 includes a cylindrical spool cylinder 5a that is accommodated in the center of the internal accommodation space of the accommodation cylinder 4aa without any gap, and a spool 5b that is slidably accommodated in the internal column space of the spool cylinder 5a. .

  The spool cylinder 5a is connected to two pipe lines from the hydraulic pump 1 at its cylinder part, and two openings 5ab for allowing the hydraulic oil to flow between these pipe lines, An opening 5ac that does not interfere with the opening 5ab and that allows the hydraulic oil to flow through the pipe line to the tank 3 is provided at the center of the spool cylinder 5a of both the openings 5ab in the cylinder axis direction. .

  The spool 5b has a shape in which two disks are skewered with a cylindrical body having an outer diameter smaller than the outer diameter of the disk, and the outer diameter of the disk portion 5bb is smaller than the inner circumference of the spool cylinder 5a. The outer diameter is slidable.

  As shown in the figure, when the spool 5b is positioned at the center, the distance between the two disk portions 5bb is between the opening 5ab on the two hydraulic pumps 1 side and the opening 5ac on the tank 3 side. It prevents the flow of hydraulic oil. In addition, when one of the spools 5b slides to the bottom side, for example, only the bottom side of the openings 5ab on the two hydraulic pumps 1 side and the flow of hydraulic oil to the opening 5ac to the tank 3 side are permitted. It has become a thing.

  The outer diameter of the middle shaft portion 5bc sandwiched between the two circular disc portions 5bb of the cylindrical body is larger than the degree of maintaining the structural strength of the entire spool 5b, and operates between its outer periphery and the inner periphery of the spool cylinder 5a. It is thinner than the oil can circulate without resistance.

  The protruding length of the outer shaft portion 5ba extending to the outside of the disc portion 5bb is to fully open the opposing check valve 4b when the spool 5b moves to the maximum, and the outer diameter thereof is checked later. It passes through the valve seat hole 4cb of the valve 4b without hindrance so that the hydraulic oil can be easily circulated with the valve seat hole 4cb.

  The respective parts constituting the spool 5b are fixed to each other, and the whole slides integrally.

  With such a configuration, the spool 5b has the above function of the disk portion 5bb, and when one outer shaft portion 5ba opens the check valve 4b on that side, the check valve 4b on this side, the hydraulic pump 1. The distribution of hydraulic oil between the tanks 3 is permitted.

  The pair of check valves 4b are configured identically to each other, and include a valve seat body 4c, a valve body 4d that slides within the valve seat body 4c, and a spring 4h that normally biases the valve body 4d in the closing direction. And.

  The valve seat body 4c is a cylindrical body that is a valve seat hole 4cb, one of which is a smaller opening, and the rod side oil chamber 2b (opposite side) of the hydraulic cylinder 2 is placed in the cylinder portion near the valve seat hole 4cb side. Then, an opening 4ca is provided that allows the hydraulic oil to flow through the pipe line to the bottom side oil chamber 2a).

  The valve body 4d is a cylindrical body whose front end is closed as a conical valve portion 4e and which is the other opening. The spring 4h is accommodated in the inner cylinder portion 4f. The rear end of the spring 4h and the valve seat The housing cylinder lid 4ab of the valve housing portion 4a regulates the rear end of the body 4c.

  The valve seat hole 4cb of the valve seat body 4c is closed by the valve portion 4e of the valve body 4d biased by the spring 4h.

  An opening 4g is provided behind the end of the valve portion 4e of the valve body 4d to allow the hydraulic oil flowing from the opening 4ca to flow also to the inner cylinder portion 4f.

  The point which this operation check valve 4 exhibits both a check valve function and a switching valve function with such a structure is demonstrated below.

FIG. 1 itself shows a stationary body, that is, a state where the hydraulic pump 1 is not rotating. In this state, no pressure is applied to the hydraulic oil from the hydraulic pump 1 side, and the hydraulic pump 1 and the operation check are performed. Hydraulic oil contained between the internal oil chambers on both sides of the switching valve 5 built in the valve 4, the switching valve 5
The hydraulic oil contained between the central side internal oil chamber and the tank 3 is stationary.

  The left and right check valves 4b of the operate check valve 4 are closed by the urging force of the spring 4h, and hydraulic oil from either the bottom side oil chamber 2a or the rod side oil chamber 2b of the hydraulic cylinder 2 is closed by the check valve 4b. Thus, the stationary state of the hydraulic cylinder 2 is maintained.

  Here, when the hydraulic pump 1 rotates so as to discharge the hydraulic oil to the bottom side port, this hydraulic pressure opens the bottom side check valve 4b, and the hydraulic oil is supplied to the bottom side oil chamber 2a of the hydraulic cylinder 2. .

  At the same time, the spool 5b of the switching valve 5 is also moved to the right side of the figure by this oil pressure to the rod side, allowing the hydraulic oil to flow between the rod side port of the hydraulic pump 1 and the tank 3, and at the same time the rod side of the spool 5b. The outer shaft portion 5ba opens the rod-side check valve 4b, allows the hydraulic oil to flow from the rod-side oil chamber 2b of the hydraulic cylinder 2, and causes the hydraulic cylinder 2 to generate a driving force in the extending direction.

  At this time, the flow of hydraulic oil between the rod side oil chamber 2b of the hydraulic cylinder 2, the check valve 4b on the rod side, and the tank 3 is permitted. In addition to the hydraulic oil from the rod side oil chamber 2b of the hydraulic cylinder 2, The hydraulic oil from the tank 3 flows into the rod side port of the hydraulic pump 1 to cover the shortage of the hydraulic oil flow rate in the rod side oil chamber 2b with respect to the bottom side oil chamber 2a of the hydraulic cylinder 2.

  On the other hand, when the hydraulic pump 1 rotates so as to discharge hydraulic oil to the rod side port, the reverse operation occurs in the switching valve 4 and the check valve 4b, causing the hydraulic cylinder 2 to generate a driving force in the contraction direction, and the hydraulic cylinder The excess hydraulic oil flow rate in the bottom side oil chamber 2 a relative to the second rod side oil chamber 2 b is returned to the tank 3.

  Thus, the interaction of the central switching valve 5 accommodated in the operation check valve 4 and the pair of check valves 4b opposed so as to sandwich the center switching valve 5 functions as a conventional operation check valve while also serving as a switching valve. Yes.

  In other words, the operation check valve 4 of the present invention is a single unit that absorbs and integrates the conventional switching valve, thereby enabling the operation check valve to be multifunctional, and a space for providing a separate switching valve. Expenses, a pipe connecting the switching valve and the check valve, and the like become unnecessary.

  In addition to the effects of the composite valve 7, the hydraulic drive unit 10 having such an operation check valve 4 can further reduce the size and cost of the apparatus while maintaining its function as a unit. .

  FIG. 4 is a configuration diagram conceptually showing another example of the hydraulic drive unit including the composite valve of the present invention.

  This hydraulic drive unit 10A is common to the hydraulic drive unit 10 of FIGS. 1 to 3 in that it includes a composite valve 7, but the operation check valve 4A does not absorb and integrate the switching valve, and the switching valve 5A. The poppet type switching valve 5A is a characteristic point.

  The operated check valve 4A includes a valve accommodating portion 4a, a pilot portion 45i accommodated in the central portion of the valve accommodating portion 4a, and a pair of check valves 4b accommodated so as to face each other with the pilot portion 45i interposed therebetween. I have.

  In this example, the valve accommodating portion 4a includes a cylindrical accommodating cylinder 4aa and an accommodating cylinder lid 4ab that closes both end openings in an oil-tight manner.

  In order to make the explanation easy to understand, the valve accommodating portion 4a is shown as a cylindrical separate independent part. However, in an actual hydraulic drive unit, the structure body is a part of the structure of the entire unit. It is incorporated therein and includes an internal housing space for the valve housing portion 4a. When the operation check valve 4A is used as a single body, it is desirable to use such a valve accommodating portion 4a.

  The pilot portion 45i and the pair of check valves 4b are oil-tightly accommodated in the internal accommodating space of the accommodating cylinder 4aa of the valve accommodating portion 4a.

  The pilot portion 45i includes a cylindrical spool cylinder 45j that is accommodated in the center of the internal accommodation space of the accommodation cylinder 4aa without a gap, and a pilot spool 45l that is slidably accommodated in the internal column space of the spool cylinder 45j. Yes.

  The spool cylinder 45j is connected to the pipe line to the two ports of the hydraulic pump 1 at the cylinder part, and also to the pipe line to the two openings 5cc of the switching valve 5A. Four openings 45k are provided that allow the hydraulic oil to flow between the hydraulic pump 1 and the switching valve 5A.

  The spool 45l has a structure in which small-diameter pilot protrusions 45lb are provided at both ends of a cylindrical body 45la whose outer diameter is slidable on the inner periphery of the spool cylinder 45j. The spool cylinder 45j is partitioned by a spool 45l, and two oil chambers communicating with the respective openings 45k are formed.

  With such a configuration, when the hydraulic pump 1 rotates while the pilot spool 45l always allows the hydraulic oil to flow between the hydraulic pump 1 and the tank 3, the hydraulic pressure of the oil chamber connected to the discharge side of the pilot spool 45l is increased. Since it becomes higher, it moves to the non-ejection side.

  That is, the pilot unit 45i exhibits the function of the pilot line OCb in the hydraulic drive unit OU of FIG.

  The pair of check valves 4b are configured identically to each other, and include a valve seat body 4c, a valve body 4d that slides within the valve seat body 4c, and a spring 4h that normally biases the valve body 4d in the closing direction. And.

  The valve seat body 4c is a cylindrical body that is a valve seat hole 4cb, one of which is a smaller opening, and the rod side oil chamber 2b (opposite side) of the hydraulic cylinder 2 is placed in the cylinder portion near the valve seat hole 4cb side. Then, an opening 4ca is provided that allows the hydraulic oil to flow through the pipe line to the bottom side oil chamber 2a).

  The valve body 4d is a cylindrical body whose front end is closed as a conical valve portion 4e and which is the other opening. The spring 4h is accommodated in the inner cylinder portion 4f. The rear end of the spring 4h and the valve seat The housing cylinder lid 4ab of the valve housing portion 4a regulates the rear end of the body 4c.

  The valve seat hole 4cb of the valve seat body 4c is closed by the valve portion 4e of the valve body 4d biased by the spring 4h.

  An opening 4g is provided behind the end of the valve portion 4e of the valve body 4d to allow the hydraulic oil flowing from the opening 4ca to flow also to the inner cylinder portion 4f.

  The function and effect of the check valve 4b are the same as those of the check valve OCa built in the operation check valve OC described in FIG. 10. As a result, the operation check valve 4A as a whole is the operation check valve OC of FIG. Exhibits the same functions and effects.

  The switching valve 5A has the same role as the switching valve OI of FIG. 10, but is characterized in that the valve structure is a poppet type.

  The structure is such that a pair of identical members are opposed to each other and are accommodated in the central portion in the valve accommodating portion 51. The valve seat cylinder 5c, the valve element 5d that slides in the valve seat cylinder 5c, and the valve element, respectively. There is provided a spring 5e for urging 5d toward each other.

  The valve accommodating part 51 is comprised from the accommodating cylinder 51a of a cylindrical body, and the accommodation cylinder cover 51b which closes the both-ends opening oil-tightly, and a pair of valve seat cylinder 5c is oil in the internal accommodation space of this accommodation cylinder 51a. Closely contained.

  In order to make the explanation easier to understand, the valve accommodating portion 51 is shown as a cylindrical separate independent part. However, in an actual hydraulic drive unit, the structure of the structural body is a part of the structural body of the entire unit. It is incorporated therein and includes an internal housing space of the valve housing portion 51 formed therein. When the switching valve 5A is used as a single unit, it is desirable to use such a valve accommodating portion 51.

  The valve seat cylinder 5c is a cylindrical body having a stepped inner periphery, and the outer periphery thereof is fitted in the inner periphery of the housing cylinder 51a without any gaps and in an oil-tight manner. The inner peripheral side includes a small diameter portion 5ca and a large diameter portion 5cb, and the small diameter portion 5ca is connected to the small diameter portion 5ca of the valve seat cylinder 5c facing each other. The peripheral wall of the large diameter portion 5cb closest to the small diameter portion 5ca is provided with an opening 5cc that enables the flow of hydraulic oil to and from the pipe line to the hydraulic pump 1, and the peripheral wall of the small diameter portion 5ca is connected to the tank 3. An opening 5cd is provided that enables the flow of hydraulic oil to and from the pipeline.

  The valve body 5d has a shape in which a stepped protrusion is provided on one of the center sides of the disc, and the outer diameter of the disc portion 5da slides with respect to the inner periphery of the large diameter portion 5cb of the valve seat cylinder 5c. It is possible.

  The stepped protrusion is composed of a state-of-the-art small-diameter portion 5db, followed by a larger-diameter medium-diameter portion 5dc, followed by a valve gradient portion 5dd. So that the valve gradient portion 5dd comes into contact with the step edge from the small diameter portion 5ca to the large diameter portion 5cb of the valve seat cylinder 5c to completely prevent the flow of hydraulic oil between the two. This is the reason why it is called a poppet type.

  The disk portion 5da is provided with a through hole 5de that allows the working oil to flow from the stepped protrusion side to the protrusionless side.

  The valve body 5d is incorporated in the valve seat cylinder 5c so that the tip of the small diameter portion 5db contacts the tip of the small diameter portion 5db of the opposing valve body 5d.

  The spring 5 e is inserted between the rear surface of the valve body 5 d and the housing cylinder lid 51 b of the valve housing portion 51.

  The switching valve 5A has a pair of poppet valves (a valve seat cylinder 5c and a valve body 5d) arranged coaxially opposite to each other so that the operation of one poppet valve in the closing direction allows the other poppet valve to operate in the opening direction. The function of the switching valve 5A having such a configuration will be described below.

  FIG. 4 itself shows a stationary body, that is, a state where the hydraulic pump 1 is not rotating. In this state, no pressure is applied to the hydraulic oil from the hydraulic pump 1 side, and the hydraulic pump 1 and the operation check are performed. The hydraulic oil contained between the internal oil chambers on both sides of the pilot portion 45i of the valve 4A and the hydraulic oil contained between the internal oil chamber of the switching valve 5A and the tank 3 are stationary.

  The left and right check valves 4b of the operating check valve 4A are closed by the biasing force of the spring 4h, and the hydraulic oil from either the bottom side oil chamber 2a or the rod side oil chamber 2b of the hydraulic cylinder 2 is closed by the check valve 4b. Thus, the stationary state of the hydraulic cylinder 2 is maintained.

  Here, when the hydraulic pump 1 rotates so as to discharge hydraulic oil to the bottom side port, the hydraulic pressure opens the bottom side check valve 4b, and the hydraulic oil is supplied to the bottom side oil chamber 2a of the hydraulic cylinder 2, At the same time, the pilot spool 45l of the pilot portion 45i is also moved to the right side of the figure by this oil pressure, to the rod side, and the rod-side outer shaft portion 45lb opens the rod-side check valve 4b. The hydraulic oil flow from 2b is allowed, and a driving force in the extending direction is generated in the hydraulic cylinder 2.

  At the same time, the bottom side valve element 5d of the switching valve 5A moves to the right side in the figure, the rod side, the rod side valve element 5d moves to the rod side, and the oil on the stepped protrusion side of the bottom side valve element 5d. The chamber allows the hydraulic oil to flow with the tank 3 via the opening 5cd of the valve seat cylinder 5c, and the amount of hydraulic oil in the rod side oil chamber 2b relative to the bottom side oil chamber 2a of the hydraulic cylinder 2 is insufficient. Is supplied from the tank 3.

  On the other hand, when the hydraulic pump 1 rotates so as to discharge hydraulic oil to the rod side port, the pair of check valves 4b, the pilot portion 45i, and the switching valve 5A of the operate check valve 4A operate in the reverse manner to the above. Driving force in the contracting direction is generated in the cylinder 2, and excess hydraulic oil at that time is allowed to flow through the tank 3 in the bottom side valve body 5 d and is returned to the tank 3.

  In any of the above-described driving cases, the closing between the valve body 5d of the switching valve 5A and the valve seat cylinder 5c is configured as a poppet type, and the flow of hydraulic oil can be completely closed. Compared with the valve, leakage between the bottom side, the rod side, and the tank can be prevented, and the pump efficiency can be improved.

  Further, the predetermined gap between the outer diameter of the intermediate diameter portion 5dc of the valve body 5d of the switching valve 5A and the small diameter portion 5ca of the valve seat cylinder 5c appropriately limits the amount of hydraulic oil passing between the two. Thus, the oil pressure on the tank 3 side acts on the area of the medium diameter portion 5dc only on the stepped protrusion side, and among the forces acting on both sides of the disc portion 5da of the valve body 5d, it acts on the stepless side relatively. The switching force is increased so that the switching action is exhibited.

    Further, the spring 5e always urges the opposing valve body 5d in the center (opposite) direction, and both the valve bodies 5d have their middle diameter portions 5dc engaged with the small diameter portion 5ca of the valve seat cylinder 5c (not shown). State), a standby state maintaining means for maintaining the standby state in which the switching action can be exhibited.

  Such a standby state maintaining means is not limited to the spring of this example, but is one that generates an elastic biasing force and is resistant to hydraulic oil, such as oil-resistant rubber, oil-resistant elastic synthetic resin, etc. There may be.

  The switching valve 5A described above with reference to FIG. 4 exhibits the above functions and effects as components of the hydraulic drive unit 10, and is used in combination with an operation check valve to control the flow of hydraulic oil in both forward and reverse directions. The above-mentioned functions and effects are exhibited as a switching valve.

  The hydraulic drive unit 10 provided with such a switching valve 5A exhibits these functions and effects as a unit in addition to the effects of the composite valve 7.

  FIG. 5 (a) is a block diagram conceptually showing another example of a hydraulic drive unit equipped with the composite valve of the present invention, (b) is a detailed view of the main part of the check valve of (a), and (c) is (b). FIG.

  The hydraulic drive unit 10B is common to the hydraulic drive unit 10A shown in FIG. 4 in that it includes a composite valve 7, but the switching valve 5B is not a poppet type but a conventionally used spool type. The difference is that the operation check valve 4B is an integral integration of a fixed slow return valve, which is characterized by the operation check valve 4B.

  The operated check valve 4B includes a valve accommodating portion 4a, a pilot portion 45m accommodated in the central portion of the valve accommodating portion 4a, and a pair of check valves 4i accommodated so as to face each other with the pilot portion 45m interposed therebetween. I have.

  The pilot portion 45m and the pair of check valves 4i are oil-tightly accommodated in the internal accommodating space of the accommodating cylinder 4aa of the valve accommodating portion 4a.

  The pilot portion 45m includes a cylindrical spool cylinder 45n accommodated in the center of the internal accommodation space of the accommodation cylinder 4aa, a pilot spool 45p slidably accommodated in the internal cylindrical space of the spool cylinder 45n, and movement restricting means. 45o.

  The spool cylinder 45n is connected to pipes to the two ports of the hydraulic pump 1 at the cylinder part and to pipes to the two openings 5fa of the switching valve 5B. Four openings 45k are provided to allow the hydraulic oil to flow between the hydraulic pump 1 and the switching valve 5B. The movement restricting means 45o is provided as a stop ring on the inner periphery of the spool cylinder 45n.

  The spool 45p has a structure in which small-diameter pilot protrusions 45pb are provided at both ends of a cylindrical body 45pa whose outer diameter is slidable on the inner periphery of the spool cylinder 45n. The spool cylinder 45n is partitioned by a spool 45p, and two oil chambers communicating with the respective openings 45k are formed.

  The length of the pilot protrusion 45pb is such that the front end protrusion 4ka of the valve body 4j constituting the check valve 4i is pushed in and the check valve is pilot-opened.

  The movement restricting means 45o determines the pilot movement amount of the pilot spool 45p, that is, the movement amount of the check valve 4i when the hydraulic oil discharged from the pump 1 is moved to the counter discharge side. The throttle passage 4kc at the front end is restricted to a functioning range, and thereby a slow return throttling function is exhibited.

  The basic configuration of the pilot section 45m is the same as that of the pilot section 45i built in the operation check valve 4A described in FIG. 4 except for the movement restricting means 45o, and exhibits the same functions and effects, that is, the pilot function. To do.

  The pair of check valves 4i are composed of exactly the same one another, and includes a valve seat body 4c, a valve body 4i that slides within the valve seat body 4c, and a spring 4h that normally biases the valve body 4i in the closing direction. And.

  The valve seat body 4c is a cylindrical body that is a valve seat hole 4cb, one of which is a smaller opening, and the rod side oil chamber 2b (opposite side) of the hydraulic cylinder 2 is placed in the cylinder portion near the valve seat hole 4cb side. Then, an opening 4ca is provided that allows the hydraulic oil to flow through the pipe line to the bottom side oil chamber 2a).

  The valve body 4j is a cylindrical body whose front end is closed as a conical valve portion 4k and which is the other opening. The spring 4h is accommodated in the inner cylindrical portion 4f. The rear end of the spring 4h and the valve seat The housing cylinder lid 4ab of the valve housing portion 4a regulates the rear end of the body 4c.

  The valve seat hole 4cb of the valve seat body 4c is closed by the valve portion 4k of the valve body 4d biased by the spring 4h.

  An opening 4g is provided behind the end of the valve portion 4k of the valve body 4j so that the hydraulic oil flowing from the opening 4ca also flows to the inner cylinder portion 4f.

  The basic configuration, function, and effect of the check valve 4j are the same as those of the check valve 4b built in the operating check valve 4A described in FIG. 4, but the tip side of the conical valve portion 4k of the valve body 4j is one step. The difference is that it is a stepped projection.

  The tip protrusion 4ka of the stepped protrusion is pushed by the hydraulic oil discharged from the hydraulic pump 1, and the valve body 4j becomes the rear end (the state where the rear end of the valve body 4j abuts against the housing lid 4ab). At this time, the valve seat hole 4cb is located and the valve 4i is fully opened.

  The step 4kb following the tip protrusion 4ka has an outer diameter that is slidable with respect to the inner diameter of the valve seat hole 4cb and prevents the flow of hydraulic oil. The width of the step 4kb is that of the check valve 4i. From the fully closed position to the opening degree opened by the pilot action of the pilot portion 45m, the flow of hydraulic oil other than that by the fixed throttle passage 4kc described below is blocked from the valve seat hole 4cb.

  The stepped portion 4 kb is provided with a fixed throttle passage 4 kc having a fixed depth from the outer periphery from the front end to a position where the conical gradient is reached, and while the check valve 4 i is opened by the pilot action, the hydraulic oil having a predetermined flow rate is provided. The reverse flow is permitted.

  The fixed throttle passage 4kc is incorporated into the check valve 4i, thereby permitting the hydraulic oil to flow from the hydraulic pump 1 to the hydraulic cylinder 2, and the check valve 4i is opened by a pilot action to open a predetermined opening. When the backflow of the hydraulic oil from the cylinder 2 to the hydraulic pump 1 is allowed, the flow of the hydraulic oil from the hydraulic cylinder 2 to the hydraulic pump 1 is permitted by the amount of the throttle passage 4kc. It can also play the role of the valve SR.

  In addition to the fixed throttle passage 4kc as described above, the check valve is provided with a fixed throttle, and the outer diameter of the stepped portion is set to the inner diameter of the valve seat hole 4cb of the check valve 4i so as to correspond to the passage area. It is also possible to make it smaller.

  The switching valve 5B includes a valve accommodating part 51, a cylindrical spool cylinder 5f that is accommodated in the valve accommodating part 51 without a gap, and a spool 5g that is slidably accommodated in an internal column space of the spool cylinder 5f. 4 that exhibits the same function as the switching valve 5A of FIG. 4 and has a common valve accommodating portion 51, but the valve accommodated in the valve accommodating portion 51 is a spool type that is conventionally used. Is different.

  The accommodating cylinder 51a and the accommodating cylinder lid 51b constituting the valve accommodating part 51 are common to the valve accommodating part 51 of FIG.

  The spool cylinder 5f is connected to two pipe lines from the operation check valve 4B at its cylinder part, and two openings 5fa for allowing the hydraulic oil to flow between these pipe lines, An opening 5fb that allows the working oil to flow through the pipe line to the tank 3 is provided at a position that does not interfere with the two openings 5fa and that is the center in the cylinder axis direction of the spool cylinder 5f of both the openings 5fa. Yes.

  The spool 5g has a shape in which two disks are skewered with a cylindrical body having an outer diameter smaller than the outer diameter of the disk, and the outer diameter of the disk portion 5gb is smaller than the inner circumference of the spool cylinder 5f. The outer diameter is slidable.

  As shown in the drawing, the distance between the two disk portions 5gb is the distance between the opening 5fa on the two operation check valves 4B side and the opening 5fb on the tank 3 side when the spool 5g is located at the center. The flow of hydraulic oil is blocked. In addition, when the spool 5g slides in one direction, for example, to the bottom side, the hydraulic oil of only the bottom side of the opening 5fa on the two operation check valves 4B side and the opening 5fb on the tank 3 side Distribution is permitted.

  The outer diameter of the central shaft portion 5gc sandwiched between the two circular disk portions 5gb of the cylindrical body is thicker than it can hold the structural strength of the entire spool 5g, and operates between its outer periphery and the inner periphery of the spool cylinder 5f. It is thinner than the oil can circulate without resistance.

  The protruding length of the outer shaft portion 5ga extending outside the disc portion 5gb is such that when the tip of the outer shaft portion 5ga comes into contact with, for example, the bottom-side storage cylinder lid 51b of the valve storage portion 51, the operation check valve 4B side The flow of hydraulic oil between only the bottom side of the opening 5fa and the opening 5fb to the tank 3 side is maintained.

  The respective parts constituting the spool 5g are fixed to each other, and the whole slides integrally.

  With such a configuration, the spool 5g has the above function of the disc portion 5gb, and in addition to the above-described function of the disc portion 5gb, when the higher pressure hydraulic oil on the discharge side of the hydraulic pump 1 is supplied to the one outer shaft portion 5ga And the tank 3 is connected to the suction side of the hydraulic pump 1. When the rotation of the hydraulic pump 1 is reversed and the discharge side and the suction side are reversed, the spool 5g operates reverse to the above.

  With such a configuration, the operation check valve 4B and the switching valve 5B constituting the hydraulic drive unit 10B have the same functions as the operation check valve OC and the switching valve OI constituting the hydraulic drive unit OU of FIG. , Show effect.

  In addition, the operation check valve 4B has a fixed flow rate of the working fluid flowing out from the hydraulic actuator 2 while the check valve 4i is pilot-opened by the cooperation of the fixed throttle passage 4kc and the movement restricting means 45o. The function of limiting or adjusting only the throttle passage 4kc is exhibited.

  In other words, the operation check valve 4B according to the present invention is an integrated absorption type of the conventional slow return valve, which allows the operation check valve to be multi-functional and a space for providing a separate slow return valve. , Cost, a pipe connecting the slow return valve and the check valve is not necessary. In addition to the effect of providing the composite valve 7, the hydraulic drive unit 10 having such an operation check valve 4B can further reduce the size and cost of the apparatus while maintaining its function.

  The switching valve 5B used in the unit 10B can be the poppet switching valve 5A shown in FIG. 4, and in that case, the poppet switching valve 5A is similar to the unit 10A shown in FIG. Demonstrate the effect.

  FIG. 6A is a block diagram conceptually showing another example of the hydraulic drive unit provided with the composite valve of the present invention, and FIG. 6B is a detailed view of the main part of the check valve of FIG.

  The hydraulic drive unit 10C shown in FIG. 6 is common to the hydraulic drive unit 10B shown in FIG. 5 in that the composite valve 7 is provided and a slow return valve is accommodated in the operation check valve 4C. The difference is that it is not a fixed type that cannot change the throttle amount of the slow return, but a variable type that can change the throttle amount.

  Specifically, the pilot unit 45m accommodated in the center of the composite valve 7, the switching valve 5B, and the operation check valves 4B and 4C is common to the unit 10C and the unit 10B of FIG.

  The difference is that the pair of check valves 4l has a variable throttle and can be adjusted in and out of the valve accommodating portion 4a 'of the operated check valve 4C. This will be described below.

  Compared with the check valve 4i of FIG. 5, the check valve 4l is configured such that the valve seat body 4m is accommodated so as to be adjustable in and out of the valve accommodating part 4a ', and the throttle part 4oa is provided in the valve part 4o of the valve element 4n. Is different.

  The portion of the valve seat body 4m on the pilot portion 45m side is common with the valve seat body 4c of the check valve 4i in FIG.

  The counter-pilot portion 45m side portion of the valve seat body 4m is provided with a disc 4ma for regulating the rear end of the spring 4h on the inner periphery, a stop ring 4mb for positioning the disc 4ma, and a rear opening of the valve seat body 4m. A lid 4mc that closes tightly is provided, and a male screw 4md is formed on the outer periphery. A locking nut 4me is externally fitted to the male screw 4md.

  Compared with the valve accommodating part 4a of FIG. 5, the valve accommodating part 4a 'does not have an accommodating cylinder cover 4ab. Instead, the female thread 4ac corresponding to the male thread 4md of the valve seat body 4m is provided inside the opening at both ends of the accommodating cylinder 4aa'. The difference is that it is formed.

  As a result, the male screw 4md of the valve seat body 4m can be screw-fitted to the female screw 4ac of the valve accommodating portion 4a ′, and the fitting state at an arbitrary position can be fixed with the lock nut 4me.

  The throttle gradient portion 4oa of the valve portion 4o is gentler than the conical gradient for closing the valve portion 4o. The protrusion 4ob at the tip is the same as the protrusion 4ka of the check valve 4i in FIG.

  According to the operation check valve 4C provided with this check valve 4l in such a configuration, not only exhibits a slow return function, but also adjusts the insertion / extraction position of the valve seat body 4m containing the valve body 4n, It is possible to adjust at which part of the throttle gradient portion 4oa of the valve portion 4o the slow return throttle is exerted, so that the variable throttle is provided.

  Further, by making the gradient of the aperture gradient portion 4oa gentler, the adjustment of the variable aperture can be adjusted more finely.

  The variable throttle can be realized by a conical gradient as in this example, but the sectional area of the fixed throttle passage 4kc at the tip of the valve body 4j of the check valve 4i shown in FIG. 5 changes in the axial direction of the valve body. It is good also as a change throttling path like this.

  The operation check valve 4C is characterized by integrating a variable type slow return valve, and the effects thereof are exhibited as the check valve 4C and the unit 10C. Further, since the unit 10C is provided with the composite valve 7, the effect is also exhibited as a unit.

  This unit 10C is similar to the unit 10B of FIG. 5 in that the spool type switching valve 5B can be the poppet type switching valve 5A of FIG.

  In Examples 4 and 5, a fixed or variable throttle is provided on the check valve side. As shown in Japanese Patent Application No. 2004-291251 by the same applicant as the present application, the throttle is piloted. It can also be provided on the part side.

  FIG. 7 is a block diagram conceptually showing another example of the hydraulic drive unit provided with the composite valve of the present invention.

  Compared with the hydraulic drive unit 10A of FIG. 4, this hydraulic drive unit 10D has the composite valve 7 and the operation check valve 4A in common, but the switching valve 5C is not a poppet type but a spool type, and a relief valve is integrated. The difference is that it has become a characteristic.

  The switching valve 5C includes a valve accommodating part 51, a cylindrical spool cylinder 5f that is oil-tightly accommodated in the valve accommodating part 51 without any gap, and a spool that is slidably accommodated in an internal column space of the spool cylinder 5f. 5h.

  The accommodating cylinder 51a, the accommodating cylinder lid 51b, the two openings 5fa constituting the spool cylinder 5f, and the opening 5fb to the tank 3 constituting the valve accommodating part 51 are the same as the corresponding parts of the switching valve 5B in FIG. .

  What is different is a spool 5h having a relief valve function. The spool 5h includes two cylindrical plates 5ha, and a spring 5hb sandwiched between the cylindrical plates 5ha to urge the cylindrical plates 5ha away from each other. A stop ring 5hc that defines a range in which the cylindrical plates 5ha are separated from each other, a cylindrical plate 5ha, a spring 5hb, and a through shaft 5hd that penetrates the center of the stop ring 5hc are provided.

  The outer diameter of the cylindrical plate 5ha is slidable to the inner diameter of the spool cylinder 5f, and the inner diameter of the cylindrical plate 5ha is slidable to the outer diameter of the through shaft 5hd. The spring 5hb is externally fitted between the two cylindrical plates 5ha of the through shaft 5hd. The stop ring 5hc is fitted in a groove provided at a predetermined position of the through shaft 5hd, and defines the maximum range in which the cylindrical plate 5ha is urged by the spring 5hb and separated from each other.

  Both ends of the penetrating shaft 5hd abut against the opposing storage cylinder lid 51b.

  The two cylindrical plates 5ha biased by the spring 5hb and separated from each other at the restriction position by the stop ring 5hc are in the same positional relationship as the two disc portions 5gb of the spool 5g of the switching valve 5B in FIG. The switching valve 5C provided with the spool 5h normally exhibits the same function and effect as the switching valve 5B of FIG.

  Among the oil chambers on both sides partitioned by the spool 5h when the hydraulic pump 1 is in operation, the discharge-side oil chamber that circulates with the discharge-side port of the pump 1 but does not circulate with the tank 3 for a certain reason or higher. When this occurs, the cylinder plate 5ha on the discharge side moves against the urging force of the spring 5hb in the direction opposite to the discharge side, and passes through the opening 5fb to the tank 3, so that the high-pressure hydraulic oil is transferred to the tank. Returned to 3.

  Thus, the function of the relief valve RV2 of the hydraulic drive unit OU of FIG. 10 is realized by the spool 5h having this configuration, and the relief valve RV2 is absorbed and integrated with the switching valve 5C. As the hydraulic drive unit 10D, In addition to the effects of the composite valve 7, the effects of cost reduction, resource saving, and compactness are further exhibited.

  Further, the switching valve 5C exhibits the effects of multi-function, space saving, resource saving, and cost reduction.

  FIG. 8 is a block diagram conceptually showing another example of the hydraulic drive unit provided with the composite valve of the present invention.

  This hydraulic drive unit 10E is common to the hydraulic drive unit 10D of FIG. 7 in that it includes a composite valve 7. However, the relief valve is integrated with the operation check valve 4D, not the switching valve 5B. Is different.

  That is, the check valve 4b accommodated in the operation check valve 4D is the same as that in FIG. 7, but the central pilot unit 46 absorbs and integrates the relief valve, and the switching valve 5B has a relief valve function. This is the same as the switching valve 5B in FIG.

  The switching valve 5B is common to the switching valve 5B of FIG. 5, and includes each part, a valve accommodating part 51 (accommodating cylinder 51a, accommodating cylinder lid 51b), a spool cylinder 5f (opening 5fa, opening 5fb), and a spool 5g (outer shaft part). 5ga, the disc portion 5gb, and the middle shaft portion 5gc) are also common to the corresponding portions, and the functions and effects are also the same.

  The pilot unit 46 includes a spool cylinder 46a and a spool 46d.

  The overall shape of the spool 46d is the same as that of the pilot portion 45i of FIG. 4 and includes two openings 46b that perform the same function at the same position. The difference is that an opening 46c connected to the pipe line to the tank 3 is provided at the center in the cylinder axis direction of the spool 46d so as not to interfere with the two openings 46b.

  The spool 46d having a relief valve function defines two cylindrical plates 46e, a spring 46f that is sandwiched between the cylindrical plates 46e and biases the cylindrical plates 46e away from each other, and a range in which the cylindrical plates 46e are separated from each other. A stop ring 46g, a cylindrical plate 46e, a spring 46f, and a through shaft 46h that passes through the stop ring 46g.

  The outer diameter of the cylindrical plate 46e is slidable to the inner diameter of the spool cylinder 46a, and the inner diameter of the cylindrical plate 46e is slidable to the outer diameter of the through shaft 46h. The spring 46f is externally fitted between the two cylindrical plates 46e of the through shaft 46h. The stop ring 46g is fitted in a groove provided at a predetermined position of the through shaft 46h, and defines a maximum range in which the cylindrical plate 46e is urged by the spring 46f and separated from each other.

  Both ends of the through-shaft 46h abut against the valve portion 4e of the valve body 4d constituting the opposing check valve 4b, and push the valve body 4d open to allow the hydraulic oil to flow.

  The two cylindrical plates 46e, which are biased by the spring 46f and are separated from each other at the restricting position by the stop ring 46g, are in any position of the pilot movement during the normal operation in which the pilot function is performed. However, the flow of the hydraulic oil between the two openings 46b to the hydraulic pump 1 and the opening 46c to the tank 3 is not permitted, and the hydraulic oil is connected to the hydraulic pump 1 and the switching valve via the opening 46b. 5B flows in a state where it is not mixed on the discharge side and suction side of the hydraulic pump 1, respectively.

  For some reason, when the hydraulic pump 1 is operating and one of the oil chambers on both sides partitioned by the spool 46d, for example, the spool 46d is pilot-moved to the most anti-discharge side by being pushed by the hydraulic oil on the discharge side. When a predetermined high pressure or higher occurs, the discharge side cylindrical plate 46e moves against the urging force of the spring 46f in the anti-discharge side direction and passes through the opening 46c to the tank 3, and the high pressure The hydraulic oil is returned to the tank 3.

  Thus, the function of the relief valve RV2 of the hydraulic drive unit OU of FIG. 10 is also realized by the pilot portion 46 of this configuration, and this relief valve RV2 is absorbed and integrated with the operation check valve 4D, and the hydraulic drive unit 10E. As a result, in addition to the effects of the composite valve 7, the effects of cost reduction, resource saving, and downsizing can be achieved.

  Further, the operation check valve 4D exhibits the effects of multi-function, space saving, resource saving, and cost reduction.

  In this example, the switching valve 5B can be a poppet type switching valve 5A (see FIG. 4) in which a pair of poppet valves are coaxially opposed to each other. Compared with the switching valve 5B, the flow of the hydraulic oil between the valve body and the valve seat can be completely closed, leakage between the bottom side, the rod side, and the tank can be prevented, and the pump efficiency can be improved.

  FIG. 9 is a block diagram conceptually showing another example of the hydraulic drive unit provided with the composite valve of the present invention.

  The hydraulic drive unit 10F is common to the unit 10 in FIGS. 1 to 3 in that the composite valve 7 is provided, and the operation check valve 4E is integrated with the switching valve 5A ′. Is common in that the switching valve 5A 'is a poppet type, and the unit 10C in FIG. 6 is common in that a variable type slow return valve is absorbed and integrated with the operation check valve 4E.

  That is, the hydraulic drive unit 10F is basically provided with a composite valve 7 in which the relief valve RV1 of the hydraulic drive unit of FIG. 10 and the emergency manual valve MV are integrated, and the switching valve to the operation check valve is provided. This is a combination of absorption integration, switching valve poppetization, and absorption integration of variable slow return valve to the operation check valve.

  Specifically, for the operation check valve 4E, the valve housing 4a 'and the check valve 4l are common to the operation check valve 4C of FIG.

  As for the switching valve 5A ′, the switching valve 5 accommodated in the operation check valve 4 in FIG. 3 is a poppet type common to that accommodated in the valve accommodating portion 51 of the switching valve 5A in FIG. is there.

  At this time, the spring 5e in the switching valve 5A in FIG. 4 is not necessary, because the spring 4h of the check valve 4l combined with the switching valve 5A ′ is substituted.

  Thus, according to the unit 10F, the effects of the various combinations described above are exhibited synergistically.

  In the first to ninth embodiments, the relief valve and the emergency manual valve are integrated into one unit to form a composite valve, while the absorption integration of the switching valve into the operation check valve is integrated, the switching valve is made into a poppet, Various combinations of the absorption integration into the operation check valve of the slow return valve, the switching valve of the relief valve, and the absorption integration into the operation check valve have been described, but these combinations are not limited to those exemplified here, Other combinations are possible, in which case the synergistic effect of the combination is exhibited.

  In addition to the hydraulic cylinders described here, the hydraulic actuators include a hydraulic rotary actuator that outputs hydraulic driving force as torque, although there are few problems in adjusting the amount of hydraulic oil flowing in and out.

  Further, the composite valve of the present invention is suitably used in a general hydraulic circuit that requires space saving and compactness, particularly in a hydraulic drive unit.

  In addition, the hydraulic drive unit of the present invention is provided with such a composite valve, can independently apply a hydraulic drive force to the driven body, and can be used in any industrial field where compactness is required.

The block diagram which shows notionally an example of the hydraulic drive unit provided with the composite valve of this invention (A) is a block diagram of a state in which the emergency manual valve of the composite valve is opened in the hydraulic drive unit of FIG. 1, and (b) is a front view showing a stop ring used in the emergency operation valve of FIG. In the hydraulic drive unit of FIG. 1, the block diagram which showed notionally the detailed structure of the operation check valve The block diagram which shows notionally other examples of the hydraulic drive unit provided with the compound valve of this invention (A) is the block diagram which shows notionally the other example of the hydraulic drive unit provided with the composite valve of this invention, (b) is a detailed view of the main part of the check valve of (a), (c) is AA of (b). Arrow view (A) is a block diagram which shows notionally other examples of the hydraulic drive unit provided with the composite valve of this invention, (b) is a check valve principal part detail drawing of (a). The block diagram which shows notionally other examples of the hydraulic drive unit provided with the composite valve of this invention The block diagram which shows notionally other examples of the hydraulic drive unit provided with the composite valve of this invention The block diagram which shows notionally other examples of the hydraulic drive unit provided with the compound valve of this invention Hydraulic circuit diagram showing the basic configuration of the hydraulic drive unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Hydraulic actuator 3 Tank 4-4E Operate check valve 4a Valve accommodating part 4b Check valve 5-5B Switching valve 7 Compound valve 7a Valve accommodating part 7h Manual valve part of emergency manual valve 7r Valve body of relief valve 73 Valve Body drop prevention means 10-10F Hydraulic drive unit

Claims (4)

  It is used in a hydraulic circuit and is interposed between a hydraulic pump that pumps a working fluid and a hydraulic actuator that is operated by the working fluid, and the working fluid between the hydraulic pump and the hydraulic actuator has a high pressure that is higher than a predetermined level. A relief valve that allows the working fluid to escape to the tank, and an emergency manual valve that allows the working fluid between the hydraulic pump and the hydraulic actuator to escape to the tank when the hydraulic pump is stopped. A compound valve characterized by a single unit on the same axis.   2. The composite valve according to claim 1, further comprising valve body drop prevention means for preventing the valve body of the emergency manual valve formed as a unit as the composite valve from dropping out of the valve housing portion. Used in a hydraulic drive unit that independently supplies a driven force by hydraulic pressure to a driven body, and is provided with an electric motor and pumps a working fluid in both forward and reverse directions, and operates with this working fluid to generate the driving force. An operation check valve that is interposed between the hydraulic actuator and that controls a bidirectional flow of a working fluid between the hydraulic pump and the hydraulic actuator, and is used between the hydraulic actuator and the operation. A relief valve that allows the working fluid to escape to the tank when the working fluid between the check valve and the hydraulic actuator becomes a predetermined high pressure or higher;
3. The emergency manual valve that enables the working fluid between the operation check valve and the hydraulic actuator to escape to the tank when the hydraulic pump is stopped is formed as a unit. The compound valve described.   A hydraulic drive unit comprising the composite valve according to claim 3.

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