JP6632269B2 - Work machine control valve units - Google Patents

Description

  The present invention relates to a control valve unit for a working machine having a warm-up function.

  2. Description of the Related Art Conventionally, various warm-up control devices have been proposed for warming a hydraulic circuit when a work machine such as a hydraulic shovel starts cold. In general warm-up control of a hydraulic circuit, each part in the hydraulic circuit is warmed by warming hydraulic oil flowing inside the hydraulic circuit, and control is performed so that the entire hydraulic circuit appropriately heats up.

  For example, in a working machine having a center bypass, which is an oil passage for returning hydraulic oil to a hydraulic oil tank when the working machine is not operated (neutral), a warm-up operation is performed by repeating a relief operation and a neutral operation. Machine is done. That is, (1) by performing an input operation on a cylinder provided in the working machine in a direction in which the cylinder is further extended from a position where the cylinder is not extended any further, or by further performing a stick cylinder operation from a position where the cylinder is not further reduced. The hydraulic oil is positively circulated through the relief flow path (relief flow path) by performing an input operation in the direction to reduce the hydraulic pressure, and (2) the hydraulic oil is circulated through the center bypass when not operated. By repeating the above, the hydraulic oil is allowed to flow through the two flow paths of the relief flow path and the center bypass, thereby warming up the entire hydraulic circuit.

  By the way, many of the recent work machines are provided with a hydraulic circuit having four metering valves that can be individually controlled for one actuator, because the performance of the hydraulic circuit can be easily adjusted. Since such a hydraulic circuit does not have a center bypass, a bypass valve is required to control system pressure.

  In addition, for example, in a temperature raising circuit of an electromagnetic valve unit disclosed in Patent Document 1, an electromagnetic valve unit having a plurality of electromagnetic valves each having a valve pressure port and a valve tank port while forming a hydraulic pressure inlet and a tank outlet. In the temperature rise circuit, each valve pressure port of the solenoid valve is connected to one common pressure oil passage, and each valve tank port of the solenoid valve is connected to one common tank oil passage. The oil is branched into two, one of which flows into a common pressure oil line and the other flows into a common tank oil line. This makes it possible to improve the warm-up function even with the addition of a small number of components.

  Patent Literature 2 discloses a warm-up unit that is directly attached to the left and right pilot pressure receiving chambers of a main control valve of a pilot hydraulic circuit. In the interior of the warm-up unit, three oil passages communicate with each other via respective connection ports directly connected to the pilot oil passage, the warm-up oil passage, and the pilot pressure receiving chambers. ing. Pressure oil from the pilot hydraulic pressure source is directly introduced from the warm-up oil passage to each pilot pressure receiving chamber via a junction of each oil passage. The pressure oil returns to the oil tank via the pilot oil passage. The pressure oil in the oil tank that has been heated in advance by the warm-up operation of the engine is circulated, and the pressure oil in each pilot pressure receiving chamber is heated in advance.

  According to the warm-up unit described in Patent Literature 2, the pilot oil passage and the warm-up oil passage can be directly connected to the pilot pressure receiving chamber via the warm-up unit. It is not necessary to connect a large number of pipes separately to each other, and it is sufficient to connect a single connection port, a warm-up unit, to each pilot pressure receiving chamber. Processing becomes easier. That is, it is described that a compact warm-up unit makes it possible to easily connect necessary pipes with a simple structure without increasing the number of parts.

JP 2000-220768 A JP 2003-004009 A

However, in the hydraulic circuit having the above metering valve, the bypass valve and relief valve, due to the biased position of the valve body of the control valve unit, even if the warm-up operation to repeat the neutral and - relief, The entire hydraulic circuit cannot be warmed.
Further, in the warm-up units disclosed in Patent Literature 1 and Patent Literature 2, it is possible to warm up the entire hydraulic circuit, but a special warm-up circuit is required in the hydraulic circuit. As a result, the hydraulic circuit becomes complicated and the production cost increases.

  The present invention has been made in view of the above-described problems, and has been developed to provide a control valve unit for a working machine that can warm up a hydraulic circuit as a whole without providing a special circuit for warming up. The purpose is to provide.

(1) In order to achieve the above object, a control valve unit of a working machine according to the present invention includes a valve body, a supply port formed in the valve body and supplied with hydraulic oil, and a control port formed in the valve body. A discharge port from which the hydraulic oil is discharged, a control valve mounted on the valve body and controlling the supply of the hydraulic oil to a hydraulic actuator, formed on the valve body, and when the hydraulic actuator is not operated, A bypass flow path that allows the hydraulic oil supplied from the supply port to flow to the discharge port while bypassing the control valve, and is interposed in the bypass flow path, and is opened when the hydraulic actuator is not operated. A work machine control valve unit comprising: a bypass valve; Together are arranged close to one end in the longitudinal direction of the I, both ports of said supply port and said discharge port is characterized in that it is arranged close to the other longitudinal end.

( 2 ) It is preferable that the valve body includes a body body and a cover body detachably attached to one end of the body body in the longitudinal direction, and the bypass valve is incorporated in the cover body.

( 3 ) It is preferable that an additional valve can be installed between the body main body and the cover body.

According to the present invention, the bypass valve is arranged near one end of the valve body, and at least one of the supply port and the discharge port is arranged in a section opposite to the one end. With this arrangement, when the hydraulic actuator is not operated, the hydraulic oil can be circulated to a region occupying most of the valve body.
Therefore, it is possible to warm up the hydraulic circuit as a whole by simply changing the arrangement of the supply port, the discharge port and the bypass valve, which are conventionally provided, without providing a special circuit for warming up.

It is a typical perspective view showing the whole work machine composition concerning one embodiment of the present invention. FIG. 1 is a schematic diagram illustrating an overall configuration of a hydraulic circuit according to an embodiment of the present invention. FIG. 1 is a schematic plan view showing a configuration of a control valve unit as one embodiment of the present invention. FIG. 9 is a schematic plan view showing a configuration of a conventional control valve unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that each embodiment described below is merely an example, and there is no intention to exclude various modifications and application of technology not explicitly described in the following embodiment. Each configuration of the following embodiments can be variously modified and implemented without departing from the spirit thereof, and can be selectively used as needed, or can be appropriately combined.
In the following embodiments, an example in which the control valve unit of the working machine of the present invention is applied to a hydraulic shovel as a working machine will be described. However, the present invention is applied to various general working machines such as a hydraulic crane other than the hydraulic shovel. can do.

[1. Configuration of hydraulic excavator]
A configuration of a hydraulic shovel 1 according to an embodiment of the present invention will be described with reference to FIG. The hydraulic excavator 1 includes a lower traveling body 2 equipped with a crawler-type traveling device, and an upper revolving superstructure 3 rotatably mounted on the lower traveling body 2. A cab 4 on which an operator (operator) rides and a front working device 5 adjacent to the cab 4 and extending forward of the vehicle are provided on the vehicle front side of the upper swing body 3. A counterweight 6 for maintaining the weight balance of the airframe is disposed at the rearmost end of the upper swing body 3, and an engine room 7 is formed immediately before the counterweight 6.

The front working device 5 includes a boom 5BM, a stick 5STK, and a bucket 5BKT. The base end of the boom 5BM is pivotally supported on the upper swing body 3 so as to be able to move up and down. Further, a boom cylinder 15BM is interposed between the boom 5BM and the upper swing body 3, and the boom 5BM swings in accordance with the expansion and contraction operation of the boom cylinder 15BM.
Similarly, the base end of the stick 5STK is pivotally supported on the distal end of the boom 5BM so as to be freely swingable, and the bucket 5BKT is supported on the distal end of the stick 5STK. A stick cylinder 15STK is interposed between the boom 5BM and the stick 5STK, and a bucket cylinder 15BKT is interposed between the stick 5STK and the bucket 5BKT. The stick 5STK and the bucket 5BKT swing in accordance with the expansion and contraction of the stick cylinder 15STK and the bucket cylinder 15BKT, respectively.

In the engine room 7, an engine 11 that generates a hydraulic pressure, which is a drive source of the excavator 1, is disposed. In a pump room (not shown) adjacent to the engine room 7, two hydraulic pumps (not shown) are arranged. The hydraulic pump is driven by the engine 11 to discharge hydraulic oil, and supplies the hydraulic oil to various hydraulic actuators such as a hydraulic cylinder and a hydraulic motor mounted on the excavator 1. The hydraulic actuator that receives the supply of the hydraulic oil from the hydraulic pump includes, for example, a boom cylinder 15BM, a stick cylinder 15STK, a bucket cylinder 15BKT, a turning motor and a traveling motor (not shown), and the like.
Inside the cab 4, various input levers and pedals for inputting the operation amounts of these various hydraulic devices are provided.

[2. Configuration of hydraulic circuit]
A configuration of a hydraulic circuit according to one embodiment of the present invention will be described with reference to FIG. 2 shows a hydraulic circuit of the boom cylinder 15BM (see FIG. 1), the stick cylinder 15STK (see FIG. 1), and the traveling motors 15TRR, 15TRL (not shown in FIG. 1), and other hydraulic circuits are omitted. I have. In the following description, for convenience, only the boom cylinder 15BM (see FIG. 1), the stick cylinder 15STK (see FIG. 1) and the hydraulic circuit of the traveling motor will be described.

In such a hydraulic circuit 10, the boom control valve 14BM, the right traveling motor control valve 14TRR, the left traveling motor control valve 14TRL, and the stick control valve 14STK are respectively operated by the lever 16BM, the pedal 17TRR, the pedal 17TRL, and the lever 16STK. You.
The boom control valve 14BM controls expansion and contraction of the boom cylinder 15BM according to the operation of the lever 16BM. The right traveling motor control valve 14TRR controls the operation of the right traveling motor 15TRR in response to the depression of the pedal 17TRR. The left traveling motor control valve 14TRL controls the operation of the left traveling motor 15TRL in response to the depression of the pedal 17TRL. The stick control valve 14STK controls the operation of the stick cylinder 15STK according to the operation of the lever 16STK.

Hereinafter, when the boom cylinder 15BM, the right traveling motor 15TRR, the left traveling motor 15TRL, and the stick cylinder 15STK are not particularly distinguished, they are referred to as a hydraulic actuator 15, and the control valves 14BM, 14TRR, 14TRL, and 14STK are not particularly distinguished. Is described as a control valve 14, the lever 16BM and 16STK are described as a lever 16 when no particular distinction is made, and the pedals 17TRR and 17TRL are described as a pedal 17 when no particular distinction is made.
It should be noted that although simplified in FIG. 2, in the present embodiment, each control valve 14 is constituted by four metering valves that can be individually controlled. Each control valve 14 is not limited to the one configured with four metering valves, and various types of valves can be used.

  The hydraulic circuit 10 is roughly divided into two circuits corresponding to two main pumps (hereinafter, also simply referred to as pumps) 12 driven by the engine 11, and a pair of traveling motors 15TRR is provided between these two circuits. , 15TRL at a constant speed, and a junction valve 19 for controlling the exchange of hydraulic oil between one circuit and the other circuit (between the two pumps 12). Is provided.

A throttle valve 22 for warming-up is provided in each pump discharge flow path 21 of each pump 12. The throttle valve 22 is a valve for warming up. When it is determined that warming up is necessary by a controller (not shown), the throttle valve 22 is controlled to the fully open position to communicate the pump discharge flow path 21 of each pump 12 with the tank 13. . That is, automatic warm-up is performed by circulating hydraulic oil.
The case where it is determined that the warm-up is necessary is a case where the pumps 12 are in an idling state or a case where the temperature of the hydraulic oil or the temperature of the engine coolant detected by a sensor (not shown) is low.

  A return flow path 23 between the pump discharge flow path 21 and the tank 13 of each pump 12 is provided with a pair of check valves 24 and a pressure setting relief between the check valves 24, 24. A valve 25 is provided. When the oil pressure exceeds the set pressure of the relief valve 25, the relief valve 25 opens and the hydraulic oil is returned to the tank 13.

A pair of bypass valves 27A and 27B are provided in another return flow path 26 between the pump discharge flow path 21 and the tank 13 of each pump 12. In other words, a return flow path 26 common to the bypass valves 27A, 27B (common to the two circuits corresponding to the two pumps 12) is formed between the bypass valves 27A, 27B.
Hereinafter, when the bypass valves 27A and 27B are not distinguished, they are referred to as bypass valves 27.

When an operation amount (stepping amount) is input from the lever 16 or the pedal 17, the controller (not shown) closes the bypass valve 27 and also controls the corresponding control according to the operation amount (stepping amount). The opening degree of the valve 14 and, consequently, the supply amount of the hydraulic oil fed to the hydraulic actuator 15 by the pump 12 are controlled.
On the other hand, when the operation amount (stepping amount) is not detected for any of the levers 16 and the pedals 17, the controller opens the bypass valve 27 and drains the operating oil pumped by the pump 12 to the tank 13. by, it stops the supply of working oil to the hydraulic actuator 1 5.

[3. Configuration of control valve unit]
A configuration of a control valve unit (hereinafter, also simply referred to as a valve unit) 30 as one embodiment of the present invention will be described with reference to FIGS.
The valve unit 30 is configured as a unit by mounting or forming a valve or a flow path in a range indicated by a chain line in FIG. 2 on the valve body 30a. That is, the valve unit 30 includes a valve body 30a and a control valve 14, a traveling straight valve 18, a merging valve 19, a throttle valve 22, a check valve 24, a relief valve 25, and bypass valves 27A and 27B provided in the valve body 30a. And is provided.
Focusing on the pump discharge flow path 21 and the return flow path 26 passing through the bypass valves 27A and 27B, the valve unit 30 includes a flow path 21A, a part of the pump discharge flow paths 21 and 21 in the valve body 30a. 21B and a flow path (bypass flow path) 26A that forms a part of the return flow path 26 are formed. The flow path 26A is provided with bypass valves 27A and 27B .
The valve unit 30 (valve body 30a) is connected to an external flow path that connects the pump 12 with pump ports (supply ports) PA and PB forming one ends of the flow paths 21A and 21B as hydraulic oil inlets. A tank port (discharge port) T forming one end is connected to an external flow path connected to the tank 13 as a hydraulic oil outlet.

When neither the lever 16 nor the pedal 17 is operated (the pedal is not depressed), the hydraulic oil pumped from the pump 12 flows into the valve unit 30 from the pump ports PA and PB when the hydraulic actuator 15 is not operated. After passing through the paths 21A and 21B, the bypass valves 27A and 27B, and the flow path 26A in this order, the gas is discharged from the valve body 30a through the tank port T and returned to the tank 13.

As shown in FIG. 3 which is a schematic plan view at the time of installation on the work machine, the valve body 30a is formed in a rectangular shape in plan view, and the bypass valves 27A and 27B are arranged in the longitudinal direction of the valve body 30a. 3 is arranged in a section on the right side in FIG. 3 with respect to a center line CL bisecting the center line CL, and the valve ports PA, PB and the tank port T are arranged in a section on the left side in FIG. ing. In addition, the bypass valves 27A and 27B are arranged (disposed at the right end) on the short side (one end in the longitudinal direction) 31a on the upper surface 31 on the right side in FIG.
In other words, the bypass valves 27A and 27B are arranged close to one end (the right short side) 31a in the longitudinal direction of the valve body 30a, and the valve ports PA and PB and the tank port T are positioned with respect to the center line CL. The bypass valves 27A and 27B are arranged in a section (a section on the left side of the center line CL) opposite to a section (a section on the right side of the center line CL).

  In the present embodiment, the valve ports PA and PB and the tank port T are respectively arranged near the left short side (the other end in the longitudinal direction) 31c in FIG. 3 (disposed at the left end). Specifically, the valve ports PA and PB are open on the side surface having the short side 31c as the upper edge, and the tank port T is open toward the short side 31c on the side surface having the long side 31b as the upper edge.

  Further, in the present embodiment, the flow paths 21A, 21B, 26A are arranged over substantially the entire valve body 30a also in the short direction (the vertical direction in FIG. 3).

  Here, to be arranged close to the short side 31a means to be arranged within a predetermined distance L0 from the short side 31a. Similarly, to be arranged close to the short side 31c is to be arranged within a predetermined distance L0 from the short side 31c. It means to arrange.

  Alternatively, disposing the bypass valves 27A and 27B close to the short side 31a of the valve body 30a means “a valve other than the bypass valves 27A and 27B and disposed closest to the short side 31a”. It can be defined that the bypass valves 27A and 27B are arranged in a region between the side 31a ". In other words, among the valves attached to the valve body 30a, if the bypass valves 27A and 27B are arranged closest to the “short side 31a” (they may be arranged on the side surface having the short side 31a as the upper edge). And the bypass valves 27A and 27B can be defined as being arranged near the short side 31a of the valve body 30a.

  Similarly, disposing the ports PA, PB, and T near the short side 31c of the valve body 30a means that the port is located between the “valve disposed closest to the short side 31c” and the “short side 31c”. , Ports PA, PB, and T can be defined. In other words, if the ports PA, PB, and T are located closer to the “short side 31c” than any of the valves attached to the valve body 30a (they may be located on the side surfaces having the short side 31c as the upper edge). ), And the ports PA, PB, and T can be defined as being arranged near the short side 31c.

  As a result of such an arrangement, the flow paths 21A and 21B are formed over substantially the entire length in the longitudinal direction across the center line CL, and the flow path 26A is also formed over the substantially entire length in the longitudinal direction across the center line CL. Will be formed. Therefore, when the hydraulic actuator is not operated, the hydraulic oil flows through the entire length of the valve body 30a in the longitudinal direction through the flow paths 21A and 21B until passing through the bypass valves 27A and 27B, and the bypass valves 27A and 27B. After passing through the valve body, the valve body 30a makes a U-turn, and flows through the entire length of the valve body 30a in the longitudinal direction again through the flow path 26A.

  The bypass valves 27A and 27B are built in a cover portion (cover body) 30b outside the section R where the throttle valve 22 (see FIG. 2) is disposed. The cover portion 30b is detachable, and when a valve (hereinafter, referred to as an additional valve) is added in accordance with the addition of an attachment or a design change, the cover portion 30b and the body 30c of the valve body 30a (the valve body 30a). (Excluding the cover portion 30b).

Here, for comparison with the valve unit 30 as one embodiment of the present invention, a conventional valve unit 130 will be described with reference to FIG.
Like the valve unit 30, the valve unit 130 is unitized by providing a range indicated by a dashed line in FIG. 2 on the valve body 130a. As shown in FIG. 4, the valve body 130a is formed in a rectangular shape in plan view, and in the valve body 130a, the pump ports PA, PB, the tank port T, and the bypass valves 27A, 27B are all on the left side of the center line CL. Is different from the valve unit 30 in that the section is concentrated near the short side of the section.
Since the flow paths 21A, 21B, and 26B are concentrated in a part of the valve unit 130, the hydraulic oil flows only to the part when the hydraulic actuator is not operated.

[4. Action / Effect]
As in the conventional valve unit 130 shown in FIG. 4, when the hydraulic oil flows only through the biased section of the valve body 130a when the hydraulic actuator 15 is not operated, only a part of the valve body becomes hot and The thermal shock due to the difference in the expansion rate causes distortion, which causes the control valve to stick and may cause insufficient warm-up of the entire valve body.

On the other hand, according to the control valve unit 30 of the working machine of one embodiment of the present invention, as shown in FIG. 3, in the valve body 30a, the bypass valves 27A and 27B are arranged close to the short side 31a. Since the ports PA, PB and the tank port T are arranged in the section opposite to the section in which the bypass valves 27A, 27B are arranged, the flow paths 21A, 21B, 26A are formed along the longitudinal direction. Can be.
Therefore, when the hydraulic actuator 15 is not operated, the entire valve body 30a can be uniformly heated, thereby preventing the occurrence of thermal shock and effectively performing warm-up.

  Also, the valve body 30a can be entirely warmed up only by changing the arrangement of the conventionally provided valve ports PA and PB, the tank port T, and the bypass valves 27A and 27B. It is possible to warm up the valve body 30a as a whole without providing the special configuration described above.

Further, since the valve ports PA and PB and the tank port T are arranged close to the short side 31c, the flow paths 21A, 21B and 26A can be formed over substantially the entire length in the longitudinal direction. Therefore, when the hydraulic actuator 15 is not operated, the entire valve body 30a can be reliably heated.

  Furthermore, since both the pump ports PA and PB serving as the hydraulic oil inlet and the tank port T serving as the hydraulic oil outlet are arranged near the short side 31c opposite to the bypass valves 27A and 27B, the pump port PA , PB return to the tank port T after passing through the bypass valves 27A and 27B. Therefore, the hydraulic oil flows back and forth over substantially the entire length of the valve body 30a, and the valve body 30a can be more effectively warmed up. Further, by arranging the flow paths 21A, 21B, 26A along the short direction (vertical direction in FIG. 3) of the valve body 30a, the valve body 30a is not only uniform in the long direction but also in the short direction. 30a can be warmed up.

Further, even when an additional valve is installed in the control unit 30, since the bypass valves 27A and 27B are attached to the cover 30b, the bypass valves 27A and 27B can be moved to the end of the valve body 30a. That is, since the additional valve is installed between the cover 30b and the body 30c, even when the additional valve is installed, the cover 30b and thus the bypass valves 27A and 27B can be arranged at the end of the valve body 30a. it can.
Therefore, even when the additional valve is installed, the flow paths 21A, 21B, 26A formed between the bypass valves 27A, 27B and the ports PA, PB, T are provided over substantially the entire length of the valve body 30a in the longitudinal direction. Can be formed.

[5. Others]
(1) The bypass valves 27A and 27B are arranged near one end of the valve body 30a, and at least one of the pump ports PA and PB and the tank port T is arranged in a section opposite to the one end. If so, the arrangement of the pump ports PA and PB, the tank port T, and the bypass valves 27A and 27B is not limited to the arrangement of the above embodiment shown in FIG.

For example, in FIG. 3, similarly to the valve ports PA and PB, the tank port T may be opened on the side surface having the short side 31c of the upper surface 31 as the upper edge. Conversely, similarly to the tank port T, the valve ports PA and PB may be opened closer to the short side 31c on the side surface having the long side 31b as the upper edge.
Alternatively, in FIG. 3, except for at least one of the valve ports PA and PB and the tank port T, the remaining ports are disposed in a section on the right side of the center line CL, as in the bypass valves 27A and 27B. May be.

(2) The throttle valves 22 and the bypass valves 27A and 27B are opened together with the throttle valve 22 so that the warm-up by the flow paths 21A, 21B and 26A is performed not only when the hydraulic actuator 15 is not operated but also during automatic warm-up. It may be performed.

5 Front Working Device 10 Hydraulic Circuit 12 Pump 13 Tank 14BM Boom Control Valve 14BKT Bucket Control Valve 14STK Stick Control Valve 14TRL Left Travel Motor Control Valve 14TRR Right Travel Motor Control Valve 15 Hydraulic Actuator 21 Pump Discharge Channels 21A, 21B Pump Discharge Out of the flow paths 21, a flow path 26 formed in the valve unit 30 26 Return flow path 26A Out of the return flow paths 26, a flow path formed in the valve unit 30 (bypass flow path)
27, 27A, 27B Bypass valve 30 Control valve unit 30a Valve body 30b Cover part (cover body) of valve body 30a
30c Body body of the valve body 30a 31 Upper surface of the valve body 30a 31c Short side of the upper surface 31 (the other end in the longitudinal direction)
31a Short side of upper surface 31 (one end in the longitudinal direction)
31b Long side of upper surface 31 L Total length of valve body 30a L0 Predetermined distance PA, PB Pump port (supply port)
R Section where throttle valve 22 is arranged T Tank port (discharge port)

Claims (3)

A valve body,
A supply port formed in the valve body and supplied with hydraulic oil;
A discharge port formed in the valve body and discharging the hydraulic oil;
A control valve mounted on the valve body and controlling supply of the hydraulic oil to a hydraulic actuator,
A bypass flow path formed in the valve body, and when the hydraulic actuator is not operated, the hydraulic oil supplied from the supply port, which bypasses the control valve and flows to the discharge port;
A bypass valve interposed in the bypass flow path, the bypass valve being opened when the hydraulic actuator is not operated, a control valve unit of a work machine,
The bypass valve is arranged near one end in the longitudinal direction of the valve body, and both the supply port and the discharge port are arranged near the other end in the longitudinal direction. A control valve unit for a working machine, comprising: The valve body includes a body body, and a cover body detachably attached to one end in the longitudinal direction of the body body,
Wherein the bypass valve is integrated in the cover body, the working machine of the control valve unit of claim 1, wherein. The control valve unit for a working machine according to claim 2 , wherein an additional valve can be installed between the body body and the cover body.

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