WO2017042211A1

WO2017042211A1 - Control valve unit of working machine

Info

Publication number: WO2017042211A1
Application number: PCT/EP2016/071077
Authority: WO
Inventors: Hideki Nakajima
Original assignee: Caterpillar Sarl
Priority date: 2015-09-07
Filing date: 2016-09-07
Publication date: 2017-03-16
Also published as: JP6632269B2; JP2017053381A

Abstract

Provided is a control valve unit of a working machine capable of entirely warming up a hydraulic circuit without particularly installing a circuit for warm-up. [Solving means] The control valve unit includes a valve body (30a), supply ports (PA and PB), a discharge port (T),a control valve,a bypass flow path (26A) configured to cause the working fluid supplied from the supply ports (PA and PB) to bypass the control valve and flow through the discharge port (T) upon non-manipulation of a hydraulic actuator, and bypass valves (27A and 27B) interposed in the bypass flow path (26A) and opened upon non-manipulation of the hydraulic actuator. The bypass valves (27A and 27B) are disposed adjacent to one end(31a)of the valve body (30a), and at least one of the supply ports (PA and PB) and the discharge port (T) is disposed at a section opposite to the one end.

Description

[Specification]

[Title of Invention]

CONTROL VALVE UNIT OF WORKING MACHINE

[Technical Field]

[0001]

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

[Background Art]

[0002]

In the related art, various warm-up control devices configured to warm up a hydraulic circuit upon cold start of a working machine such as a hydraulic shovel have been proposed. In warm-up control of general hydraulic circuits, control is performed to warm up portions in a hydraulic circuit and moderately increase a temperature of the entire hydraulic circuit by warming up a working fluid flowing through the hydraulic circuit.

[0003]

For example, in a working machine having a center bypass serving as an oil passage configured to recirculate a working fluid to a working fluid tank upon non-manipulation (a neutral position) of the working machine, the warm-up is performed by performing warm-up manipulation of repeating relief and neutral positions. That is, the entire hydraulic circuit is warmed up as the working fluid flows through two flow paths of a relief flow path and a center bypass, by repeating (1) positively flowing the working fluid through a flow path for relief (a relief flow path) by performing input manipulation in a direction of further expanding a cylinder from a position at which the cylinder installed in the working machine is not expanded further or performing input manipulation in a direction further contracting a stick cylinder from a position at which the cylinder is not contracted further, and (2) flowing the working fluid through the center bypass upon non-manipulation. [0004]

Incidentally, in a state-of-the-art working machine, since performance of the hydraulic circuit is easily adjusted, in many cases, the working machine includes a hydraulic circuit having four metering valves that can be individually controlled with respect to one actuator. In the above-mentioned hydraulic circuit, since a center bypass is not provided, a bypass valve is required to control a system pressure.

[0005]

In addition, for example, in a temperature rising circuit of a solenoid valve unit disclosed in Patent Document 1 , in which a hydraulic inlet and a tank outlet are formed, and which as a temperature rising circuit of a solenoid valve unit having a plurality of solenoid valves each having a valve pressure port and a valve tank port, the valve pressure ports of the solenoid valves are connected to one common pressure oil passage, the valve tank ports of the solenoid valves are connected to one common tank oil passage, the working fluid from the hydraulic inlet is divided into two parts, one of which flows to the common pressure oil passage, and the other flows to the common tank oil passage. Accordingly, even when a few parts are added, a warm-up function can be improved.

[0006]

In addition, Patent Document 2 discloses a warm-up unit directly attached to left and right pilot pressure receiving chambers of a main control valve of a pilot hydraulic circuit. Three oil passages come in communication with the inside of the warm-up unit via connecting ports directly connected to a pilot oil passage, a warm-up oil passage and the pilot pressure receiving chambers, and each of the oil passages is partially merged to the warm-up unit. Pressure oil from the pilot hydraulic power source is directly introduced into the pilot pressure receiving chambers via merging sections of the oil passages from the warm-up oil passage. The pressure oil is recirculated to an oil tank via the pilot oil passage. The pressure oil in the oil tank previously heated by a warm-up operation of an engine is circulated, and the pressure oil in the pilot pressure receiving chamber is preheated.

[0007]

According to the warm-up unit disclosed in Patent Document 2, since the pilot oil passage and the warm-up oil passage can be directly connected to the pilot pressure receiving chambers via the warm-up unit, there is no need to individually connect a plurality of pipelines to the pilot pressure receiving chambers of the main control valve, and further, since it is sufficient to connect the warm-up unit serving as a single connecting port to the pilot pressure receiving chambers, machining of the pilot pressure receiving chambers of the main control valve is simplified. That is, necessary pipelines can be easily connected by a compact warm-up unit using a simple structure without increasing the number of parts.

[Prior Art Document]

[Patent Document]

[0008]

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No.

2000-220768

[Patent Document 2] Japanese Unexamined Patent Application, First Publication No.

2003-004009

[Summary of Invention]

[Problems to be Solved]

[0009]

However, in the hydraulic circuit having the metering valves, since the bypass valve or the relief valve is disposed at a one-side position in the valve body of the control valve unit, even when the warm-up manipulation of repeating the relief and neutral positions is performed, the entire hydraulic circuit cannot be warmed up.

In addition, in the warm-up unit disclosed in Patent Document 1 and Patent

Document 2, while the hydraulic circuit can be entirely warmed up, since a circuit configured to particularly warm up the hydraulic circuit is needed, complication of the hydraulic circuit may cause an increase in manufacturing cost.

[0010]

In consideration of the above-mentioned problems, the present invention is directed to provide a control valve unit of a working machine capable of entirely warming up a hydraulic circuit without particularly installing a circuit for warm-up.

[Means for Solving the Problems]

[0011]

(1) In order to accomplish the above-mentioned purpose, a control valve unit of a working machine of the present invention is a control valve unit of a working machine including: a valve body; a supply port formed at the valve body and into which a working fluid is supplied; a discharge port formed at the valve body and from which the working fluid is discharged; a control valve mounted in the valve body and configured to control supply of the working fluid into a hydraulic actuator; a bypass flow path formed in the valve body and configured to cause the working fluid supplied from the supply port to bypass the control valve to flow through the discharge port upon non-manipulation of the hydraulic actuator; and a bypass valve interposed in the bypass flow path and opened upon non-manipulation of the hydraulic actuator, wherein the bypass valve is disposed adjacent to one end of the valve body, and at least one of the supply port and the discharge port is disposed at a section opposite to the one end.

[0012]

(2) The at least one port may be disposed adjacent to the other end in the longitudinal direction.

[0013]

(3) Both of the supply port and the discharge port may be disposed adjacent to the other end in the longitudinal direction. [0014]

(4) The valve body may include a main body and a cover body detachably attached to one end in the longitudinal direction of the main body, and the bypass valve may be incorporated in the cover body.

[0015]

(5) An additional valve may be able to be installed between the main body and the cover body.

[Effects of Invention]

[0016]

According to the present invention, the bypass valve is disposed adjacent to one end of the valve body, and at least one of the supply port and the discharge port is disposed at a section opposite to the one end. According to the disposition, upon non-manipulation of the hydraulic actuator, the working fluid can flow through a region that occupies the most part of the valve body.

Accordingly, by only modifying the disposition of the supply port, the discharge port and the bypass valve that are installed in the related art, the hydraulic circuit can be entirely warmed up without particularly installing the circuit for warm-up.

[Brief Description of Drawings]

[0017]

Fig. 1 is a schematic perspective view showing the entire configuration of a working machine according to an embodiment of the present invention.

Fig. 2 is a schematic view showing the entire configuration of a hydraulic circuit according to the embodiment of the present invention.

Fig. 3 is a schematic plan view showing a configuration of a control valve unit serving as the embodiment of the present invention.

Fig. 4 is a schematic plan view showing a configuration of a control valve unit of the related art.

[Modes for Carrying out the Invention]

[0018]

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

Further, the embodiment described below is merely exemplarily provided, and is not intended to exclude application of various modifications or techniques clearly indicated in the following embodiment. Components of the following embodiment can be variously modified, optionally selected or appropriately assembled according to necessity, without departing from the spirit of the present invention.

In the following embodiment, while a control valve unit of a working machine of the present invention is an example of application to a hydraulic shovel serving as the working machine, the control valve unit can be generally applied to various working machines such as a hydraulic crane or the like, in addition to the hydraulic shovel.

[0019]

[1. Configuration of hydraulic shovel]

A configuration of a hydraulic shovel 1 according to the embodiment of the present invention will be described with reference to Fig. 1. The hydraulic shovel 1 includes a lower traveling body 2 provided with a crawler type traveling apparatus, and an upper turning body 3 turnably mounted on the lower traveling body 2. A cab 4 in which an operator rides and a front working apparatus 5 adjacent to the cab 4 and extending in front of a vehicle are installed at a vehicle front side of the upper turning body 3. In addition, a counterweight 6 configured to hold a weight balance of a machine body is disposed at a rearmost end portion of the upper turning body 3, and an engine room 7 is formed at an immediately forward side thereof.

[0020] The front working apparatus 5 includes a boom 5BM, a stick 5STK and a bucket 5BKT. The boom 5BM has a proximal end portion axially supported to rise and fall with respect to the upper turning body 3. In addition, a boom cylinder 15BM is interposed between the boom 5BM and the upper turning body 3, and the boom 5BM is swung according to an expansion and contraction operation of the boom cylinder 15BM.

Similarly, a proximal end portion of the stick 5STK is axially and swingably supported with respect to a distal end portion of the boom 5BM, and further, the bucket 5BKT is axially supported by the distal end portion 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 are swung according to the expansion and contraction operations of the stick cylinder 15STK and the bucket cylinder 15BKT.

[0021]

An engine 11 serving as a driving power source of the hydraulic shovel 1 and configured to generate a hydraulic pressure is disposed in the engine room 7. In addition, two hydraulic pumps (not shown) are disposed in a pump room (not shown) adjacent to the engine room 7. The hydraulic pump is driven by the engine 11 to discharge a working fluid, and supplies the working fluid to various hydraulic actuators such as a hydraulic cylinder, a hydraulic motor, or the like, mounted in the hydraulic shovel 1. Further, the boom cylinder 15BM, the stick cylinder 15STK, the bucket cylinder 15BKT, a turning motor (not shown), a traveling motor (not shown), or the like, may be exemplified as a hydraulic actuator into which the working fluid is supplied from the hydraulic pump.

Various input levers or pedals configured to input working amounts of these various hydraulic apparatuses are installed in the cab 4.

[0022]

[2. Configuration of hydraulic circuit] A configuration of the hydraulic circuit according to the embodiment of the present invention will be described with reference to Fig. 2. Further, in Fig. 2, hydraulic circuits of the boom cylinder 15BM (see Fig. 1), the stick cylinder 15STK (see Fig. 1) and traveling motors 15TRR and 15TRL (omitted in Fig. 1) are shown, and the other hydraulic circuits are omitted. Even in the following description, for the sake of convenience, only the hydraulic circuits of the boom cylinder 15BM (see Fig. 1), the stick cylinder 15STK (see Fig. 1) and the traveling motors will be described.

[0023]

In such a hydraulic circuit 10, a boom control valve 14BM, a right traveling motor control valve 14TRR, a left traveling motor control valve 14TRL and a stick control valve 14STK are manipulated by a lever 16BM, a pedal 17TRR, a pedal 17TRL and a lever 16STK, respectively.

The boom control valve 14BM controls expansion and contraction of the boom cylinder 15BM according to manipulation of the lever 16BM. The right traveling motor control valve 14TRR controls operation of the right traveling motor 15TRR according to pedaling of the pedal 17TRR. The left traveling motor control valve 14TRL controls operation of the left traveling motor 15TRL according to pedaling of the pedal 17TRL. The stick control valve 14STK controls operation of the stick cylinder 15STK according to manipulation of the lever 16STK.

[0024]

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 expressed as the hydraulic actuators 15, when the control valves 14BM, 14TRR, 14TRL and 14STK are not particularly distinguished, they are expressed as the control valves 14, when the levers 16BM and 16STK are not particularly distinguished, they are expressed as the levers 16, and when the pedals 17TRR and 17TRL are not particularly distinguished, they are expressed as the pedals 17.

Further, while simply shown in Fig. 2, in the embodiment, each of the control valves 14 is constituted by four metering valves that can be individually controlled. Each of the control valves 14 is not limited to being constituted by four metering valves, thus various types of valves may be used.

[0025]

The hydraulic circuit 10 is generally divided into two circuits corresponding to two main pumps (hereinafter, simply referred to as pumps) 12 driven by the engine 11 , a straight-travel valve 18 configured to operate the pair of traveling motors 15TR and 15TRL at an equal speed is installed between the two circuits, and further, a merging valve 19 configured to control exchange of the working fluid is installed between one circuit and the other circuit (between the two pumps 12).

[0026]

A throttle valve 22 for warm-up is installed at each of pump discharge flow paths 21 of the pumps 12. The throttle valve 22 is a valve for warm-up, and brings a pump discharge flow path 21 of the pumps 12 controlled to a fully open position in communication with tanks 13 when a controller (not shown) determines that warm-up is needed. That is, automatic warm-up is performed as the working fluid flows therethrough.

The case in which it is determined that the warm-up is needed is a case of an idling state in which the pumps 12 are started, or a case in which a temperature of the working fluid or a temperature of engine cooling water detected by a sensor (not shown) is low.

[0027]

A pair of check valves 24 are interposed in return flow paths 23 between the pump discharge flow paths 21 of the pumps 12 and the tanks 13, and a relief valve 25 configured to set a pressure between the check valves 24 and 24 is installed. When the hydraulic pressure exceeds a set pressure of the relief valve 25, the relief valve 25 is opened, and the working fluid is returned into a tank 13.

[0028]

A pair of bypass valves 27 A and 27B are installed at another return flow path 26 between the pump discharge flow paths 21 of the pumps 12 and the tanks 13. In other words, the return flow path 26 (common to the two circuits corresponding to the two pumps 12) common to the bypass valves 27A and 27B is formed between the bypass valves 27A and 27B.

Hereinafter, when the bypass valves 27A and 27B are not distinguished, they are expressed as the bypass valves 27.

[0029]

When a manipulation amount (a pedaling amount) is input from the lever 16 or the pedal 17, the controller (not shown) closes the bypass valves 27, and controls an opening degree of the corresponding control valve 14 and a supply amount of the working fluid pumped to a hydraulic actuator 15 by the pump 12 according to the manipulation amount (the pedaling amount).

Meanwhile, when no manipulation amount (no pedaling amount) is detected from all of the levers 16 and the pedals 17, the controller opens the bypass valve 27 to drain the working fluid pumped by the pump 12 into the tank 13 and stops supply of the working fluid into the hydraulic actuators 15.

[0030]

[3. Configuration of control valve unit]

A configuration of the control valve unit (hereinafter, simply referred to as a valve unit) 30 serving as the embodiment of the present invention will be described with reference to Figs. 2 and 3.

The valve unit 30 is configured as a unit as the valves or the flow paths within a range shown by a chain line of Fig. 2 are installed or formed in a valve body 30a. That is, the valve unit 30 includes the valve body 30a, and the control valves 14, the straight-travel valve 18, the merging valve 19, the throttle valves 22, the check valves 24, the relief valve 25 and the bypass valves 27A and 27B, which are installed in the valve body 30a.

Regarding the pump discharge flow path 21 and the return flow path 26 passing through the bypass valves 27 A and 27B, flow paths 21 A and 2 IB that constitute parts of the pump discharge paths 21 and 21 and a flow path (a bypass flow path) 26A that constitutes a part of the return flow path 26 are formed in the valve body 30a of the valve unit 30. The bypass valves 27A and 27B are installed at the flow path 26A.

The valve unit 30 (the valve body 30a) connects pump ports (supply ports) PA and PB formed at one end each of the flow paths 21 A and 2 IB to an external flow path serving as a working fluid inlet and connected to the pumps 12, and connects a tank port (a discharge port) T formed at one end of the flow path 26A to an external flow path serving as a working fluid outlet and connected to a tank 13.

[0031]

Upon non-manipulation of the hydraulic actuator 15 in which none of the levers 16 and the pedals 17 are manipulated (pedaled), the working fluid pumped from the pump 12 is introduced into the valve unit 30 through the pump ports PA and PB, sequentially passes through the flow paths 21 A and 21B, the bypass valves 27A and 27B and the flow path 26A, is discharged from the valve body 30a by the tank port T, and is returned into a tank 13.

[0032]

As shown in Fig. 3 serving as a schematic plan view upon installation in the working machine, the valve body 30a is formed in a rectangular shape when seen in a plan view, the bypass valves 27A and 27B are disposed closer to a right section of Fig. 3 than a centerline CL that divides the valve body 30a in a longitudinal direction (left-right direction in Fig. 3) into two parts, and the pump ports PA and PB and the tank port T are disposed closer to a left section of Fig. 3 than the centerline CL. In addition, the bypass valves 27A and 27B are installed adjacent to a right short side (one end in the longitudinal direction) 31a in Fig. 3 of an upper surface 31 (disposed at a right end).

That is, the bypass valves 27 A and 27B are disposed adjacent to the one end (the right short side) 3 la in the longitudinal direction of the valve body 30a, and the pump ports PA and PB and the tank port T are disposed at a section (a section further leftward than the centerline CL) opposite to the section, at which the bypass valves 27A and 27B are disposed, (a section further rightward than the centerline CL) with respect to the centerline CL.

[0033]

In the embodiment, the pump ports PA and PB and the tank port T are installed adjacent to the left short side of Fig. 3 (the other end in the longitudinal direction) 31c (disposed at the left end). Specifically, the pump ports PA and PB are opened at a side surface having the short side 3 lc as an upper edge, and the tank port T is opened adjacent to the short side 31c at a side surface having a long side 31b serving as an upper edge.

[0034]

Further, in the embodiment, the flow paths 21 A, 2 IB and 26 A are arranged throughout the valve body 30a even in the short-side direction (up-down direction of Fig. 3).

[0035]

Here, disposition adjacent to the short side 31a is disposition within a predetermined distance L0 from the short side 31a, and similarly, disposition adjacent to the short side 31c is disposition within the predetermined distance L0 from the short side 31c.

[0036]

Alternatively, the disposition of the bypass valves 27 A and 27B adjacent to the short side 3 la of the valve body 30a can be defined as the disposition of the bypass valves 27A and 27B in a region between "a valve serving as a valve except for the bypass valves 27A and 27B and disposed closest to the short side 31a" and "the short side 31a." In other words, among the valves attached in the valve body 30a, when the bypass valves 27 A and 27B are disposed closest to "the short side 31a" side (including disposition on the side surface having the short side 3 la as the upper edge), the bypass valves 27A and 27B can be defined as being disposed adjacent to the short side 3 la of the valve body 30a.

[0037]

Similarly, the disposition of the ports PA, PB and T adjacent to the short side 3 lc of the valve body 30a can be defined as the disposition of the ports PA, PB and T in a region between "the valve disposed closest to the short side 31c" and "the short side 31c." In other words, when the ports PA, PB and T are disposed closer to "the short side 31c" side than any one of the valves attached to the valve body 30a (including disposition on the side surface having the short side 3 lc as the upper edge), the ports PA, PB and T can be defined as being disposed adjacent to the short side 31c.

[0038]

As a result of the disposition, the flow paths 21 A and 2 IB are formed throughout the length in the longitudinal direction over the centerline CL, and further, the flow path 26A is also formed throughout the length in the longitudinal direction over the centerline CL.

Accordingly, upon non-manipulation of a hydraulic actuator, the working fluid flows throughout the length in the longitudinal direction of the valve body 30a through the flow paths 21 A and 2 IB until passing through the bypass valves 27 A and 27B, and makes a U-turn and flows throughout the length in the longitudinal direction of the valve body 30a again through the flow path 26 A after passing through the bypass valves 27 A and 27B.

[0039]

In addition, the bypass valves 27A and 27B are built in a cover section (a cover body) 30b outside a section R in which the throttle valves 22 (see Fig. 2) are disposed.

When the cover section 30b can be removed and valves (hereinafter, referred to additional valves) are increased according to addition or design change of the attachment, the additional valves are installed between the cover section 30b and a main body 30c (a portion except for the cover section 30b from the valve body 30a) of the valve body 30a.

[0040]

Here, in comparison with the valve unit 30 serving as the embodiment of the present invention, a valve unit 130 of the related art will be described with reference to Fig. 4.

Like the valve unit 30, the valve unit 130 is configured as a unit within a range shown in a chain line of Fig. 2 is provided in a valve body 130a. The valve body 130a is formed in a rectangular shape as shown in Fig. 4, and distinguished from the valve unit 30 in that, in the valve body 130a, all of the pump ports PA and PB, the tank port T and the bypass valves 27A and 27B are concentrated and disposed closer to the short side of the left section than the center line CL.

Since the flow paths 21 A, 2 IB and 26B are concentrated at a portion of the valve unit 130 in this way, upon non-manipulation of a hydraulic actuator, the working fluid flows through only the portion.

[0041]

[4. Action/effect]

Like the valve unit 130 of the related art shown in Fig. 4, when the working fluid flows through only a one-side section of the valve body 130a upon non-manipulation of a hydraulic actuator 15, only a portion of the valve body has a high temperature, the control valve having distortion generated by a thermal shock due to a difference between expansion rates of the portions is stuck, and the warm-up may be insufficient in the entire valve body.

[0042]

On the other hand, according to the control valve unit 30 of the working machine of the embodiment of the present invention, as shown in Fig. 3, in the valve body 30a, since the bypass valves 27 A and 27B are disposed adjacent to the short side 31a and the pump ports PA and PB and the tank port T are disposed at a section opposite to the section at which the bypass valves 27 A and 27B are disposed, the flow paths 21 A, 2 IB and 26 A can be formed in the longitudinal direction.

Accordingly, upon non-manipulation of a hydraulic actuator 15, the entirety of the valve body 30a can be uniformly heated, and warm-up can be effectively performed while preventing occurrence of thermal shock.

[0043]

In addition, since the valve body 30a can be entirely warmed up by changing the disposition of the pump ports PA and PB, the tank port T and the bypass valves 27A and 27B that are provided in the related art, the valve body 30a can be entirely warmed up without a particular configuration for warm-up.

[0044]

Further, since the pump ports PA and PB and the tank port T are disposed adjacent to the short side 31c, the flow paths 21 A, 2 IB and 26 A can be formed throughout the length in the longitudinal direction. Accordingly, upon non-manipulation of a hydraulic actuator 15, the entire valve body 30a can be reliably heated.

[0045]

Further, since both of the pump ports PA and PB serving as the working fluid inlets and the tank port T serving as the working fluid outlet are disposed adjacent to the short side 31c opposite to the bypass valves 27 A and 27B, the working fluid introduced from the pump ports PA and PB is turned back after passing through the bypass valves 27A and 27B to flow toward the tank port T. Accordingly, the working fluid is reciprocated to pass throughout the length of the valve body 30a, and the valve body 30a can be more effectively warmed up. Further, as the flow paths 21 A, 2 IB and 26 A are disposed in the short- side direction (the up-down direction of Fig. 3) of the valve body 30a, the valve body 30a can be uniformly warmed up in not only the longitudinal direction but also the short-side direction.

[0046]

Further, even when the additional valves are installed in the control valve unit 30, since the bypass valves 27A and 27B are attached in the cover section 30b, the bypass valves 27 A and 27B can approach an end of the valve body 30a. That is, since the additional valves are installed between the cover section 30b and the main body 30c, even when the additional valves are installed, not only the cover section 30b but also the bypass valves 27 A and 27B can be disposed at the end of the valve body 30a.

Accordingly, when the additional valves are installed, the flow paths 21 A, 2 IB and 26A formed between the bypass valves 27A and 27B and the ports PA, PB and T can be formed throughout the length in the longitudinal direction of the valve body 30a.

[0047]

[5. Others]

(1) When the bypass valves 27 A and 27B are disposed adjacent to one end of the valve body 30a and at least one of the pump ports PA and PB and the tank port T is disposed at a section opposite to the one end, the disposition of the pump ports PA and PB, the tank port T and the bypass valves 27A and 27B is not limited to the disposition of the embodiment shown in Fig. 3.

[0048]

For example, in Fig. 3, like the pump ports PA and PB, the tank port T may be opened at the side surface having the short side 3 lc of the upper surface 31 as the upper edge. On the contrary, like the tank port T, the pump ports PA and PB may be opened adjacent to the short side 3 lc on the side surface having the long side 3 lb of the upper surface 31 as the upper edge.

Alternatively, in Fig. 3, at least one port among the pump ports PA and PB and the tank port T remains, and the other ports may be disposed closer to the right section than the centerline CL, like the bypass valves 27A and 27B.

[0049]

(2) Upon not only non-manipulation of a hydraulic actuator 15 and automatic warm-up, the bypass valves 27A and 27B are opened together with the throttle valves 22, and the warm-up by the flow paths 21 A, 2 IB and 26 A may be collectively performed.

[Explanation of References]

[0050]

5 front working apparatus

10 hydraulic circuit

12 pump

13 tank

14BM boom control valve

14BKT bucket control valve

14ST stick control valve

14TRL left traveling motor control valve

14TRR right traveling motor control valve

15 hydraulic actuator

21 pump discharge flow path

21 A, 2 IB flow path formed in pump discharge flow path 21 and valve unit 30

26 return flow path

26 A flow path (bypass flow path) formed in return flow path 26 and valve unit 30

27, 27A, 27B bypass valve

30 control valve unit

30a valve body

30b cover section (cover body) of valve body 30a

30c main body of valve body 30a

31 upper surface of valve body 30a

31c short side of upper surface 31 (other end in longitudinal direction)

31a short side of upper surface 31 (one end in longitudinal direction) 31b long side of upper surface 31

L entire length of valve body 30a

L0 predetermined distance

PA, PB pump port (supply port)

R section in which throttle valve 22 is disposed

T tank port (discharge port)

Claims

[Claims]

[Claim 1]

A control valve unit of a working machine comprising:

a valve body;

a supply port formed at the valve body and into which a working fluid is supplied; a discharge port formed at the valve body and from which the working fluid is discharged;

a control valve mounted in the valve body and configured to control supply of the working fluid into a hydraulic actuator;

a bypass flow path formed in the valve body and configured to cause the working fluid supplied from the supply port to bypass the control valve to flow through the discharge port upon non-manipulation of the hydraulic actuator; and

a bypass valve interposed in the bypass flow path and opened upon non-manipulation of the hydraulic actuator,

wherein the bypass valve is disposed adjacent to one end of the valve body, and at least one of the supply port and the discharge port is disposed at a section opposite to the one end.

[Claim 2]

The control valve unit of the working machine according to claim 1 , wherein the at least one port is disposed adjacent to the other end in the longitudinal direction.

[Claim 3]

The control valve unit of the working machine according to claim 2, wherein both of the supply port and the discharge port are disposed adjacent to the other end in the

longitudinal direction.

[Claim 4]

The control valve unit of the working machine according to any one of claims 1 to 3, wherein the valve body comprises a main body and a cover body detachably attached to one end in the longitudinal direction of the main body, and

the bypass valve is incorporated in the cover body.

[Claim 5]

The control valve unit of the working machine according to claim 4, wherein an additional valve is able to be installed between the main body and the cover body.