Control valve

Abstract

To provide a control valve which enables simplification of arrangement of a harness even if various sensors and electric components etc. are attached.SOLUTION: A control valve (CV) controls a flow direction of working fluid supplied to a hydraulic actuator from a hydraulic pump and includes: a base housing (50) having a pump port connected to the hydraulic pump; and a plurality of section housings (60, 160) each having actuator ports (62a-1, 62a-2) connected to the hydraulic actuator and communicating with the base housing through internal oil passages. The respective section housings are detachably attached to one side surface (50a) and the other side surface (50b) at the base housing and respectively incorporate spools (61a, 161a) for switching the flow direction of the working fluid. The base housing has a plurality of housing parts (53a, 53b) which houses state detection sensors (75. 76) which detect the states of the respective section housings.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control valve. [Background technology]

[0002] For example, a work machine such as a hydraulic excavator is equipped with a work device driven by a hydraulic actuator. The hydraulic actuator is operated by hydraulic oil supplied from a hydraulic pump. A control valve is provided between the hydraulic actuator and the hydraulic pump, and the control valve switches the flow direction of the hydraulic oil to control the operation of the hydraulic actuator.

[0003] As an example of prior art related to this type of control valve, Patent Document 1 describes the following configuration: "The multi-control valve device has a long casing. The casing is provided with ten spool valves, and these ten spool valves are arranged in two rows in the longitudinal direction. The casing is also composed of three blocks connected together, and has first and second dividing surfaces for dividing the casing into these three blocks. These first and second dividing surfaces pass between two spool valves adjacent in the longitudinal direction and are perpendicular to the longitudinal direction" (see abstract). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-112123 A Summary of the Invention [Problem to be solved by the invention]

[0005] With the recent advancement of mechatronics, there is a trend toward a demand for control valves to which various sensors, electrical components, etc. can be attached. However, the control valve described in Patent Document 1 does not assume that various sensors, electrical components, etc. will be attached to the control valve itself. Therefore, if various sensors, electrical components, etc. are simply attached to the control valve described in Patent Document 1, there is a problem in that these components protrude or stick out from the control valve, interfering with the wiring of the harness.

[0006] The present invention has been made in view of the above-mentioned state of the art, and its object is to provide a control valve which allows for simplified wiring of the harness even when various sensors, electrical components, etc. are attached. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, one aspect of the present invention is a control valve that controls the flow direction of hydraulic oil supplied from a hydraulic pump to a hydraulic actuator, the control valve comprising a base housing having a pump port connected to the hydraulic pump, and a plurality of section housings having actuator ports connected to the hydraulic actuator and communicating with the base housing via internal oil passages, the plurality of section housings are each detachably attached to one side and the other side of the base housing, and incorporate a spool that switches the flow direction of the hydraulic oil, and the base housing is provided with a plurality of accommodating portions that accommodate status detection sensors that detect the status of each section housing. Effect of the Invention

[0008] According to the present invention, it is possible to provide a control valve that can simplify the wiring of the harness even when various sensors, electrical components, etc. are attached. Note that problems, configurations, and effects other than those described above will become apparent from the description of the following embodiments. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view of a hydraulic excavator to which the present invention is applied. [Diagram 2] FIG. 2 is a hydraulic circuit diagram of the hydraulic excavator shown in FIG. [Diagram 3] FIG. 2 is a perspective view of a control valve according to an embodiment of the present invention. [Figure 4] FIG. 2 is an exploded perspective view of a portion of a section housing of the control valve. [Diagram 5] FIG. [Figure 6] 6 is a cross-sectional view of the control valve shown in FIG. 3 taken along the line VI-VI. [Figure 7] 7 is a cross-sectional view taken along line VII-VII of the control valve shown in FIG. 5. [Figure 8] FIG. 13 is an oblique view of a control valve according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First, a hydraulic excavator 1 to which the control valve according to the present invention is applied (mounted) will be described with reference to the drawings. However, the subject to which the present invention is applied is not limited to the hydraulic excavator 1. The present invention can be applied to wheel loaders and any other work machines. Furthermore, in this specification, front, back, left and right are based on the viewpoint of an operator who is on board and operating the hydraulic excavator 1, unless otherwise specified.

[0011] Fig. 1 is a side view of a hydraulic excavator 1. As shown in Fig. 1, the hydraulic excavator 1 includes a lower traveling structure 2 and an upper rotating structure 3 supported by the lower traveling structure 2. The lower traveling structure 2 includes a pair of left and right crawlers 4 which are endless tracks. The pair of left and right crawlers 4 are rotated independently by driving a traveling motor 5. As a result, the hydraulic excavator 1 travels. However, the lower traveling structure 2 may be of a wheeled type instead of the crawlers 4.

[0012] The upper rotating body 3 is supported on the lower traveling body 2 so as to be rotatable by a swing motor 6 which is a hydraulic actuator. That is, the upper rotating body 3 swings relative to the lower traveling body 2 as the swing motor 6 rotates. The upper rotating body 3 mainly includes a swing frame 7 which serves as a base, a counterweight 9 arranged at the rear of the swing frame 7, a front working machine 10 attached to the front center of the swing frame 7 so as to be rotatable in the vertical direction, and a cab 20 arranged on the front left side of the swing frame 7.

[0013] The front working machine 10 includes a boom 11 supported on the upper rotating body 3 so that it can be raised and lowered, an arm 12 supported at the end of the boom 11 so that it can be rotated (crowd, dump), a bucket 13 (attachment) supported at the end of the arm 12 so that it can be rotated (crowd, dump), a boom cylinder 14 that drives the boom 11, an arm cylinder 15 that drives the arm 12, and a bucket cylinder 16 that drives the bucket 13.

[0014] Here, the swing motor 6, the boom cylinder 14, the arm cylinder 15, and the bucket cylinder 16 are examples of hydraulic actuators according to the present invention, and will be referred to as hydraulic actuators as appropriate in the following description.

[0015] In addition, specific examples of the attachment are not limited to the bucket 13, but may be a grapple, a cutter, a crusher, a breaker, etc. The counterweight 9 is used to balance the weight with the front working mechanism 10, and is a heavy object having an arc shape when viewed from above.

[0016] The cab 20 is disposed adjacent to the front working implement 10 in the left-right direction (width direction of the vehicle body). More specifically, the cab 20 is disposed to the left (one side in the left-right direction) of the front working implement 10. However, the location of the cab 20 is not limited to the example described above, and the cab 20 may be disposed on one side of the front working implement 10 in the left-right direction.

[0017] Next, the hydraulic circuit of the hydraulic excavator 1 will be described. Fig. 2 is a hydraulic circuit diagram of the hydraulic excavator 1. As shown in Fig. 2, the hydraulic excavator 1 mainly includes an engine 31, a hydraulic oil tank 32, a main pump 33 (hydraulic pump), a pilot pump 34, and a control valve CV according to an embodiment of the present invention. However, the specific configuration of the hydraulic circuit is not limited to the example in Fig. 2.

[0018] The engine 31 is a power source that generates a driving force for driving the hydraulic excavator 1. The hydraulic oil tank 32 stores hydraulic oil. The main pump 33 is rotated by the power of the engine 31, and pressure-feeds the hydraulic oil stored in the hydraulic oil tank 32 to the hydraulic oil supply oil passage L1. The pilot pump 34 is rotated by the power of the engine 31, and pressure-feeds the hydraulic oil stored in the hydraulic oil tank 32 to the pilot supply oil passage L3 as pilot pressure oil.

[0019] The hydraulic oil supply passage L1 is a flow path that supplies hydraulic oil pressure-fed by the main pump 33 to the hydraulic actuators 6, 14 to 16 via the control valve CV. The hydraulic oil supply passage L1 is connected to a pump port 51 of the control valve CV (see FIG. 3).

[0020] The hydraulic oil return passage L2 is a flow path that returns the hydraulic oil discharged from the hydraulic actuators 6, 14-16 to the hydraulic oil tank 32 via the control valve CV. The hydraulic oil return passage L2 is connected to the tank ports 52a and 52b of the control valve CV (see FIG. 3).

[0021] The pilot supply oil passage L3 is a flow passage that supplies pilot pressure oil (hydraulic oil) pressure-fed by the pilot pump 34 to the pilot ports 55a, 65a, 55b, 165a, etc. via the pilot control valves 42a, 42b, 43a, 43b, etc.

[0022] The pilot return oil passage L4 is a flow passage that returns pilot pressure oil (hydraulic oil) discharged from the pilot ports 55a, 65a, 55b, 165a, etc. to the hydraulic oil tank 32 via the pilot control valves 42a, 42b, 43a, 43b, etc.

[0023] 2, the control valve CV is provided between the main pump 33 and the hydraulic actuators 6, 14 to 16. The control valve CV incorporates spools 61a, 161a that switch the flow direction of the hydraulic oil, and the like.

[0024] The spools are provided in a number corresponding to the number of hydraulic actuators, but in FIG. 2, only the spool 61a that controls the bucket cylinder 16 and the spool 161a that controls the arm cylinder 15 are labeled with reference numerals.

[0025] Next, the operation of the spools will be described. Note that since the operation of the spools is basically the same, the spool 61a that controls the bucket cylinder 16 will be described as an example, and the operation of the other spools will not be described.

[0026] Pilot pressure oil is introduced into pilot ports 55a, 65a of the spool 61a from the pilot pump 34. Pilot control valves 43a, 43b constituted by solenoid valves are provided between the pilot pump 34 and the pilot ports 55a, 65a, and pilot pressure oil acts on one of the pilot ports 55a, 65a by turning on and off the energization of the pilot control valves 43a, 43b.

[0027] Due to the pressure of the pilot pressure oil, the spool 61a moves in the axial direction (longitudinal direction in FIG. 3) between a neutral position (initial position) A, a close position B, and a distant position C. The neutral position A is located between the close position B and the distant position C, and when the spool 61a moves between the close position B and the distant position C, the spool 61a always passes through the neutral position A.

[0028] The neutral position A is a position where the hydraulic oil supply passage L1 and the hydraulic oil return passage L2 are blocked to stop the supply and discharge of hydraulic oil to the bucket cylinder 16. The spool 61a is normally held in the neutral position A by the biasing force of the spring 68a (see FIG. 6).

[0029] The proximity position B is a position where the spool 61a is closest to the base housing 50. Specifically, in Fig. 6, it is a position where the spool 61a has moved to the rightmost position. Then, when the spool 61a switches to the proximity position B, hydraulic oil is supplied to the bottom chamber of the bucket cylinder 16 and hydraulic oil is discharged from the rod chamber. In this way, the bucket cylinder 16 extends.

[0030] The distant position C is the position where the spool 61a is farthest from the base housing 50. Specifically, in FIG. 6, it is the position where the spool 61a has moved to the leftmost position. Then, when the spool 61a switches to the distant position C, hydraulic oil is supplied to the rod chamber of the bucket cylinder 16 and hydraulic oil is discharged from the bottom chamber. In this way, the bucket cylinder 16 retracts.

[0031] Next, a specific configuration of a control valve according to the present invention will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a perspective view of a control valve CV according to an embodiment of the present invention, Fig. 4 is an exploded perspective view in which section housings 60, 160, 260, and 360 of the control valve CV are partially exploded, Fig. 5 is a plan view of the control valve CV, Fig. 6 is a cross-sectional view taken along line VI-VI of the control valve CV shown in Fig. 3, and Fig. 7 is a cross-sectional view taken along line VII-VII of the control valve CV shown in Fig. 5.

[0032] As shown in FIG. 3, the control valve CV includes a base housing 50 and a plurality of section housings 60, 160, 260, and 360 (four in this embodiment).

[0033] The base housing 50 has a solid block shape and has a pump port 51 connected to the main pump 33 and tank ports 52a, 52b connected to the hydraulic oil tank 32 on its end faces in the width direction.

[0034] 6, the base housing 50 has a primary pressure oil passage 70 and return oil passages 71a, 71b (internal oil passages) therein, and communicates with the section housings 60, 160, ... via these oil passages 70, 71a, 71b. Therefore, hydraulic oil can flow between the base housing 50 and the section housings 60, 160, 260, 360.

[0035] Furthermore, the base housing 50 has two actuator ports 62a-1, 62a-2 and four storage portions 53a to 53d consisting of square holes on its upper surface. Similarly, two actuator ports and four storage portions 53e, 53f, ... are provided on the lower surface of the base housing 50 (see FIG. 6). The two actuator ports 62a-1, 62a-2 are connected to the bucket cylinder 16 (see FIG. 2).

[0036] 7, each of the accommodating portions 53a,... has at its bottom a pilot port 55a, a pressure sensor port 57a, and a pilot pressure oil passage 72. The number of the accommodating portions 53a, 53b,... is the same as the number of the spools 61a, 161a,...

[0037] For example, accommodating portion 53a accommodates pilot control valve 43a, which is an example of an electronic component / device, stroke sensor 75, which is an example of a state detection sensor, and pressure sensor 76 (see FIG. 5). Stroke sensor 75 detects the stroke amount of spool 61a. Pressure sensor 76 detects the pressure of pilot pressure oil passage 72 (see FIG. 7). Other accommodating portions 53b, 53c, ... can similarly accommodate pilot control valves, stroke sensors, and pressure sensors.

[0038] 4, the section housings 60, 160, 260, and 360 each have a solid block shape and are detachably fixed to a longitudinal end face of the base housing 50 by bolts 80. Specifically, the section housings 60 and 260 are detachably fixed to one side face 50a of the base housing 50, and the section housings 160 and 360 are detachably fixed to the other side face 50b of the base housing 50. The section housings 60, 160, 260, and 360 are sealed against the end face of the base housing 50 via an O-ring 81.

[0039] Next, the structure of the section housings will be described. However, since the structure of each section housing is the same, the following will describe section housing 60 in detail, and descriptions of the other section housings 160, 260, 360 will be omitted.

[0040] 6, the section housing 60 incorporates a pair of spools 61a, 61b arranged side by side in the vertical direction. The spool 61a controls the bucket cylinder 16, and the spool 61b controls a hydraulic actuator (not shown).

[0041] Further, section valves 63a, 63b are attached to one end side in the longitudinal direction of the section housing 60. The section valves 63a, 63b have springs 68a, 68b and pilot ports 65a, 65b. The pilot port 65a is connected to the pilot control valve 43a (see FIG. 2). The other pilot ports 65b, etc. are similarly connected to pilot control valves.

[0042] As explained above, when pilot pressure acts on pilot port 65a, spool 61a moves in a direction approaching base housing 50 in Fig. 6 (to the right in Fig. 6). When pilot pressure acts on pilot port 55a, spool 61a moves in a direction away from base housing 50 in Fig. 6 (to the left in Fig. 6). When pilot pressure does not act on pilot ports 55a and 65a, spool 61a is held in the neutral position shown in Fig. 6 by the biasing force of spring 68a.

[0043] According to the control valve CV according to the present embodiment configured as described above, the pilot control valves 42a, 43a, the stroke sensor 75, and the pressure sensor 76 can be accommodated in the accommodation sections 53a, 53b, etc. of the base housing 50. Therefore, electronic components and the like do not protrude around the control valve CV, and do not interfere with the wiring of the harness. This increases the degree of freedom in wiring the harness. In addition, since the section housings 60, 160, etc. can be detachably fixed to one side surface 50a or the other side surface 50b of the base housing 50, respectively, when maintenance work such as internal inspection or part replacement is to be performed, only the section housing to be inspected can be removed, thereby increasing the efficiency of the maintenance work.

[0044] Next, a modified example of the control valve will be described with reference to Fig. 8. Fig. 8 is a perspective view of a control valve CV1 according to a modified example. In Fig. 8, the same components as those in the above-mentioned embodiment are denoted by the same reference numerals.

[0045] A base housing and a section housing are added to the control valve CV1 according to the modified example. Specifically, as shown in Fig. 8, the control valve CV1 includes two base housings 50, 150 and five section housings 60, 160, 260, 360, 460. The base housing 150 is provided on the other end side of the base housing 50 in the width direction, and the section housing 460 is provided on the other end side of the section housing 360 in the width direction and on the other end side of the base housing 150 in the longitudinal direction.

[0046] According to this configuration, the number of spools can be easily increased by arbitrarily attaching the base housing and the section housing, which allows a larger number of hydraulic actuators to be controlled and increases the expandability of the control valve.

[0047] The above describes the embodiment and the modified examples of the present invention. Note that the present invention is not limited to the above-described embodiment and modified examples, and includes various other modified examples. For example, the above-described embodiment and modified examples have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of this embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of this embodiment with another configuration.

[0048] For example, the accommodation sections 53a, 53b, etc. may be divided into a first accommodation section and a second accommodation section, and the space may be used depending on the type of electric component or device to be accommodated. Specifically, the pilot control valves 42a, 42b, etc. may be accommodated in the first accommodation section, and the stroke sensor 75 and the pressure sensor 76 may be accommodated in the second accommodation section. Of course, it is possible to arbitrarily determine which electronic component is accommodated in which space.

[0049] Furthermore, the number of spools 61a, 61b, etc. housed in each section housing 60, 160, etc. is not limited to two. The number may be one, or three or more. [Explanation of symbols]

[0050] 1. Hydraulic excavator 2 Undercarriage 3. Upper rotating body 4. Crawler 5. Travel motor 6 Swing motor (hydraulic actuator) 7 Swivel Frame 9 Counterweight 10 Front work machine 11. Boom 12 Arm 13. Bucket 14 Boom cylinder (hydraulic actuator) 15 Arm cylinder (hydraulic actuator) 16 Bucket cylinder (hydraulic actuator) 20 Cab 31 Engine 32 Hydraulic Oil Tank 33 Main pump (hydraulic pump) 34 Pilot pump 42a, 42b, ... Pilot control valve (solenoid valve) 50,150 Base Housing 50a one side 50b Other side 51 Pump port 52a, 52b Tank port 53a, 53b, 53c, 53d,... Storage section 55a, 55b, ... Pilot port 56a, Stroke sensor port 57a, Pressure Sensor Port 60, 160, 460 Section housing 61a, 61b, 161a, 161b... Spool 62a-1, 62a-2, 462a-2 Actuator port 63a, 63b,..., 463b Section valve 65a, 65b, , 165b Pilot port 68a, 68b,....168b Spring 70 Primary pressure oil passage (internal oil passage) 71a, 71b Return oil path (internal oil path) 72 Pilot pressure oil passage (internal oil passage) 75 Stroke sensor (status detection sensor) 76 Pressure sensor (status detection sensor) 80 Volts 81 O-ring CV, CV1 Control valve

Claims

1. In a control valve for controlling the flow direction of hydraulic oil supplied from a hydraulic pump to a hydraulic actuator, The control valve is a base housing having a pump port connected to the hydraulic pump; a plurality of section housings each having an actuator port connected to the hydraulic actuator and communicating with the base housing via an internal oil passage; The plurality of section housings are each detachably attached to one side surface and the other side surface of the base housing, and each have a built-in spool that switches the flow direction of the hydraulic oil, The base housing is provided with a plurality of housings for housing status detection sensors that detect the status of each of the section housings. A control valve characterized by:

2. 2. The control valve according to claim 1, The spool reciprocates in an axial direction between a close position where it is close to the base housing and a separate position where it is separated from the base housing, a stroke sensor serving as the state detection sensor for detecting a stroke amount of the spool, The stroke sensor is accommodated in the accommodation portion. A control valve characterized by:

3. 2. The control valve according to claim 1, A pressure sensor is provided as the condition detection sensor for detecting the pressure of the internal oil passage, The pressure sensor is accommodated in the accommodation portion. A control valve characterized by:

4. 4. The control valve according to claim 3, a solenoid valve for introducing pilot pressure oil to a pilot port of the spool in order to reciprocate the spool in the axial direction; The solenoid valve is accommodated in the accommodation portion together with the pressure sensor. A control valve characterized by:

5. 2. The control valve according to claim 1, At least one of the plurality of section housings houses a plurality of the spools, The plurality of spools switch the flow of the hydraulic oil to different hydraulic actuators. A control valve characterized by:

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