Control valve

Abstract

To reduce man-hours of connection work for electronic devices such as solenoid valves and harnesses installed in a control valve.SOLUTION: A control valve comprises: a housing internally comprising spools; a plurality of electronic devices fixed to the housing, and each comprising first terminals; and a block in which a plurality of harnesses comprising second terminals are internally passed. The respective second terminals of the plurality of harnesses are attached to the block. The plurality of first terminals and the second terminals are disconnected and connected in association with detachment and attachment of the block with respect to the housing.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a control valve provided in a construction machine such as a hydraulic excavator. [Background technology]

[0002] Some control valves used in construction machinery such as hydraulic excavators are equipped with a solenoid valve that generates pilot pressure to drive the spool. The solenoid valve is driven by a command signal input from a controller via a harness.

[0003] In recent years, in the field of construction machinery, there has been a trend toward an increase in the number of electronic devices, such as solenoid valves and pressure sensors, installed in control valves in order to keep up with improvements in the performance of electronic control functions, such as machine control.

[0004] As a method of mounting electronic devices on a control valve, Patent Document 1 discloses a structure in which a pilot cap that forms a spring chamber for a spool that controls the supply of hydraulic pressure to each hydraulic actuator is installed on the side of the main housing, and a solenoid valve that controls the spool is directly connected to the pilot cap. With this structure, by replacing the pilot cap, it is possible to change whether or not the solenoid valve controls the pilot pressure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6944407 Summary of the Invention [Problem to be solved by the invention]

[0006] In a control valve that applies the technology of Patent Document 1, it is necessary to individually connect the corresponding harness to the terminal of each solenoid valve that is connected to the pilot cap. As the number of solenoid valves installed in a control valve increases, the number of harnesses connected to the solenoid valves also increases, and the labor required to connect the harnesses to the solenoid valves during assembly and maintenance increases.

[0007] An object of the present invention is to provide a control valve that can reduce the number of steps required to connect an electronic device, such as an electromagnetic valve, to a harness. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a control valve comprising a housing having a spool therein, a plurality of electronic devices fixed to the housing and each having a first terminal, and a block through which a plurality of harnesses having second terminals pass, wherein each second terminal of the plurality of harnesses is attached to the block, and the plurality of first terminals and second terminals are disconnected and connected as the block is attached to and detached from the housing. [Effects of the Invention]

[0009] According to the present invention, it is possible to reduce the number of steps required to connect an electronic device, such as an electromagnetic valve, mounted on a control valve to a harness. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view of a hydraulic excavator, which is an example of a construction machine to which a control valve according to an embodiment of the present invention is applied; [Figure 2] FIG. 1 is a perspective view showing the appearance of a control valve according to an embodiment of the present invention. [Figure 3] Cross-sectional view taken along the arrow AA in Figure 2 [Figure 4] Cross-sectional view of arrow BB in Figure 2 [Figure 5] Enlarged view of part C in Figure 4 DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] -Construction machinery- Figure 1 is a side view of a hydraulic excavator, which is an example of construction machinery to which a control valve according to one embodiment of the present invention is applied. In the figure, a hydraulic excavator 1 is shown as an example of construction machinery, but the control valve according to the present invention can be applied to other types of construction machinery, such as wheel loaders and cranes, used for various types of work such as civil engineering work, construction work, and demolition work. Although the hydraulic excavator 1 is a crawler type, the control valve according to the present invention can also be applied to wheeled construction machinery.

[0013] The hydraulic excavator 1 is configured to include a vehicle body 4 and a front work implement 10 attached to the vehicle body 4. The vehicle body 4 is configured to include a running body 2 and a rotating body 3 that is rotatably attached to the running body 2. The running body 2 runs by driving left and right crawlers with a traveling hydraulic motor. The rotating body 3 has a cab 7 in which an operator sits, and is driven to rotate relative to the running body 2 by a rotating hydraulic motor attached to the vehicle body 4. Inside the cab 7, in addition to the traveling hydraulic motor and the rotating hydraulic motor, various operating devices are provided for operating the hydraulic actuators mounted on the hydraulic excavator 1, such as a boom cylinder 15, an arm cylinder 16, and a bucket cylinder 17, which will be described later.

[0014] The front work implement 10 is a work device in which an attachment appropriate for the work (a bucket 14 in the example of FIG. 1) is attached to a multi-jointed work arm 11, and is connected to the rotating body 3. The work arm 11 includes a boom 12 connected to the front part of the rotating body 3 so that it can rotate up and down, and an arm 13 connected to the tip of the boom 12 so that it can rotate back and forth. The boom 12 is driven by a boom cylinder 15, the arm 13 by an arm cylinder 16, and the bucket 14 by a bucket cylinder 17. While FIG. 1 shows an example of a configuration in which the bucket 14 is attached to the work arm 11 as an attachment, the bucket 14 can be replaced with another attachment such as a grapple depending on the work being performed.

[0015] In the hydraulic excavator 1 configured as described above, hydraulic actuators such as the boom cylinder 15 and arm cylinder 16 are driven by pressure oil discharged from a hydraulic pump. The supply direction and supply flow rate of pressure oil to the hydraulic actuators are controlled by a control valve mounted on the hydraulic excavator 1, and the operating direction and operating speed of the hydraulic actuators are changed.

[0016] -Control valve- Fig. 2 is a perspective view showing the appearance of a control valve according to one embodiment of the present invention, Fig. 3 is a cross-sectional view taken along the line AA in Fig. 2 and Fig. 4, and Fig. 4 is a cross-sectional view taken along the line BB in Fig. 2 and Fig. 3. Fig. 5 is an enlarged view of part C in Fig. 4.

[0017] The control valve 100 shown in FIGS. 2-5 includes a housing 110 having multiple (four in this example) spools 150A-150D therein, multiple (four in this example) solenoid valves 120A-120D as electronic devices fixed to the housing 110, and a block 130 through which multiple (four in this example) harnesses 140A-140D pass. The multiple solenoid valves 120A-120D are electromagnetically driven control valves that control the hydraulic pressure supplied to the spools 150A-150D, and each has a first terminal 121 connected to a solenoid. Each of the multiple harnesses 140A-140D has a second terminal 141. Although the solenoid valves 120C and 120D are not shown, they are located at positions corresponding to the harnesses 140C and 140D in FIG. 3.

[0018] The block 130 can be fixed to the housing 110 only in a single, predetermined angular position. In this embodiment, the block 130 has a cylindrical shape, is fitted into a mounting hole 111, which is a cylindrical recess formed in the housing 110, and is fixed to the housing 110 with at least one bolt B1 (two in this embodiment). The block 130 has a through hole 131 through which the bolt B1 passes, and screw holes 112 into which the bolt B1 is screwed are formed at the bottom of the mounting hole 111 in the housing 110 at unequal intervals in the circumferential direction, avoiding the centers of the cylindrical block 130 and the mounting hole 111. In this embodiment, by positioning the through hole 131, the screw hole 112, and the bolt B1 at unequal intervals in the circumferential direction, the block 130 can be fixed to the housing 110 only in a single, predetermined angular position.

[0019] However, it is acceptable as long as the through holes 131 and the screw holes 112 do not align unless they are in a predetermined angular position. For example, even if multiple bolts B1 are arranged at equal intervals around the circumference of the block 130, it is acceptable as long as the radial distances of the bolts B1 from the center of the block 130 are not uniform. Alternatively, to secure the block 130 to the housing 110 only in a predetermined angular position, the housing 110 may only fit into the block 130 in a predetermined angular position. For example, a positioning spigot joint structure offset from the center of the block 130 may be provided on the opposing surfaces of the housing 110 and the block 130, or the mounting hole 111 of the housing 110 and the block 130 may be formed into an irregular polygonal shape. However, in this embodiment, the cylindrical shape of the block 130 and the mounting hole 111 has the great advantage of facilitating machining and is also suitable for the application of a seal structure, which will be described later.

[0020] The housing 110 is divided into one main housing 110a, two section housings 110b, and two pilot housings 110c. The main housing 110a is located in the center, and pilot housings 110c are located at both left and right ends (both ends in the X direction), with a section housing 110b interposed between the main housing 110a and each of the left and right pilot housings 110c. The main housing 110a and the left and right section housings 110b are each fastened with a plurality of bolts B2. The pilot housings 110c are fastened to each of the left and right section housings 110b with bolts B3.

[0021] As shown in FIG. 3, the control valve 100 has pump lines L1-L3 passing through it.

[0022] The first pump line L1 is connected to a pump pipe (discharge pipe) of a hydraulic pump provided in the hydraulic excavator 1. This pump line is a single oil passage provided in the housing 110 (main housing 110a).

[0023] 3, the second pump line L2 is an oil passage that passes through the inside of the block 130, and the outlet of the pump line L1 is connected to its inlet opening α. In this embodiment, the pump line L2 branches into multiple lines as shown in FIG. 3, and has multiple (two) outlet openings β.

[0024] The third pump line L3 passes through the housing 110 (the main housing 110a and the left and right section housings 110b). This pump line L3 has multiple systems (two systems in this embodiment). The inlet of each system is connected to a corresponding outlet opening β of the second pump line L2, and each system branches off to connect to corresponding two of the spool chambers that house the spools 150A-150D. In this embodiment, as shown in FIG. 3, the pump line L3 on the left side in the figure branches off into two lines, each connected to the spool chambers of the spools 150A and 150C. On the other hand, the pump line L3 on the right side in the figure also branches off into two lines, each connected to the spool chambers of the spools 150B and 150D.

[0025] As described above, block 130 can only be fixed to housing 110 in a single, predetermined angular position. Control valve 100 is configured such that, when block 130 is fixed to housing 110 in this predetermined angular position, inlet openings α of pump line L1 and pump line L2 automatically communicate with each other. Of course, not only pump lines L1 and L2 but also the multiple outlet openings β of pump line L2 and the multiple pump lines L3 corresponding to these outlet openings automatically communicate with each other when block 130 is fixed to housing 110 in the predetermined angular position.

[0026] As described above, in this embodiment, the oil passage passing through the housing 110 of the control valve 100 is divided midway to form the first pump line L1 and the third pump line L3, and the second pump line L2 (second oil passage) connecting these pump lines L1 and L3 (first oil passage) passes through the block 130. In other words, the block 130 is laid out without avoiding the pump lines.

[0027] 4, each pilot housing 110c has a plurality of (four in this embodiment) spring chambers 152 disposed coaxially with the spools 150A-150D housed inside the housing 110. Each spring chamber 152 houses a spring 153, and each spring 153 biases a corresponding one of the spools 150A-150D. A tank line L4, actuator lines L5A-L5D, and pilot lines L6A-L6D also pass through the control valve 100.

[0028] The tank line L4 is connected to a tank pipe (discharge pipe) that leads to a hydraulic oil tank provided in the hydraulic excavator 1. As shown in Fig. 2, in this embodiment, the outlet of the tank line L4 is provided in the main housing 110a.

[0029] Actuator lines L5A-L5D pass through the left and right section housings 110b. Actuator lines L5A-L5D are each connected to an actuator pipe that is connected to an oil chamber of an actuator provided in the hydraulic excavator 1, and the spool chamber of the spool 150A is connected to the actuator pipe. In this embodiment, actuator line L5A is connected to an actuator pipe that is connected to an oil chamber on the bottom side of the boom cylinder 15, actuator line L5B is connected to an actuator pipe that is connected to a rod-side oil chamber of the boom cylinder 15, actuator line L5C is connected to an actuator pipe that is connected to a bottom-side oil chamber of the arm cylinder 16, and actuator line L5D is connected to an actuator pipe that is connected to a rod-side oil chamber of the arm cylinder 16.

[0030] The pilot lines L6A-L6D pass through the inside of the main housing 110a. Pilot piping leading to a pilot pump provided in the hydraulic excavator 1 is connected to the pilot lines L6A-L6D. The pilot line L6A is connected to a pilot chamber 151A corresponding to the spool 150A via a solenoid valve 120A. The pilot line L6B is connected to a pilot chamber 151B corresponding to the spool 150B via a solenoid valve 120B. The pilot line L6C is connected to a pilot chamber 151C corresponding to the spool 150C via a solenoid valve 120C. The pilot line L6D is connected to a pilot chamber 151D corresponding to the spool 150D via a solenoid valve 120D.

[0031] For example, suppose that the solenoid of solenoid valve 120A is energized and the solenoid of solenoid valve 120B is de-energized in response to a command signal output from the controller (control device) of the hydraulic excavator 1 in response to operation of the operating device in the operator's cab 7. In this case, solenoid valve 120A is driven by the command signal from the controller, pilot line L6A is connected to pilot chamber 151A, and pilot pressure generated by solenoid valve 120A acts on pilot chamber 151A. This drives spool 150A, connecting pump line L3 to actuator line L5A, supplying pressure oil discharged from the hydraulic pump to the bottom-side oil chamber, extending boom cylinder 15, and raising boom 12. Pressure oil discharged from the rod-side oil chamber of boom cylinder 15 passes through actuator line L5B and the tank line and is discharged into hydraulic oil tank T.

[0032] Here, as shown in Fig. 5, a plurality of (four in this embodiment) insertion openings 111a are provided on the bottom surface of the mounting hole 111 provided in the main housing 110a. The solenoid valves 120A-120D are rigidly fixed by inserting their lower portions (lower portions in the Y direction in Fig. 5) into the corresponding insertion openings 111a. The block 130 is provided with a plurality of (four in this embodiment) valve chambers 113 that open facing the bottom surface of the mounting hole 111 of the main housing 110a, and the upper portions (upper portions in the Y direction in Fig. 5) of the solenoid valves 120A-120D are accommodated in the corresponding valve chambers 113. As a result, first terminals 121 provided at the upper end portions of the solenoid valves 120A-120D are located inside the respective valve chambers 113.

[0033] The block 130 is also provided with a plurality of (four in this embodiment) harness passage holes 132 through which the harnesses 140A-140D pass. While the inlets of these harness passage holes 132 may be independent of each other, in this embodiment, one harness passage hole 132 opens to the top surface of the block 130 (the surface facing upward in the Y direction in FIG. 5). On the other hand, the outlet of each harness passage hole 132 opens to the corresponding valve chamber 113. In other words, in this embodiment, the harness passage holes 132 share a common inlet and branch inside the block 130, resulting in separate outlets. Each harness 140A-140D passes through a corresponding harness passage hole 132, and a second terminal 141 at the tip of each harness 140A-140D faces the corresponding valve chamber 113.

[0034] Each second terminal 141 has a contact portion 141a for contacting the first terminal 121 made of metal, and an elastic body (rubber) 141b, and is fixed to the outlet portion of the harness-through hole 132 and faces the valve chamber 113. When the block 130 is fixed to the housing 110 with the bolt B1, the first terminals 121 of the solenoid valves 120A-120D come into contact with the second terminals 141 of the harnesses 140A-140D. The contact portion 141a of each second terminal 141 is pressed against the elastic body 141b and tightly contacts the first terminal 121. As described above, the block 130 can only be fixed to the housing 110 in a single predetermined angular position, and all four first terminals 121 and second terminals 141 are only connected when the block 130 is fixed to the housing 110 with the bolt B1.

[0035] Since each second terminal 141 of the harnesses 140A-140D is attached to the block 130, the first terminal 121 and the second terminal 141 are respectively disconnected and connected as the block 130 is attached to or detached from the housing 110. Connecting refers to the first terminal 121 and the second terminal 141 being electrically connected, and disconnecting refers to the release of that connection. In this embodiment, no tape or tube is provided to protect the first terminal 121 and the second terminal 141, and the first terminal 121 and the second terminal 141 are exposed inside the valve chamber 113 and are in contact with each other.

[0036] 5, a first seal groove 133a and a second seal groove 133b are formed in the outer peripheral surface of the block 130. The first seal groove 133a and the second seal groove 133b are formed around the entire outer peripheral surface (circumferential surface) of the block 130, and a first seal material 134a is held in the first seal groove 133a, and a second seal material 134b is held in the second seal groove 133b. The first seal material 134a and the second seal groove 133b are, for example, O-rings, and hold an inlet opening α and two outlet openings β of the pump line L2 that passes through the block 130 between them.

[0037] 5, the first sealant 134a is located below the inlet opening α and the outlet opening β and is positioned between the opening of the pump line L2 (the inlet opening α and the outlet opening β) of the pump line L2 and each valve chamber 113, and seals between the opening of the pump line L2 in the block 130 and the second terminal 141. On the other hand, the second sealant 134b is located on the opposite side (upper side in FIG. 5) of the first sealant 134a across the opening of the pump line L2 (the inlet opening α and the outlet opening β) of the pump line L2 and is positioned between the opening of the pump line L2 (the inlet opening α and the outlet opening β) of the pump line L2 and the outer surface of the block 130 (the upper surface in FIG. 5), and seals between the opening of the pump line L2 in the block 130 and the outer surface of the control valve 100.

[0038] With this configuration, even if hydraulic oil leaks from the inlet opening α and the outlet opening β of the pump line L2, the leaked oil is sealed between the first seal material 134a and the second seal material 134b. This prevents hydraulic oil leaking from the inlet opening α and the outlet opening β of the pump line L2 from leaking outside the control valve 100 or into the valve chamber 113 that houses the solenoid valves 120A-120D.

[0039] -effect- (1) In this embodiment, the second terminals 141 of the harnesses 140A-140D are attached to the block 130, and the first terminals 121 and the second terminals 141 of the solenoid valves 120A-120D are disconnected and connected as the block 130 is attached to and detached from the housing 110. This reduces the number of steps required to connect the solenoid valves 120A-120D mounted on the control valve 100 to the harnesses 140A-140D. Furthermore, because a reduction in the number of steps required to connect the terminals can be expected, mistakes in connecting the solenoid valves 120A-120D to the harnesses 140A-140D can also be reduced.

[0040] (2) The block 130 can be fixed to the housing 110 only at a single predetermined angular position, which prevents the block 130 from being incorrectly assembled to the housing 110.

[0041] (3) In addition, generally, as the number of solenoid valves installed in a control valve increases, the number of harnesses connected to the solenoid valves also increases, which may make it easier for mistakes to occur in connecting the solenoid valves and harnesses.

[0042] In contrast, in this embodiment, all of the first terminals 121 and the second terminals 141 are connected only when the block 130 is fixed in a single predetermined angular position relative to the housing 110. This makes it possible to prevent incorrect connections between the solenoid valves 120A-120D and the harnesses 140A-140D.

[0043] (4) Block 130 has pump line L2 therein, which communicates with pump lines L1 and L3 passing through the interior of housing 110. In this embodiment, the oil passage passing through housing 110 of control valve 100 is divided into pump lines L1 and L3 along the way, and pump line L2, which connects these pump lines L1 and L3, passes through block 130. By passing pump line L2 through block 130 in this way, it is not necessary to lay out block 130 in a way that avoids the oil passage inside housing 110, and control valve 100 can be configured compactly.

[0044] (5) As with the first terminal 121 and the second terminal 141, the pump lines L1-L3 are automatically connected by fixing the block 130 at a single predetermined angular position relative to the housing 110. This prevents the oil passages from being disconnected due to incorrect assembly of the block 130.

[0045] (6) The first sealant 134a is provided to seal between the openings (inlet opening α and outlet opening β) of the pump line L2 in the block 130 and the second terminal 141, thereby preventing leakage oil and dust from the pump line L2 from entering the terminal contact portion. This prevents poor terminal connection without protecting the first terminal 121 and the second terminal 141 with tape or a tube.

[0046] (7) Furthermore, the block 130 is provided with the second seal 134b on the opposite side of the first seal 134a across the openings (inlet opening α and outlet opening β) of the pump line L2, which makes it possible to prevent leakage of oil from the pump line L2 to the outside of the control valve 100. It is also possible to prevent dust, water, and the like from entering between the opposing surfaces of the housing 110 and the block 130 from the outside of the control valve 100.

[0047] (8) Because the block 130 is cylindrical, it is possible to easily process the mounting hole 111 of the housing 110 and the block 130. In addition, because the block 130 is cylindrical, it is also suitable for applying O-rings to the first seal material 134a and the second seal material 134b, and a necessary and sufficient sealing structure can be easily realized.

[0048] -Additional remarks- The present invention is not limited to the above-described embodiments and may include various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to a configuration including all of the described components. For example, it is possible to replace or change part of the configuration with another configuration. It is also possible to delete part of the configuration of the embodiment, or to add another configuration to the configuration of the embodiment.

[0049] For example, in the above embodiment, a configuration was exemplified in which a portion of the pump line (pump line L2) connecting the pump piping Lp and the spools 150A-150D passes through the inside of block 130, but this is not limited to the pump line; the tank line L4, actuator lines L5A-L5D, and pilot lines L6A-L6D may also pass through block 130.

[0050] Furthermore, although an example of a configuration in which O-rings are used as the first sealing material 134a and the second sealing material 134b has been described, sealing materials other than O-rings, for example, formed from an elastic material that can ensure sealing properties, can also be used as the first sealing material 134a and the second sealing material 134b.

[0051] The number of spools 150A-150D, solenoid valves 120A-120D, harnesses 140A-140D, etc., the route of the oil passages passing through the housing, and the configuration of spools 150A-150D can also be modified as appropriate.

[0052] Furthermore, the solenoid valves 120A-120D have been used as an example of electronic devices whose terminals are connected when the block 130 is attached or detached. However, the electronic devices whose terminals are connected when the block 130 is attached or detached are not limited to solenoid valves. For example, other electronic devices such as pressure sensors may be configured to be connected to the terminals when the block 130 is attached or detached.

[0053] Furthermore, the control valve 100 can be used as a directional control valve for controlling the boom cylinder 15 and the arm cylinder 16, but the control valve 100 can also be applied to other valves, such as directional control valves for controlling the bucket cylinder 17, swing motor, or other hydraulic actuators. Furthermore, the control valve 100 is not limited to the hydraulic excavator 1, but can also be applied to other types of construction machinery, such as wheel loaders and cranes, used for various types of work such as civil engineering work and demolition work, and can also be used to operate the hydraulic actuators of these construction machinery. [Explanation of symbols]

[0054] 100...control valve, 110...housing, 120A-120D...solenoid valve (electronic device), 121...first terminal, 130...block, 134a...first sealant, 134b...second sealant, 140A-140D...harness, 141...second terminal, 150A-150D...spool, L1...pump line (first oil passage), L2...pump line (second oil passage), L3...pump line (first oil passage), α...inlet opening (opening of second oil passage), β...outlet opening (opening of second oil passage)

Claims

1. a housing having a spool therein; a plurality of electronic devices fixed to the housing, each having a first terminal; a block attached to a mounting hole formed in the housing, through which a plurality of harnesses having second terminals pass; A control valve characterized in that each second terminal of the plurality of harnesses is attached to the block, and the plurality of first terminals and second terminals are configured to be disconnected and connected as the block is attached to and detached from the housing.

2. 2. The control valve according to claim 1, A control valve characterized in that the block can be fixed only in a single predetermined angular position relative to the housing.

3. 3. The control valve according to claim 2, A control valve characterized in that all of the first terminals and the second terminals are configured to be connected only when the block is fixed in the predetermined angular position relative to the housing.

4. 4. The control valve according to claim 3, A control valve characterized in that the block has a second oil passage therein that communicates with a first oil passage passing through the inside of the housing.

5. 5. The control valve according to claim 4, A control valve characterized in that the first oil passage and the second oil passage are configured to communicate with each other when the block is fixed in the predetermined angular position relative to the housing.

6. 6. The control valve according to claim 5, A control valve comprising: a first seal member that seals between the opening of the second oil passage in the block and the second terminal.

7. 7. The control valve according to claim 6, A control valve comprising a second seal member disposed on the opposite side of the opening of the second oil passage from the first seal member.

8. 2. The control valve according to claim 1, The control valve is characterized in that the electronic device is a solenoid valve.

9. 3. The control valve according to claim 2, A control valve characterized in that the block is cylindrical.

Images