Inlet housing

Abstract

In an inlet housing 1, inlet ports 11 and internal flow passages 12 are provided between a left-side travel control valve 4 and a right-side travel control valve 5. The inlet ports 11 are between a pair of travel supply / discharge ports 67, 68 of the left-side travel control valve 4 and a pair of travel supply / discharge ports 67, 68 of the right-side travel control valve 5, and are offset with respect to a virtual line L1 passing through the travel supply / discharge ports 67 disposed on the same one side and a virtual line L2 passing through the travel supply / discharge ports 68 on the other side. A distance D1 between the pair of travel supply / discharge ports 67, 68 of the left-side travel control valve 4 and the pair of travel supply / discharge ports 67, 68 of the right-side travel control valve 5 is smaller than a diameter D2 of the inlet ports 11.

Description

Inlet Housing

[0001] The present invention relates to an inlet housing.

[0002] JP2003-227503A discloses a hydraulic circuit structure having an end block to which oil discharged from a main pump is supplied via a pressure oil supply line, and a right-travel control valve and a left-travel control valve. In this hydraulic circuit structure, the end block, the right-travel control valve, and the left-travel control valve are arranged in this order.

[0003] In the above hydraulic circuit structure, the difference in oil passage length from the end block to the right-hand travel control valve and the oil passage length from the end block to the left-hand travel control valve can cause a difference in left-hand travel, which can affect straight-line driving. Also, the housing width is determined by the port size for each of the end block, right-hand travel control valve, and left-hand travel control valve, which can limit downsizing.

[0004] The present invention has been made in view of the above-mentioned problems, and aims to suppress the occurrence of left-right running difference and to achieve size reduction.

[0005] According to one aspect of the present invention, there is provided an inlet housing to which hydraulic fluid is supplied from a hydraulic pressure supply source, the inlet housing including a left-side running control valve incorporated inside the inlet housing and controlling a left-side running motor, a right-side running control valve incorporated inside the inlet housing and controlling a right-side running motor, an inlet port opening to an outer surface of the inlet housing and communicating with the hydraulic pressure supply source, and an internal flow path communicating with the inlet port and connected to a pump passage that introduces hydraulic fluid to the left-side running control valve and the right-side running control valve, the left-side running control valve having a pair of openings to the outer surface and supplying and discharging hydraulic fluid to the left-side running motor. an inlet housing having a left-side running supply / discharge port, and the right-side running control valve having a pair of right-side running supply / discharge ports that open to an outer surface and supply / discharge working fluid to the right-side running motor, the inlet port and the internal flow path being provided between the left-side running control valve and the right-side running control valve, the inlet ports being offset with respect to each of imaginary lines that pass through two supply / discharge port rows formed by the left-side running supply / discharge port and the right-side running supply / discharge port that are arranged on the same side in the left-side running control valve and the right-side running control valve, and the distance between the pair of left-side running supply / discharge ports and the pair of right-side running supply / discharge ports is smaller than the diameter of the inlet ports.

[0006] Fig. 1 is a schematic diagram of a fluid pressure control device according to an embodiment of the present invention. Fig. 2 is a cross-sectional view corresponding to the AA-AA cross section or the AB-AB cross section in Fig. 1. Fig. 3 is a cross-sectional view of an inlet housing taken along the BB cross section shown in Fig. 1.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0008] Fig. 1 is a schematic diagram of a fluid pressure control device 100. Fig. 2 is a cross-sectional view corresponding to the AA-AA cross section or the AB-AB cross section which is similar to the AA-AA cross section in Fig. 1. Fig. 3 is a view showing the inlet housing 1 at the BB cross section shown in Fig. 1.

[0009] The fluid pressure control device 100 shown in FIG. 1 is mounted on a construction machine (e.g., a hydraulic excavator) that is a vehicle having hydraulic drive sources on the left and right sides, and controls the operation of actuators such as a left-side travel motor 8 and a right-side travel motor 9 (described later) and hydraulic cylinders (not shown) by controlling the supply and discharge of hydraulic oil to these actuators.

[0010] The fluid pressure control device 100 includes an inlet housing 1 and multiple valve housings 2. For example, a hydraulic cylinder (not shown) is connected to each of the multiple valve housings 2 via an oil passage. The hydraulic cylinder drives a driven object (not shown), such as the boom, arm, or bucket of a hydraulic excavator. Hydraulic oil corresponds to the working fluid. In addition to hydraulic oil, an incompressible fluid such as water may also be used as the working fluid. In FIG. 1, valve housing 2A and valve housing 2B are shown as examples of the multiple valve housings 2. The multiple valve housings 2 and the inlet housing 1 are connected to form an integrated valve block, thereby constituting the fluid pressure control device 100.

[0011] The inlet housing 1 is a single housing to which hydraulic oil is supplied from outside the fluid pressure control device 100, and has two inlet ports 11 formed in the inlet housing 1. The two inlet ports 11 are arranged side by side in the horizontal direction so that their center positions in the width direction are the same, and each inlet port 11 has an installation portion 111 to which a joint (not shown) is assembled, and which has a counterbore portion and a female thread portion.

[0012] Each inlet port 11 opens to the top surface of the inlet housing 1 via an installation portion 111. The two inlet ports 11 may open to an outer surface other than the top surface of the inlet housing 1, and do not have to be provided on the same surface. The same applies to travel supply / discharge ports 67, 68, which will be described later, as well as the inlet port 11 and travel supply / discharge ports 67, 68. The travel supply / discharge ports 67, 68 also have installation portions 671, 681 similar to the inlet port 11. Hereinafter, one of the two inlet ports 11 (the inlet port 11 on the left in FIG. 1 ) will also be referred to as inlet port 11A, and the other inlet port 11 (the inlet port 11 on the right in FIG. 1 ) will also be referred to as inlet port 11B.

[0013] Hydraulic oil is supplied into the fluid pressure control device 100 through each inlet port 11 by a pump 3, which is a fluid pressure supply source. An oil passage (piping) branches off from the common pump 3 and is connected to each inlet port 11. The oil passage (piping) from the common pump 3 may be branched off using a joint and connected to each inlet port 11. Alternatively, a separate pump may be provided for each inlet port 11. Hydraulic oil supplied into the inlet housing 1 is supplied to each valve housing 2 through an oil passage formed in the valve block. A control valve is provided in each valve housing 2, and the control valve controls the hydraulic oil supplied to and discharged from the corresponding hydraulic cylinder.

[0014] As shown in Figures 1 and 2, the inlet housing 1 further has a left-hand running control valve 4 at the AA-AA cross section in Figure 1, and a right-hand running control valve 5 at the AB-AB cross section. The left-hand running control valve 4 and the right-hand running control valve 5 are incorporated inside the inlet housing 1 and arranged side by side in the width direction. Therefore, the width direction can be said to be the direction in which the left-hand running control valve 4 and the right-hand running control valve 5 are arranged side by side. Note that the following description will mainly use the left-hand running control valve 4 as an example, but the same applies to the right-hand running control valve 5.

[0015] The left-side traveling control valve 4 has a spool valve 61 whose position can be switched between a plurality of switching positions, and an accommodation hole 62 that slidably accommodates the spool valve 61. The left-side traveling control valve 4 has three switching positions, namely a neutral position, a forward rotation position, and a reverse rotation position, and in Figure 2, the spool valve 61 is in the neutral position.

[0016] The accommodation hole 62 is formed with an annular recess 63 provided in the center, a pump port 64 provided adjacent to the annular recess 63, supply ports 65, 66 provided outside the annular recess 63 and the pump port 64, a pair of traveling supply and discharge ports 67, 68 provided outside the supply ports 65, 66 and opening onto the top surface of the inlet housing 1, and a discharge port 69 provided outside the pair of traveling supply and discharge ports 67, 68.

[0017] The pump port 64 is connected to the pump 3 (see FIG. 1) through a pump passage 80 that extends in the width direction of the inlet housing 1 (the up-and-down direction in FIG. 1). Hydraulic oil discharged from the pump 3 is constantly guided to the pump port 64. The pair of travel supply / discharge ports 67, 68 are connected to the left travel motor 8 (see FIG. 1), and the discharge port 69 is connected to the tank T (see FIG. 1) through tank passages 81, 82 that extend in the width direction. Note that in the case of the right travel control valve 5 located at the AB-AB cross section shown in FIG. 1, the pair of travel supply / discharge ports 67, 68 are connected to the right travel motor 9. The left travel motor 8 and the right travel motor 9 are both hydraulic motors that constitute travel drive sources operated by hydraulic pressure.

[0018] In the left-hand travel control valve 4 located at the AA-AA cross section shown in FIG. 1 , one of the pair of travel supply / discharge ports 67, 68, the travel supply / discharge port 67, is connected to the first port 8a of the left-hand travel motor 8, and the other travel supply / discharge port 68 is connected to the second port 8b of the left-hand travel motor 8. In the right-hand travel control valve 5 located at the AB-AB cross section, one of the travel supply / discharge ports 67 is connected to the first port 9a of the right-hand travel motor 9, and the other travel supply / discharge port 68 is connected to the second port 9b of the right-hand travel motor 9. The pair of travel supply / discharge ports 67, 68 are arranged side by side in the horizontal direction so that their widthwise centers are aligned, and form a pair in the horizontal direction of the inlet housing 1 (the left-right direction in FIG. 1 ). Therefore, the horizontal direction can be said to be the direction in which the pair of travel supply / discharge ports 67, 68 are lined up or the direction in which they form a pair.

[0019] 2, the left-hand travel control valve 4 further includes a valve accommodating hole 70 formed perpendicular to the accommodating hole 62, and a compensator valve 71 slidably accommodated in the valve accommodating hole 70. The annular recess 63 and the supply ports 65, 66 communicate with each other through the compensator valve 71, and the degree of communication between them varies according to the pressure of the hydraulic oil acting on the compensator valve 71.

[0020] When the spool valve 61 is in the neutral position, it has a first annular groove 11a formed in a position facing the pump port 64, a second annular groove 11b formed in a position facing the annular recess 63, a third annular groove 11c formed in a position facing one of the travel supply / discharge ports 67, and a fourth annular groove 11d formed in a position facing the other of the travel supply / discharge ports 68. A first pilot chamber 22 and a centering spring 23 are provided at one end of the spool valve 61, and a second pilot chamber 24 and a centering spring 25 are provided at the other end of the spool valve 61.

[0021] When pilot pressure is introduced into the first pilot chamber 22 and the spool valve 61 moves to the normal rotation position on the right side in the lateral direction, the pump port 64 and the annular recess 63 communicate with each other through the first annular groove 11a and a notch (not shown) that communicates with the first annular groove 11a, and hydraulic oil is introduced to the supply ports 65 and 66. The hydraulic oil introduced to the supply port 65 passes through the third annular groove 11c and one of the travel supply / discharge ports 67 that communicates with the supply port 65, and then flows toward the first port 8a of the left travel motor 8 (see FIG. 1). The hydraulic oil supplied to the left travel motor 8 is then introduced from the second port 8b to the other travel supply / discharge port 68, and is discharged to the tank T (see FIG. 1) through the fourth annular groove 11d and a discharge port 69 that communicates with the other travel supply / discharge port 68 and through tank passages 81 and 82.

[0022] When pilot pressure is introduced into the second pilot chamber 24 and the spool valve 61 moves to the reverse position on the left side in the lateral direction, the pump port 64 and the annular recess 63 communicate with each other through the second annular groove 11b and a notch (not shown) that communicates with the second annular groove 11b, and hydraulic oil is introduced to the supply ports 65 and 66. The hydraulic oil introduced to the supply port 66 passes through the fourth annular groove 11d and the other traveling supply / discharge port 68 that communicates with the supply port 66, and then flows to the second port 8b of the left traveling motor 8 (see FIG. 1). The hydraulic oil supplied to the left traveling motor 8 is then introduced from the first port 8a to one traveling supply / discharge port 67, and then passes through the third annular groove 11c, a discharge port 69 that communicates with the one traveling supply / discharge port 67, and tank passages 81 and 82, before being discharged to the tank T (see FIG. 1).

[0023] Therefore, the pair of travel supply / discharge ports 67, 68 supply / discharge hydraulic oil to / from the left travel motor 8 depending on the switching position of the spool valve 61. In the case of the right travel control valve 5, the pair of travel supply / discharge ports 67, 68 supply / discharge hydraulic oil to / from the right travel motor 9. The pair of travel supply / discharge ports 67, 68 of the left travel control valve 4 correspond to the left travel supply / discharge ports, and the pair of travel supply / discharge ports 67, 68 of the right travel control valve 5 correspond to the right travel supply / discharge ports.

[0024] When traveling forward, both the left and right travel control valves 4 and 5 are switched to the normal rotation position (upper side in FIG. 2 ). As a result, hydraulic oil is supplied to the first port 8a of the left travel motor 8 through the left travel control valve 4 and to the first port 9a of the right travel motor 9 through the right travel control valve 5, and both the left and right travel motors 8 and 9 are driven in the normal rotation direction.

[0025] When the vehicle is traveling in reverse, both the left-side traveling control valve 4 and the right-side traveling control valve 5 are switched to the reverse position (lower side in FIG. 2 ). As a result, hydraulic oil is supplied to the second port 8b of the left-side traveling motor 8 through the left-side traveling control valve 4 and to the second port 9b of the right-side traveling motor 9 through the right-side traveling control valve 5, and both the left-side traveling motor 8 and the right-side traveling motor 9 are driven in the reverse direction.

[0026] 1 and 3, the inlet housing 1 has an inlet portion 10 provided between the left-hand running control valve 4 and the right-hand running control valve 5. The inlet portion 10 is a portion sandwiched between the left-hand running control valve 4 and the right-hand running control valve 5 in the width direction of the inlet housing 1, and as shown in Fig. 3, the inlet portion 10 is formed with two inlet ports 11, as well as two internal flow paths 12 connected to the two inlet ports 11, and a junction portion 13 at which the two internal flow paths 12 join together. The inlet portion 10 is formed with an installation portion 111 for the inlet ports 11.

[0027] In addition, a pump passage 80 and tank passages 81, 82 are also formed in the inlet portion 10. The pump passage 80 and the tank passages 81, 82 penetrate the inlet housing 1 in the width direction, thereby forming a flow path extending from the left-hand traveling control valve 4, the inlet portion 10, and the right-hand traveling control valve 5.

[0028] The junction 13 communicates with the pump passage 80 at an end opposite to the side where the two internal flow paths 12 join (the lower side in FIG. 3 ). Therefore, the hydraulic oil discharged from the pump 3 is supplied from each inlet port 11 into the inlet housing 1, and then through each internal flow path 12, the junction 13, and the pump passage 80 formed in the inlet 10, to the left-hand travel control valve 4 and right-hand travel control valve 5, and further to each valve housing 2 (see FIG. 1 ).

[0029] In this way, the internal flow path 12 communicates with the inlet port 11 and communicates (connects) with the pump passage 80, and guides the hydraulic oil to the left-hand running control valve 4 and the right-hand running control valve 5 through the pump passage 80. The internal flow path 12 communicates with the inlet port 11 and is provided in the inlet portion 10 together with the inlet port 11, and is therefore provided between the left-hand running control valve 4 and the right-hand running control valve 5 together with the inlet port 11.

[0030] In the inlet housing 1 configured as described above, as shown in FIG. 1 , one of the traveling supply / discharge ports 67 of the left-hand traveling control valve 4 and the right-hand traveling control valve 5 is disposed on the same side (left side in FIG. 1 ) of the left-hand traveling control valve 4 and the right-hand traveling control valve 5. Similarly, the other of the traveling supply / discharge ports 68 of the left-hand traveling control valve 4 and the right-hand traveling control valve 5 is disposed on the same side (right side in FIG. 1 ) of the left-hand traveling control valve 4 and the right-hand traveling control valve 5. The one of the traveling supply / discharge ports 67 is disposed on the same side in the lateral direction and is also disposed side by side in the width direction so that their lateral center positions are the same. The same is true for the other of the traveling supply / discharge ports 68.

[0031] The inlet port 11A is disposed between a pair of traveling supply / discharge ports 67, 68 of each of the left-hand traveling control valve 4 and the right-hand traveling control valve 5, offset from an imaginary line L1 that passes through one of the traveling supply / discharge ports 67 located on the same side. The inlet port 11B is disposed between a pair of traveling supply / discharge ports 67, 68 of each of the left-hand traveling control valve 4 and the right-hand traveling control valve 5, offset from an imaginary line L2 that passes through the other of the traveling supply / discharge ports 68 located on the same side. The inlet port 11A is also disposed offset from the imaginary line L2, and the inlet port 11B is also disposed offset from the imaginary line L1. Both the inlet port 11A and the inlet port 11B are offset laterally. The inlet port 11A and the inlet port 11B are disposed offset outside the imaginary lines L1 and L2. The inlet port 11A and the inlet port 11B may also be disposed offset inside the imaginary lines L1 and L2.

[0032] The imaginary line L1 passes through the center of each of the travel supply / discharge ports 67, and the imaginary line L2 passes through the center of each of the travel supply / discharge ports 68. Therefore, the inlet port 11A is provided offset from the imaginary line L1, which is a center line passing through the centers of the one of the travel supply / discharge ports 67, and the inlet port 11B is provided offset from the imaginary line L2, which is a center line passing through the centers of the other of the travel supply / discharge ports 68.

[0033] The distance D1 between the pair of traveling supply / discharge ports 67, 68 of the left-side traveling control valve 4 and the pair of traveling supply / discharge ports 67, 68 of the right-side traveling control valve 5 is smaller than the diameter D2 of the inlet port 11. The distance D1 is the distance along the width direction (shortest distance) and is the distance between the counterbore portions of one traveling supply / discharge port 67 or the other traveling supply / discharge port 68 arranged on the same side. The diameter D2 of the inlet port 11 is the diameter of the counterbore portion of the inlet port 11.

[0034] For this reason, when viewed in a predetermined direction perpendicular to the width direction (for example, a lateral view S along the lateral direction), the inlet port 11 overlaps with both the pair of traveling supply / discharge ports 67, 68 of the left traveling control valve 4 and the pair of traveling supply / discharge ports 67, 68 of the right traveling control valve 5. In other words, the inlet port 11 does not overlap with these ports when viewed in the vertical direction, which is one direction perpendicular to the width direction, but overlaps with these ports when viewed in a predetermined direction, which is another direction perpendicular to the width direction. The inlet port 11 may overlap with at least one of the pair of traveling supply / discharge ports 67, 68 of the left traveling control valve 4 and the pair of traveling supply / discharge ports 67, 68 of the right traveling control valve 5 when viewed in the predetermined direction.

[0035] The inlet port 11A further overlaps with each of the traveling supply / discharge ports 67 arranged on the same side in the left-hand traveling control valve 4 and the right-hand traveling control valve 5, as viewed in the width direction W (the up-down direction in FIG. 1 ). The inlet port 11B overlaps with each of the traveling supply / discharge ports 68 arranged on the same side in the width direction W in the left-hand traveling control valve 4 and the right-hand traveling control valve 5. Therefore, the inlet ports 11A and 11B are individually provided to overlap with each of the traveling supply / discharge ports 67 arranged on the same side and each of the traveling supply / discharge ports 68 arranged on the same side, as viewed in the width direction W. Each of the traveling supply / discharge ports 67 arranged on the same side and each of the traveling supply / discharge ports 68 arranged on the same side constitute two supply / discharge port rows.

[0036] In the inlet housing 1 incorporating the left-hand running control valve 4 and the right-hand running control valve 5, the inlet port 11 is offset from the imaginary lines L1 and L2, and the distance D1 is made smaller than the diameter D2 of the inlet port 11. This allows the housing to be made smaller overall in width and more compact than when valve housings for the left and right running motors are provided separately from the inlet housing (in other words, when the inlet portion 10, the left-hand running control valve 4, and the right-hand running control valve 5 are not provided in a single inlet housing 1 but are provided in separate housings and connected to each other). Furthermore, integrating them in this manner also makes it unnecessary to seal the mating surfaces between the inlet portion 10 and the left-hand running control valve 4 and the right-hand running control valve 5.

[0037] When the inlet port 11 and the travel supply / discharge ports 67, 68 overlap when viewed in the predetermined direction or the width direction W, the counterbore of the portion opening into the top surface of the inlet port 11A and the counterbore of the portion opening into the top surface of one of the travel supply / discharge ports 67 can overlap when viewed in the predetermined direction or the width direction W. In other words, overlapping the inlet port 11 and the travel supply / discharge ports 67, 68 when viewed in the predetermined direction or the width direction W includes overlapping the counterbore of the inlet port 11A and the counterbore of the travel supply / discharge ports 67, 68 when viewed in the predetermined direction or the lateral direction S. The inlet port 11 may overlap at least one of the one travel supply / discharge port 67 and the other travel supply / discharge port 68 when viewed in the width direction W.

[0038] As shown in FIG. 3 , the inlet housing 1 is formed with two inlet ports 11 and two internal flow paths 12. The inlet housing 1 also has a junction 13 inside where the two internal flow paths 12 join. The two internal flow paths 12 are formed symmetrically with respect to each other in the horizontal direction with the junction 13 as the center, and both extend vertically inward from the corresponding inlet port 11 and then extend horizontally inward to connect to the junction 13. The junction 13 is formed inside the inlet housing 1 and joins the hydraulic oil from the two inlet ports 11 through the two internal flow paths 12. The junction 13 is located in the center of the inlet housing 1 and extends along the vertical direction.

[0039] The hydraulic oil from the two internal flow paths 12 joins upstream at the joining section 13 and flows downstream. At the joining section 13, the hydraulic oil from the two internal flow paths 12 joins immediately at the joining section 13 without passing through any control valves provided in the valve housing 2, the left-hand running control valve 4, or the right-hand running control valve 5. In other words, the connection between the two internal flow paths 12 and the joining section 13 does not involve any control valves provided in the valve housing 2, or any control valves including the left-hand running control valve 4 or the right-hand running control valve 5, and the two internal flow paths 12 and the joining section 13 are configured to be constantly in communication with each other.

[0040] In the inlet housing 1 configured in this manner, the two inlet ports 11 are provided as split ports obtained by dividing a single inlet port into two, so to speak. This allows the size of each inlet port 11 to be smaller than in the case of a single inlet port, provided that the flow rate of hydraulic oil is the same, thereby enabling a further reduction in the width of the housing.

[0041] The number of inlet ports 11 may be one or more than two. Even in this case, the width of the housing as a whole can be reduced by offsetting the inlet port 11 from both the imaginary lines L1 and L2 and making the distance D1 smaller than the diameter D2 of the inlet port 11.

[0042] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0043] The inlet housing 1 is a housing into which hydraulic oil as a working fluid is supplied from a pump 3 which is a fluid pressure supply source, and is equipped with a left-hand running control valve 4 which is incorporated inside the inlet housing 1 and controls a left-hand running motor 8, a right-hand running control valve 5 which is incorporated inside the inlet housing 1 and controls a right-hand running motor 9, an inlet port 11 which opens to the outer surface of the inlet housing 1 and communicates with the pump 3, and an internal flow path 12 which communicates with the inlet port 11 and is connected to a pump passage 80 which guides hydraulic oil to the left-hand running control valve 4 and the right-hand running control valve 5. The left-hand running control valve 4 has a pair of running supply / discharge ports 67, 68 which open to the outer surface of the inlet housing 1 and serve as left-hand running supply / discharge ports for supplying and discharging hydraulic fluid to the left-hand running motor 8, and the right-hand running control valve 5 has a pair of running supply / discharge ports 67, 68 which open to the outer surface of the inlet housing 1 and serve as right-hand running supply / discharge ports for supplying and discharging hydraulic oil to the right-hand running motor 9. The inlet port 11 and the internal flow path 12 are provided between the left-side traveling control valve 4 and the right-side traveling control valve 5, and the inlet port 11 is offset with respect to an imaginary line L1 passing through one row of supply and discharge ports constituted by each of the one traveling supply and discharge ports 67 arranged on the same side in the left-side traveling control valve 4 and the right-side traveling control valve 5, and an imaginary line L2 passing through the other row of supply and discharge ports constituted by each of the other traveling supply and discharge ports 68, and a distance D1 between the pair of traveling supply and discharge ports 67, 68 of the left-side traveling control valve 4 and the pair of traveling supply and discharge ports 67, 68 of the right-side traveling control valve 5 is smaller than a diameter D2 of the inlet port 11.

[0044] With this configuration, the inlet port 11 and internal flow path 12 are provided between the left-hand running control valve 4 and the right-hand running control valve 5, so the flow path lengths from the inlet port 11 to each pair of running supply / discharge ports 67, 68 of the left-hand running control valve 4 and the right-hand running control valve 5 are equalized, thereby suppressing the occurrence of differences in running between the left and right sides. Also, while the left-hand running control valve 4 and the right-hand running control valve 5 are incorporated internally, the inlet port 11 is positioned offset from both the one running supply / discharge port 67 and the other running supply / discharge port 68 positioned on the same side, and the distance D1 is made smaller than the diameter D2 of the inlet port 11, so the width of the housing as a whole can be reduced, resulting in a more compact housing, compared to when valve housings for the left and right running motors are provided separately from the inlet housing.

[0045] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0046] This application claims priority based on Japanese Patent Application No. 2023-185293, filed with the Japan Patent Office on October 30, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. An inlet housing to which a working fluid is supplied from a fluid pressure supply source, the inlet housing comprising: a left-hand running control valve incorporated inside the inlet housing and controlling a left-hand running motor; a right-hand running control valve incorporated inside the inlet housing and controlling a right-hand running motor; an inlet port opening to an outer surface of the inlet housing and communicating with the fluid pressure supply source; and an internal flow path communicating with the inlet port and connected to a pump passage that guides working fluid to the left-hand running control valve and the right-hand running control valve, the left-hand running control valve having a pair of left-hand running supply and discharge ports opening to the outer surface and supplying and discharging working fluid to the left-hand running motor, the right-hand running control valve having a pair of right-hand running supply and discharge ports opening to the outer surface and supplying and discharging working fluid to the right-hand running motor, the inlet port and the internal flow path being provided between the left-hand running control valve and the right-hand running control valve, an inlet housing, wherein the inlet port is offset with respect to each of imaginary lines passing through two supply and exhaust port rows constituted by the left side traveling supply and exhaust port and the right side traveling supply and exhaust port arranged on the same side in the left side traveling control valve and the right side traveling control valve, and a distance between the pair of left side traveling supply and exhaust ports and the pair of right side traveling supply and exhaust ports is smaller than a diameter of the inlet port.

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