Inlet housing

Abstract

To suppress the occurrence of left / right difference when driving, and enable miniaturization.SOLUTION: In an inlet housing 1, an inlet port 11 and an internal flow path 12 are provided between a left-side running control valve 4 and a right-side running control valve 5. The inlet port 11 is offset with respect to an imaginary line L1 passing through each of running supply and exhaust ports 67 arranged on the same side between each pair of running supply and exhaust ports 67, 68 of the left-side running control valve 4 and the right-side running control valve 5, and an imaginary line L2 passing through each of the running supply and exhaust ports 68 on the other side. A distance D1 between the pair of running supply and exhaust ports 67, 68 of the left-side running control valve 4 and the pair of running supply and exhaust ports 67, 68 of the right-side running control valve 5 is smaller than a diameter D2 of the inlet port 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 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-side traveling control valve and a left-side traveling control valve. In this hydraulic circuit structure, the end block, the right-side traveling control valve, and the left-side traveling control valve are arranged in this order. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-227503 (see, for example, FIG. 3) Summary of the Invention [Problem to be solved by the invention]

[0004] In the above hydraulic circuit structure, the difference in the oil passage length from the end block to the right-side travel control valve and the oil passage length from the end block to the left-side travel control valve causes a difference in the left-side travel, which may affect straight-line travel. In addition, the housing width is determined by the port size in each of the end block, the right-side travel control valve, and the left-side travel control valve, which may limit miniaturization.

[0005] The present invention has been made in view of the above problems, and has an object to suppress the occurrence of left / right running difference and to achieve size reduction. [Means for solving the problem]

[0006] The present invention provides an inlet housing to which a working fluid is supplied from a fluid pressure supply source, the inlet housing including a left-hand running control valve that is incorporated inside the inlet housing and controls a left-hand running motor, a right-hand running control valve that is incorporated inside the inlet housing and controls a right-hand running motor, an inlet port that opens to an outer surface of the inlet housing and communicates with the fluid pressure supply source, and an internal flow path that communicates with the inlet port and is connected to a pump passage that guides the working fluid to the left-hand running control valve and the right-hand running control valve. The left-hand running control valve has a pair of valves that open to the outer surface and supply and discharge the working fluid to the left-hand running motor. the right-side running control valve has a pair of right-side running supply and exhaust ports that open to an outer surface and supply and exhaust working fluid to the right-side running motor, the inlet port and the internal flow path are provided between the left-side running control valve and the right-side running control valve, the inlet port is offset with respect to each of imaginary lines that pass through two supply and exhaust port rows constituted by the left-side running supply and exhaust port and the right-side running supply and exhaust port 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 and exhaust ports and the pair of right-side running supply and exhaust ports is smaller than a diameter of the inlet port.

[0007] According to this invention, since the inlet port and the internal flow passage are provided between the left-side running control valve and the right-side running control valve, the flow passage lengths from the inlet port to each supply / exhaust port are equalized, thereby suppressing the occurrence of a difference in left and right running. Also, while incorporating the left-side running control valve and the right-side running control valve inside, the inlet port is arranged offset from both the left-side running supply / exhaust port and the right-side running supply / exhaust port arranged on the same side, and the distance between the pair of left-side running supply / exhaust ports and the pair of right-side running supply / exhaust ports is made smaller than the diameter of the inlet port, so that the width of the housing as a whole can be reduced and the size can be reduced compared to a case where valve housings for the left and right running motors are provided separately from the inlet housing. Effect of the Invention

[0008] According to these inventions, it is possible to suppress the occurrence of left / right running difference and to achieve size reduction. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a fluid pressure control device according to an embodiment of the present invention; [Diagram 2] 2 is a cross-sectional view corresponding to the AA-AA cross section or the AB-AB cross section in FIG. 1. [Diagram 3] 2 is a view showing an inlet housing along the cross section BB shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] Fig. 1 is a schematic configuration diagram of a fluid pressure control device 100. Fig. 2 is a cross-sectional view corresponding to the AA-AA cross section in Fig. 1, or the AB-AB cross section similar to the AA-AA cross section. Fig. 3 is a view showing the inlet housing 1 along the BB cross section shown in Fig. 1.

[0012] The fluid pressure control device 100 shown in FIG. 1 is mounted on a construction machine (e.g., a hydraulic excavator) as a vehicle having hydraulic driving sources on the left and right sides, and controls the operation of the actuators by controlling the supply and discharge of hydraulic oil to actuators such as a left side travel motor 8 and a right side travel motor 9 and hydraulic cylinders (not shown), which will be described later.

[0013] 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 a boom, arm, or bucket of a hydraulic excavator. Hydraulic oil corresponds to the working fluid. In addition to hydraulic oil, a non-compressible fluid such as water may 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.

[0014] 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 attached and which has a countersunk portion and a female thread portion.

[0015] Each inlet port 11 opens to the top surface of the inlet housing 1 through 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 may not be provided on the same surface. The same applies to the travel supply / exhaust ports 67, 68, the inlet port 11, and the travel supply / exhaust ports 67, 68, which will be described later. The travel supply / exhaust 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) is also referred to as the inlet port 11A, and the other inlet port 11 (the inlet port 11 on the right in FIG. 1) is also referred to as the inlet port 11B.

[0016] Hydraulic oil is supplied into the fluid pressure control device 100 through each inlet port 11 by the pump 3, which is a fluid pressure supply source. An oil passage (piping) branches off from the common pump 3 to each inlet port 11. An oil passage (piping) from the common pump 3 may be branched off using a joint and connected to each inlet port 11. Also, 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 via 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.

[0017] As shown in Figures 1 and 2, the inlet housing 1 further has a left-side running control valve 4 at the AA-AA cross section in Figure 1, and a right-side running control valve 5 at the AB-AB cross section. The left-side running control valve 4 and the right-side running control valve 5 are incorporated inside the inlet housing 1 and arranged side by side in the width direction. In other words, the width direction is the direction in which the left-side running control valve 4 and the right-side running control valve 5 are arranged side by side. Note that, although the following description will be mainly given taking the left-side running control valve 4 as an example, the same applies to the right-side running control valve 5.

[0018] The left-side running 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 running control valve 4 has three switching positions, a neutral position, a forward rotation position, and a reverse rotation position, as the plurality of switching positions, and in Fig. 2, the spool valve 61 is in the neutral position.

[0019] The accommodating 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 travel supply and discharge ports 67, 68 provided outside the supply ports 65, 66 and opening to the upper surface of the inlet housing 1, and a discharge port 69 provided outside the pair of travel supply and discharge ports 67, 68.

[0020] 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-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 and 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. 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 and 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 and constitute travel drive sources operated by hydraulic pressure.

[0021] In the left-side traveling control valve 4 at the AA-AA cross section shown in FIG. 1, one of the pair of traveling supply / exhaust ports 67, 68 is connected to the first port 8a of the left-side traveling motor 8, and the other traveling supply / exhaust port 68 is connected to the second port 8b of the left-side traveling motor 8. In the right-side traveling control valve 5 at the AB-AB cross section, one of the traveling supply / exhaust ports 67 is connected to the first port 9a of the right-side traveling motor 9, and the other traveling supply / exhaust port 68 is connected to the second port 9b of the right-side traveling motor 9. The pair of traveling supply / exhaust ports 67, 68 are arranged side by side in the horizontal direction so that their widthwise center positions are the same, and form a pair in the horizontal direction of the inlet housing 1 (left and right direction in FIG. 1). Therefore, the horizontal direction can be said to be the direction in which the pair of traveling supply / exhaust ports 67, 68 are arranged side by side, or the direction in which they form a pair.

[0022] 2, the left-side traveling control valve 4 further has 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 changes according to the pressure of the hydraulic oil acting on the compensator valve 71.

[0023] When in the neutral position, the spool valve 61 has a first annular groove 11a formed at a position facing the pump port 64, a second annular groove 11b formed at a position facing the annular recess 63, a third annular groove 11c formed at a position facing the traveling supply / discharge port 67 on one side, and a fourth annular groove 11d formed at a position facing the traveling supply / discharge port 68 on the other side. 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.

[0024] When pilot pressure is introduced to 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, 66. The hydraulic oil introduced to the supply port 65 passes through one of the supply and discharge ports 67 for traveling that communicates with the supply port 65 through the third annular groove 11c, and proceeds to the first port 8a of the left traveling motor 8 (see FIG. 1). The hydraulic oil supplied to the left traveling motor 8 is then introduced from the second port 8b to the other supply and discharge port 68 for traveling, and is discharged to the tank T (see FIG. 1) through the discharge port 69 that communicates with the other supply and discharge port 68 for traveling through the fourth annular groove 11d and the tank passages 81, 82.

[0025] When pilot pressure is introduced to 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) communicating 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 other supply and discharge port 68 for traveling that communicates with the supply port 66 through the fourth annular groove 11d, and proceeds 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 of the supply and discharge ports 67 for traveling, and is discharged to the tank T (see FIG. 1) through the discharge port 69 that communicates with the one of the supply and discharge ports 67 for traveling through the third annular groove 11c and the tank passages 81 and 82.

[0026] Therefore, the pair of traveling supply / exhaust ports 67, 68 supply / exhaust hydraulic oil to the left traveling motor 8 depending on the switching position of the spool valve 61. In the case of the right traveling control valve 5, the pair of traveling supply / exhaust ports 67, 68 supply / exhaust hydraulic oil to the right traveling motor 9. The pair of traveling supply / exhaust ports 67, 68 of the left traveling control valve 4 correspond to the left traveling supply / exhaust ports, and the pair of traveling supply / exhaust ports 67, 68 of the right traveling control valve 5 correspond to the right traveling supply / exhaust ports.

[0027] When traveling forward, both the left-side traveling control valve 4 and the right-side traveling control valve 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-side traveling motor 8 through the left-side traveling control valve 4 and to the first port 9a 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 normal rotation direction.

[0028] When traveling backward, 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.

[0029] As shown in Figures 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 Figure 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 that joins the two internal flow paths 12. The inlet portion 10 is formed with an installation portion 111 for the inlet port 11.

[0030] 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, and are formed as flow paths extending from the left side traveling control valve 4, the inlet portion 10, and the right side traveling control valve 5.

[0031] The junction 13 communicates with a pump passage 80 at an end opposite to the side where the two internal flow paths 12 are joined (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 side running control valve 4 and the right side running control valve 5, and further to each valve housing 2 (see FIG. 1).

[0032] In this way, the internal flow passage 12 communicates with the inlet port 11 and communicates (connects) with the pump passage 80, and guides the hydraulic oil to the left side running control valve 4 and the right side running control valve 5 through the pump passage 80. The internal flow passage 12 communicates with the inlet port 11 and is provided in the inlet portion 10 together with the inlet port 11, and is thereby provided between the left side running control valve 4 and the right side running control valve 5 together with the inlet port 11.

[0033] In the inlet housing 1 configured as above, as shown in FIG. 1, one of the traveling supply / exhaust ports 67 of the left-hand running control valve 4 and the right-hand running control valve 5 is disposed on the same side (left side in FIG. 1) of the left-hand running control valve 4 and the right-hand running control valve 5. Similarly, the other of the traveling supply / exhaust ports 68 of the left-hand running control valve 4 and the right-hand running control valve 5 is disposed on the same side (right side in FIG. 1) of the left-hand running control valve 4 and the right-hand running control valve 5. One of the traveling supply / exhaust 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 the lateral center positions are the same. The same is true for the other of the traveling supply / exhaust ports 68.

[0034] The inlet port 11A is provided offset with respect to a virtual line L1 passing through each of the pair of traveling supply / exhaust ports 67, 68 of the left-side traveling control valve 4 and the right-side traveling control valve 5, which are arranged on the same side. The inlet port 11B is provided offset with respect to a virtual line L2 passing through each of the other traveling supply / exhaust ports 68 arranged on the same side, between each of the pair of traveling supply / exhaust ports 67, 68 of the left-side traveling control valve 4 and the right-side traveling control valve 5. The inlet port 11A is also provided offset with respect to the virtual line L2, and the inlet port 11B is also provided offset with respect to the virtual line L1. Both the inlet port 11A and the inlet port 11B are offset in the lateral direction. The inlet port 11A and the inlet port 11B are provided offset outside the virtual line L1 and the virtual line L2. The inlet port 11A and the inlet port 11B may be provided offset inside the virtual line L1 and the virtual line L2.

[0035] 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 as a center line passing through the centers of each of the travel supply / discharge ports 67 on one side, and the inlet port 11B is provided offset from the imaginary line L2 as a center line passing through the centers of each of the travel supply / discharge ports 68 on the other side.

[0036] A distance D1 between the pair of traveling supply / exhaust ports 67, 68 of the left-side traveling control valve 4 and the pair of traveling supply / exhaust ports 67, 68 of the right-side traveling control valve 5 is smaller than a 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 / exhaust port 67 or the other traveling supply / exhaust 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.

[0037] Therefore, the inlet port 11 overlaps with both the pair of traveling supply / exhaust ports 67, 68 of the left traveling control valve 4 and the pair of traveling supply / exhaust ports 67, 68 of the right traveling control valve 5 when viewed in a predetermined direction perpendicular to the width direction (for example, a horizontal view S when viewed in the horizontal direction). In other words, the inlet port 11 does not overlap with these when viewed in the vertical direction, which is a part of the direction perpendicular to the width direction, but overlaps with these when viewed in a predetermined direction, which is another part of the direction perpendicular to the width direction. The inlet port 11 may overlap with at least one of the pair of traveling supply / exhaust ports 67, 68 of the left traveling control valve 4 and the pair of traveling supply / exhaust ports 67, 68 of the right traveling control valve 5 when viewed in the predetermined direction.

[0038] The inlet port 11A further overlaps with each of the one of the traveling supply / exhaust ports 67 arranged on the same side in the left-hand traveling control valve 4 and the right-hand traveling control valve 5 in the width direction W as viewed along the width direction (the up-down direction in FIG. 1). The inlet port 11B overlaps with each of the other of the traveling supply / exhaust 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 provided so as to overlap with each of the one of the traveling supply / exhaust ports 67 arranged on the same side and each of the other of the traveling supply / exhaust ports 68 arranged on the same side individually in the width direction W. Each of the one of the traveling supply / exhaust ports 67 arranged on the same side and each of the other of the traveling supply / exhaust ports 68 arranged on the same side constitute two supply / exhaust port rows.

[0039] In the inlet housing 1 incorporating the left-hand running control valve 4 and the right-hand running control valve 5 therein, 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, thereby making it possible to reduce the overall width of the housing and achieve miniaturization, compared to a case in which valve housings for the left and right running motors are provided separately from the inlet housing (that is, a case in which 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 way 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.

[0040] When the inlet port 11 and the supply / discharge ports 67, 68 for traveling are overlapped as viewed in a predetermined direction or in the width direction W, the counterbore of the portion opening on the upper surface of the inlet port 11A and the counterbore of the portion opening on the upper surface of each of the supply / discharge ports 67 for traveling on one side can be overlapped as viewed in the predetermined direction or in the width direction W. In other words, overlapping the inlet port 11 and the supply / discharge ports 67, 68 for traveling as viewed in a predetermined direction or in the width direction W includes overlapping the counterbore of the inlet port 11A and the counterbore of the supply / discharge ports 67, 68 for traveling on the other side or in the width direction S. The inlet port 11 may overlap at least one of each of the supply / discharge ports 67 for traveling on one side and each of the supply / discharge ports 68 for traveling on the other side as viewed in the width direction W.

[0041] 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 from the corresponding inlet ports 11 inward in the vertical direction, and then extend inward in the horizontal direction 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 provided in the center of the inlet housing 1 and extends along the vertical direction.

[0042] 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 a control valve provided in the valve housing 2, the left-side running control valve 4, or the right-side 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 valve provided in the valve housing 2, including the left-side running control valve 4 and the right-side running control valve 5, and the two internal flow paths 12 and the joining section 13 are structured to be constantly in communication with each other.

[0043] 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 that of a single inlet port under the condition that the flow rate of hydraulic oil is the same, thereby enabling a further reduction in the width of the housing.

[0044] The number of inlet ports 11 may be one or more than two. Even in this case, by offsetting the inlet port 11 with respect to both the imaginary lines L1 and L2 and making the distance D1 smaller than the diameter D2 of the inlet port 11, the width of the housing as a whole can be reduced.

[0045] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0046] The inlet housing 1 is a housing to which hydraulic oil as a working fluid is supplied from a pump 3 which is a fluid pressure supply source, and is provided with: a left-side traveling control valve 4 which is incorporated inside the inlet housing 1 and controls a left-side traveling motor 8; a right-side traveling control valve 5 which is incorporated inside the inlet housing 1 and controls a right-side traveling 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 introduces hydraulic oil to the left-side traveling control valve 4 and the right-side traveling control valve 5. The left-side traveling control valve 4 has traveling supply / discharge ports 67, 68 which open to the outer surface of the inlet housing 1 and serve as a pair of left-side traveling supply / discharge ports which supply / discharge the working fluid to the left-side traveling motor 8, and the right-side traveling control valve 5 has traveling supply / discharge ports 67, 68 which open to the outer surface of the inlet housing 1 and serve as a pair of right-side traveling supply / discharge ports which supply / discharge the hydraulic oil to the right-side traveling motor 9. The inlet port 11 and the internal flow path 12 are provided between the left-side running control valve 4 and the right-side running control valve 5, and the inlet port 11 is offset with respect to an imaginary line L1 passing through one row of supply and exhaust ports constituted by each of the one running supply and exhaust ports 67 arranged on the same side in the left-side running control valve 4 and the right-side running control valve 5, and an imaginary line L2 passing through the other row of supply and exhaust ports constituted by each of the other running supply and exhaust ports 68, and a distance D1 between the pair of running supply and exhaust ports 67, 68 of the left-side running control valve 4 and the pair of running supply and exhaust ports 67, 68 of the right-side running control valve 5 is smaller than a diameter D2 of the inlet port 11.

[0047] According to this configuration, the inlet port 11 and the internal flow path 12 are provided between the left-hand running control valve 4 and the right-hand running control valve 5, so that the flow path lengths from the inlet port 11 to each pair of running supply / exhaust 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 a difference in left and right running. Also, while incorporating the left-hand running control valve 4 and the right-hand running control valve 5 inside, the inlet port 11 is positioned offset from both the one running supply / exhaust port 67 and the other running supply / exhaust port 68 positioned on the same side, and the distance D1 is made smaller than the diameter D2 of the inlet port 11, so that the width of the housing as a whole can be reduced and the size can be reduced compared to a case where valve housings for the left and right running motors are provided separately from the inlet housing. [Explanation of symbols]

[0048] 1 inlet housing, 3 pump (fluid pressure supply source), 4 left-hand drive control valve, 5 right-hand drive control valve, 10 inlet section, 11 inlet port, 12 internal flow path, 13 junction section, 67 travel supply / discharge port, 68 travel supply / discharge port, 100 fluid pressure control device, L1 virtual line, L2 virtual line

Claims

[Claim 1] An inlet housing to which a working fluid is supplied from a fluid pressure supply source, a left-side traveling control valve that is incorporated inside the inlet housing and controls a left-side traveling motor; a right-side travel control valve that is incorporated inside the inlet housing and controls a right-side travel motor; an inlet port that opens to an outer surface of the inlet housing and communicates with the fluid pressure supply source; an internal flow passage connected to the inlet port and a pump passage that guides a working fluid to the left side traveling control valve and the right side traveling control valve; Equipped with the left-side traveling control valve has a pair of left-side traveling supply / discharge ports that open to the outer surface and supply / discharge working fluid to / from the left-side traveling motor, the right side traveling control valve has a pair of right side traveling supply / discharge ports that open to the outer surface and supply / discharge working fluid to / from the right side traveling motor, the inlet port and the internal flow passage are provided between the left side travel control valve and the right side travel control valve, the inlet port is offset with respect to each of imaginary lines passing through two supply / exhaust port rows constituted by the left side running supply / exhaust port and the right side running supply / exhaust port arranged on the same side in the left side running control valve and the right side running control valve, a distance between the pair of left-side traveling supply / exhaust ports and the pair of right-side traveling supply / exhaust ports is smaller than a diameter of the inlet port; An inlet housing comprising:

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