Inlet block and valve device

Abstract

Reduce the one-way dimension of the inlet block. 【Solution means】The inlet block 100 includes a confluence control valve 21 that joins or blocks the working fluid discharged from the first pump 111 and the working fluid discharged from the second pump 114, a first unloading valve 31 connected to the first fluid pressure passage, a second unloading valve 32 connected to the second fluid pressure passage, a valve body 151 in which the first fluid pressure passage and the second fluid pressure passage are formed and the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are provided. The confluence control valve 21 is provided apart from the first unloading valve 31 and the second unloading valve 32 in a vertical direction perpendicular to the parallel direction in which the first unloading valve 31 and the second unloading valve 32 are arranged and their axial directions, and is provided between the first unloading valve 31 and the second unloading valve 32 in the parallel direction.

Description

Technical Field

[0001] The present invention relates to an inlet block and a valve device.

Background Art

[0002] Patent Document 1 discloses a hydraulic system including a first hydraulic circuit that controls a plurality of actuators, a second hydraulic circuit that controls a plurality of actuators, and a control valve that joins or shuts off hydraulic oil supplied to the first hydraulic circuit and hydraulic oil supplied to the second hydraulic circuit. The hydraulic system has a pump, a valve unit that controls each actuator, and a tank. The valve unit has an inlet block for taking in pressure oil, an unloading block, a valve block that controls each actuator, and an outlet block for discharging oil. The inlet block has a joining control valve that joins and shuts off the first hydraulic circuit and the second hydraulic circuit, and the unloading block has a first unloading valve that unloads the hydraulic oil of the first hydraulic circuit and a second unloading valve that unloads the hydraulic oil of the second hydraulic circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the hydraulic system described in Patent Document 1, the joining control valve is provided in the inlet block, and the first unloading valve and the second unloading valve are provided in the unloading block arranged side by side with the inlet block. Therefore, there is a problem that the valve unit becomes long in one direction (specifically, the direction in which the inlet block and the unloading block are arranged side by side), taking up space.

[0005] The present invention has been made in view of the above problems, and aims to reduce the one-way dimension of the valve block.

Means for Solving the Problems

[0006] The present invention is an inlet block, including a confluence control valve for confluencing or blocking the working fluid discharged from the first pump through the first fluid pressure passage and the working fluid discharged from the second pump through the second fluid pressure passage, a first unloading valve connected to the first fluid pressure passage for unloading the working fluid discharged from the first pump, a second unloading valve connected to the second fluid pressure passage for unloading the working fluid discharged from the second pump, a valve body in which the first fluid pressure passage and the second fluid pressure passage are formed and the confluence control valve, the first unloading valve, and the second unloading valve are provided. The first unloading valve and the second unloading valve are arranged side by side such that their axes are parallel to each other. The confluence control valve is provided apart from the first unloading valve and the second unloading valve in a vertical direction perpendicular to the parallel direction in which the first unloading valve and the second unloading valve are arranged and is provided between the first unloading valve and the second unloading valve in the parallel direction.

[0007] In this invention, the confluence control valve, the first unloading valve, and the second unloading valve are all provided in the valve body of the inlet block. Therefore, compared with a configuration in which the confluence control valve, the first unloading valve, and the second unloading valve are provided in separate valve blocks and arranged side by side, the dimension of the entire valve block in one direction (the parallel direction in which the first unloading valve and the second unloading valve are arranged) can be reduced. Further, since the confluence control valve is provided apart from the first unloading valve and the second unloading valve in the vertical direction and is provided between the first unloading valve and the second unloading valve in the parallel direction, the dimension of the valve block in one direction (the parallel direction) can be made smaller.

[0008] The present invention is characterized in that the valve body has two accommodation holes in which a first unloading valve and a second unloading valve are respectively accommodated, and a tank passage formed between the two accommodation holes and communicating with the tank, and the working fluid unloaded by the first unloading valve and the second unloading valve is guided to the tank passage.

[0009] In this invention, since the tank passage is shared by the first unloading valve and the second unloading valve, the flow path configuration of the valve block can be simplified.

[0010] In the present invention, on the outer surface of the valve body, a first pump port communicating with the first pump and guiding the working fluid to the first fluid pressure passage and a second pump port communicating with the second pump and guiding the working fluid to the second fluid pressure passage are formed by openings. The first pump port is formed such that at least a part of the first unloading valve overlaps on its extension line in the vertical direction, and the second pump port is formed such that at least a part of the second unloading valve overlaps on its extension line in the vertical direction.

[0011] In this invention, since the flow paths from the first pump port to the first unloading valve and from the second pump port to the second unloading valve can be made substantially linear, the flow path configuration of the valve block can be simplified.

[0012] The present invention is a valve device including the above inlet block, an actuator block connected to the inlet block and having an actuator control valve that controls the operation of the actuator by being supplied with the working fluid from the first fluid pressure passage or the second fluid pressure passage, and a pilot passage that guides the pilot fluid to the actuator control valve. The first unloading valve and the second unloading valve are respectively accommodated in two accommodation holes formed by openings on one end surface of the valve body, and at least a part of the pilot passage is formed in a region between the other end surface opposite to the one end surface of the valve body and the first unloading valve and the second unloading valve.

[0013] In the present invention, there is a dead space beside the first unloading valve and the second unloading valve in the valve body. Since a pilot passage is formed in the dead space, the dead space of the valve body can be effectively utilized.

Advantages of the Invention

[0014] According to the present invention, the one-way dimension of the valve block can be reduced.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0016] Referring to the drawings, a hydraulic system 1 including an inlet block 100 according to an embodiment of the present invention will be described. The hydraulic system 1 is mounted on construction machinery, agricultural machinery, industrial machinery, etc. Hereinafter, a hydraulic system 1 mounted on a hydraulic excavator and used to operate various actuators of the hydraulic excavator will be described as an example. In the following embodiments, an example using hydraulic oil as the working fluid will be described, but other fluids such as working water may be used as the working fluid.

[0017] As shown in FIG. 1, the hydraulic circuit of the hydraulic system 1 includes a first hydraulic circuit HC1 to which hydraulic oil is supplied from a first pump 111 and which controls a plurality of actuators MR, AS, and a second hydraulic circuit HC2 to which hydraulic oil is supplied from a second pump 114 and which controls a plurality of actuators ML, BS. The hydraulic oil supplied to the first hydraulic circuit HC1 and the hydraulic oil supplied to the second hydraulic circuit HC2 are merged or blocked by a merging control valve 21 described later. First, the first hydraulic circuit HC1 and the second hydraulic circuit HC2 will be described.

[0018] The first hydraulic circuit HC1 is a circuit that controls the drive of actuators such as the right travel motor MR and the arm cylinder AS, and the second hydraulic circuit HC2 is a circuit that controls the drive of actuators such as the left travel motor ML and the boom cylinder BS.

[0019] The first hydraulic circuit HC1 has a first pump 111 as a hydraulic supply source, a first main supply passage 121a as a first fluid pressure passage, a tank passage 122a, a control valve 110a, a control valve 110b, and a first unloading valve 31.

[0020] The first pump 111 is a piston pump, and its discharge capacity changes when the inclination of the swash plate 113a is changed by the regulator 113. The regulator 113 is led with the higher maximum discharge pressure among the discharge pressures of the first pump 111 or the second pump 114, and the maximum load pressures of the respective actuators MR, AS, ML, BS. The discharge capacity of the first pump 111 is controlled by so-called load sensing control so that the differential pressure between the maximum discharge pressure and the maximum load pressure becomes a predetermined value. In FIG. 1, the illustration of the circuit for leading the maximum discharge pressure to the regulator 113 is omitted.

[0021] The first main supply passage 121a is connected to the first discharge port 111a of the first pump 111, and the hydraulic oil discharged from the first discharge port 111a is supplied to the respective actuators MR, AS. The tank passage 122a is connected to the tank 112 and guides the hydraulic oil discharged from the respective actuators MR, AS to the tank 112. The control valve 110a controls the flow of the hydraulic oil supplied from the first main supply passage 121a to the right traveling motor MR, and the control valve 110b controls the flow of the hydraulic oil supplied from the first main supply passage 121a to the arm cylinder AS. Each of the control valves 110a, 110b is switched by, for example, the pilot pressure output according to the operation of an operation lever (not shown).

[0022] The first unloading valve 31 unloads the hydraulic oil discharged from the first pump 111. The maximum load pressure of the first hydraulic circuit HC1 is input to the first unloading valve 31. When the pressure of the first main supply passage 121a becomes larger than the maximum load pressure of the first hydraulic circuit HC1 by a predetermined value or more, the first unloading valve 31 opens to unload the hydraulic oil discharged from the first pump 111.

[0023] The second hydraulic circuit HC2 includes a second pump 114 as a hydraulic supply source, a second main supply passage 121b as a second fluid pressure passage, a tank passage 122b, a control valve 120a, a control valve 120b, and a second unloading valve 32.

[0024] The second pump 114 has the same configuration as the first pump 111. The regulator is led with the higher maximum discharge pressure among the discharge pressures of the first pump 111 or the second pump 114, and the maximum load pressures of the respective actuators MR, AS, ML, BS. The discharge capacity of the second pump 114 is controlled by so-called load sensing control such that the differential pressure between the maximum discharge pressure and the maximum load pressure becomes a predetermined value. In FIG. 1, illustration of the regulator and the circuit that leads the maximum discharge pressure to the regulator is omitted. First pump 111

[0025] The second main supply passage 121b is connected to the second discharge port 114a of the second pump 114, and the hydraulic oil discharged from the second discharge port 114a is supplied to the respective actuators ML, BS. The tank passage 122b is connected to the tank passage 122a and the tank 112, and guides the hydraulic oil discharged from the respective actuators ML, BS to the tank 112. The control valve 120a controls the flow of the hydraulic oil supplied from the second main supply passage 121b to the left travel motor ML, and the control valve 120b controls the flow of the hydraulic oil supplied from the second main supply passage 121b to the boom cylinder BS. Each of the control valves 120a, 120b is switched by, for example, a pilot pressure output according to the operation of an operation lever (not shown).

[0026] The second unloading valve 32 unloads the hydraulic oil discharged from the second pump 114. The maximum load pressure of the second hydraulic circuit HC2 is input to the second unloading valve 32, and when the pressure of the second main supply passage 121b becomes greater than the maximum load pressure of the second hydraulic circuit HC2 by a predetermined value or more, the second unloading valve 32 opens to unload the hydraulic oil discharged from the second pump 114.

[0027] The first main supply passage 121a is connected to a first sub-supply passage 161a to which the hydraulic oil discharged from the first pump 111 is supplied. The second main supply passage 121b is connected to a second sub-supply passage 161b to which the hydraulic oil discharged from the second pump 114 is supplied. A confluence control valve 21 for switching the confluence and interruption between the first sub-supply passage 161a and the second sub-supply passage 161b is provided between the first sub-supply passage 161a and the second sub-supply passage 161b.

[0028] The confluence control valve 21 is a pilot-operated direction switching valve in which a spool 153 (see FIGS. 5 and 6), which is slidably accommodated in a main accommodation hole 152 (see FIGS. 5 and 6) formed in a valve body 151 as will be described later, is switched between a communication position (Y) and a cutoff position (X). When the confluence control valve 21 is in the communication position (Y), the first sub-supply passage 161a and the second sub-supply passage 161b communicate with each other, so that the first hydraulic circuit HC1 and the second hydraulic circuit HC2 communicate with each other. That is, the confluence control valve 21 can connect the first hydraulic circuit HC1 and the second hydraulic circuit HC2 and cause the hydraulic oil discharged from the first pump 111 and the hydraulic oil discharged from the second pump 114 to merge. When the confluence control valve 21 is in the cutoff position (X), the communication between the first sub-supply passage 161a and the second sub-supply passage 161b is cut off, so that the communication between the first hydraulic circuit HC1 and the second hydraulic circuit HC2 is cut off.

[0029] A check passage 55, in which a first check valve 51 and a second check valve 52 are provided, is connected between the upstream side of the first unloading valve 31 in the first main supply passage 121a and the upstream side of the second unloading valve 32 in the second main supply passage 121b. Further, a relief passage 62, in which a relief valve 60 is provided, is connected between the space between the first check valve 51 and the second check valve 52 in the check passage 55 and the tank passage 163. The first check valve 51 allows only the flow of the hydraulic oil from the first main supply passage 121a to the relief passage 62, and the second check valve 52 allows only the flow of the hydraulic oil from the second main supply passage 121b to the relief passage 62. Therefore, the hydraulic oil with the higher pressure between the first main supply passage 121a and the second main supply passage 121b is led to the relief passage 62, and the led hydraulic oil is relieved by the relief valve 60. That is, the relief valve 60 relieves the higher pressure between the first main supply passage 121a and the second main supply passage 121b. In other words, the relief valve 60 defines the maximum pressure of the first hydraulic circuit HC1 and the second hydraulic circuit HC2.

[0030] Further, the hydraulic circuit of the hydraulic system 1 includes a first load pressure passage 162a to which the highest load pressure among the load pressures of a plurality of actuators MR, AS controlled by the first hydraulic circuit HC1 is led, a second load pressure passage 162b to which the highest load pressure among the load pressures of a plurality of actuators ML, BS controlled by the second hydraulic circuit HC2 is led, and a load pressure selection valve 35. In FIG. 1, the circuits for leading the load pressure to the first load pressure passage 162a and the second load pressure passage 162b are not shown.

[0031] The first load pressure passage 162a and the second load pressure passage 162b are connected to the load pressure selection valve 35. The load pressure selection valve 35 is a high-pressure selection valve that selects the higher one between the maximum load pressure of the first hydraulic circuit HC1 and the maximum load pressure of the second hydraulic circuit HC2. The maximum load pressure selected by the load pressure selection valve 35 is led to the regulator 113 of the first pump 111 and the regulator of the second pump 114 through the maximum load pressure passage 35a, and is used to control the inclination angles of the swash plate 113a of the first pump 111 and the swash plate (not shown) of the second pump 114.

[0032] A first pressure relief passage 164a is connected to the first load pressure passage 162a to prevent pressure from accumulating therein. Similarly, a second pressure relief passage 164b is connected to the second load pressure passage 162b to prevent pressure from accumulating therein. The first pressure relief passage 164a and the second pressure relief passage 164b are each connected to the tank 112 via a tank passage 122a. A first throttle 131 for holding the pressure in the first load pressure passage 162a is provided in the first pressure relief passage 164a, and a second throttle 132 for holding the pressure in the second load pressure passage 162b is provided in the second pressure relief passage 164b.

[0033] Next, the valve device 10 constituting the hydraulic system 1 will be described.

[0034] As shown in FIG. 1, the valve device 10 includes an inlet block 100 for taking in pressure oil and actuator blocks B11, B12, B21, B22 corresponding to the respective actuators MR, AS, ML, BS. In FIG. 1, the boundaries of the inlet block 100 and the respective actuator blocks B11, B12, B21, B22 are indicated by a two-dot chain line. The inlet block 100 is a block to which the hydraulic oil discharged from the first pump 111 and the second pump 114 is first supplied, and the hydraulic oil is supplied from the inlet block 100 to the respective actuator blocks B11, B12, B21, B22. The actuator blocks B11, B12 are arranged on one side of the inlet block 100, and the actuator blocks B21, B22 are arranged on the other side of the inlet block 100. The inlet block 100 and the respective actuator blocks B11, B12, B21, B22 are connected by bolts or the like to constitute the valve device 10.

[0035] The inlet block 100 includes the above-mentioned confluence control valve 21, the first unloading valve 31 and the second unloading valve 32, the first check valve 51 and the second check valve 52, the relief valve 60, and the load pressure selection valve 35. Further, the inlet block 100 includes the above-mentioned first main supply passage 121a, the first sub-supply passage 161a, the check passage 55, the relief passage 62, the first load pressure passage 162a, the second load pressure passage 162b, the first pressure relief passage 164a, the second pressure relief passage 164b, the first throttle 131, the second throttle 132, and the tank passage 122a. Details of the configuration of the valve body 151 will be described later.

[0036] The actuator block B11 includes the above-mentioned control valve 110a, the first main supply passage 121a, the first load pressure passage 162a, and the tank passage 122a. The actuator block B12 includes the above-mentioned control valve 110b, the first main supply passage 121a, the first load pressure passage 162a, and the tank passage 122a. The actuator block B21 includes the above-mentioned control valve 120a, the second main supply passage 121b, the second load pressure passage 162b, and the tank passage 122b. The actuator block B22 includes the above-mentioned control valve 120b, the second main supply passage 121b, the second load pressure passage 162b, and the tank passage 122b.

[0037] Note that the valve device 10 also includes a valve block that controls an actuator (not shown) for driving a swing motor that swings the hydraulic excavator, a bucket, a dozer, etc. (not shown), but the illustration thereof is omitted in FIG. 1.

[0038] Next, with reference to FIGS. 2-10, the specific structure of the inlet block 100 will be described.

[0039] FIG. 2 is a plan view of the inlet block 100, and FIG. 3 is a front view of the inlet block 100. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2, FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3, FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 2, FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 3, FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 3, and FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 3. FIG. 10 is a side view of the inlet block 100 as seen from arrow X in FIG. 3. FIGS. 5, 7-9 are shown in the same orientation as FIG. 2, and FIGS. 4, 6 are shown in the same orientation as FIG. 3. Hereinafter, for convenience of explanation, the vertical direction in FIG. 2 is also referred to as the D1 direction, the horizontal direction in FIG. 2 is also referred to as the D2 direction, and the direction perpendicular to the plane of the paper in FIG. 2 is also referred to as the D3 direction.

[0040] As shown in FIG. 2, on the upper surface 151a of the valve body 151 of the inlet block 100, a first pump port 260a communicating with the first pump 111 and a second pump port 260b communicating with the second pump 114 are formed by being opened. Pipes are connected to the first pump port 260a and the second pump port 260b, respectively, to communicate with the first pump 111 and the second pump 114, respectively. Further, on the upper surface 151a of the valve body 151, a first load pressure port 234a communicating with the first load pressure passage 162a and a second load pressure port 234b communicating with the second load pressure passage 162b are formed by being opened.

[0041] As shown in FIG. 4, the valve body 151 has a first supply passage 261a formed to communicate with the first pump port 260a and a second supply passage 262a (see FIG. 5) formed to communicate with the second pump port 260b. The first supply passage 261a corresponds to the first main supply passage 121a and the first sub-supply passage 161a of the hydraulic circuit shown in FIGS. 1 and 2, and the second supply passage 262a corresponds to the second main supply passage 121b and the second sub-supply passage 161b of the hydraulic circuit shown in FIGS. 1 and 2. The first supply passage 261a and the second supply passage 262a have a symmetrical shape with respect to the main accommodation hole 152.

[0042] The first supply passage 261a is formed by branching. Specifically, the first supply passage 261a includes a main passage 261b that extends substantially linearly in the D3 direction from the first pump port 260a to the first unloading valve 31, a first sub-passage 261c that extends in the D2 direction from the main passage 261b to the first check valve 51, and a second sub-passage 261d (see FIG. 5) that extends in the D1 direction from the main passage 261b to the main accommodation hole 152 in which the spool 153 is slidably accommodated and the rear surface 151c of the valve body 151. As shown in FIG. 5, a first supply port 221a communicating with the second sub-passage 261d is formed by opening on the rear surface 151c of the valve body 151. The hydraulic oil supplied from the first pump port 260a is guided to the first unloading valve 31, the main accommodation hole 152, the first supply port 221a, and the first check valve 51 through the first supply passage 261a.

[0043] Similar to the first supply passage 261a, the second supply passage 262a includes a main passage 262b (see FIG. 7) that extends substantially linearly in the D3 direction from the second pump port 260b to the second unloading valve 32, a first sub-passage (not shown) that extends in the D2 direction from the main passage 262b to the second check valve 52, and a second sub-passage 262d (see FIG. 5) that extends in the D1 direction from the main passage 262b to the main accommodation hole 152 and the front surface 151b of the valve body 151. The main passage 262b and the first sub-passage 262c correspond to the second main supply passage 121b of the hydraulic circuit shown in FIG. 1, and the second sub-passage 262d corresponds to the second sub-supply passage 161b. As shown in FIG. 5, a second supply port 221b communicating with the second sub-passage 262d is formed by opening on the front surface 151b of the valve body 151. The hydraulic oil supplied from the second pump port 260b is guided to the second unloading valve 32, the main accommodation hole 152, the second supply port 221b, and the second check valve 52 through the second supply passage 262a.

[0044] As shown in FIGS. 6, 7, and 9, the valve body 151 has a first load pressure passage 162a and a second load pressure passage 162b. Working oil is introduced into the first load pressure passage 162a and the second load pressure passage 162b through load pressure ports 166a and 166b (see FIG. 9) formed on the outer surface of the valve body 151, respectively. The first load pressure passage 162a and the second load pressure passage 162b are formed to extend in the D2 direction and the D1 direction on the cross section shown in FIG. 9, and are also formed to extend in the D3 direction from the cross section (see the first load pressure passage 162a in FIG. 4). The first load pressure passage 162a communicates with a first unloading valve 31 (see FIGS. 4 and 8), a main accommodation hole 152 (see FIGS. 5 and 6), a load pressure selection valve 35 (see FIG. 7), and a first throttle 131 (see FIG. 9). Similarly, the second load pressure passage 162b communicates with a second unloading valve 32 (see FIG. 8), a main accommodation hole 152 (see FIGS. 5 and 6), a load pressure selection valve 35 (see FIG. 7), and a second throttle 132 (see FIG. 9).

[0045] As shown in FIG. 7, the valve body 151 is provided with a load pressure port 165 for guiding the highest load pressure selected by the load pressure selection valve 35 to the outside. The load pressure port 165 communicates with the load pressure selection valve 35 and is provided on one side surface 151d of the valve body 151. The load pressure port 165 guides the highest load pressure to the regulator 113 of the first pump 111 and the regulator of the second pump 114, respectively.

[0046] As shown in FIG. 6, the valve body 151 has a tank passage 122a communicating with the tank 112. The tank passage 122a communicates with the main accommodation hole 152 in the cross section shown in FIG. 6 and is formed in a Y shape. Further, as shown in FIG. 8, the tank passage 122a is formed to extend in the D1 direction between the first unloading valve 31 and the second unloading valve 32. When the first unloading valve 31 and the second unloading valve 32 are opened, the hydraulic oil in the first supply passage 261a and the second supply passage 262a is respectively led to the tank 112. In other words, the tank passage 122a is formed between a first accommodation hole 231 and a second accommodation hole 232, which will be described later, in which the first unloading valve 31 and the second unloading valve 32 are respectively accommodated. Further, as shown in FIG. 9, the tank passage 122a is formed to extend in the D1 direction between the first throttle 131 and the second throttle 132, and the hydraulic oil in the first load pressure passage 162a and the second load pressure passage 162b is led to the tank 112 through the first throttle 131 and the second throttle 132. Tank ports 223a and 223b communicating with the tank passage 122a are formed on the upper surface 151a of the valve body 151 (see FIGS. 2 and 6), and a tank port 223c communicating with the tank passage 122a is formed on the front surface 151b of the valve body 151 (see FIG. 3).

[0047] As shown in FIGS. 5 and 6, a first supply passage 261a, a second supply passage 262a, a first load pressure passage 162a, a second load pressure passage 162b, and a tank passage 122a communicate with the main accommodation hole 152, and the communication is blocked by a first land portion 171, a second land portion 172, and a third land portion 173 provided on the spool 153. An opening on one side (the right side in FIGS. 5 and 6) of the main accommodation hole 152 is blocked by a first pilot cap 170a provided with a drain chamber 21a connected to the tank 112. An opening on the other side (the left side in FIGS. 5 and 6) is blocked by a second pilot cap 170b provided with a pilot chamber 21b into which a pilot pressure for switching the spool 153 to the blocking position (X) is input. A spring 154 for biasing the first pilot cap 170a in a direction to switch the spool 153 from the blocking position (X) to the communicating position (Y) is provided. The spool 153 moves axially according to the pilot pressure input to the pilot chamber 21b.

[0048] The first land portion 171 communicates or blocks the adjacent first supply passage 261a and second supply passage 262a. When no pilot pressure is introduced into the pilot chamber 21b and the spool 153 is in the communicating position (Y) as shown in FIGS. 5 and 6, the first supply passage 261a and the second supply passage 262a communicate with each other through an annular groove between the first land portion 171 and the second land portion 172. When pilot pressure is introduced into the pilot chamber 21b and the spool 153 moves to the right side in FIGS. 5 and 6 from the communicating position (Y) to the blocking position (X), the communication between the first supply passage 261a and the second supply passage 262a is blocked by the second land portion 172.

[0049] Further, the first land portion 171 communicates or blocks the adjacent first load pressure passage 162a and second load pressure passage 162b. When the spool 153 is in the communication position (Y), as shown in FIGS. 5 and 6, the first load pressure passage 162a and the second load pressure passage 162b communicate with each other through an annular groove between the first land portion 171 and the third land portion 173. Also, when the spool 153 is in the blocking position (X), the communication between the first load pressure passage 162a and the second load pressure passage 162b is blocked by the first land portion 171.

[0050] As shown in FIG. 7, the valve body 151 has a first check valve 51, a second check valve 52, and a check passage 55. The first check valve 51 and the second check valve 52 are provided on the other side surface 151e of the valve body 151 and are arranged parallel to each other on the same plane (in the cross section shown in FIG. 7). A relief port 167 that communicates the check passage 55 and the relief passage 62 is formed and opened on the other side surface 151e of the valve body 151.

[0051] As shown in FIG. 8, the valve body 151 has a first accommodation hole 231 and a second accommodation hole 232 that respectively accommodate a first unloading valve 31 and a second unloading valve 32. The first accommodation hole 231 and the second accommodation hole 232 open on one side surface 151d of the valve body 151 and are formed parallel to each other on the same plane (in the cross section shown in FIG. 8). In other words, the first unloading valve 31 and the second unloading valve 32 are respectively accommodated in the first accommodation hole 231 and the second accommodation hole 232 such that their axes (specifically, spools 31a and 32a described later) are parallel to each other, and are arranged side by side in the D1 direction and extend in the D2 direction. The D1 direction is the parallel direction in which the first unloading valve 31 and the second unloading valve 32 are arranged. Here, "parallel" includes not only being completely parallel but also a state that is not strictly parallel but slightly inclined due to manufacturing errors or the like. The first load pressure passage 162a, the main passage 261b of the first supply passage 261a, and the tank passage 122a open in the first accommodation hole 231, and the second load pressure passage 162b, the main passage 262b of the second supply passage 262a, and the tank passage 122a open in the second accommodation hole 232.

[0052] In the spool 31a of the first unloading valve 31, a spool passage 31b communicating with the first load pressure passage 162a is formed, and the hydraulic oil in the first load pressure passage 162a is guided through the spool passage 31b, and pressure acts to close the spool 31a together with the spring 31d. Further, in the spool 31a, a spool passage 31c communicating with the main passage 261b of the first supply passage 261a is formed, and the hydraulic oil in the main passage 261b is guided through the spool passage 31c, and pressure acts to open the spool 31a. When the load due to the pressure in the spool passage 31c exceeds the total load of the load due to the pressure in the spool passage 31b and the biasing force of the spring 31d, the first unloading valve 31 opens, and the hydraulic oil is guided from the main passage 261b to the tank passage 122a through a notch (not shown) formed on the outer peripheral surface of the spool 31a, and the hydraulic oil is unloaded.

[0053] In the spool 32a of the second unloading valve 32, similarly to the spool 31a, a spool passage 32b communicating with the second load pressure passage 162b and a spool passage 32c communicating with the main passage 262b of the second supply passage 262a are formed. The hydraulic oil in the second load pressure passage 162b is guided through the spool passage 32b, and pressure acts to close the spool 32a together with the spring 32d. The hydraulic oil in the main passage 262b is guided through the spool passage 32c, and pressure acts to open the spool 32a. When the load due to the pressure in the spool passage 32c exceeds the total load of the load due to the pressure in the spool passage 32b and the biasing force of the spring 32d, the second unloading valve 32 opens, and the hydraulic oil is guided from the main passage 262b to the tank passage 122a through a notch (not shown) formed on the outer peripheral surface of the spool 32a, and the hydraulic oil is unloaded.

[0054] In this embodiment, as described above, the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are all provided in the valve body 151 of the inlet block 100. Therefore, compared with a configuration in which the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are provided in separate valve blocks and arranged side by side, the dimension of the entire inlet block 100 in one direction (the parallel direction D1 in which the first unloading valve 31 and the second unloading valve 32 are arranged) can be reduced.

[0055] Furthermore, in this embodiment, as shown in FIG. 10, the confluence control valve 21 (specifically, the spool 153) is provided away from the first unloading valve 31 and the second unloading valve 32 in the vertical direction (D3 direction) perpendicular to the parallel direction (D1 direction) in which the first unloading valve 31 and the second unloading valve 32 are arranged and the axial direction (D2 direction) of both. In other words, the spool 153 is provided at a predetermined distance without overlapping the first unloading valve 31 and the second unloading valve 32 in the D3 direction. Therefore, since the first unloading valve 31 and the second unloading valve 32 can be arranged close to each other in the D1 direction, the dimension of the inlet block 100 in the D1 direction can be made smaller. Furthermore, the confluence control valve 21 (specifically, the spool 153) is provided between the first unloading valve 31 and the second unloading valve 32 in the D1 direction. In other words, the spool 153 is not located outside the valve body 151 more than the first unloading valve 31 and is not located outside the valve body 151 more than the second unloading valve 32 in the D1 direction. Therefore, the dimension of the inlet block 100 in the D1 direction can be made smaller.

[0056] Also, in this embodiment, since the tank passage 122a is shared by the first unloading valve 31 and the second unloading valve 32, the flow path configuration of the inlet block 100 can be simplified.

[0057] Further, in the present embodiment, as shown in FIGS. 2, 4, and 8, the first pump port 260a is formed such that a part of the first unloading valve 31 overlaps on its extension line in the vertical direction (D3 direction), and the second pump port 260b is formed such that a part of the second unloading valve 32 overlaps on its extension line in the vertical direction. Thereby, as described above, the flow paths from the first pump port 260a to the first unloading valve 31 and from the second pump port 260b to the second unloading valve 32 can be made substantially linear, so that the flow path configuration of the inlet block 100 can be simplified. Note that the first pump port 260a and the second pump port 260b may be formed such that the entire first unloading valve 31 and the second unloading valve 32 overlap on their extension lines in the D3 direction, respectively.

[0058] Also, in the present embodiment, as shown in FIG. 8, since both the first unloading valve 31 and the second unloading valve 32 are provided on one side surface 151d of the valve body 151, there is a dead space in the valve body 151, laterally of the first unloading valve 31 and the second unloading valve 32 (specifically, between the other side surface 151e in the D2 direction and the first unloading valve 31 and the second unloading valve 32). A pilot passage 270 provided in the valve device 10 is formed in this dead space. The pilot passage 270 guides pilot fluid to a control valve 110a (see FIG. 1) as an actuator control valve that controls the operation of the actuator MR by supplying hydraulic oil from the first supply passage 261a (first hydraulic circuit HC1). Note that in FIG. 1, the illustration of the pilot passage 270 is omitted. The pilot passage 270 is, for example, a passage that guides the primary pressure to a pressure reducing valve (not shown) that generates the pilot pressure. A part of the pilot passage 270 is formed in a region between the other side surface 151e on the side opposite to one side surface 151d of the valve body 151 and the first unloading valve 31 and the second unloading valve 32. In other words, a part of the pilot passage 270 is formed between the other side surface 151e and the first unloading valve 31 and the second unloading valve 32 in the D2 direction. Thereby, the dead space of the valve body 151 can be effectively utilized. Note that the entire pilot passage 270 may be formed in the dead space, or other passages such as a drain passage of the pressure reducing valve may be formed in the dead space. Also, a pilot passage 270 that guides pilot fluid to control valves 110b, 120a, and 120b different from the control valve 110a may be formed in the dead space.

[0059] According to the above-described embodiment, the following operational effects are obtained.

[0060] In the inlet block 100, the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are all provided in the valve body 151. Therefore, the dimension of the entire valve body 151 in the D1 direction can be made smaller than the configuration in which the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are provided in separate valve bodies 151 and arranged side by side. Further, the spool 153 is provided away from the first unloading valve 31 and the second unloading valve 32 in the D3 direction and is provided between the first unloading valve 31 and the second unloading valve 32 in the D1 direction, so that the dimension of the valve body 151 in the D1 direction can be made even smaller.

[0061] The following modifications are also within the scope of the present invention, and it is also possible to combine the configurations shown in the modifications with the configurations described in the above-described embodiments, or to combine the configurations described in the following different modifications with each other.

[0062] <Modification 1> In the above embodiment, the form in which the first throttle 131, the second throttle 132, the first check valve 51, and the second check valve 52 are provided in the valve body 151 of the inlet block 100 has been described, but the present invention is not limited thereto. Each of the above configurations may be provided outside the valve body 151. Further, the relief valve 60 may be provided in the valve body 151.

[0063] <Modification 2> In the above embodiment, the form in which the first pump 111 and the second pump 114 supply hydraulic oil to the first hydraulic circuit HC1 and the second hydraulic circuit HC2 respectively has been described. However, the present invention may be a form in which hydraulic oil is supplied from one split-flow type pump to the first hydraulic circuit HC1 and the second hydraulic circuit HC2. In this form, the first pump 111 and the second pump 114 are provided in one pump, and one pump has two discharge ports.

[0064] <Modification 3> In the above-described embodiment, an example in which the present invention is applied to the hydraulic system 1 of a hydraulic excavator has been described. However, the present invention is not limited to this. The present invention can be applied to the hydraulic systems of various working machines such as crawler cranes, wheel loaders, forklifts, and the like.

[0065] Hereinafter, the configuration, operation, and effects of the embodiments of the present invention will be collectively described.

[0066] The inlet block 100 includes a confluence control valve 21 that joins or shuts off the working fluid discharged from the first pump 111 through the first fluid pressure passage (first main supply passage 121a) and the working fluid discharged from the second pump 114 through the second fluid pressure passage (second main supply passage 121b), a first unloading valve 31 connected to the first fluid pressure passage and unloading the working fluid discharged from the first pump 111, a second unloading valve 32 connected to the second fluid pressure passage and unloading the working fluid discharged from the second pump 114, a valve body 151 in which the first fluid pressure passage and the second fluid pressure passage are formed and the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are provided. The first unloading valve 31 and the second unloading valve 32 are arranged side by side such that their axes are parallel to each other. The confluence control valve 21 is provided apart from the first unloading valve 31 and the second unloading valve 32 in the vertical direction (D3) perpendicular to the parallel direction (D1) in which the first unloading valve 31 and the second unloading valve 32 are arranged and the axial direction (D2) of both, and is provided between the first unloading valve 31 and the second unloading valve 32 in the parallel direction.

[0067] In this configuration, the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are all provided on the valve body 151. Therefore, the dimension of the entire valve body 151 in one direction (the parallel direction in which the first unloading valve 31 and the second unloading valve 32 are arranged side by side) can be made smaller than the configuration in which the confluence control valve 21, the first unloading valve 31, and the second unloading valve 32 are provided on separate valve bodies 151 and arranged side by side. Further, the confluence control valve 21 is provided apart from the first unloading valve 31 and the second unloading valve 32 in the vertical direction and is provided between the first unloading valve 31 and the second unloading valve 32 in the parallel direction, so that the dimension of the inlet block 100 in one direction (the parallel direction) can be made even smaller.

[0068] Further, the inlet block 100 has two accommodation holes 231, 232 in which the first unloading valve 31 and the second unloading valve 32 are respectively accommodated, and a tank passage 122a formed between the two accommodation holes 231, 232 and communicating with the tank 112. The working fluid unloaded by the first unloading valve 31 and the second unloading valve 32 is guided to the tank passage 122a.

[0069] In this configuration, since the tank passage 122a is shared by the first unloading valve 31 and the second unloading valve 32, the flow path configuration of the inlet block 100 can be simplified.

[0070] Also, in the inlet block 100, on the outer surface of the valve body 151, a first pump port 260a communicating with the first pump 111 and guiding the working fluid to the first fluid pressure passage and a second pump port 260b communicating with the second pump 114 and guiding the working fluid to the second fluid pressure passage are formed to open. The first pump port 260a is formed such that at least a part of the first unloading valve 31 overlaps on its extension line in the vertical direction, and the second pump port 260b is formed such that at least a part of the second unloading valve 32 overlaps on its extension line in the vertical direction.

[0071] In this configuration, since the flow paths from the ports of the first pump 111 to the first unloading valve 31 and from the ports of the second pump 114 to the second unloading valve 32 can be made substantially linear, the flow path configuration of the inlet block 100 can be simplified.

[0072] Also, in the valve device 10 including the inlet block 100, an actuator block connected to the inlet block 100 and having actuator control valves (control valves 110a, 110b, 120a, 120b) that are supplied with operating fluid from a first fluid pressure passage (first main supply passage 121a) or a second fluid pressure passage (second main supply passage 121b) to control the operation of actuators (MR, AS, ML, BS), and a pilot passage 270 that guides pilot fluid to the actuator control valves, the first unloading valve 31 and the second unloading valve 32 are respectively accommodated in two accommodation holes 231, 232 formed to open on one end surface of the valve body 151, and at least a part of the pilot passage 270 is formed in a region between the other end surface of the valve body 151 opposite to the one end surface and the first unloading valve 31 and the second unloading valve 32.

[0073] In this configuration, there is a dead space beside the first unloading valve 31 and the second unloading valve 32 in the valve body 151. Since the pilot passage 270 is formed in the dead space, the dead space of the inlet block 100 can be effectively utilized.

[0074] As described above, the embodiments of the present invention have been explained. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Explanation of Reference Numerals

[0075] 10… Valve device, 21… Confluence control valve, 31… First unloading valve, 32… Second unloading valve, 100… Inlet block, 110… Control valve (actuator control valve), 111… First pump, 112… Tank, 114… Second pump, 121a… First main supply passage (first fluid pressure passage), 121b… Second main supply passage (second fluid pressure passage), 122a… Tank passage, 151… Valve body, 151a… Upper surface (outer surface), 151d… One side surface (one end surface), 151e… The other side surface (the other end surface), 231, 232… Accommodation holes, 260a… First pump port, 260b… Second pump port, 270… Pilot passage, D1… Parallel direction, D3… Vertical direction

Claims

1. An inlet block, comprising: A confluence control valve for merging or blocking the working fluid discharged from the first pump through the first fluid pressure passage and the working fluid discharged from the second pump through the second fluid pressure passage; A first unloading valve connected to the first fluid pressure passage for unloading the working fluid discharged from the first pump; A second unloading valve connected to the second fluid pressure passage for unloading the working fluid discharged from the second pump; A valve body in which the first fluid pressure passage and the second fluid pressure passage are formed, and the confluence control valve, the first unloading valve, and the second unloading valve are provided; The first unloading valve and the second unloading valve are arranged side by side such that their axes are parallel to each other; The confluence control valve is provided apart from the first unloading valve and the second unloading valve in a vertical direction perpendicular to the parallel direction in which the first unloading valve and the second unloading valve are arranged and the axial directions of both, and is provided between the first unloading valve and the second unloading valve in the parallel direction. An inlet block characterized by this.

2. The inlet block according to claim 1, wherein: The valve body includes: Two accommodation holes in which the first unloading valve and the second unloading valve are respectively accommodated; A tank passage formed between the two accommodation holes and communicating with the tank; The working fluid unloaded by the first unloading valve and the second unloading valve is guided to the tank passage. An inlet block characterized by this.

3. The inlet block according to claim 1, wherein: On the outer surface of the valve body, a first pump port communicating with the first pump and guiding the working fluid to the first fluid pressure passage, and a second pump port communicating with the second pump and guiding the working fluid to the second fluid pressure passage are formed by openings; The first pump port is formed such that at least a part of the first unloading valve overlaps on its extension line in the vertical direction; The second pump port is formed such that at least a part of the second unloading valve overlaps on its extension line in the vertical direction. An inlet block characterized by this.

4. The inlet block according to claim 1, and An actuator block connected to the inlet block and having an actuator control valve that is supplied with working fluid from the first fluid pressure passage or the second fluid pressure passage to control the operation of the actuator; A valve device comprising a pilot passage for guiding pilot fluid to the actuator control valve; The first unloading valve and the second unloading valve are respectively accommodated in two accommodation holes formed by opening on one end surface of the valve body; The valve device is characterized in that at least a part of the pilot passage is formed in a region between the other end surface of the valve body opposite to the one end surface and the first unloading valve and the second unloading valve.

Images