# US 10,767,346 B2 · Work machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,346 B2 - Document ID: US10767346B2 - Status: Granted - Kind: B2 - Application number: 16/427,353 - Filed: 2019-05-31 - Published: 2020-01-23 - Granted: 2020-09-08 - Earliest claimed: 2018-07-20 - Assignees: Kubota Corporation - Applicants: Kubota Corporation - Inventors: Keigo Honda; Yuji Fukuda; Takahiro Usami; Hiroshi Fujiwara - Web page: https://patentgrep.com/patent/US10767346B2 ## CPC - E02F 9/2285: {Pilot-operated systems} - E02F 9/0875: {Arrangement of valve arrangements on superstructures (arrangement of hydraulic hoses E02F9/2275 takes precedence; valves per se E02F9/2267)} - E02F 9/226: {Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating} - E02F 9/2267: {Valves or distributors (position of valves arrangements on upper-structures E02F9/0875)} - E02F 9/2282: {Systems using center bypass type changeover valves} - E02F 9/2289: {Closed circuit} - E02F 9/0883: {Tanks, e.g. oil tank, urea tank, fuel tank (for vehicles in general B60K15/00)} - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract A work machine includes a hydraulic actuator configured to be driven via hydraulic oil. A control valve has a first pilot port and is connected to the hydraulic actuator to control the hydraulic actuator. The hydraulic actuator is configured to move in a first mode when a first pilot pressure is applied to the first pilot port. A first pilot valve is connected to the first pilot port of the control valve via the first pilot oil supply pipe to control applying the first pilot pressure to the first pilot port. The hydraulic oil is configured to be drained via a drain pipe. The drain pipe and the first pilot oil supply pipe are provided in a heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the first pilot oil supply pipe via the heat exchanger. ## Claims ### Claim 1 A work machine comprising: a hydraulic actuator configured to be driven via hydraulic oil; a control valve having a first pilot port and connected to the hydraulic actuator to control the hydraulic actuator, the hydraulic actuator being configured to move in a first mode when a first pilot pressure is applied to the first pilot port; a first pilot oil supply pipe; a first pilot valve connected to the first pilot port of the control valve via the first pilot oil supply pipe to control applying the first pilot pressure to the first pilot port; a drain pipe via which the hydraulic oil is configured to be drained; and a heat exchanger in which the drain pipe and the first pilot oil supply pipe are provided to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the first pilot oil supply pipe via the heat exchanger. ### Claim 2 (depends on 1) The work machine according to claim 1, wherein the control valve has a second port, the hydraulic actuator being configured to move in a second mode different from the first mode when a second pilot pressure is applied to the second pilot port, wherein the work machine further comprises: a second pilot oil supply pipe; a second pilot valve connected to the second pilot port of the control valve via the second oil supply pipe to control applying the second pilot pressure to the second pilot port, and wherein the drain pipe and the second pilot oil supply pipe are provided in the heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the second pilot oil supply pipe via the heat exchanger. ### Claim 3 (depends on 1) The work machine according to claim 1, further comprising: an additional hydraulic actuator configured to be driven via the hydraulic oil; an additional control valve having an additional pilot port and connected to the additional hydraulic actuator to control the additional hydraulic actuator, the hydraulic actuator being configured to move in an additional mode when an additional pilot pressure is applied to the additional pilot port; an additional pilot oil supply pipe; an additional pilot valve connected to the additional pilot port of the additional control valve via the additional pilot oil supply pipe to control applying the additional pilot pressure to the additional pilot port of the additional control valve, wherein the drain pipe and the additional pilot oil supply pipe are provided in the heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the additional pilot oil supply pipe via the heat exchanger. ### Claim 4 (depends on 2) The work machine according to claim 2, wherein the first pilot oil supply pipe and the second pilot oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the second pilot oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the second pilot oil supply pipe such that the drain pipe does not pass through the gap and does not intersect with either of the first pilot oil supply pipe and the second pilot oil supply pipe. ### Claim 5 (depends on 3) The work machine according to claim 3, wherein the first pilot oil supply pipe and the additional pilot oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the additional pilot oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the additional pilot oil supply pipe such that the drain pipe does not pass through the gap and does not intersect with either of the first pilot oil supply pipe and the additional pilot oil supply pipe. ### Claim 6 (depends on 3) The work machine according to claim 3, wherein the first pilot oil supply pipe and the additional pilot oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the additional pilot oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the additional pilot oil supply pipe such that the drain pipe passes through the gap and does not intersect with either of the first pilot oil supply pipe and the additional pilot oil supply pipe. ### Claim 7 (depends on 1) The work machine according to claim 1, wherein the first pilot oil supply pipe extends in a first direction, and wherein the drain pipe extends in a second direction substantially perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction such that the drain pipe does not intersect with the first oil supply pipe. ### Claim 8 (depends on 1) The work machine according to claim 1, wherein the first pilot oil supply pipe extends in a first direction, and wherein the drain pipe extends in a second direction that is neither parallel nor perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction such that the drain pipe does not intersect with the first oil supply pipe. ### Claim 9 (depends on 2) The work machine according to claim 2, further comprising: an additional hydraulic actuator configured to be driven via the hydraulic oil; an additional control valve having an additional pilot port and connected to the additional hydraulic actuator to control the additional hydraulic actuator, the hydraulic actuator being configured to move in an additional mode when an additional pilot pressure is applied to the additional pilot port; an additional pilot oil supply pipe; and an additional pilot valve connected to the additional pilot port of the additional control valve via the additional pilot oil supply pipe to control applying the additional pilot pressure to the additional pilot port of the additional control valve, wherein the drain pipe and the additional pilot oil supply pipe are provided in the heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the additional pilot oil supply pipe via the heat exchanger, and wherein the first pilot oil supply pipe, the second pilot oil supply pipe, and the additional pilot oil supply pipe are arranged around the drain pipe in the heat exchanger. ### Claim 10 (depends on 1) The work machine according to claim 1, further comprising: an additional oil supply pipe; and a hydraulic pump configured to supply the hydraulic oil to the first pilot valve via the additional oil supply pipe, wherein the additional oil supply pipe is provided in the heat exchanger to exchange heat between the hydraulic oil in the additional oil supply pipe and the hydraulic oil in the first pilot oil supply pipe via the heat exchanger. ### Claim 11 (depends on 10) The work machine according to claim 10, wherein the first pilot oil supply pipe and the additional oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the additional oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the additional oil supply pipe such that the drain pipe does not pass through the gap and does not intersect with either of the first pilot oil supply pipe and the additional oil supply pipe. ### Claim 12 (depends on 10) The work machine according to claim 10, wherein the first pilot oil supply pipe and the additional oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the additional oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the additional oil supply pipe such that the drain pipe passes through the gap and does not intersect with either of the first pilot oil supply pipe and the additional oil supply pipe. ### Claim 13 (depends on 11) The work machine according to claim 11, wherein the first pilot oil supply pipe and the additional oil supply pipe extend in a first direction, and wherein the drain pipe extends in a second direction substantially perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction. ### Claim 14 (depends on 12) The work machine according to claim 12, wherein the first pilot oil supply pipe and the additional oil supply pipe extend in a first direction, and wherein the drain pipe extends in a second direction substantially perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction. ### Claim 15 (depends on 12) The work machine according to claim 12, wherein the first pilot oil supply pipe and the additional oil supply pipe extend in a first direction, and wherein the drain pipe extends in a second direction that is neither parallel nor perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction. ### Claim 16 (depends on 10) The work machine according to claim 10, wherein the control valve has a second port, the hydraulic actuator being configured to move in a second mode different from the first mode when a second pilot pressure is applied to the second pilot port, wherein the work machine further comprises: a second pilot oil supply pipe; a second pilot valve connected to the second pilot port of the control valve via the second oil supply pipe to control applying the second pilot pressure to the second pilot port, wherein the drain pipe and the second pilot oil supply pipe are provided in the heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the second pilot oil supply pipe via the heat exchanger, and wherein the first pilot oil supply pipe, the second pilot oil supply pipe, and the additional oil supply pipe are arranged around the drain pipe in the heat exchanger. ### Claim 17 (depends on 10) The work machine according to claim 10, further comprising: an additional hydraulic actuator configured to be driven via the hydraulic oil; an additional control valve having an additional pilot port and connected to the additional hydraulic actuator to control the additional hydraulic actuator, the hydraulic actuator being configured to move in an additional mode when an additional pilot pressure is applied to the additional pilot port; an additional pilot oil supply pipe; and an additional pilot valve connected to the additional pilot port of the additional control valve via the additional pilot oil supply pipe to control applying the additional pilot pressure to the additional pilot port of the additional control valve, wherein the drain pipe and the additional pilot oil supply pipe are provided in the heat exchanger to exchange heat between the hydraulic oil in the drain pipe and the hydraulic oil in the additional pilot oil supply pipe via the heat exchanger, wherein the first pilot oil supply pipe, the additional pilot oil supply pipe, and the additional oil supply pipe are arranged around the drain pipe in the heat exchanger. ### Claim 18 A work machine comprising: a hydraulic pump configured to supply hydraulic oil; a hydraulic actuator configured to be driven via the hydraulic oil; a control valve having a first pilot port and connected to the hydraulic actuator to control the hydraulic actuator, the hydraulic actuator being configured to move in a first mode when a first pilot pressure is applied to the first pilot port; a first pilot oil supply pipe; an additional oil supply pipe; a first pilot valve connected to the hydraulic pump via the additional oil supply pipe to receive the hydraulic oil and connected to the first pilot port of the control valve via the first pilot oil supply pipe to control applying the first pilot pressure to the first pilot port; a branch pipe which is connected to the additional oil supply pipe; and a heat exchanger in which the branch pipe and the first pilot oil supply pipe are provided to exchange heat between the hydraulic oil in the branch pipe and the hydraulic oil in the first pilot oil supply pipe via the heat exchanger. ### Claim 19 (depends on 18) The work machine according to claim 18, wherein the first pilot oil supply pipe extends in a first direction, and wherein the branch pipe extends in a fourth direction non-parallel to the first direction as viewed in a fifth direction substantially perpendicular to the first direction and the fourth direction such that the branch pipe does not intersect with the first oil supply pipe. ### Claim 20 (depends on 1) The work machine according to claim 1, wherein the heat exchanger includes a metallic material member having a first hole and a second hole, a surface of the first hole defining an inner surface of a part of the first pilot oil supply pipe, a surface of the second hole defining an inner surface of a part of the second pilot oil supply pipe. ### Claim 21 (depends on 2) The work machine according to claim 2, wherein the first pilot oil supply pipe and the second pilot oil supply pipe are provided substantially in parallel to provide a gap between the first pilot oil supply pipe and the second pilot oil supply pipe, and wherein the drain pipe extends non-parallel to both of the first pilot oil supply pipe and the second pilot oil supply pipe such that the drain pipe passes through the gap and does not intersect with either of the first pilot oil supply pipe and the second pilot oil supply pipe. ### Claim 22 (depends on 11) The work machine according to claim 11, wherein the first pilot oil supply pipe and the additional oil supply pipe extend in a first direction, and wherein the drain pipe extends in a second direction that is neither parallel nor perpendicular to the first direction as viewed in a third direction substantially perpendicular to the first direction and the second direction.