IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0962627
(2004-10-11)
|
발명자
/ 주소 |
- Cherney,Mark John
- Radke,Daniel Dean
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출원인 / 주소 |
|
인용정보 |
피인용 횟수 :
53 인용 특허 :
6 |
초록
▼
Hydraulic circuits used to manipulate tools in, for example construction equipment, uses less power for a retraction of a hydraulic cylinder than for an extension of that cylinder. Provided is a hydraulic circuit that uses the stored energy from the low energy phase to lower the energy load on the h
Hydraulic circuits used to manipulate tools in, for example construction equipment, uses less power for a retraction of a hydraulic cylinder than for an extension of that cylinder. Provided is a hydraulic circuit that uses the stored energy from the low energy phase to lower the energy load on the hydraulic pump during the high energy phase. Energy from the hydraulic pump is increased during the low energy phase to increase the amount of stored hydraulic energy. The increased amount of stored energy is then used to intensify or add to the energy generated by the hydraulic pump for the high energy phase.
대표청구항
▼
What is claimed is: 1. A hydraulic energy intensifying circuit for a work vehicle, the work vehicle including a frame, a tool, a linkage between the frame and the tool, a boom between the frame and the tool, a hydraulic cylinder to manipulate the tool, the hydraulic cylinder having a first chamber
What is claimed is: 1. A hydraulic energy intensifying circuit for a work vehicle, the work vehicle including a frame, a tool, a linkage between the frame and the tool, a boom between the frame and the tool, a hydraulic cylinder to manipulate the tool, the hydraulic cylinder having a first chamber and a second chamber, the hydraulic cylinder extending against a first load under an application of a first volume of fluid at a first pressure to the first chamber, the hydraulic cylinder retracting under a second load and an application of a second volume of fluid at a second pressure to the second chamber, a first chamber reaction pressure being produced in the first chamber when the hydraulic cylinder is retracting, the hydraulic energy intensifying circuit comprising: a hydraulic pump to displace the first volume of fluid at the first pressure and the second volume of fluid at the second pressure, the hydraulic pump having a pump inlet; at least one displacement control valve to direct the first volume of fluid to the first chamber to extend the cylinder rod and the second volume of fluid to the second chamber to retract the cylinder rod on demand, the at least one displacement control valve capable of blocking fluid flow from the first chamber; an accumulator capable of storing a predefined volume of fluid from the first chamber of the hydraulic cylinder under an accumulator reaction pressure, the predefined volume being determined when the hydraulic cylinder is in an extended position, the accumulator being pre-charged to a first pre-charge pressure that allows the predefined volume of fluid to be stored in the accumulator when the second volume of fluid at the second pressure is applied to the second chamber in combination with the second load; at least one accumulator valve to allow the predefined volume of fluid from the first chamber to be stored in the accumulator, the at least one accumulator valve allowing the fluid stored in the accumulator under the accumulator reaction pressure to be released from the accumulator, the at least one displacement control valve directing the second volume of fluid from the hydraulic pump to the second chamber and blocking the fluid flow from the first chamber to, thereby, divert the fluid flow from the first chamber to the at least one accumulator valve, the at least one accumulator valve opening to allow the predefined volume of fluid from the first chamber to be stored in the accumulator, the accumulator storing the predefined volume of fluid at the accumulator reaction pressure. 2. The hydraulic energy intensifying circuit of claim 1, wherein the at least one accumulator valve comprises: an accumulator charge valve to allow the fluid from the first chamber to be stored in the accumulator; and an accumulator discharge valve to allow the fluid stored in the accumulator under the accumulator reaction pressure to be released from the accumulator; the at least one displacement control valve directing the second volume of fluid from the hydraulic pump to the second chamber and blocking the fluid flow from the first chamber to, thereby, divert the fluid from the first chamber to the accumulator charge valve, the accumulator charge valve opening to allow the predetermined volume of fluid from the first chamber to be stored in the accumulator, the accumulator storing the predefined volume of fluid at the accumulator reaction pressure. 3. The hydraulic energy intensifying circuit of claim 2, wherein the accumulator discharge valve opens to release the predefined volume of fluid stored in the accumulator. 4. The hydraulic energy intensifying circuit of claim 3 wherein the accumulator reaction pressure is applied to the pump inlet to reduce a load on the pump. 5. The hydraulic energy intensifying circuit of claim 1, wherein the at least one displacement control valve comprises a first displacement control valve and a second displacement control valve, the first displacement control valve directing the first hydraulic energy to the first chamber, the second displacement control valve directing the second hydraulic energy to the second chamber. 6. The hydraulic energy intensifying circuit of claim 1, wherein the hydraulic pump is a load sensitive variable displacement hydraulic pump having a load sensor. 7. The hydraulic energy intensifying circuit of claim 6, further comprising means for delivering a load sense of a first hydraulic pressure on the first chamber and a second hydraulic pressure on the second chamber to the load sensor. 8. The hydraulic energy intensifying circuit of claim 7, wherein the means for delivering the load sense comprises a shuttle check valve. 9. The hydraulic energy intensifying circuit of claim 7, wherein the second load is a retraction load resulting from an action of gravity. 10. The hydraulic energy intensifying circuit of claim 7, wherein the first pressure is the highest pilot pressure. 11. The hydraulic energy intensifying circuit of claim 7, wherein the second pressure is the load sense. 12. The hydraulic energy intensifying circuit of claim 1, wherein the predefined volume of fluid is a full volume of fluid contained in the first chamber of the hydraulic cylinder at a fully extended position. 13. A hydraulic energy intensifying circuit, comprising: a hydraulic cylinder to manipulate a first load and a second load, the hydraulic cylinder a having a first chamber, a second chamber and a cylinder rod, the cylinder rod having a piston and a piston rod, the piston having a first application surface and a second application surface, the hydraulic cylinder extending against the first load under an application of a first volume of fluid at a first pressure to the first chamber, the first pressure producing a first force as the first pressure is applied against the first application surface, the hydraulic cylinder retracting under a second load and an application of a second volume of fluid at a second pressure to the second chamber, the second pressure producing a second force as the second pressure is applied against the second application surface, a first chamber reaction pressure being produced in the first chamber when the hydraulic cylinder is retracting; a hydraulic pump to generate the first volume of fluid at the first pressure and the second volume at the second pressure, the hydraulic pump having a pump inlet; at least one displacement control valve to direct the first volume of fluid at the first pressure to the first chamber and the second volume of fluid at the second pressure to the second chamber, the at least one displacement control valve capable of blocking fluid flow from the first chamber; an accumulator capable of storing a predefined volume of fluid from the first chamber at an accumulator reaction pressure, the accumulator being pre-charged to a first pressure that allows the predefined volume of fluid to be stored in the accumulator only under the first chamber reaction pressure produced when at least one of the second force is greater than the second load and the second hydraulic energy is applied in combination with the second load; at least one accumulator valve to allow the predefined volume of fluid to be stored in the accumulator under the first chamber reaction pressure, the at least one accumulator valve allowing the predefined volume of fluid to be released from the accumulator on demand, the at least one displacement control valve directing the second volume of fluid from the hydraulic pump to the second chamber and blocking the fluid flow from the first chamber to, thereby, divert the fluid from the first chamber to the at least one accumulator valve, the at least one accumulator valve opening to allow the predefined volume of fluid from the first chamber to be stored in the accumulator, the accumulator storing the predefined volume of fluid at the accumulator reaction pressure. 14. The hydraulic energy intensifying circuit of claim 13, wherein the at least one accumulator valve comprises: an accumulator charge valve to allow the fluid from the first chamber to be stored in the accumulator; and an accumulator discharge valve to allow the fluid stored in the accumulator under the accumulator reaction pressure to be released from the accumulator; the at least one displacement control valve directing the second volume of fluid from the hydraulic pump to the second chamber and blocking the fluid flow from the first chamber to, thereby, divert the fluid from the first chamber to the at least one accumulator valve, the accumulator charge valve opening to allow the predefined volume of fluid from the first chamber to be stored in the accumulator, the accumulator discharge valve being closed, the accumulator storing the predefined volume of fluid at the accumulator reaction pressure. 15. The hydraulic energy intensifying circuit of claim 14, wherein the accumulator discharge valve opens to release the predefined volume of fluid stored in the accumulator. 16. The hydraulic energy intensifying circuit of claim 15 wherein the accumulator reaction pressure is applied to the pump inlet to reduce a load on the pump. 17. The hydraulic energy intensifying circuit of claim 13, wherein the at least one displacement control valve comprises a first displacement control valve and a second displacement control valve, the first displacement control valve directing the first volume of fluid to the first chamber, the second displacement control valve directing the second volume of fluid to the second chamber. 18. The hydraulic energy intensifying circuit of claim 13, wherein the hydraulic pump is a load sensitive variable displacement hydraulic pump having a load sensor. 19. The hydraulic energy intensifying circuit of claim 18, further comprising means for delivering a load sense of a first hydraulic pressure at the first chamber and a second hydraulic pressure at the second chamber to the load sensor. 20. The hydraulic energy intensifying circuit of claim 19, wherein the means for delivering the load sense comprises a shuttle check valve. 21. The hydraulic energy intensifying circuit of claim 19, wherein the second load is a retraction load resulting from an action of gravity. 22. The hydraulic energy intensifying circuit of claim 19, wherein the first pressure is greater than the load sense. 23. The hydraulic energy intensifying circuit of claim 19, wherein the second a pressure is greater than the load sense. 24. The hydraulic energy intensifying circuit of claim 13, wherein the predefined volume of fluid is a full volume of fluid contained in the first chamber of the hydraulic cylinder at a fully extended position. 25. A method of intensifying energy in a hydraulic circuit for a work vehicle, the hydraulic circuit including a hydraulic cylinder to manipulate a load, the hydraulic cylinder having a first chamber and a second chamber, the hydraulic cylinder extending against a first load under an application of a first volume of fluid at a first pressure to the first chamber, the hydraulic cylinder retracting under a second load and a second force produced by an application of a second volume of fluid at a second pressure to the second chamber, a first chamber reaction pressure being produced in the first chamber when the hydraulic cylinder is retracting, a hydraulic pump to displace the first volume of fluid at the first pressure and the second volume of fluid at the second pressure, the hydraulic pump having a pump inlet, at least one displacement control valve to direct the first volume of fluid to the first chamber and the second volume of fluid to the second chamber on demand, an accumulator capable of storing a predefined volume of fluid at an accumulator reaction pressure, an accumulator charge valve to allow the predefined volume of fluid to be stored in the accumulator, an accumulator discharge valve to allow the predefined volume of fluid to be released from the accumulator, the method comprising: pre-charging the accumulator to a first pressure that allows the pre-defined volume of fluid to be stored in the accumulator under the first chamber reaction pressure produced when at least one of the second force is greater than the second load and the second hydraulic energy is applied in combination with the second load; displacing the second volume of fluid at the second pressure with the hydraulic pump; opening the at least one displacement control valve to the second chamber to direct the second volume of fluid to the second chamber while closing the at least one displacement control valve to the first chamber to divert fluid flow from the first chamber to the accumulator charge valve; and opening the accumulator charge valve to allow the accumulator to store the pre-defined volume of fluid at the accumulator reaction pressure, the accumulator discharge valve being closed. 26. The method of claim 25, further comprising closing the accumulator charge valve after the pre-defined volume of fluid is stored in the accumulator. 27. The method of claim 26, further comprising: opening the accumulator discharge valve at a time of high demand for hydraulic energy to release the predefined volume of fluid stored in the accumulator; and applying the accumulator reaction pressure to the pump inlet to reduce a load on the hydraulic pump. 28. The method of claim 26, further comprising: opening the accumulator discharge valve at a time of high demand for hydraulic energy to release the predefined volume of fluid stored in the accumulator; and applying the accumulator reaction pressure to reduce a load on the hydraulic pump. 29. The method of claim 25, wherein the second load is a retraction load resulting from an action of gravity. 30. The method of claim 25, wherein the predefined volume of fluid is a full volume of fluid contained in the first chamber of the hydraulic cylinder at a fully extended position. 31. A method of intensifying energy in a hydraulic circuit for a work vehicle, the hydraulic circuit including a hydraulic cylinder to manipulate a load, the hydraulic cylinder having a first chamber and a second chamber, the hydraulic cylinder extending against a first load under an application of a first volume of fluid at a first pressure to the first chamber, the hydraulic cylinder retracting under a second load and an application of a second volume of fluid at a second pressure to the second chamber, a first chamber reaction pressure being produced in the first chamber when the cylinder rod is retracting, a hydraulic pump to displace the first volume of fluid at the first pressure and the second volume of fluid at the second pressure, the hydraulic pump having a pump inlet, at least one displacement control valve to direct the first volume of fluid to the first chamber and the second volume of fluid to the second chamber on demand, an accumulator capable of storing a predefined volume of fluid form the first chamber at an accumulator reaction pressure, an accumulator charge valve to allow the predefined volume of fluid to be stored in the accumulator, an accumulator discharge valve to allow the predefined volume of fluid to be released from the accumulator, the method comprising: pre-charging the accumulator to a pre-charge pressure that allows the pre-defined volume of fluid to be stored in the accumulator under the first chamber reaction pressure produced when the second hydraulic energy and the second load are applied; generating the second volume of fluid at the second pressure with the hydraulic pump; opening the at least one displacement control valve to the second chamber to direct the volume of fluid to the second chamber while closing the at least one displacement control valve to the first chamber to divert fluid flow from the first chamber to the accumulator charge valve; and opening the accumulator charge valve to allow the accumulator to store the pre-defined volume of fluid at the accumulator reaction pressure, the accumulator discharge valve being closed. 32. The method of claim 31, further comprising closing the accumulator charge valve after the pre-defined volume of fluid is stored in the accumulator. 33. The method of claim 32, further comprising: opening the accumulator discharge valve at a time of high demand for hydraulic energy to release the third hydraulic energy stored in the accumulator; and applying the accumulator reaction pressure to the pump inlet to reduce a load on the hydraulic pump. 34. The method of claim 31, wherein the second load is a retraction load resulting from an action of gravity. 35. The method of claim 31, wherein the predefined volume of fluid is a full volume of fluid contained in the first chamber of the hydraulic cylinder at a fully extended position.
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