CN-122029363-A - Hydraulic drive system and multi-control valve

CN122029363ACN 122029363 ACN122029363 ACN 122029363ACN-122029363-A

Abstract

The hydraulic drive system includes a first hydraulic pump that discharges a working fluid to a first passage portion of a first pump passage, a second hydraulic pump that discharges the working fluid to a second passage portion of the first pump passage, a main control valve that includes a first valve block having the first passage portion, a plurality of main valves, and an additional valve that includes a second valve block having the second passage portion and provided to the first valve block, and an additional valve inserted into the second valve block, the plurality of main valves including a first main valve that controls a flow of the working fluid supplied from the first passage portion to the first hydraulic actuator by performing a stroke, and the additional valve that controls the flow of the working fluid supplied from the second passage portion to the first hydraulic actuator by performing a stroke so as to merge with the working fluid supplied from the first passage portion to the first hydraulic actuator via the first main valve.

Inventors

Chuan Shangliao
SAKAMOTO JUNICHI

Assignees

川崎重工业株式会社

Dates

Publication Date: 20260512
Application Date: 20240326
Priority Date: 20230810

Claims (8)

1. A hydraulic drive system is characterized in that, The hydraulic drive system is configured to supply a working fluid to each of a plurality of hydraulic actuators including a first hydraulic actuator, and to control the flow of the supplied working fluid, and includes: a first hydraulic pump that discharges a working fluid to a first passage portion of a first pump passage; A second hydraulic pump that discharges a working fluid to a second passage portion of the first pump passage; A main control valve including a first valve block having the first passage portion, and a plurality of main valve bodies respectively inserted into the first valve block in correspondence with each of the hydraulic actuators and controlling flow of the working fluid supplied from the first passage portion to the corresponding hydraulic actuator by performing a stroke, and An additional valve including a second valve block having the second passage portion and provided to the first valve block, and an additional valve body inserted into the second valve block, The plurality of main valve bodies include a first main valve body that controls a flow of the working fluid supplied from the first passage portion to the first hydraulic actuator by performing a stroke, The additional valve body controls the flow of the hydraulic fluid supplied from the second passage portion to the first hydraulic actuator by performing a stroke, and merges the hydraulic fluid supplied from the first passage portion to the first hydraulic actuator through the first main valve body.
2. The hydraulic drive system according to claim 1, wherein, And a third hydraulic pump that discharges the working fluid to the second pump passage, The first valve block also has the second pump passage, The plurality of main valve bodies have a second main valve body inserted through the first valve block, The second main valve body is stroked to control the flow of the working fluid supplied from the second pump passage to the first hydraulic actuator, and to merge with the working fluid supplied from the first passage portion to the first hydraulic actuator.
3. The hydraulic drive system according to claim 1, wherein, The main control valve further comprises an unloading valve, The first valve block has a tank passage formed therein in communication with a tank, The unloading valve communicates the first passage portion with the tank passage according to an input signal.
4. The hydraulic drive system according to claim 1, wherein, The second valve block comprises a first block body inserted with a first additional valve body as the additional valve body and a second block body arranged on the first block body, The additional valve further comprises a second additional valve body inserted through the second block, The second passage portion extends in the first block and the second block, The second additional valve body controls the flow of the working fluid supplied from the second passage portion to the second hydraulic actuator that is one of the plurality of hydraulic actuators by performing a stroke.
5. The hydraulic drive system according to claim 1, wherein, The first valve block and the second valve block are laminated in a predetermined direction, The first pump passage extends in a predetermined direction in the first valve block and the second valve block, The first hydraulic pump is connected to the first passage portion located on one side of the first pump passage in a predetermined direction, The second hydraulic pump is connected to the second passage portion located on the other side of the first pump passage in the predetermined direction.
6. The hydraulic drive system according to claim 1, wherein, Further comprising a control device for controlling the operation of the first main valve body and the additional valve body, The control device calculates the opening degrees of the first main valve body and the additional valve body from the supply flow rate of the working fluid to be supplied to the first hydraulic actuator calculated based on the input command, and controls the operations of the first main valve body and the additional valve body based on the calculated opening degrees.
7. The hydraulic drive system according to claim 6, wherein, The first hydraulic pump changes the discharge capacity according to the first capacity signal, The second hydraulic pump changes the discharge capacity according to the second capacity signal, The control device outputs a first displacement signal and a second displacement signal based on a supply flow rate calculated based on an input command, and controls discharge capacities of the first hydraulic pump and the second hydraulic pump.
8. A multi-control valve is characterized in that, A multi-control valve for controlling the flow of a working fluid supplied to each of a plurality of hydraulic actuators including a first hydraulic actuator, the multi-control valve comprising: A main control valve including a first valve block having a first passage portion of a first pump passage and having a first hydraulic pump connected to the first passage portion, and a plurality of main valve bodies respectively inserted into the first valve block in correspondence with each of the hydraulic actuators and controlling flow of a working fluid supplied from the first passage portion to the corresponding hydraulic actuator by performing a stroke, and An additional valve including a second valve block having a second passage portion of the first pump passage and connected to the second passage portion, and an additional valve body inserted into the second valve block and provided to the first valve block, The plurality of main valve bodies include a first main valve body that controls a flow of the working fluid supplied from the first passage portion to the first hydraulic actuator by performing a stroke, The additional valve body controls the flow of the hydraulic fluid supplied from the second passage portion to the first hydraulic actuator by performing a stroke, and merges the hydraulic fluid supplied from the first passage portion to the first hydraulic actuator through the first main valve body.

Description

Hydraulic drive system and multi-control valve Technical Field The present disclosure relates to a hydraulic drive system and a multi-control valve that control a flow of a working fluid supplied to each of a plurality of hydraulic actuators. Background Hydraulic vehicles such as industrial vehicles and construction vehicles are provided with various actuators. The hydraulic vehicle performs various operations by operating various actuators. In such a hydraulic vehicle, a hydraulic drive system is equipped. The hydraulic drive system supplies the hydraulic fluid discharged from the hydraulic pump to each hydraulic actuator, and drives each hydraulic actuator. The hydraulic drive system controls the flow of the supplied hydraulic fluid to control the operation of each hydraulic actuator. As an example of the hydraulic drive system, a fluid pressure control device of patent document 1 is known, for example. In the fluid pressure control device of patent document 1, a plurality of spools are connected in parallel to a pump passage to which a first hydraulic pump is connected. The valve body is stroked (stroked) to control the flow of the hydraulic fluid supplied to each hydraulic actuator. Prior art literature: Patent literature: patent document 1, japanese patent laid-open No. 2015-78748. Disclosure of Invention Problems to be solved by the invention: The larger the size of the hydraulic vehicle, the larger the flow rate of the hydraulic fluid (i.e., the required flow rate) required to drive the hydraulic actuator (e.g., the boom cylinder of the excavator) becomes. Here, in the fluid pressure control device of patent document 1, the other hydraulic pump is further connected to the first pump passage. Thus, it is considered that the two hydraulic pumps discharge the hydraulic fluid at the required flow rate to the first pump passage. At this time, however, the required flow rate may exceed the rated flow rate of the original spool. Therefore, in order to increase the rated flow rate, the valve element (i.e., the valve body) needs to be enlarged. Accordingly, an object of the present disclosure is to provide a hydraulic drive system and a multi-control valve capable of suppressing the flow rate of a working fluid flowing to a valve body. Means for solving the problems: The hydraulic drive system of the present disclosure is a hydraulic drive system that supplies a working fluid to each of a plurality of hydraulic actuators including a first hydraulic actuator, and controls the flow of the supplied working fluid, and includes a first hydraulic pump that discharges the working fluid to a first passage portion of a first pump passage, a second hydraulic pump that discharges the working fluid to a second passage portion of the first pump passage, a main control valve that includes a first valve block having the first passage portion, and a plurality of main valve bodies that are respectively inserted in the first valve block in correspondence with each of the hydraulic actuators and that control the flow of the working fluid supplied from the first passage portion to the corresponding hydraulic actuator by performing a stroke, and an additional valve that includes a second valve block having the second passage portion and provided to the first valve block, and an additional valve body that is inserted in the second valve block, the plurality of main valve bodies including a main valve body that controls the flow of the working fluid supplied from the first passage portion to the first hydraulic actuator by performing a stroke, and the additional valve bodies that control the flow of the working fluid from the first passage portion to the first hydraulic actuator by the first passage portion. According to the present disclosure, the additional valve includes a second valve block having a second passage portion of a first pump passage and a second hydraulic pump connected to the second passage portion, and an additional valve body inserted through the second valve block. The additional valve body is controlled to be joined to the hydraulic fluid supplied from the first passage portion to the first hydraulic actuator by performing a stroke to control the hydraulic fluid supplied from the second passage portion to the first hydraulic actuator. Such additional valve is provided to the first valve block. Thus, the hydraulic fluid discharged from the first hydraulic pump can be supplied to the first hydraulic actuator via the first main valve body, and the hydraulic fluid discharged from the second hydraulic pump can be supplied to the first hydraulic actuator via the additional valve body. That is, since the working fluid can be supplied from the two valve bodies to the first hydraulic actuator, the flow rate of the working fluid supplied to each valve body can be suppressed. This can suppress enlargement of each valve element. Further, since the two hydraulic pumps share the first pump passage, an increase in the number