CN-117108587-B - Buffer device of linear reciprocating motion type hydraulic cylinder

CN117108587BCN 117108587 BCN117108587 BCN 117108587BCN-117108587-B

Abstract

The invention discloses a buffer device of a linear reciprocating motion type hydraulic cylinder, which mainly comprises a one-way valve assembly, a hydraulic cylinder moving part, a cylinder sleeve and a piston cavity. According to the invention, the free movable sealing body in the check valve assembly is used as a control element to control the opening and closing of the check valve hydraulic fluid channel, so that the hydraulic flow area of the buffer device is variable, the impact of the hydraulic cylinder moving part at the movement end point is reduced, and the hydraulic cylinder moving part can reach the end point position in time. The opening and closing time of the hydraulic fluid channel of the check valve can be variable according to the moving speed of the hydraulic cylinder moving part and the flow speed of the fluid, and the check valve is simple in structure, so that the buffer requirement of the hydraulic cylinder moving part under variable working conditions can be met. The invention solves the problem of contradiction between the stopping lag of the hydraulic cylinder and the impact of the hydraulic cylinder in the prior art, and has important significance for improving the safety of the reciprocating type hydraulic cylinder.

Inventors

XIE ZONGFA
ZHANG XU

Assignees

山东大学

Dates

Publication Date: 20260505
Application Date: 20230815

Claims (8)

1. The damping device of the linear reciprocating type hydraulic cylinder is characterized by comprising a one-way valve assembly, a hydraulic cylinder moving part and a cylinder sleeve, wherein: The check valve assembly comprises a check valve seat, a check valve cover and a free movable sealing body, wherein a check valve hydraulic fluid channel is arranged on the check valve seat, and when the free movable sealing body is positioned on the check valve seat, the free movable sealing body and the check valve seat form a seal, and the check valve is closed at the moment; the cylinder sleeve is used for supporting and guiding the hydraulic cylinder moving part, and one end of the cylinder sleeve is connected with the one-way valve cover; When the hydraulic cylinder moving part moves to approach the one-way valve assembly, the free movable sealing body is pushed to move towards the one-way valve seat, so that the minimum flow area of the reverse taper formed between the one-way valve seat and the free movable sealing body is smaller than the area of a hydraulic fluid passage of the one-way valve; the cylinder sleeve, the end face of the hydraulic cylinder moving part and the one-way valve cover form a hydraulic cavity of the hydraulic cylinder moving part, and a bypass channel communicated with the hydraulic cavity is arranged on the cylinder sleeve; the center of the hydraulic cylinder moving part, which is close to one side end part of the one-way valve assembly, is provided with a pit structure, and the shape of the pit structure is matched with the shape of the surface of the free movable sealing body; The central circular pit structure is arranged on the protrusion with a certain height.
2. The buffer device of the linear reciprocating hydraulic cylinder according to claim 1, wherein the area of the reverse-cone-shaped minimum flow passage is larger than that of the hydraulic fluid passage of the check valve, L is the distance from the free movable sealing body to the check valve seat, R is the radius of the hydraulic fluid passage of the check valve, and R is the radius of the free movable sealing body.
3. The damping device for a linear reciprocating cylinder as claimed in claim 1, wherein a spring is provided between the free movable sealing body and the check valve seat in the check valve assembly.
4. The damping device of a linear reciprocating cylinder according to claim 1, wherein the bypass passage is one or more, and the flow area of the bypass passage is fixed or variable.
5. The buffering mechanism of linear reciprocating cylinder as claimed in claim 4, wherein the variable throttle passage is formed by a U-shaped bypass passage formed in the cylinder liner, and the U-shaped groove in the side of the cylinder liner is gradually covered or gradually opened in response to the movement of the cylinder moving member.
6. The cushioning device of a linear reciprocating cylinder of claim 1, wherein the freely movable seal in the check valve assembly is a body of revolution.
7. The buffer device of the linear reciprocating hydraulic cylinder according to claim 1, wherein a countersunk through hole matched with the free movable sealing body is arranged at the center of the one-way valve cover, the diameter of the through hole is smaller than that of the free movable sealing body, and the diameter of the countersunk hole is larger than that of the free movable sealing body.
8. The buffering mechanism of a linear reciprocating cylinder as claimed in claim 1, wherein the cylinder moving member has a hollow structure inside.

Description

Buffer device of linear reciprocating motion type hydraulic cylinder Technical Field The invention relates to an actuating element hydraulic cylinder in a hydraulic transmission system, in particular to a hydraulic buffer device with a variable hydraulic flow area for a linear reciprocating type hydraulic cylinder. Background In the hydraulic system, a hydraulic cylinder is used as an actuating element to drive a mechanism with a certain mass, and when a hydraulic cylinder moving part (a hydraulic piston or a hydraulic plunger) moves to the end of a stroke, the hydraulic cylinder moving part has larger kinetic energy, if no deceleration treatment is performed, the hydraulic cylinder moving part and a cylinder cover are in mechanical collision, so that impact and noise are generated, and the hydraulic system is destructive. In order to alleviate and prevent such damage, it is necessary to provide a damper in the hydraulic circuit or to provide a damper in the cylinder. The traditional hydraulic buffer device adopts a method for installing a unidirectional damping hole at the movement end position of a hydraulic cylinder. The method has certain disadvantages that the damping action always exists in the reverse movement process of the linear reciprocating type hydraulic cylinder, the time of the damping action cannot be changed, so that when the damping action is strong, the whole movement process of the piston or the plunger is slow, the temperature of oil liquid is increased, the hydraulic cylinder stops, hysteresis exists, when the damping is weak, the piston or the plunger rapidly moves to generate impact, the hydraulic cylinder stops, hysteresis and hydraulic cylinder impact are contradictory, and the problems of high energy consumption, hydraulic cylinder stop hysteresis, hydraulic cylinder impact and the like exist by adopting the method. An actuator with a seating buffer structure and a hydraulic full-variable valve mechanism are disclosed in Chinese patent No. 217950485U, and the mechanism can reduce the impact of a valve on an engine by utilizing a one-way valve, a buffer conical surface of a piston top section and a side wall oil hole on a piston sleeve to control the speed of a valve moving end section in a matching way. The check valve of the mechanism controls the opening and closing by driving the movable steel ball through oil, and the steel ball in the check valve of the mechanism is close to the oil passage of the check valve, so that the reverse taper area formed by the steel ball and the oil passage of the check valve is smaller than the area of the oil passage of the check valve, thereby forming throttling. In the process of engine valve seating, the steel ball can be adsorbed to the one-way valve oil duct to enable the one-way valve to be in a closed state in the whole process of engine valve seating, oil in the piston cavity can only flow out through the side wall oil hole, at the moment, the valve can be subjected to a certain damping effect, the tail end of the valve is subjected to the damping effect again due to the shielding of the side wall oil hole, the problem that the valve is delayed when the moving speed is slower can be caused, meanwhile, the temperature of the oil can be increased due to the fact that throttling always exists, in the process of engine valve opening, the mechanism oil can be subjected to the throttling effect to reduce the valve opening speed when flowing into the piston cavity through the one-way valve oil duct, the oil temperature is increased and the like. Disclosure of Invention The invention provides a hydraulic buffer device with a variable flow area, which aims at the existing technical problem of a buffer device of a linear reciprocating type hydraulic cylinder, so as to reduce the impact of a hydraulic cylinder moving part at the moving end and enable the hydraulic cylinder moving part to reach the end position in time. The damping device is mainly characterized in that the minimum flow area of the check valve of the damping device is controlled by the hydraulic cylinder moving part, so that the opening and closing time of the check valve can be changed according to the moving speed of the hydraulic cylinder moving part and the flow speed of fluid, and the damping device is simple in structure, can meet the damping requirement of the hydraulic cylinder moving part under variable working conditions, and can avoid the problem that the hydraulic cylinder stops lagging and the hydraulic cylinder impacts contradict each other. The invention discloses a buffer device of a linear reciprocating motion type hydraulic cylinder, which comprises a one-way valve assembly, a hydraulic cylinder moving part, a cylinder sleeve and a hydraulic cavity, wherein: The check valve assembly comprises a check valve seat, a check valve cover and a free movable sealing body, wherein a check valve hydraulic fluid channel is arranged on the check valve seat, and when the free mo