A hydraulic cylinder with adjustable limit position and limit position adjustment method

Abstract

The present application relates to a hydraulic cylinder with adjustable extreme position and a method for adjusting the extreme position, the hydraulic cylinder comprising: a cylinder body; a piston and a piston rod, the piston being arranged in the cylinder body; a position piston forming a position control chamber; a position adjustment mechanism connected to the position control chamber and used to flow oil into or out of the position control chamber to adjust the position of the position piston. The above-mentioned hydraulic cylinder with adjustable extreme position and the method for adjusting the extreme position are provided with a position piston and a position control chamber in the cylinder body, the position of the position piston being the extreme position of the piston stroke, and the position of the position piston being adjusted by flowing oil into or out of the position control chamber. When the hydraulic cylinder is working normally, the position of the position piston can be maintained because the position control chamber is filled with oil and is in a closed state.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic equipment, in particular to a hydraulic cylinder with adjustable extreme position and an extreme position adjustment method. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] For hydraulically driven press assemblies and stackers, when press-fitting different parts or stacking shelves at different heights, the limit position of the hydraulic cylinder needs to be adjustable to facilitate fixed-stroke operations each time the hydraulic cylinder reaches the end.

[0004] At present, after the mechanical design of the hydraulic cylinder of the hydraulic system is determined, the limit position of the hydraulic cylinder cannot be adjusted. For applications that require the hydraulic cylinder to repeatedly stay at a precise position, it is necessary to use a screw limit mechanism or add a displacement sensor and an electronic control system to achieve it. The first method is cumbersome to operate, and the size of the double-rod structure of the hydraulic cylinder needs to be doubled, and the stroke adjustment is manual; the second method requires the cost of increasing the displacement sensor and controller, which lacks economic efficiency. Summary of the invention

[0005] In view of the above, it is necessary to provide a hydraulic cylinder with adjustable limit position and a limit position adjustment method to facilitate adjustment of the limit position of the hydraulic cylinder.

[0006] A hydraulic cylinder with adjustable limit position, comprising:

[0007] The cylinder body includes a cavity;

[0008] A piston and a piston rod, wherein the piston is disposed in the cavity of the cylinder body and divides the cavity into a positive cavity and a negative cavity, one end of the piston rod is connected to the piston, and the other end passes through the negative cavity and extends out of the cylinder body;

[0009] A position piston is disposed in the cavity, and a position control cavity is formed between the position piston and the cavity;

[0010] The position adjustment mechanism is connected to the position control chamber and is used to flow oil into or out of the position control chamber to adjust the position of the position piston.

[0011] Preferably, the position adjustment mechanism comprises a variable-volume adjuster connected to the position control chamber and configured to allow oil to flow into or out of between the adjuster and the position control chamber to adjust the position of the position piston.

[0012] Preferably, the position adjustment mechanism includes a position control switch, which is connected to the position control chamber. When the position control switch is in a closed state, the position control chamber is filled with oil to maintain the position of the position piston; when the position control switch is in an open state, the oil flows into or out of the position control chamber through the position control switch to adjust the position of the position piston.

[0013] Preferably, the position control switch is a switch valve, and the position control chamber is connected to the positive chamber or the negative chamber through the switch valve, so that the oil flows into or flows out of the positive chamber or the negative chamber.

[0014] Preferably, it also includes:

[0015] An oil pump mechanism, used for pumping oil from an output end, wherein the output end is connected to the position control chamber via the position control switch, so that the oil flows between the oil pump mechanism and the position control chamber to adjust the position of the position piston;

[0016] A reversing valve connected to the reverse chamber of the cylinder;

[0017] The hydraulic lock has an input end connected to the output end of the reversing valve, an output end connected to the positive cavity of the cylinder body, and a control end connected to the negative cavity of the cylinder body.

[0018] Preferably, the position control switch is a switch valve, the position control chamber is connected to the oil pump mechanism via the switch valve, and oil flows in or out between the oil pump mechanism and the position control chamber.

[0019] Preferably, it further comprises a pressure sensor, which is connected to the oil pump mechanism and is used to detect the oil pressure at the output end of the oil pump mechanism.

[0020] A method for adjusting the limit position of a hydraulic cylinder with adjustable limit position comprises the following steps:

[0021] When the position control chamber is in a closed state, the position control chamber is filled with oil to maintain the position of the position piston;

[0022] The position adjustment mechanism flows oil into or out of the position control chamber to adjust the position of the position piston.

[0023] Preferably, the position adjustment mechanism flows oil into or out of the position control chamber to adjust the position of the position piston, including:

[0024] The oil is pumped into the cylinder so that the piston moves in a direction close to the position piston until the oil in the oil pump mechanism is greater than a preset value, and the position adjustment mechanism opens so that the oil in the position control chamber flows out;

[0025] When the piston pushes the position piston to move to a preset position, the position adjustment mechanism is closed to keep the position piston at the preset position.

[0026] Preferably, the position adjustment mechanism flows oil into or out of the position control chamber to adjust the position of the position piston and further comprises:

[0027] When the oil is pumped into the cylinder body so that the piston moves to a preset position, the cylinder body is closed so that the piston remains at the preset position;

[0028] Filling the position control chamber with oil so that the position piston moves in a direction close to the piston, and when the piston blocks the position piston, the oil pressure of the oil pump mechanism increases;

[0029] When the oil pressure of the oil pump mechanism is greater than a preset value, it is determined that the position piston moves to the preset position, and the position adjustment mechanism is closed to keep the position piston at the preset position.

[0030] Compared with the prior art, the above-mentioned hydraulic cylinder with adjustable limit position and limit position adjustment method are provided with a position piston and a position control chamber in the cylinder body, the position of the position piston is the limit position of the piston stroke, and the position of the position piston is adjusted by flowing oil into or out of the position control chamber. When the hydraulic cylinder is working normally, the position of the position piston can be maintained because the position control chamber is filled with oil and is in a closed state. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0032] Figure 1 It is a schematic structural diagram of a hydraulic cylinder with adjustable limit position in a first embodiment.

[0033] Figure 2 It is a schematic structural diagram of a hydraulic cylinder with adjustable limit position in a second embodiment.

[0034] Figure 3 It is a schematic structural diagram of a hydraulic cylinder with adjustable limit position in a third embodiment.

[0035] Figure 4 It is a flow chart of a method for adjusting the limit position of a hydraulic cylinder with adjustable limit position.

[0036] Main component symbols

[0037]

[0038]

[0039] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0040] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention, and the embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present invention.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0042] In the various embodiments of the present invention, for the convenience of description and not to limit the present invention, the term "connection" used in the patent application specification and claims of the present invention is not limited to physical or mechanical connection, but may include electrical connection, whether direct or indirect. "Up", "down", "below", "left", "right", etc. are only used to indicate relative position relationship. When the absolute position of the described object changes, the relative position relationship also changes accordingly.

[0043] First embodiment

[0044] Figure 1 Schematic diagram of the structure of the hydraulic cylinder with adjustable limit position in the first embodiment. Figure 1 As shown, the hydraulic cylinder with adjustable limit position includes a cylinder body 10, a piston 20 and a piston rod 21, a position piston 30 and a position adjustment mechanism 40. The position piston 30 is arranged in the cylinder body 10 to limit the stroke of the piston 20, and the position adjustment mechanism 40 is used to adjust the position of the position piston 30, so that the limit position of the piston 20 can be changed.

[0045] The cylinder body 10 is generally cylindrical, and has a cavity (i.e., piston 20 cavity) for accommodating the piston 20 and the piston rod 21. In addition, the cylinder body 10 is also provided with an interface (not shown in the figure) for connecting an oil pipe, which is used to fill the cavity of the cylinder body 10 with oil or discharge the oil from the cavity of the cylinder body 10, so as to control the extension or retraction of the piston rod 21. The piston 20 and the piston rod 21, the piston 20 is arranged in the cavity of the cylinder body 10, and the cavity is divided into a positive cavity 11 and a negative cavity 12, one end of the piston rod 21 is connected to the piston 20, and the other end passes through the negative cavity 12 and extends from the cylinder body 10.

[0046] The position piston 30 is disposed in the cavity, and a position control cavity 13 is formed between the position piston 30 and the side wall of the cavity. Specifically, the position piston 30 can be disposed in the positive cavity 11 or the negative cavity 12 of the cylinder body 10. As an example, Figure 1 In the illustrated embodiment, the position piston 30 is located in the counter chamber 12 of the cylinder 10 , so that the limit position of the right stroke of the piston 20 can be limited.

[0047] The position adjustment mechanism 40 is connected to the position control chamber 13, and is used to flow oil into or out of the position control chamber 13 to adjust the position of the position piston 30. In this embodiment, the position adjustment mechanism 40 includes a variable volume adjuster 41, and the adjuster 41 is connected to the position control chamber 13, and is used to flow oil into or out between the adjuster 41 and the position control chamber 13 to adjust the position of the position piston 30.

[0048] In this embodiment, the above-mentioned adjuster 41 can also be a container connected to the position control chamber 13, and a movable adjustment plate 411 is arranged in the container, and the volume is adjusted by moving the adjustment plate 411. When the hydraulic cylinder is in normal working state, the total volume of the adjuster 41 and the position control chamber 13 remains unchanged and is filled with oil, so that the position piston 30 remains unchanged under the pressure of the oil, and even if the oil pressure in the counter chamber 12 fluctuates during the movement of the piston 20, the position piston 30 will remain constant under the action of the oil (the elastic deformation of the oil has a slight movement that can be ignored). When it is necessary to adjust the extreme position to the left, that is, to shorten the stroke position of the piston 20, the adjustment plate 411 is moved to reduce the volume of the chamber connected to the position controller, and the oil flows from the adjuster 41 into the position control chamber 13 to push the position piston 30 to move to the left, thereby achieving the purpose of adjusting the extreme position to the left. When it is necessary to extend the limit position, that is, to move the position piston 30 to the right, the adjustment plate 411 is moved to expand the volume of the cavity connected to the position controller, so that the oil in the position control cavity 13 flows back to the adjuster 41, thereby moving the position piston 30 to the right, thereby achieving the purpose of adjusting the limit position to the right.

[0049] Those skilled in the art understand that the adjuster 41 may also be other types of structures that can change the volume, such as a deformable plastic bag. The adjuster 41 is connected to the position control cavity 13, and the volume of the adjuster 41 is changed by shrinking or expanding.

[0050] Second embodiment

[0051] Figure 2 Schematic diagram of the structure of the hydraulic cylinder with adjustable limit position in the second embodiment. Figure 2 As shown, the position adjustment mechanism 40 includes a position control switch 42, which is connected to the position control chamber 13, so that the oil in the position control chamber 13 can be discharged through the position control switch 42, thereby adjusting the position of the position piston 30 and changing the limit position of the piston 20. As an example, the position control switch 42 can be a valve switch, which is used to open or close the position control chamber 13 to discharge the oil.

[0052] When the hydraulic cylinder is in normal use, the position control switch 42 is in the closed state, and the position control chamber 13 is filled with oil, so that the position piston 30 is kept under the pressure of the oil. When the position of the position piston 30 needs to be adjusted, the oil in the position control chamber 13 can be discharged when the position control switch 42 is turned on, so that the position piston 30 can move to the right to extend the stroke of the piston 20, and the adjustment of the limit position is completed. In addition, the position control switch 42 can also be used to inject oil into the position control chamber 13 through the position controller, so that the position piston 30 moves to the left to shorten the stroke of the piston 20, and the adjustment of the limit position is completed.

[0053] As a preference, Figure 2 In the illustrated embodiment, one end of the position control switch 42 is connected to the position control chamber 13, and the other end is connected to the positive chamber 11 of the hydraulic cylinder. When the position control switch 42 is in the closed state, the positive chamber 11 and the position control chamber 13 are isolated from each other, and the position piston 30 is kept in a fixed position by the oil of the position controller and does not move.

[0054] When the extreme position needs to be adjusted, the position control switch 42 is turned on, and the oil flows into or out of the position control chamber 13 through the position control switch 42 to adjust the position of the position piston 30. Specifically, the position control switch 42 is turned on, and the oil is rushed into the reverse chamber 12, so that the oil in the positive chamber 11 flows into the position control chamber 13 through the position control switch 42, thereby pushing the position piston 30 to move in the direction close to the piston 20, that is, adjusting the position piston 30 to the left, and completing the operation of adjusting the extreme position to the left. Similarly, the position control switch 42 is turned on, and the oil is rushed into the positive chamber 11, so that after the oil in the reverse chamber 12 is discharged, the piston 20 contacts the position piston 30 and pushes the position piston 30 to move to the right, and the oil in the position control chamber 13 flows into the positive chamber 11 through the position control switch 42, and the position piston 30 is adjusted to the right, that is, the operation of adjusting the extreme position to the right is completed.

[0055] Third embodiment

[0056] Figure 3 Schematic diagram of the structure of the hydraulic cylinder with adjustable limit position in the third embodiment. Figure 3 As shown, the hydraulic cylinder includes a cylinder body 10, a piston 20 and a piston rod 21, a position piston 30 and a position adjustment mechanism 40. The position piston 30 is arranged in the cylinder body 10 to limit the stroke of the piston 20, and the position adjustment mechanism 40 is used to adjust the position of the position piston 30, so that the limit position of the piston 20 can be changed.

[0057] In addition, the hydraulic cylinder also includes an oil pump mechanism 50, a reversing valve 60, a hydraulic lock 70 and a pressure sensor. The oil pump mechanism 50 includes a motor pump 51, a speed regulating valve 53, a relief valve 54 and an oil tank 52. The motor pump 51 is connected to the oil tank 52 for pumping out oil. One end of the relief valve 54 is connected to the output end of the motor pump 51, and the other end is connected to the oil tank 52. When the oil pressure of the oil pump mechanism 50 exceeds a preset value, the oil pump mechanism 50 enters an overflow state, that is, the relief valve 54 is turned on to unload the hydraulic pressure of the oil pump mechanism. The output end of the motor pump 5 is connected to the position control chamber 13 through the position control switch 42, so that the oil flows between the oil pump mechanism 50 and the position control chamber 13 to adjust the position of the position piston 30. The reversing valve 60 connects the reverse chamber 12 of the cylinder 10 and the oil pump mechanism 50, so that the oil output by the oil pump mechanism 50 can enter the reverse chamber 12 through the reversing valve 60, or the oil discharged from the reverse chamber 12 can flow back to the oil pump mechanism 50 through the reversing valve 60. In this embodiment, the reversing valve 60 is connected to the oil tank 52 through the speed regulating valve 53. The input end of the hydraulic lock 70 is connected to the output end of the reversing valve 60, the output end is connected to the positive chamber 11 of the cylinder 10, and the control end is connected to the reverse chamber 12 of the cylinder 10. When the oil pressure of the reverse chamber 12 exceeds a preset value, the hydraulic lock 70 is opened so that the oil can flow in the reverse direction, that is, from the input end to the output end of the hydraulic lock 70. The pressure sensor is connected to the oil pump mechanism 50, and is used to detect the oil pressure at the output end of the oil pump mechanism 50.

[0058] In this embodiment, the position control switch 42 includes a switch valve, the position control chamber 13 is connected to the oil pump mechanism 50 via the switch valve, and oil flows in or out between the oil pump mechanism 50 and the position control chamber 13 .

[0059] The following combination Figure 4 The method for adjusting the limit position of the hydraulic cylinder provided in this embodiment is described in detail. The method for adjusting the limit position of the hydraulic cylinder comprises steps S401 to

[0060] Step S401 : when the position control chamber 13 is in a closed state, the position control chamber 13 is filled with oil to maintain the position of the position piston 30 .

[0061] In this embodiment, the position piston 30 can be controlled to move to the left to reduce the stroke of the piston 20, or the position piston 30 can be controlled to move to the right to expand the stroke of the piston 20. Among them, steps S402 to S405 are to adjust the movement of the position piston 30 to increase the stroke of the piston 20, that is, to adjust the position piston 30 to move to the right to adjust the limit position. Steps S406 to S409 are to adjust the movement of the position piston 30 to reduce the stroke of the piston 20, that is, to control the position piston 30 to move to the left to adjust the limit position.

[0062] When it is necessary to control the position piston 30 to move leftward to reduce the stroke of the piston 20, steps S402 to S405 are executed.

[0063] Step S402: When the oil is pumped into the cylinder 10 so that the piston 20 moves to the preset position, the oil in the positive cavity 11 cannot be discharged through the hydraulic lock 70, thereby closing the positive cavity 11 of the cylinder 10 and keeping the piston 20 at the preset position.

[0064] Step S403 : opening the switch valve to fill the position control chamber 13 with oil, so that the position piston 30 moves in a direction close to the piston 20 .

[0065] Step S404: When the position piston 30 contacts the piston 20, the movement of the position piston 30 is blocked by the piston 20, so that the oil pressure of the oil pump mechanism 50 increases;

[0066] Step S405: When the oil pressure of the oil pump mechanism 50 is greater than the preset value, it indicates that the position piston 30 has moved to the preset position, and it is determined that the position piston 30 has moved to the preset position, and the operation of moving the position piston 30 to the left to the extreme position is completed, and the position adjustment mechanism 40 is closed to keep the position piston 30 at the preset position.

[0067] When it is necessary to control the position piston 30 to move rightward to increase the stroke of the piston 20, steps S406 to S409 are executed.

[0068] Step S406 : the switch valve is closed, and the oil pump mechanism 50 pumps oil into the positive cavity 11 of the cylinder body 10 to move the piston 20 in a direction close to the position piston 30 until the piston 20 is close to the position piston 30 .

[0069] Step S407: Since the position piston 30 blocks the movement of the piston 20, the pressure of the oil pump mechanism 50 increases, and the oil pump mechanism 50 enters an overflow state;

[0070] Step S408: when the pressure sensor detects that the oil pump mechanism 50 is in an overflow state (i.e., the oil pressure exceeds a preset value), the switch valve is opened so that the oil in the position control chamber 13 can be discharged through the switch valve;

[0071] Step S409 : the oil pump mechanism 50 drives the piston 20 to push the position piston 30 to move to a preset position. After the extreme position adjustment of the position piston 30 is completed, the switch valve is closed to maintain the position of the position piston 30 .

[0072] The above-mentioned hydraulic cylinder with adjustable limit position and limit position adjustment method are provided with a position piston 30 and a position control chamber 13 in the cylinder body 10. The position of the position piston 30 is the limit position of the stroke of the piston 20. The position of the position piston 30 is adjusted by flowing oil into or out of the position control chamber 13. When the hydraulic cylinder is working normally, the position of the position piston 30 can be maintained because the position control chamber 13 is filled with oil and is in a closed state.

[0073] In several specific embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "including" does not exclude other units or steps, and the singular does not exclude the plural. The words first, second, etc. are used to indicate names, and do not indicate any specific order.

[0074] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for adjusting the limit position of a hydraulic cylinder with adjustable limit position, characterized in that the hydraulic cylinder include: The cylinder body includes a cavity; A piston and a piston rod, wherein the piston is arranged in the cavity of the cylinder body, dividing the cavity into a positive cavity and a negative cavity, one end of the piston rod is connected to the piston, and the other end passes through the negative cavity and extends out of the cylinder body; A position piston is disposed in the cavity, and a position control cavity is formed between the position piston and the side wall of the cavity; A position adjustment mechanism is connected to the position control chamber and is used to flow oil into or out of the position control chamber to adjust the position of the position piston; An oil pump mechanism is used to pump oil from an output end, and the output end is connected to the position control cavity through a position adjustment mechanism, so that the oil flows between the oil pump mechanism and the position control cavity to adjust the position of the position piston; The reversing valve is connected to the reverse chamber of the cylinder; A hydraulic lock, the input end of which is connected to the output end of the reversing valve, the output end of which is connected to the positive cavity of the cylinder body, and the control end of which is connected to the negative cavity of the cylinder body; The limit position adjustment method includes the following steps: When the position control chamber is in a closed state, the position control chamber is filled with oil to maintain the position of the position piston; The position adjustment mechanism flows oil into or out of the position control chamber to adjust the position of the position piston: The oil is pumped into the cylinder body so that the piston moves in a direction close to the position piston until the oil pressure value of the oil pumped out from the output end of the oil pump mechanism is greater than a first preset value, and the position adjustment mechanism opens so that the oil in the position control chamber flows out; When the piston pushes the position piston to move to the first preset position, the position adjustment mechanism is closed to keep the position piston at the first preset position, and the first preset position is the first preset position to which the position piston moves under the push of the piston; When the oil is pumped into the cylinder body so that the piston moves to the second preset position, the cylinder body is closed so that the piston remains at the second preset position; Filling the position control chamber with oil causes the position piston to move in a direction close to the piston, and when the piston blocks the position piston, the oil pressure of the oil pumped out from the output end of the oil pump mechanism increases; When the oil pressure value of the oil pumped out from the output end of the oil pump mechanism is greater than a second preset value, it is determined that the position piston moves to the target position, and the position adjustment mechanism is closed to keep the position piston at the target position.

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