Non-linear hydraulic buffer structure for eliminating oil cylinder descending bottom impact and oil cylinder

Abstract

The utility model provides a non-linear hydraulic buffer structure for eliminating oil cylinder descending bottom impact, which relates to an oil cylinder and comprises a buffer piston arranged in the oil cylinder and a buffer plunger coaxially pressed with the bottom of the oil cylinder into a whole, an oil duct is arranged in the buffer plunger, and the section of the buffer plunger is a streamline variable section. And the buffer plunger enters the cavity of the buffer piston to form multi-section buffer. The utility model further provides the oil cylinder which comprises the nonlinear hydraulic buffering structure for eliminating the impact of the descending bottom of the oil cylinder. The buffer plunger with the oil duct inside is arranged, the cavity correspondingly matched with the buffer plunger is arranged in the buffer plunger, and the buffer plunger is in a streamline variable cross-section design, so that a buffer curve is smoother, multi-section speed reduction is realized in the whole buffer process, the abrupt feeling is eliminated, the buffer process tends to be gentle, internal oil pressure is balanced, and the service life of the buffer plunger is prolonged. And the impact of parts of the oil cylinder is reduced to the minimum, and the service life of the oil cylinder is effectively prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of oil cylinders, in particular to a nonlinear hydraulic buffer structure and an oil cylinder for eliminating the impact of the bottom of the oil cylinder when it is descending. Background Art

[0002] The oil cylinder is the actuator of the hydraulic system, and its function is to convert fluid energy into mechanical energy. When the oil cylinder runs to the lower limit, the piston or piston rod of the oil cylinder will impact the bottom of the cylinder. Especially for some high-speed and heavy-loaded oil cylinders, the impact on the bottom is huge, which seriously affects the life of the oil cylinder and the stability of the hydraulic system. Therefore, it is necessary to set a buffer device in the oil cylinder to reduce the impact. The general buffer device will cause the size of the oil cylinder to be increased due to its structure, which is not economical and also brings difficulties to installation. Utility Model Content

[0003] In order to solve the above problems, the utility model aims to propose a nonlinear hydraulic buffer structure and a cylinder that eliminates the impact on the bottom of the cylinder when it is downward, while not increasing the size of the cylinder, avoiding the impact on the bottom of the cylinder when the cylinder runs to the lower limit, avoiding the vibration caused by strong impact, and ensuring the smooth operation of the hydraulic cylinder and the entire hydraulic system.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] A nonlinear hydraulic buffer structure for eliminating the impact on the bottom of an oil cylinder during downward movement relates to an oil cylinder, comprising a buffer piston installed in the oil cylinder and a buffer plunger coaxially pressed together with the bottom of the oil cylinder and provided with an oil channel inside. The cross-section of the buffer plunger is a streamlined variable cross-section. When the buffer piston moves, the buffer plunger enters the cavity of the buffer piston to form multi-stage buffering.

[0006] Furthermore, it also includes a buffer sleeve and a sealing ring. The sealing ring and the buffer sleeve are press-fitted as one body, and the press-fitted assembly is located in the cavity of the buffer piston. The buffer sleeve and the buffer plunger cooperate with each other to form a multi-stage buffer structure.

[0007] Furthermore, the sealing ring is a copper-based sealing ring, and the copper-based sealing ring and the buffer sleeve are pressed and matched in the form of an inverted cone angle.

[0008] Furthermore, the sealing ring and the buffer sleeve are press-fitted bodies suspended in the cavity of the buffer piston, so that the buffer sleeve and the buffer plunger can be aligned before the buffer piston reaches the bottom.

[0009] Furthermore, a set gap is maintained between the press-fit body of the sealing ring and the buffer sleeve and the buffer piston cavity.

[0010] Furthermore, the gap between the streamlined variable cross-section of the buffer plunger and the buffer sleeve changes nonlinearly.

[0011] Furthermore, the multi-stage buffering of the buffer plunger includes an introduction state, a deceleration state and a buffering state.

[0012] In order to achieve the above-mentioned purpose, the utility model also provides an oil cylinder, including the nonlinear hydraulic buffer structure as mentioned above for eliminating the impact on the bottom of the oil cylinder when it is descending.

[0013] Beneficial effects: The utility model is provided with a buffer plunger with an oil channel inside, and a cavity corresponding to the buffer plunger is provided in the buffer piston. The buffer plunger is of streamlined variable cross-section design, which makes the buffer curve smoother and enables the entire buffer process to achieve multi-stage deceleration, eliminating the above-mentioned abruptness, making the buffer process tend to be smooth, and the internal oil pressure is balanced, the impact of the cylinder parts is minimized, and the service life of the cylinder is effectively improved; the design advantage of this structure is that it is insensitive to changes in impact loads, has strong versatility, and effectively reduces design costs and technical management costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0015] Figure 1 It is a schematic diagram of a nonlinear hydraulic buffer structure for eliminating the impact of the bottom of the oil cylinder when it is downward according to an embodiment of the utility model;

[0016] Figure 2 A buffering principle diagram of a buffer plunger of a nonlinear hydraulic buffering structure for eliminating the impact of the bottom of the oil cylinder when it is downward, as described in an embodiment of the utility model;

[0017] Figure 3 It is a schematic diagram of the introduction state of the buffer plunger of the nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder downward according to the embodiment of the utility model;

[0018] Figure 4 It is a schematic diagram of the deceleration state of the buffer plunger of the nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder downward according to the embodiment of the utility model;

[0019] Figure 5 It is a schematic diagram of the buffer state of the buffer plunger of the nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it is descending according to an embodiment of the utility model. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] Example 1

[0022] See also Figure 1-5 : A nonlinear hydraulic buffer structure for eliminating the impact on the bottom of the oil cylinder when it is descending, which relates to the oil cylinder, including a buffer piston 1 installed in the oil cylinder and a buffer plunger 2 which is coaxially pressed together with the bottom of the oil cylinder and is provided with an oil channel inside. The cross-section of the buffer plunger 2 is a streamlined variable cross-section. When the buffer piston 1 moves, the buffer plunger 2 enters the cavity of the buffer piston 1 to form multi-stage buffering.

[0023] It should be noted that when the oil cylinder is moving downward, due to the long stroke and fast downward speed of the general lifting cylinder, there will be an obvious abrupt feeling when the oil cylinder is decelerated in a short time to achieve a buffered landing, and the buffering effect is limited. This embodiment is provided with a buffer plunger with an oil channel inside, and a cavity corresponding to the buffer plunger is provided in the buffer piston. The buffer plunger is a streamlined variable cross-section design, which makes the buffer curve smoother and enables the entire buffering process to achieve multi-stage deceleration, eliminating the above-mentioned abrupt feeling, making the buffering process tend to be gentle, the internal oil pressure is balanced, and the impact of the oil cylinder parts is minimized, which effectively increases the service life of the oil cylinder; the design advantage of this structure is that it is insensitive to changes in impact loads, has strong versatility, and effectively reduces design costs and technical management costs.

[0024] In a specific example, it also includes a buffer sleeve 3 and a sealing ring 4. The sealing ring 2 and the buffer sleeve 3 are press-fitted as a whole, and the press-fit assembly is located in the cavity of the buffer piston 1. The buffer sleeve 3 and the buffer plunger 2 correspond to each other to form a multi-stage buffer structure.

[0025] In a specific example, the sealing ring 4 is a copper-based sealing ring, and the copper-based sealing ring and the buffer sleeve 3 are pressed and matched in the form of an inverted cone angle.

[0026] The sealing ring of this embodiment is made of a copper-based material with good plasticity, and is rolled and matched with the buffer sleeve in the form of an inverted cone angle, in order to prevent the two from falling off during work; the sealing ring is made of a copper-based material with good plasticity, and fully utilizes the pressure formed by the impact oil pressure to cause the sealing ring to produce a slight deformation, thereby utilizing the hydraulic impact force to impact and run-in the sealing ring, automatically forming a sealing surface that can be tightly combined with the piston, thereby enhancing the sealing between the sealing ring and the buffer piston, reducing the processing requirements for the sealing parts, and improving the qualified rate of parts.

[0027] In a specific example, the sealing ring 4 and the buffer sleeve 3 are press-fitted bodies suspended in the cavity of the buffer piston 1, so that the buffer sleeve 3 and the buffer plunger 2 can be aligned and centered before the buffer piston 1 reaches the bottom.

[0028] When the buffer piston of this embodiment moves forward from the bottom, the sealing ring and the buffer oil cylinder are automatically connected under the action of the hydraulic oil to form a lifting oil circuit; its effect characteristics can be described as: when the oil cylinder moves downward for buffering, the main oil circuit is closed and the buffer oil circuit is started; when the oil cylinder moves upward, the main oil circuit is opened and the buffer oil circuit is "closed".

[0029] In a specific example, a set gap is maintained between the press-fit body of the sealing ring 2 and the buffer sleeve 3 and the cavity of the buffer piston 1 .

[0030] In this embodiment, a set gap is maintained between the pressed body of the sealing ring and buffer sleeve and the buffer piston cavity, thereby realizing a floating buffer sleeve and sealing ring design, effectively achieving automatic alignment of the buffer device when the piston moves downward, reducing the requirements for part processing accuracy, and greatly improving the first-time qualified rate of assembly.

[0031] In a specific example, the gap between the streamlined variable cross-section of the buffer plunger 2 and the buffer sleeve 3 changes nonlinearly.

[0032] In a specific example, the multiple buffering stages of the buffer plunger are an introduction state, a deceleration state and a buffering state.

[0033] like Figure 2-5 As shown: The buffering process of this embodiment is as follows:

[0034] When the oil cylinder moves downward and approaches the bottom, the arc cone surface of the buffer plunger is aligned with the buffer sleeve, the floating buffer sleeve is automatically aligned, and the head of the buffer plunger enters the buffer sleeve. At this time, a hydraulic buffer high-pressure area is formed in area A. Under the action of high pressure, the buffer sleeve is pushed to the left, so that the sealing ring is pressed on the buffer piston to form a sealing surface, the return oil circuit is closed, and the buffer overflow channel is established;

[0035] The buffer piston continues to move downward, and the high-pressure oil in area A overflows to the main oil circuit through the gap between the buffer sleeve and the buffer plunger. At this time, the gap is larger, the piston moves downward faster, and the overflow time Δt is short. A buffer pressure reduction zone is quickly formed in area A, and the buffer piston enters the initial deceleration state, effectively resisting the high-speed impact of the piston on the bottom of the cylinder.

[0036] As the piston continues to descend, the buffer plunger enters the buffer zone. At this time, the downward speed of the piston has slowed down, the overflow gap between the buffer sleeve and the buffer plunger is reduced, the overflow amount is reduced, the piston falls smoothly, and the buffering process ends.

[0037] In summary: the nonlinear hydraulic buffer structure of this embodiment is particularly suitable for the lifting cylinders of various forklifts; it avoids the impact of the piston on the bottom of the cylinder when the cylinder descends to the lower limit at high speed, and to a certain extent eliminates the vibration, abnormal noise, piston deformation and shortened cylinder life caused by strong impact, ensuring the stable operation of the hydraulic cylinder and the entire hydraulic system. This embodiment adopts the nonlinear design concept of the hydraulic buffer process. According to the force and return speed of the cylinder, through the pressure feedback at the bottom of the cylinder, the buffer force is automatically adjusted on the nonlinear variable diameter section of the buffer plunger, eliminating the abruptness of the buffer process and making the buffering smoother.

[0038] Example 2

[0039] In order to achieve the above-mentioned purpose, the present embodiment further provides an oil cylinder, comprising the above-mentioned nonlinear hydraulic buffer structure for eliminating the impact on the bottom of the oil cylinder when it is descending.

[0040] The advantages of the oil cylinder of this embodiment and the above-mentioned nonlinear hydraulic buffer structure for eliminating the impact of the bottom of the oil cylinder when it is downwardly moved are the same as those of the prior art, and will not be described in detail here.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A nonlinear hydraulic buffer structure for eliminating the impact of the bottom of the oil cylinder when it descends, involving the oil cylinder, characterized in that: The invention comprises a buffer piston (1) installed in an oil cylinder and a buffer plunger (2) coaxially pressed together with the bottom of the oil cylinder and provided with an oil passage inside. The cross section of the buffer plunger (2) is a streamlined variable cross section. When the buffer piston (1) moves, the buffer plunger (2) enters the cavity of the buffer piston (1) to form a multi-stage buffer.

2. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it descends according to claim 1, characterized in that: It also includes a buffer sleeve (3) and a sealing ring (4), wherein the sealing ring and the buffer sleeve (3) are press-fitted as a whole, and the press-fit assembly is located in the mold cavity of the buffer piston (1), and the buffer sleeve (3) and the buffer plunger (2) are correspondingly matched to form a multi-stage buffer structure.

3. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it descends according to claim 2, characterized in that: The sealing ring (4) is a copper-based sealing ring, and the copper-based sealing ring and the buffer sleeve (3) are pressed and matched in the form of an inverted cone angle.

4. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when descending according to claim 2 is characterized in that: The sealing ring (4) and the buffer sleeve (3) are press-fitted bodies suspended in the cavity of the buffer piston (1), so that the buffer sleeve (3) and the buffer plunger (2) can be aligned before the buffer piston (1) reaches the bottom.

5. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it descends according to claim 4, characterized in that: A set gap is maintained between the press-fit body of the sealing ring and the buffer sleeve (3) and the cavity of the buffer piston (1).

6. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it descends according to claim 2, characterized in that: The gap between the streamlined variable cross-section of the buffer plunger (2) and the buffer sleeve (3) changes nonlinearly.

7. The nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when descending according to claim 1 is characterized in that: The multiple-stage buffering of the buffer plunger (2) comprises an introduction state, a deceleration state and a buffering state.

8. An oil cylinder, characterized in that: It comprises a nonlinear hydraulic buffer structure for eliminating the bottom impact of the oil cylinder when it is descending as described in any one of claims 1 to 7.

Images