Hydraulic control device suitable for plunger type cylinder

Abstract

According to the hydraulic control device suitable for the plunger type cylinder, the plunger type cylinder, a valve block, a sequence valve, a proportional overflow valve, a pressure reducing valve and an electromagnetic reversing valve are arranged in a combined mode, the sequence valve, the proportional overflow valve, the pressure reducing valve and the electromagnetic reversing valve are correspondingly matched with the valve block, the oil inlet pressure and the oil return back pressure of the plunger type cylinder can be adjusted respectively, different pressures are set according to different loads, and proportional adjustment can be conducted; the smoothness and safety of extension or retraction of the plunger cylinder are improved, and impact is reduced; the method is suitable for accurately controlling the extension pressure and the retraction back pressure of the plunger cylinder, the impact caused by the load action on the plunger cylinder is relieved, the vibration of a bearing system caused by the impact is attenuated, and the smoothness and the stability of the plunger cylinder under the extension and retraction working conditions are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydraulic control, and particularly relates to a hydraulic control device applicable to a plunger cylinder. Background Art

[0002] Plunger cylinders are widely used in equipment such as construction machinery, aerial work platforms, and special vehicles. When extending, they rely on hydraulic oil to overcome resistance, and when descending and retracting, they rely on the self-weight of the load. When extending, since the load position changes from low to high, the resistance is large, and the pressure needs to be gradually reduced at the end of the movement to avoid impact; especially when the plunger cylinder is a multi-stage cylinder, due to the sudden change in the acting area, the impact is more obvious; when descending, factors such as the different weights of the load and the variable diameter of the plunger cylinder cause sudden changes in speed and impact, resulting in poor smoothness and stability of the mechanism. Although technicians have made many attempts, such as increasing damping and increasing back pressure, the impact and vibration have been improved, but when the external load is variable, the smoothness of the system still does not meet the requirements. Summary of the Invention

[0003] The purpose of the utility model is to provide a hydraulic control device applicable to a plunger cylinder to achieve smooth and reliable extension and retraction of the plunger cylinder in view of the above-mentioned deficiencies of the prior art.

[0004] To solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A hydraulic control device applicable to a plunger cylinder includes a plunger cylinder, a valve block, and a sequence valve, a proportional relief valve, a pressure reducing valve, and an electromagnetic reversing valve correspondingly arranged therewith, and the proportional relief valve includes a first proportional relief valve and a second proportional relief valve arranged in parallel;

[0006] The oil port of the plunger cylinder is connected to the A oil port of the valve block through a pipeline, and a first check valve and a second check valve with opposite directions are arranged on the lower pipeline thereof, and the B oil port of the valve block is connected to a pressure sensor;

[0007] The third oil port of the sequence valve and the oil outlet of the first check valve are connected to the B oil port of the valve block through an internal channel;

[0008] The first oil port of the sequence valve, the oil inlet of the first check valve, the oil inlet of the second check valve, and the oil inlet of the pressure reducing valve are connected through the internal channel of the valve block;

[0009] The second oil port of the sequence valve is connected to the oil inlet of the first proportional relief valve;

[0010] The oil outlet of the second check valve, the second oil port of the pressure reducing valve, and the fourth oil port of the electromagnetic reversing valve are connected and communicated, and the third oil port of the pressure reducing valve is connected and communicated with the oil inlet of the second proportional relief valve;

[0011] The second oil port of the electromagnetic directional valve, the oil outlet of the second proportional relief valve, and the oil outlet of the first proportional relief valve are all connected to the T port of the valve block. The third oil port of the electromagnetic directional valve is blocked, and its first oil port is connected to the P port of the valve block.

[0012] The pressure of the sequence valve is set independently by the first proportional relief valve according to the load size.

[0013] The pressure of the pressure reducing valve is set independently by the second proportional relief valve according to the load size.

[0014] And respectively limit the extension pressure and the retraction back pressure value of the plunger cylinder.

[0015] The first proportional relief valve and the second proportional relief valve can be adjusted proportionally separately.

[0016] The electromagnetic directional valve adopts a plate valve or a cartridge valve and controls the extension or descent of the plunger cylinder.

[0017] The pressure sensor can display the pressure of the plunger cylinder in real time.

[0018] The first check valve controls the inflow of hydraulic oil according to the state of the plunger cylinder.

[0019] The second check valve prevents the inflow of hydraulic oil according to the state of the plunger cylinder.

[0020] The beneficial effects of the present utility model are as follows:

[0021] (1) The hydraulic control device applicable to the plunger cylinder is set up by combining the plunger cylinder, the valve block and the correspondingly configured sequence valve, proportional relief valve, pressure reducing valve and electromagnetic directional valve. It can respectively adjust the inlet pressure and the return oil back pressure of the plunger cylinder, set different pressures according to different loads, and can perform proportional adjustment, improving the smoothness and safety of the extension or retraction of the plunger cylinder and reducing the impact.

[0022] It is applicable to accurately control the extension pressure and the retraction back pressure of the plunger cylinder, slow down the impact caused by the load acting on the plunger cylinder, attenuate the vibration of the bearing system caused thereby, and improve the smoothness and stability of the plunger cylinder in the extension and retraction conditions.

[0023] (2) It solves the problem that the inlet pressure and the return oil back pressure cannot be adjusted after the parameters of the existing mechanism are determined, and can improve the smoothness and safety of the plunger cylinder mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the hydraulic schematic diagram of the present utility model;

[0025] Figure 2 is the external shape diagram of the integrated valve block of the present utility model. DETAILED DESCRIPTION OF THE INVENTION

[0026] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

[0027] Please refer to Figure 1 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present utility model. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the implementation scope of the present utility model. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the implementation scope of the present utility model.

[0028] The present utility model provides a hydraulic control device applicable to a plunger cylinder, as Figure 1 and Figure 2 shown.

[0029] A hydraulic control device applicable to a plunger cylinder includes a plunger cylinder 1, a valve block 9, and a correspondingly arranged sequence valve 3, a proportional overflow valve, a pressure reducing valve 5, and an electromagnetic reversing valve 7. The proportional overflow valve includes a first proportional overflow valve 4 and a second proportional overflow valve 8 arranged in parallel;

[0030] The oil port of the plunger cylinder 1 is connected to the A oil port of the valve block 9 through a pipeline 11, and a first check valve 2 and a second check valve 6 with opposite directions are arranged on the lower pipeline thereof. The B oil port of the valve block 9 is connected to a pressure sensor 10;

[0031] The third oil port 33 of the sequence valve 3 and the oil outlet of the first check valve 2 are connected to the B oil port of the valve block through an internal channel;

[0032] The first oil port 31 of the sequence valve 3, the oil inlet 21 of the first check valve 2, the oil inlet 61 of the second check valve 6 and the oil inlet 51 of the pressure reducing valve 5 are connected through the internal channel of the valve block 9;

[0033] The second oil port 32 of the sequence valve 3 is connected to the oil inlet 41 of the first proportional overflow valve 4;

[0034] The oil outlet 62 of the second one-way valve 6, the second oil port 52 of the pressure reducing valve 5 are connected to the fourth oil port 74 of the electromagnetic directional valve 7, while the third oil port 53 of the pressure reducing valve 5 is connected to the oil inlet 81 of the second proportional overflow valve 8;

[0035] The second oil port 72 of the electromagnetic directional valve 7, the oil outlet 82 of the second proportional overflow valve 8 and the oil outlet 42 of the first proportional overflow valve 4 are all connected to the T port of the valve block 9, and the third oil port 73 of the electromagnetic directional valve 7 is blocked, while its first oil port 71 is connected to the P port of the valve block 9.

[0036] The pressure of the sequence valve 3 is set separately by the first proportional overflow valve 4 according to the load size, and the pressure of the pressure reducing valve 5 is set separately by the second proportional overflow valve 8 according to the load size, and respectively limit the extension pressure and the retraction back pressure value of the plunger cylinder 1.

[0037] The first proportional overflow valve 4 and the second proportional overflow valve 8 can be adjusted separately in proportion.

[0038] The electromagnetic directional valve 7 adopts a plate valve or a cartridge valve and controls the extension or descent of the plunger cylinder.

[0039] The pressure sensor 10 can display the pressure of the plunger cylinder 1 in real time.

[0040] The first one-way valve 2 controls the inflow of hydraulic oil according to the state of the plunger cylinder 1.

[0041] The second one-way valve 6 prevents the inflow of hydraulic oil according to the state of the plunger cylinder 1.

[0042] The working principle of the present utility model is as follows:

[0043] (1) The plunger cylinder hydraulic control device controls the extension working condition of the plunger cylinder 1:

[0044] According to the working condition parameters of the load size, calculate the pressure when the plunger cylinder 1 extends, and preset a certain value for the control current of the second proportional overflow valve 8, which is converted into the outlet pressure of the pressure reducing valve 5.

[0045] When the electromagnet of the electromagnetic directional valve 7 is energized, its spool changes direction and is in the left position. The first oil port 71 and the fourth oil port 74 of the valve are connected. The hydraulic oil flows from the P port through the first oil port 71 and the fourth oil port 74 of the electromagnetic valve 7, reaches the second oil port 52 of the pressure reducing valve 5, and flows out from the first oil port 51 of the pressure reducing valve 5, enters the oil inlet 21 of the first one-way valve 2, flows out from the oil outlet 22 of the first one-way valve 2, flows out from the S1 port of the valve block 9, that is, the A oil port, passes through the pipeline 11, enters the oil inlet of the plunger cylinder 1, and pushes the plunger to extend; the pressure sensor 10 installed at the S2 port of the valve block 9, that is, the B oil port, can display the system pressure of the plunger cylinder 1 during extension in real time.

[0046] (2)Hydraulic control device of plunger cylinder controls the retraction condition of plunger cylinder 1:

[0047] The electromagnet of electromagnetic directional valve 7 loses power. Under the action of the spring, the spool is in the right position. The fourth oil port 74 and the second oil port 72 of solenoid valve 7 are connected, and the third oil port 73 and the first oil port 71 are connected. The plunger of plunger cylinder 1 presses the hydraulic oil inside it out from the oil inlet under the action of external load, reaches the third oil port 33 of sequence valve 3, and the preset current of the first proportional relief valve 4 is converted into the pressure value of sequence valve 3.

[0048] When the pressure reaches the pressure value, it pushes the spool of sequence valve 3 to move to the right. The third oil port 33 of sequence valve 3 is connected to the first oil port 31. The hydraulic oil flows out from the first oil port 31 of sequence valve 3, reaches the oil inlet 61 of the second check valve 6, flows out from the oil outlet 62 of the second check valve 6, reaches the fourth oil port 74 of electromagnetic directional valve 7, and flows out from the second oil port 72 of electromagnetic directional valve 7, and flows out through the T port of valve block 9. By adjusting the current of proportional relief valve 4, the opening pressure of sequence valve 3 can be set, that is, the back pressure when plunger cylinder 1 retracts and descends. The current changes linearly, the opening pressure of sequence valve 3 changes linearly, and the back pressure of the system also changes linearly. The pressure sensor 10 installed at the S2 port (i.e., B oil port) of valve block 9 can display the system pressure of plunger cylinder 1 during retraction in real time.

[0049] The hydraulic control device of this plunger cylinder is suitable for accurately controlling the extension pressure and retraction back pressure of the plunger cylinder, reducing the impact caused by the load acting on the plunger cylinder, attenuating the vibration of the bearing system caused thereby, and improving the smoothness and stability of the plunger cylinder during extension and retraction conditions.

[0050] If terms such as "first" and "second" are used to limit components in this patent, those skilled in the art should be aware that the use of "first" and "second" is only for the convenience of describing this utility model and simplifying the description, and these terms have no special meaning.

[0051] The above shows and describes the basic principle, main features and advantages of this utility model. Those skilled in the industry should understand that this utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of this utility model. Without departing from the spirit and scope of this utility model, this utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the utility model claimed. The scope of protection claimed by this utility model is defined by the appended claims and their equivalents.

[0052] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "center", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation on the protected content of the present utility model.

[0053] The above embodiments are only illustrative of the principles and effects of the present utility model, rather than limiting the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A hydraulic control device suitable for a plunger cylinder, characterized in that: It includes a plunger cylinder, a valve block, and corresponding sequence valves, a proportional relief valve, a pressure reducing valve, and an electromagnetic reversing valve, wherein the proportional relief valve includes a first proportional relief valve and a second proportional relief valve arranged in parallel; The oil port of the plunger cylinder is connected to the A oil port of the valve block through a pipeline, and the lower end pipeline is equipped with a first check valve and a second check valve with reverse directions, and the B oil port of the valve block is connected to the pressure sensor; The third oil port of the sequence valve and the oil outlet of the first check valve are connected to the B oil port of the valve block through an internal channel; The first oil port of the sequence valve, the oil inlet of the first check valve, the oil inlet of the second check valve and the oil inlet of the pressure reducing valve are connected through an internal channel of the valve block; The second oil port of the sequence valve is connected to the oil inlet of the first proportional relief valve; The oil outlet of the second one-way valve, the second oil port of the pressure reducing valve and the fourth oil port of the electromagnetic reversing valve are connected, and the third oil port of the pressure reducing valve is connected to the oil inlet of the second proportional relief valve; The second oil port of the electromagnetic reversing valve, the oil outlet of the second proportional relief valve and the oil outlet of the first proportional relief valve are all connected to the T port of the valve block, and the third oil port of the electromagnetic reversing valve is blocked, while its first oil port is connected to the P port of the valve block.

2. A hydraulic control device suitable for a plunger cylinder according to claim 1, characterized in that: The pressure of the sequence valve is set individually by the first proportional relief valve according to the load size. The pressure of the pressure reducing valve is set individually by the second proportional relief valve according to the load size. And limit the extension pressure and retraction back pressure of the plunger cylinder respectively.

3. A hydraulic control device suitable for a plunger cylinder according to claim 1, characterized in that: The first proportional relief valve and the second proportional relief valve can be adjusted proportionally independently.

4. A hydraulic control device suitable for a plunger cylinder according to any one of claims 1 to 3, characterized in that: The electromagnetic reversing valve adopts a plate valve or a cartridge valve, and controls the extension or descent of the plunger cylinder.

5. A hydraulic control device suitable for a plunger cylinder according to claim 4, characterized in that: The pressure sensor can display the pressure of the plunger cylinder in real time.

6. A hydraulic control device suitable for a plunger cylinder according to claim 4, characterized in that: The first one-way valve controls the inflow of hydraulic oil according to the state of the plunger cylinder.

7. A hydraulic control device suitable for a plunger cylinder according to claim 4, characterized in that: The second one-way valve blocks the inflow of hydraulic oil according to the state of the plunger cylinder.

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