WO2003101881A1

WO2003101881A1 - The control method and device of a hydraulic apparatus whose cylinder is able to come to a desired work position iteratively

Info

Publication number: WO2003101881A1
Application number: PCT/CN2003/000130
Authority: WO
Inventors: Xuanzhe Hu; Zhenhua Hu; Aiwu Hu
Original assignee: Xuanzhe Hu; Zhenhua Hu; Aiwu Hu
Priority date: 2002-05-31
Filing date: 2003-02-11
Publication date: 2003-12-11
Also published as: CN1204036C; CN1461729A; AU2003211851A1

Abstract

The control method of a hydraulic apparatus whose cylinder is able to come to a desired work position iteratively uses hydraulic control members which control a high-pressure accumulator communicated to the chamber with piston-rod of a hydraulic cylinder and a low-pressure accumulator communicated with the chamber without piston-rod of said hydraulic cylinder respectively to accumulate the energy in different grades, such that said hydraulic apparatus can lift said hydraulic cylinder to a desired work position automatically and iteratively when it is in nonload and startup state. In unload state, oil in said chamber without piston-rod enters said high-pressure accumulator; in normal state, oil in said chamber without piston-rod is introduced into said low-pressure accumulator in order to be used as the energy source of driving the cylinder to desired work positions in nonload state for the next work operation. The present invention overcomes the drawback of oil leakage from the vent port of the oil tank in the prior art, and has a simple hydraulic circuit structure, good seal, and accurate & reliable operation. Furthermore, because of accumulating the energy in different grades, convenient operation, good ordinate control, long work stroke and being able to come to the desired work position iteratively and automatically, the invention not only improves the work efficiency and the apparatus's life, but also reduces the workload of the operator.

Description

Control method of repeatedly in place hydraulic machine and control device thereof

The invention relates to a control method and a control device for a hydraulic tool for lifting a load, in particular to a control method and a device for a hydraulic tool that can be repeatedly loaded in place without load. Background 4

Most of the existing hydraulic cylinders are single-stage single-acting cylinders with an adjusting screw, which requires repeated adjustment of the screw height and the tedious operation of resetting the piston by hand. It is extremely inconvenient to adjust the piston position under the pressure drop of the vehicle, and Many occasions require the jack to be in place quickly to work. For example, at present, high-end vehicles have higher and higher requirements for the top position, and the height difference between the bottom of the vehicle has increased. The top joint must be fast. The majority of users have high requirements for the operating performance of the jack. The known hydraulic jack cannot meet the no-load energy at the bottom of the vehicle. It can be lifted and lowered, it can be automatically positioned repeatedly, and it can be adjusted flexibly. The original height should be low, but the working stroke must be large. The latest published Chinese patents "99115237. 9" and "00113302. 0" respectively disclose a "hydraulic jack-up full-automatic device" and a "full-automatic hydraulic jack". Although the above two hydraulic jacks achieve automatic unloaded position, Automatic reset after heavy load, but due to the use of an accumulator, it still cannot meet the operating requirements of repeated automatic arrival in no-load under the vehicle. In addition, the multi-valve combination joint control is controlled by the top lever operating the reverse check valve. It is difficult to seal. The oil cylinder is in place automatically. On one side, the piston is lifted up by spring force to quickly suck oil from the fuel tank. On the other side, it is released by the accumulator to pressure drop its piston to the (re) position and quickly drain to the fuel tank. Oil and oil flow in and out of the fuel tank quickly and in large quantities, and the breathing port is required to be particularly unobstructed. When the machine is turned upside down, oil cannot be run from the breathing port, so the handling at the breathing port is cumbersome. The known hydraulic jack also has defects such as partial incoordination and complicated structure.

In addition, the currently widely used manual hydraulic tools, such as hydraulic hinge trucks, forklifts, and pallet trailers, need to repeatedly adjust the hydraulic pump during work, exacerbating the wear of the oil pump, and the adjustment is cumbersome. The speed of the implement approaching the load is slow and the no-load running speed is low. Summary of the Invention

The technical problem to be solved by the present invention is to provide a control method and a control device for a hydraulic machine that can store energy in stages, is easy to operate, has a coordinated control, a large working stroke, and can be repeatedly and automatically placed at no load.

The technical solution of the present invention is: a control method of a hydraulic tool repeatedly in place, which uses a hydraulic control element to control a high-pressure accumulator connected to a rod cavity of a hydraulic cylinder and a low-pressure accumulator connected to a rod-less cavity, respectively. Graded energy storage enables the hydraulic oil rainbow to be lifted automatically and repeatedly into position when the hydraulic machine is started without load; when unloaded, the hydraulic fluid in the rodless cavity of the hydraulic pump enters the high-pressure accumulator for energy storage; said hydraulic machine When entering the normal state, the hydraulic oil in the rodless cavity of the hydraulic cylinder is introduced into the low-pressure accumulator, which is used as the energy for the automatic load in place at the next operation.

Wherein, when the hydraulic implement is in the no-load starting state, the connection between the lifting port of the rodless cavity of the hydraulic cylinder and the low-pressure-level accumulator is disconnected, so that the high-pressure-level accumulator and the rodless cavity of the hydraulic cylinder are conducted. The low-pressure accumulator and the high-pressure accumulator release energy to the rodless cavity of the hydraulic cylinder at the same time, so that the no-load state of the hydraulic machine can be automatically in place.

When the hydraulic implement finishes working, under the action of the load, the hydraulic oil of the rodless cavity of the hydraulic cylinder enters the high-pressure stage accumulator through the lifting oil port to accumulate energy.

When the hydraulic implement enters a normal state, the lifting port of the rodless cavity of the hydraulic cylinder is controlled to communicate with a low-pressure accumulator, the high-pressure accumulator has a rod cavity to release energy to the hydraulic cylinder, and the pressure drop hydraulic cylinder is automatically reset. The hydraulic oil enters the low-pressure accumulator for energy storage through the lifting port of the rodless cavity of the hydraulic cylinder.

The control device for implementing the above control method includes a hydraulic cylinder, an oil pump, a high-pressure stage accumulator, a low-pressure stage accumulator, and a hydraulic control circuit; wherein the high-pressure stage accumulator is connected to a rod cavity of the hydraulic cylinder, The low-pressure accumulator is connected to a rodless cavity of a hydraulic cylinder, and the hydraulic control circuit is composed of a two-position two-way oil return rotary valve connected to a double control check valve and a hydraulic control check valve; wherein the oil return The first port of the rotary valve is connected to the rodless cavity of the hydraulic cylinder and the A first valve port, a second valve port thereof, respectively, an oil inlet of a rodless cavity of a hydraulic cylinder, a low-pressure accumulator, a second valve port of a hydraulic check valve and an oil pump, The valve port is connected to the first valve port of the hydraulically controlled one-way valve, and at the same time connected to the high-pressure stage accumulator via a pipeline, and the third valve port of the dual-control one-way valve is connected to the oil supply pipeline of the oil pump. The control port of the pilot valve is connected to the oil pump.

As described above for the control device of the repeatedly in place hydraulic tool, the valve core of the two-position two-way oil return rotary valve is connected with the valve body through a screw thread at a large diameter, and the valve body is tightly fitted with the valve shaft at the small diameter. A hook-shaped groove is provided, and a through hole is provided in the center of the valve core, and a control jack is provided therein. The jack has an extended end, which is disposed in the hook-shaped groove. A power control mechanism is connected, and the front end of the ejector is the control end of the first valve port of the dual-control check valve.

As described above, the control device of the repeatedly-positioned hydraulic implement further includes a control spring provided between the first valve port of the hydraulically controlled check valve and the second valve port of the double-controlled check valve.

As described above, the repeatedly-in-place hydraulic implement control device has the power control mechanism having two supports provided on the valve body, a handle tube seat is hinged with the two supports, and a handle is rotatably sleeved on the handle tube seat. Inside, and connected with the rear end of the above-mentioned ejector rod; the handle tube base has a bent and extended power arm, and the power arm is connected with the oil pump. A flexible shaft is connected between the handle and the ejector. The handle and the ejector rod can also be connected by a universal joint. And the bottom of the hydraulic implement is provided with wheels.

As described above, the control device of the hydraulic tool repeatedly in place, the hydraulic cylinder has a two-stage piston, a bottom plate of the first-stage piston is provided with a positioning plate, the positioning plate is provided with a plurality of through holes, and the second-stage piston is sleeved In the first-stage piston, one end of a return spring is fixed to the top of the second-stage piston, and the other end is fixed to a positioning plate at the bottom of the first-stage piston.

The control device for implementing the above control method may further include a hydraulic cylinder, an oil pump, a high-pressure stage accumulator, a low-pressure stage accumulator, and a hydraulic control circuit; wherein the high-pressure stage accumulator and the hydraulic cylinder have a rod cavity. Connection, the low-pressure accumulator is connected to the rodless cavity of the hydraulic cylinder; the hydraulic control circuit has a P-type three-position four-way oil return rotary valve, and its oil supply port is connected to an oil pump The oil return port is respectively connected to the oil inlet of the rodless cavity of the hydraulic cylinder, the low-pressure accumulator and the oil pump. The first working oil port of the oil return rotary valve is connected to the lifting port of the rodless cavity of the hydraulic cylinder. The working oil port is connected to a high-pressure accumulator.

Further, the valve core of the oil return rotary valve is connected with a power control mechanism. The power control mechanism has two supports arranged on the valve body, a handle pipe socket is hinged with the two supports, and a handle is rotatably sleeved. The handle pipe seat is arranged in the handle pipe seat and is connected with the valve core of the oil return rotary valve; the handle pipe seat has a bent and extended power arm, and the power arm is connected with the oil pump.

The working principle of the invention is: In the no-load starting state, the pressure oil in the high-pressure accumulator and the low-pressure accumulator connected to the rod cavity and the non-rod cavity of the hydraulic cylinder are respectively controlled by a hydraulic control element through a hydraulic control element. The hydraulic differential circuit releases energy to the rodless cavity of the hydraulic cylinder at the same time, and the push piston is automatically in place repeatedly. At the end of the work, the piston is pressure-dropped by the load lifted by the hydraulic cylinder. Under the control of the hydraulic control element, the hydraulic cylinder is forced to The oil in the rod cavity enters the high-pressure stage accumulator for energy storage through the differential circuit, and recovers the energy dropped by the load for use in the next operation cycle when the no-load is automatically in place.

The features and advantages of the present invention are: Because the present invention uses high and low pressure energy accumulators, when the high pressure energy accumulator releases energy to the hydraulic cylinder's rod cavity, and the pressure drop piston is in place, the hydraulic cylinder has no rod cavity. The oil enters the low-pressure stage accumulator to store energy, which is used to lift the piston again without load and automatically in place, thereby achieving effective energy conversion and making full use of energy. The above control method and device overcome the problem of oil leakage from the gas tank breathing port in the known technology. The hydraulic circuit structure has a single cylinder, good sealing performance, and accurate and reliable movement. By operating the handle, the oil pump and the oil return rotary valve can be controlled in combination to operate the bowl.

The invention adopts a two-stage Han-acting oil cylinder, which is as stable as a pagoda and has a large lifting stroke. Because the secondary cylinder is automatically reset by a tension spring using a secondary piston, it ensures that the no-load process is in place. The primary piston is raised first, and the secondary piston is raised later.

The invention is provided with wheels at the bottom of the implement, thereby making the movement of the hydraulic implement more convenient and flexible, reducing the labor intensity of the operator and improving the work efficiency. N03 00130 The present invention can also meet the control requirements of a variety of hydraulic implements, such as the control of manual hydraulic hinges, forklifts, pallet trailers, etc., so that the above-mentioned implements can be automatically and repeatedly placed in no-load, improving operating efficiency, and the service life of the implements. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a hydraulic principle diagram of a first embodiment of the present invention;

2 is a schematic structural diagram of a hydraulic system according to a first embodiment of the present invention;

3 is a hydraulic principle diagram of a second embodiment of the present invention;

4 is a schematic structural diagram of a hydraulic system according to a second embodiment of the present invention, wherein the hydraulic cylinder shown is a double-acting hydraulic rainbow;

FIG. 5 is a partial schematic view in the direction of F in FIG. 2, showing the hinged structure of the stem tube seat and the support in the present invention; FIG. 6 is a schematic diagram of a seal ring provided at each gap seal of the valve core and the valve body in the second embodiment of the present invention . detailed description

The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The invention proposes a control method for a hydraulic tool that can be repeatedly put in place. The hydraulic control element is used to separately control the high-pressure stage accumulator 4 connected to the hydraulic cylinder 1 with a rod cavity and the low-pressure stage accumulator 3 connected to a rodless cavity. Energy storage enables the hydraulic cylinder to be automatically lifted into position when the hydraulic implement is started without load; when unloaded, the oil in the rodless cavity of the hydraulic cylinder enters the high-pressure accumulator 4 to store energy; the hydraulic implement enters In the normal state, the hydraulic oil in the rodless cavity of the hydraulic cylinder is introduced into the low-pressure accumulator 3, which is used as an energy source for automatic no-load operation in the next operation.

Example 1

As shown in Figs. 1 and 2, the repeatedly in place hydraulic implement control device of the present invention includes a hydraulic cylinder 1, an oil pump 1, a high-pressure stage accumulator 4, a low-pressure stage accumulator 3, and a hydraulic control circuit; The high-pressure stage accumulator 4 is connected to the rod cavity of the hydraulic cylinder 1, and the high-pressure stage accumulator 3 is connected to the rodless cavity of the hydraulic cylinder. The hydraulic control circuit is composed of two positions in this embodiment. The two-way oil return rotary valve Ί is connected with a non-return check valve 5 and a hydraulically controlled check valve 6; wherein the first port 7 of the oil return rotary valve ₇ respectively opens the rodless cavity of the hydraulic cylinder 2 And the first port P _{51 of the} double-control check valve 5, and the second port T _{7 of the} oil return rotary valve ₇ are connected to the low-pressure accumulator 3 and the second port P of the hydraulic check valve 6 respectively. _62. The second valve port P _{52 of} the dual-control check valve 5 is connected to the first valve port P _{61 of} the hydraulic control check valve 6 and is connected to the high-pressure stage accumulator 4 through the pipeline 40. The third valve port P _{53 of the} double-control check valve 5 is in communication with the oil pump 1 via the oil supply line 50, and the control port K of the hydraulic control check valve 6 is connected to the pump chamber of the oil pump 1.

Wherein, the first valve port P _{61 of} the hydraulic control check valve 6 and the second valve port of the double control check valve 5

A control spring 51 is provided between P _52, and the left port (first port) of the dual control check valve 5 is caused by the abutment of the control spring 51 to the right port ( ₅₁ ) of the double control check valve 5 ( 2nd valve port) P _{62 is} normally closed.

The spool of the two-position two-way oil return rotary valve 7 is connected with the valve body by a large diameter, and the valve body is closely fitted with the small diameter. A hook groove 72 is provided on the spool of the spool. The center is provided with a through hole, which is provided with a control jack ^ ^: stem 71, the jack 71 has an extended end 711, and the extended end 711 is disposed in the above-mentioned hook groove 72. The rear end of the jack is connected with a power The control mechanism is connected, and its front end is the control end of the first valve port P ₅₁ of the dual-control check valve 5 described above.

Referring to FIG. 5, the power control mechanism has two supports 9 provided on the valve body, a handle tube holder 93 is hinged to the two supports 9 through a pin 94, and a handle 92 is rotatably sleeved on the handle tube. The base 93 is connected to the rear end of the ejector 71 through a universal joint shaft 91. The handle base 93 has a bent and extended power arm 96, which is connected to the oil pump 1. When the operating handle 92 rotates, the protruding end 711 of the ejector 71 connected to the handle 92 is driven to slide along the hook groove 72 provided on the oil return rotary valve and spool body, so that the ejector 71 It moves back and forth in the oil return rotary valve Ί to control the opening and closing of the first valve port P ₅₁ of the dual-control check valve 5. When the operating handle 92 swings around the pin shaft 94, the oil pump 1 can be driven to supply oil to the above-mentioned hydraulic oil passage. To facilitate moving the hydraulic control implement in use, wheels 95 are provided on the bottom of the implement. The hand 4 bar 92 and the ejector rod 71 can also be connected through a flexible shaft 97 (as shown in FIG. 4). The control method and operation process of this embodiment are: In a normal state, the first port P _{51 of} the dual-control check valve 5 and the second port P _{62 of the} hydraulic check valve 6 are normally closed, and the oil return rotary valve Ί In the normally open state, the valve ports of A ₇ and T _{7 are} conducting, as shown in Figure 1. At this time, the high-pressure stage accumulator 4 releases energy to the rod cavity of the hydraulic cylinder 2, the pressure drop piston 21 is retracted into the hydraulic cylinder 2, and the oil of the rodless cavity of the hydraulic cylinder 1 enters the low-pressure stage through the rotary valve 7 and the pipeline 70. Accumulator 3, oil is stored in accumulators 4, 3 respectively. Among them, the low-pressure accumulator 3 is an accumulator with a fuel tank function.

In the no-load starting working state, the operating handle 92 rotates in a positive direction, which drives the ejector lever 71 to move forward. The oil return rotary valve 7 is controlled to close first, the oil return rotary valve 7 is in the left position, and the valve ports Α ₇ and Τ _{7 are} disconnected. Then, the first valve port P _{51 of the} check valve 5 is opened by the control of the ejector pin 71. At this time, the double-control check valve 5 is in the neutral position, and the valve ports of P ₅₁ and P _{52 are} turned on. The pressure oil enters the rodless cavity of the hydraulic cylinder 2 through the pipeline 40 and the one-way valve 5, and the pressure oil in the low-pressure stage accumulator 3 enters the rodless cavity of the hydraulic cylinder 2 through the check valve 31. Then, the accumulator 4, The pressure oil of 3 meets in the rodless cavity of the hydraulic cylinder, and the resultant force lifts up the piston 21. During the jacking process, the hydraulic oil in the rod cavity of the hydraulic cylinder 2 is continuously discharged from the pipeline 20 and merges with the pressure oil of the high-pressure stage accumulator 4 to supply oil to the rodless cavity of the hydraulic cylinder, forming a differential circuit. In order to make the piston 21 rise quickly and automatically into position, that is, the piston 21 contacts the load.

In the working state, when the piston 21 is lifted into position and enters the working state, the handle 92 is continuously turned to drive the ejector rod 71 to move forward, and the abutment against the dual-control check valve 5 completely closes the second valve port P ₅₂ . The operator's handle 92 swings up and down about the pin 94 to control the pressure oil of the oil pump 1 to pump the oil to the rodless cavity of the hydraulic cylinder 2 through the check valve 11, the pipeline 50, and the double control check valve 5. When the oil pump 1 pumps oil, it simultaneously sends high-pressure oil to the control port K of the hydraulic control check valve 6, so that the second valve port P _{62 is} opened. Then, the hydraulic oil in the rod cavity of the hydraulic cylinder 2 passes through the lines 20, 40, and The check valve 6 and the pipeline 60 discharge the oil to the accumulator 3 which also has the function of the fuel tank. When the oil pump 1 sucks oil, the control port K of the hydraulic check valve 6 loses pressure, and the check is closed in time by the spring 51 To the second valve port P _{δ2 of the} valve 6.

At the end of the operation, the handle 92 rotates in the reverse direction, which drives the ejector rod 71 to move backward, and slowly opens the second valve port P _{52 of the} double control check valve 5. The hydraulic oil in the rodless cavity of the hydraulic cylinder 2 is under load. Make The first wide port P ₅₁ , the second valve port P ₅₂ , and the pipeline 40 passing through the check valve 5 enter the high-pressure accumulator 4 to store energy, and at the same time, can supply oil to the rod cavity of the hydraulic cylinder 2 to Acceleration resets the piston 21. After the piston 21 is reset, continue to rotate the handle 92 in the reverse direction, so that the first valve port P _{51 of} the dual-control check valve 5 is completely closed, and the oil return rotary valve 7 is opened, and enters a normal state to complete a working cycle.

In the repeatedly-positioned hydraulic implement of the present invention, in the no-load starting state, the oil return rotary valve 7 is controlled to disconnect the lifting port B of the rodless cavity of the hydraulic cylinder 1 and the low-pressure accumulator 3, and the ejector 71 The non-return check valve 5 is actuated, and the valve port P _{51 is} opened, so that the above-mentioned high-pressure stage accumulator 4 releases energy, and the pressure oil is conducted to the rodless cavity of the hydraulic cylinder 2 through its differential circuit. The device 3 releases energy, and the pressure oil enters the rodless cavity of the hydraulic cylinder 2 through the pipeline .30, the replenishment check valve 31, and the oil inlet C, so that the above-mentioned hydraulic implement can be automatically and repeatedly lifted into position without load. When the work is completed and the unloading state is reached, the control handle 92 keeps the oil return rotary valve 7 and the hydraulic control check valve 6 in the closed position. The pressure of the hydraulic cylinder 2 pressure drops the piston 21, forcing the hydraulic cylinder 2 to The oil in the rod cavity enters the high-pressure stage accumulator 4 for energy storage through a differential circuit formed by a double-control check valve 5. When unloaded, the machine enters the normal state, and is controlled by opening the oil return rotary valve 7 to be in a conducting state. The hydraulic cylinder 2 has a rod-less cavity lifting port B in communication with the low-pressure stage accumulator 3, and the high-pressure stage energy storage. The device 4 releases energy from the rod cavity to the hydraulic cylinder, and continues to drop the pressure of the piston 21 to automatically reset. The hydraulic oil enters the low-pressure stage accumulator 4 through the lifting port B of the rodless cavity of the hydraulic cylinder to achieve the static balance of the hydraulic circuit and recover it. The energy of the load drop is stored in the high- and low-pressure level accumulators respectively, which are used as the energy when the no-load automatic lifting is in place in the next working cycle.

Because the present invention uses high and low pressure accumulators 4, 3, when the high pressure accumulator 4 releases energy from the rod cavity to the hydraulic cylinder 2 and the pressure drop piston 21 is in place, the oil in the rodless cavity of the hydraulic cylinder Entering the low-pressure stage accumulator 3 stores energy, which is used to lift the piston again without load and automatically in place, thereby achieving effective energy conversion and making full use of energy. The above control method and device overcome the problem of oil leakage from the gas tank breathing port in the known technology. The control circuit composed of the oil return rotary valve 7 and the Huan check valve 5 and the hydraulic control check valve 6 has good sealing performance and accurate and reliable operation. . By operating the handle 92, the oil pump 1 and the oil return rotary valve can be controlled together, and the operation is simple and convenient. Example 1

The structure, principle, and beneficial effects of this embodiment are the same as those of Embodiment 1, except that another type of hydraulic control circuit that can repeatedly achieve automatic positioning of the hydraulic implement is used. Therefore, the same components are given the same reference numerals.

As shown in Figs. 3 and 4 (wherein Fig. 4 is a structural schematic diagram of the hydraulic system of this embodiment, and the hydraulic rainbow is a two-stage double-acting hydraulic cylinder 2,), in the description of the hydraulic circuit and control process of this embodiment The description is still based on the ordinary hydraulic cylinder 2. This embodiment includes an oil pump 1, a hydraulic cylinder 2, a piston 21, a high-pressure accumulator 4, a low-pressure accumulator 3, and a hydraulic control circuit. The high-pressure accumulator 4 is connected to the rod-shaped cavity of the hydraulic cylinder 2, and the low-pressure accumulator 3 is connected to the rod-free cavity of the hydraulic cylinder 1. The hydraulic control circuit has a P-type three-position four-way oil return rotary valve 8 whose oil supply port P _s is connected to the oil pump 1 through a pipeline 50 with a one-way valve 11 interposed therebetween, and the oil return port T is managed by a pipe The road 70 is connected to the low-pressure accumulator 3 and the oil pump 1 respectively; the first working port A _{8 of the} oil return rotary valve 8 is connected to the lifting port B of the cylinder 2 without a rod cavity, and the second working port 8 ₈ passes through the channel. The 40-connected hydraulic cylinder 1 has a rod cavity and a high-pressure stage accumulator 4, and the ^ pressure-level accumulator 3 is connected to the oil inlet C of the cylinder 2 without a rod cavity via a fuel check valve 31 and a pipeline 30.

Sealing rings 81 (as shown in FIG. 6) are provided at each gap seal between the valve core and the wide body of the P-type three-position four-way oil return rotary valve 8. The return oil to the valve block 8-bit port right condition is normal equipment, the oil supply port P _s the second working port B ₈ is turned on, the first working port and the return port ₈ human T is turned on; the The neutral side of the oil return rotary valve 8! The state of the oil port is P-type, that is, the machine is started and unloaded with no load, the oil return port T is closed, and the oil supply port P ₈ , the first working port A ₈ , and the second working port B _{8 are} connected; The condition of the left port oil port of the oil return rotary valve 8 is the working state of the implement. _{8 is} connected to person ₈ and ^ is connected to T.

The spool of the three-position four-way oil return rotary valve 8 is connected to one end of the flexible shaft 97, and the other end of the flexible shaft 97 is connected to the hand 4 bar 92; of course, the valve core of the oil return rotary valve 8 can also be connected by a universal joint. The shaft 91 is connected to the handle 92 (see FIG. 2).

The control process of this embodiment is as follows: When the implement is in a normal state, the oil return rotary valve 8 is in a right position, The first working port person ₈ communicates with the return port T. The fuel supply port? ₈ communicates with the second working oil port B _{8. The} piston 21 is automatically reset by the release of the high-pressure accumulator 4. The oil in the lower chamber of the hydraulic cylinder 2 enters the low-pressure accumulator 3 through the channels A ₈ and T. No-load energy in place automatically. At the start of no-load operation, the forward rotation is 4 bar 92, and the spool is driven by the flexible shaft 97 (or universal shaft 91). With the oil return rotary valve 8 in the neutral position, the oil return port T is closed, P ₈ and A ₈ and B ₈ communicate with each other to form a differential circuit. The high and low pressure accumulators 4 and 3 jointly release energy to the rodless cavity of the hydraulic cylinder 2. The piston 21 is lifted up, and the piston 21 is completed in a no-load state through the differential circuit. Automatically in place. Then it turns into the working state, that is, the oil return rotary valve 8 is controlled to the left position. At this time, P ₈ and A ₈ communicate with each other and B ₈ and T communicate with each other. The hand 4 bar 92 is repeatedly pressed, and the power arm on the handle base 93 is passed. 96 drives the oil pump 1, which pumps out the pressure oil flow and lifts the weight. After work, the handle 92 reverse, with the valve body continues to exit, passing through the median port, the port is closed _{_{Τ, Ρ 8, Α 8, Β}} 8 composed of three differential circuit, which voltage drop the load piston 21, forces hydraulic The oil in the rodless cavity of the cylinder 2 enters the high-pressure accumulator 4 to store energy, and finally returns to the normal state.

In this embodiment, the low-pressure stage accumulator 3 is connected to the rodless cavity of the hydraulic cylinder 2 through a charge check valve 31, and a high-pressure stage accumulator 4 is provided in the rod cavity of the hydraulic cylinder 2 for staged storage. Yes, by turning the hand 4 bar 92 (by a flexible shaft or universal coupling) to drive the wide core of the P-type three-position four-way oil return rotary valve 8 and pushing the handle 92 through the power arm of the handle base The oil pump 1 pumps out high-pressure oil flow, thereby realizing control of three states of normal state, no-load starting state and working state.

In this embodiment, since the P-type function three-position four-way valve 8 is directly controlled, it is easy to debug. The middle port of the P-type functional oil return rotary valve 8 is closed for the T port, and the three ports P ₈ , Α ₈ and Β ₈ communicate with each other to form a differential circuit, thereby achieving effective energy conversion, such as no-load process, high The low-pressure stage accumulator simultaneously releases the energy through its differential circuit. The piston is automatically pushed into place. During the heavy load process, the heavy object pressure drops its piston, forcing its lower cavity oil to enter the high-pressure stage accumulator through its differential circuit to store energy and recover. The energy of the falling weight is prepared as the automatic energy source. Because the sealing ring is provided at the gap seal between the wide core and the gang body, the reliability of the machine is greatly improved, and because the rotary valve core advances and retreats by the thread, it fully meets the requirements of the jack switch in the field. Requirements for intentional and deterministic actions. And the hydraulic control circuit is simple and easy to implement. Other structures, operation processes, working principles, and beneficial effects obtained in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

Example 3

Other structural principles and control methods of the hydraulic control circuit and the like in this embodiment are the same as those in Embodiments 1 and 2, except that a two-stage hydraulic cylinder 2 'is proposed.

As shown in FIG. 4, in the structural schematic diagram of the hydraulic system according to the second embodiment of the present invention, a double-stage double-acting hydraulic cylinder 2 is used instead of the ordinary hydraulic cylinder 2, wherein the two-stage hydraulic cylinder V has a two-stage piston. 21, 22, the bottom of the first stage piston 21, is provided with a positioning plate 24, the positioning plate is provided with a plurality of through holes to form a positioning sieve plate; the second stage piston 22 'is sleeved on the first One end of a return spring 23 ′ in the stage piston 21 ′ is fixed to the top of the second stage piston 22 ′, and the other end is fixed to a positioning plate 24 at the bottom of the first stage piston 2 ′.

Wherein, the second-stage piston 22 'is automatically reset by the elastic force of the tension spring 23, and the first-stage piston 21 is automatically reset by the release of the high-pressure stage accumulator 4.

In the hydraulic control circuit, the above-mentioned double-stage double-acting hydraulic cylinder V, and its two-stage pistons 21, 22, are as stable as a pagoda, and the lifting stroke is greatly increased. Since the second-stage piston 22 'is automatically reset by the tension of the tension spring 23, the first-stage piston 21 is lifted first, and the second-stage piston 22' is lifted in the order of no-load in place.

According to the principle of the present invention, the above-mentioned control method and control device can also meet the control requirements of a variety of hydraulic implements, such as the control of manual hydraulic hinges, forklifts, pallet trailers, etc., so that the above-mentioned implements can be automatically and repeatedly in place without load, improving the operation Efficiency, and tool life.

The above mentioned are only specific embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by it, the replacement of equivalent components or the equivalent changes and modifications made in accordance with the scope of patent protection of the present invention should all be applied. Still covered by this patent.

Claims

Claim

1. A control method of a hydraulic tool repeatedly in place, which is characterized by: using a hydraulic control element to control a high-pressure stage accumulator connected to a hydraulic cylinder with a rod cavity and a low-pressure stage accumulator connected to a non-rod cavity to a hierarchical storage It can realize that the hydraulic cylinder can be lifted up and down automatically when the hydraulic implement is started without load; when in the unloaded state, the oil in the rodless cavity of the hydraulic cylinder enters the high-pressure accumulator to store energy; when the hydraulic implement enters the normal state The hydraulic oil of the hydraulic cylinder without a pestle cavity is introduced into a low-pressure accumulator, which is used as an energy source for automatic no-load operation in the next operation.

2. The control method of the repeatedly-positioned hydraulic implement according to claim 1, characterized in that: when the hydraulic implement is in the no-load starting state, disconnecting between the lifting port of the rodless cavity of the hydraulic cylinder and the low-pressure accumulator The connection between the high-pressure accumulator and the rodless cavity of the hydraulic cylinder, and the low-pressure and high-pressure accumulators release energy to the rodless cavity of the hydraulic cylinder at the same time, so that the hydraulic machine can be in place automatically under no-load conditions. .

3. The control method of the repeatedly in place hydraulic implement according to claim 1, characterized in that: when the hydraulic implement finishes working, under the action of the load, the hydraulic oil of the rodless cavity of the hydraulic cylinder enters the high pressure through the lifting oil port. Secondary accumulators store energy.

4. The control method of the repeatedly in place hydraulic tool according to claim 1, characterized in that: when the hydraulic tool enters a normal state, the hydraulic rainbow is controlled; the lifting oil port of the If cavity communicates with the low-pressure accumulator The high-pressure level accumulator has a rod cavity to release energy to the hydraulic cylinder, the pressure drop hydraulic cylinder is automatically reset, and the hydraulic oil enters the low-pressure level accumulator to accumulate energy through the lifting port of the rodless cavity of the hydraulic cylinder.

5. A control device capable of realizing the control method of a hydraulic tool repeatedly in place according to claim 1, characterized in that the control device comprises a hydraulic cylinder, an oil pump, a high-pressure accumulator, a low-pressure accumulator, A hydraulic control circuit; wherein the high-pressure accumulator is connected to a rod-shaped cavity of a hydraulic cylinder, the low-pressure accumulator is connected to a rod-less cavity of a hydraulic cylinder, and the hydraulic control circuit is returned to oil by a two-position two-way The rotary valve is connected to a double-control check valve and a hydraulic control check valve; wherein the first port of the oil return rotary valve is respectively connected to the non-dry chamber of the hydraulic cylinder and the first The valve port, its second valve port are respectively the oil inlet of the rodless cavity of the hydraulic cylinder, the low-pressure stage accumulator, the second valve port of the hydraulic control check valve and the oil pump, and the second valve port of the dual control check valve It is connected to the first valve port of the hydraulic control check valve, and at the same time connected to the high-pressure stage accumulator via a pipeline. The third valve port of the dual control check valve is connected to the oil supply pipeline of the oil pump. The control port of the check valve is connected to the oil pump.

6. The control device of the repeatedly-positioned hydraulic implement according to claim 5, characterized in that: the valve core of the two-position two-way oil return rotary valve is connected with the valve body through a thread at a large diameter, and the valve body at the small diameter is A close-fitting groove is provided on the spool core, a through hole is provided in the center of the spool, and a control jack is provided in the spool. The jack has an extended end, and the extended end is arranged in the hook shape. A power control mechanism is connected to the rear end of the ejector rod, and the front end of the ejector rod is the control end of the first valve port of the dual-control check valve.

7. The control device of the repeatedly-positioned hydraulic implement according to claim 5, wherein a control spring is provided between a first port of the hydraulic control check valve and a second port of the dual control check valve.

8. The repeatedly in place hydraulic machine control device according to claim 6, characterized in that: the power control mechanism has two supports provided on the valve body, a handle pipe seat is hinged with the two supports, and a handle can It is rotatably sleeved in the handle pipe base, and is connected with the rear end of the ejector rod; the handle pipe base has a bent and extended power arm, and the power arm is connected with the oil pump.

9. The control device of the repeatedly-positioned hydraulic implement according to claim 8, characterized in that: a flexible shaft is connected between the hand 4 bar and the ejector rod.

10. The control device of the repeatedly-positioned hydraulic implement according to claim 8, characterized in that: the handle and the ejector rod are connected by a universal joint.

11. The control device of the hydraulic tool repeatedly in place according to claim 5, wherein: a wheel is provided at the bottom of the hydraulic tool.

12. The control device of the repeatedly-positioned hydraulic implement according to claim 5, wherein the hydraulic cylinder has a two-stage piston, and a positioning plate is provided at the bottom of the first-stage piston, and a plurality of positioning plates are provided on the positioning plate. Through hole, the second stage piston is sleeved in the first stage piston, a reset bomb One end of the spring is fixed to the top of the second-stage piston, and the other end is fixed to the positioning plate at the bottom of the first-stage piston.

13. A control device capable of implementing the control method of a hydraulic tool repeatedly in place according to claim 1, characterized in that the control device includes a hydraulic cylinder, an oil pump, a high-pressure accumulator, and a low-pressure accumulator, A hydraulic control circuit; wherein the high-pressure accumulator is connected with the rod cavity of the hydraulic cylinder, and the low-pressure accumulator is connected with the rod-less cavity of the hydraulic cylinder; the hydraulic control circuit has a P-type function with three positions A four-way oil return rotary valve whose oil supply port is connected to an oil pump, and the oil return port is respectively connected to an oil inlet of a rodless cavity of a hydraulic cylinder, a low-pressure accumulator and an oil pump, and the first working oil port of the oil return rotary valve It is connected to the lifting port of the rodless cavity of the hydraulic cylinder, and the second working port is connected to the high-pressure accumulator.

14. The control device of the repeatedly-positioned hydraulic implement according to claim 13, characterized in that: a valve core of the oil return rotary valve is connected with a power control mechanism, and the power control mechanism has two supports provided on the valve body A handle pipe seat is hinged with the two supports, and a handle is rotatably sleeved in the handle pipe seat, and is connected with the valve core of the oil return rotary valve; the handle pipe seat has a bent and extended A power arm, which is connected to the oil pump.

15. The control device of the repeatedly in place hydraulic machine according to claim 14, characterized in that: the hand 4 bar and the spool of the oil return rotary valve are connected by a flexible shaft.

16. The control device of the repeatedly in place hydraulic machine according to claim 14, characterized in that: the hand 4 bar and the spool of the oil return rotary valve are connected by a universal joint.

17. The control device of the repeatedly-positioned hydraulic tool according to claim 13, wherein: a wheel is provided at the bottom of the hydraulic tool.

18. The control device of the repeatedly-positioned hydraulic implement according to claim 13, wherein the hydraulic cylinder has a two-stage piston, and a positioning plate is provided at the bottom of the first-stage piston, and a plurality of positioning plates are provided on the positioning plate. Through-hole, the second-stage piston is sleeved in the first-stage piston, one end of a return spring is fixed to the top of the second-stage piston, and the other end is fixed to the positioning plate at the bottom of the first-stage piston.