A non-action side differential pressure position keeping method, system and device for a dual rotary head tool magazine

Abstract

The present application relates to the technical field of tool magazine hydraulic control, and particularly relates to a tool magazine double-rotary-head non-action-side differential pressure position holding method, system and device, the method comprising: determining an action rotary head for executing a current tool changing action and a non-action rotary head for keeping a current position in the double-rotary-head according to a tool magazine tool changing instruction and a tool changing action timing; carrying out hydraulic isolation on the non-action rotary head during the action rotary head executes the current tool changing action; obtaining a holding differential pressure of the non-action rotary head in the hydraulic isolation state, and judging whether the non-action rotary head meets a preset position holding condition; when the non-action rotary head does not meet the preset position holding condition, carrying out differential pressure compensation on the non-action rotary head, so that the non-action rotary head keeps in the current position; and when the action rotary head completes the current tool changing action, releasing the hydraulic isolation state of the non-action rotary head. Through the present application, the problem that the non-action side is difficult to stably keep a given position when the double-rotary-head of the tool magazine shares hydraulic power is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology for tool magazines, and in particular to a method, system, and device for maintaining the position of the non-operating side of a tool magazine's dual rotating heads under differential pressure. Background Technology

[0002] A tool magazine is a machine tool accessory in CNC machine tools used to store cutting tools and work with the tool changing mechanism to complete automatic tool changing. Some tool magazine tool changing mechanisms use hydraulic motors or hydraulic rotary actuators to achieve actions such as tool indexing, tool changing arm rotation, and tool holder flipping. In the prior art, patent CN118372067B discloses a hydraulically driven tool changing mechanism and its control method, which can realize tool changing actions and abnormal protection through hydraulic actuators, oil supply and return systems, and energy storage structures; patent CN112343876B discloses a dual hydraulic motor pressure balance self-protection hydraulic system, which can perform pressure balance and abnormal protection when the two hydraulic motors are working in parallel. While the aforementioned existing technologies involve hydraulic tool changer control and dual hydraulic motor pressure protection, their focus is mainly on the motion drive, pressure balance, or fault protection of hydraulic actuators. They do not address the problem of pressure disturbance in the common oil circuit when one rotary head is performing an action, which makes it difficult for the other non-operating rotary head to maintain a stable position. Therefore, in tool magazines with alternating actions of the two rotary heads, there may still be instability in the non-operating side's position holding, affecting the reliability of tool changing.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] This invention provides a method, system, and device for maintaining the position of the non-operating side of the dual rotating head of a tool magazine under differential pressure, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for maintaining the position of a tool magazine dual rotary heads on the non-operating side using differential pressure, wherein the dual rotary heads obtain hydraulic power through a common oil circuit, the method comprising: Based on the tool change command and the timing of the tool change action, the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position are determined among the dual rotary heads. During the current tool change operation performed by the rotating head, the non-rotating head is hydraulically isolated to isolate it from pressure disturbances in the common oil circuit. Obtain the holding differential pressure of the non-operating rotary head in the hydraulic isolation state, and determine whether the non-operating rotary head meets the preset position holding conditions based on the holding differential pressure; When the non-operating rotating head does not meet the preset position-keeping condition, differential pressure compensation is performed on the non-operating rotating head to keep it in the current position. Once the rotating head completes the current tool change action, the hydraulic isolation state of the non-rotating head is released.

[0006] Furthermore, the holding differential pressure is the pressure difference between the first working chamber pressure and the second working chamber pressure of the non-operating rotary head, and the direction of the holding differential pressure is used to characterize the hydraulic pressure direction required for the non-operating rotary head to maintain the current position.

[0007] Furthermore, the preset position holding condition is that the position holding differential pressure is within the position holding allowable range defined by the position holding allowable fluctuation amount of the non-acting rotary head, based on the reference position holding differential pressure formed before the non-acting rotary head enters the hydraulic isolation state.

[0008] Furthermore, the hydraulic isolation includes cutting off the connection between the two working chambers of the non-operating rotary head and the oil supply side and oil return side of the common oil circuit, respectively, so that the two working chambers of the non-operating rotary head are in a pressure-holding and locked state.

[0009] Furthermore, the determination of the reference differential pressure includes: Before the rotating head performs the current tool change action, the first working chamber pressure and the second working chamber pressure are obtained when the non-rotating head is in the current position; The initial holding differential pressure of the non-operating rotary head when it is not disturbed by the pressure of the common oil circuit is calculated based on the pressure of the first working chamber and the pressure of the second working chamber. The initial holding differential pressure is latched as the reference holding differential pressure, and the reference holding differential pressure is used as the target value for differential pressure compensation during the current tool change action performed by the rotating head.

[0010] Further, differential pressure compensation is performed on the non-operating rotating head, including: During the period when the non-operating rotary head is in the hydraulically isolated state, the current holding differential pressure of the non-operating rotary head is acquired; The compensation deviation is determined based on the difference between the current holding differential pressure and the reference holding differential pressure; Based on the direction of the compensation deviation, a compensation working chamber is determined in the first and second working chambers of the non-operating rotary head; Perform flow-limited oil replenishment or pressure-limited oil unloading on the compensation working chamber to restore the current holding differential pressure toward the reference holding differential pressure; When the current differential pressure is within the allowable range of the position, stop performing the flow-limiting oil replenishment or the pressure-limiting oil unloading on the compensation working chamber.

[0011] Further, releasing the hydraulic isolation state of the non-operating rotating head includes: After the rotating head completes the current tool change action, the isolation side pressure of the control oil circuit corresponding to the non-rotating head and the main oil circuit pressure of the common oil circuit are obtained. Calculate the differential pressure based on the isolation side pressure and the main oil circuit pressure; When the access differential pressure is higher than the preset access differential pressure threshold, the control oil circuit corresponding to the non-operating rotary head and the common oil circuit are pressure transitioned through throttling or pulse connection. When the access differential pressure decreases to no higher than the preset access differential pressure threshold, the hydraulic isolation state of the non-operating rotating head is released.

[0012] Furthermore, when the non-operating rotating head does not meet the preset position-keeping condition, the non-operating rotating head is interlocked for protection, the interlocking protection including: During the differential pressure compensation process for the non-operating rotary head, the number of compensations or the duration of compensation are recorded. When the number of compensations reaches the preset number of compensations or the compensation duration reaches the preset compensation time and the non-operating rotating head still does not meet the preset position-keeping condition, the hydraulic isolation state of the non-operating rotating head is maintained. After maintaining the hydraulic isolation state of the non-operating rotary head, the execution of the next tool change action corresponding to the tool change command of the tool magazine is prohibited; After prohibiting the next tool change action from being executed, a protection signal corresponding to the differential pressure position maintenance abnormality of the non-operating rotary head is output.

[0013] A tool magazine dual-rotating head non-operating side differential pressure positioning system, the system comprising: The tool change timing recognition module determines the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position among the two rotary heads based on the tool magazine tool change command and the timing of the tool change action. The non-operating side isolation module hydraulically isolates the non-operating rotary head during the current tool changing operation of the operating rotary head, thus isolating the non-operating rotary head from pressure disturbances in the common oil circuit. The differential pressure detection module acquires the differential pressure of the non-operating rotating head in the hydraulic isolation state, and determines whether the non-operating rotating head meets the preset position holding conditions based on the differential pressure. The differential pressure position keeping compensation module compensates for the non-operating rotating head by differential pressure when the non-operating rotating head does not meet the preset position keeping conditions, so that the non-operating rotating head remains in the current position. The isolation state release module releases the hydraulic isolation state of the non-moving rotating head after the moving rotating head completes the current tool change action.

[0014] A differential pressure positioning device for the non-operating side of a tool magazine dual rotating head is used to implement the aforementioned differential pressure positioning method for the non-operating side of the tool magazine dual rotating head.

[0015] The technical solution of this invention can achieve the following technical effects: The action head and non-action head are identified by the tool change sequence. During the tool change action on the action side, the non-action side is hydraulically isolated. Judgment and compensation are made based on the differential pressure maintained on the non-action side to achieve stable positioning of the non-action side. This effectively solves the problem that the non-action side is difficult to maintain a fixed position when the two rotary heads of the tool magazine share the same hydraulic power.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the differential pressure position holding method for the non-operating side of the dual rotating heads of the tool magazine; Figure 2 This is a schematic diagram of the differential pressure positioning system on the non-operating side of the dual rotary heads of the tool magazine. Figure 3 This is a schematic diagram of the hydraulic isolation and differential pressure compensation principle on the non-acting side. Figure 4 To maintain the timing diagram of differential pressure changes with the access differential pressure; Figure 5 This is a schematic diagram showing the switching state between the active and inactive sides of the dual rotating heads. Reference numerals: T1, Baseline established; T2, Hydraulic isolation; T3, Differential pressure offset; T4, Differential pressure compensation; T5, Action completed; T6, Pressure transition; T7, Isolation released. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] Example 1; like Figure 1 and Figure 2 As shown, this application provides a differential pressure positioning method for the non-operating side of a tool magazine dual rotary head, the method comprising: S10: Based on the tool change command and the timing of the tool change action, determine the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position in the dual rotary heads; S20: During the current tool change operation of the rotating head, the non-rotating head is hydraulically isolated to isolate the non-rotating head from pressure disturbances in the common oil circuit; S30: Obtain the holding differential pressure of the non-operating rotary head in the hydraulic isolation state, and determine whether the non-operating rotary head meets the preset holding conditions based on the holding differential pressure; S40: When the non-operating rotating head does not meet the preset position holding conditions, differential pressure compensation is performed on the non-operating rotating head to keep the non-operating rotating head in the current position. S50: After the rotating head completes the current tool change action, the hydraulic isolation state of the non-rotating head is released.

[0022] Specifically, this embodiment provides a differential pressure positioning method for the non-operating side of a tool magazine with dual rotating heads, applicable to tool magazine changing mechanisms where two hydraulic rotating heads obtain hydraulic power through a common oil circuit. The two rotating heads can be used to perform tool changing-related actions such as tool magazine indexing, tool holder flipping, tool changer arm rotation, or reset. Upon receiving a tool change command, the controller determines the rotating head that needs to perform the tool change action as the active rotating head based on the tool change command and the timing of the tool change action, and determines the other rotating head that needs to maintain its current position as the non-active rotating head. During the current tool change operation performed by the rotating head, the controller controls the isolation valve (hydraulic isolation unit), lock-up valve or directional valve in the corresponding oil circuit of the non-rotating head to operate, so that the direct connection between the non-rotating head and the common oil circuit is cut off, thereby isolating the non-rotating head from the pressure disturbance in the common oil circuit. After the non-operating rotary head is in a hydraulically isolated state, the controller obtains the holding differential pressure of the non-operating rotary head; the holding differential pressure can be obtained from the pressure difference between the two working chambers of the non-operating rotary head, and is used to reflect the hydraulic force state required for the non-operating rotary head to maintain its current position; the controller determines whether the non-operating rotary head meets the preset position-keeping conditions based on the holding differential pressure; When the non-operating rotary head meets the preset position holding conditions, the controller maintains the hydraulic isolation state of the non-operating rotary head; when the non-operating rotary head does not meet the preset position holding conditions, the controller performs differential pressure compensation for the non-operating rotary head. Differential pressure compensation can be achieved by replenishing oil to the corresponding working chamber, unloading oil from the corresponding working chamber, or adjusting the pressure of the two working chambers, so that the non-operating rotary head can be restored and maintained in the current position. After the rotating head completes the current tool change action, the controller releases the hydraulic isolation state of the non-rotating head, allowing the non-rotating head to reconnect to the common oil circuit so that subsequent tool change actions can continue to be executed according to the tool change action sequence. Through this method, when the rotating head is working, the non-rotating head can stably maintain its predetermined position even when there is pressure disturbance in the common oil circuit.

[0023] The technical solution of this invention identifies the active and non-active rotating heads according to the tool change sequence, performs hydraulic isolation on the non-active side during the tool change action on the active side, and makes judgments and compensations based on the differential pressure maintained on the non-active side to achieve stable positioning of the non-active side. This effectively solves the problem that the non-active side is difficult to maintain a fixed position when the two rotating heads of the tool magazine share the same hydraulic power.

[0024] Furthermore, the differential pressure is maintained as the pressure difference between the first working chamber pressure and the second working chamber pressure of the non-operating rotary head, and the direction of the differential pressure is used to characterize the direction of the hydraulic pressure required for the non-operating rotary head to maintain its current position.

[0025] As a preferred embodiment of the above embodiment, the non-operating rotary head has a first working chamber and a second working chamber, which are located on both sides of the hydraulic action of the non-operating rotary head, respectively, and are used to generate a torque to maintain the current position of the non-operating rotary head under the action of hydraulic pressure. The first working chamber and the second working chamber can be connected to the control oil circuit of the non-operating rotary head through corresponding oil ports, and form a pressure holding state when the non-operating rotary head is in a hydraulic isolation state. After the non-operating rotary head enters the hydraulic isolation state, the controller obtains the pressure of the first working chamber and the pressure of the second working chamber, and determines the holding differential pressure according to the pressure difference between the pressure of the first working chamber and the pressure of the second working chamber. Specifically, the holding differential pressure can be obtained by subtracting the pressure of the second working chamber from the pressure of the first working chamber, or by subtracting the pressure of the first working chamber from the pressure of the second working chamber, as long as the same calculation direction is maintained during the control process. The differential pressure is used not only to indicate the difference in hydraulic pressure between the two sides of the non-operating rotary head, but also to indicate the direction of the hydraulic pressure required for the non-operating rotary head to maintain its current position. When the differential pressure is in the first direction, it means that the first working chamber provides the main position-maintaining hydraulic pressure relative to the second working chamber. When the differential pressure is in the second direction, it means that the second working chamber provides the main position-maintaining hydraulic pressure relative to the first working chamber. The controller can determine the direction of force on which the non-operating rotary head depends for maintaining its current position based on the direction of the differential pressure, thereby providing a basis for determining the oil replenishment side or the oil unloading side during subsequent differential pressure compensation.

[0026] Furthermore, the preset position holding condition is to maintain the differential pressure within the allowable position holding range, which is based on the reference differential pressure formed before the non-operating rotary head enters the hydraulic isolation state and is limited by the allowable position holding fluctuation of the non-operating rotary head.

[0027] As a preferred embodiment of the above, the preset position holding condition is used to determine whether the non-operating rotary head can stably maintain its current position under the hydraulic isolation state; before the non-operating rotary head enters the hydraulic isolation state, its holding differential pressure is obtained, and the holding differential pressure is used as the reference holding differential pressure. The reference holding differential pressure is used to represent the actual hydraulic force state required for the non-operating rotary head to maintain its current position when it is not disturbed by the common oil circuit pressure. After the non-operating rotary head enters the hydraulic isolation state, it continues to acquire its holding differential pressure and compares it with the reference holding differential pressure. If the change in the holding differential pressure relative to the reference holding differential pressure is within the allowable holding range, it is determined that the non-operating rotary head meets the preset holding condition. If the change in the holding differential pressure relative to the reference holding differential pressure exceeds the allowable holding range, it is determined that the non-operating rotary head does not meet the preset holding condition.

[0028] The allowable position holding range is determined by the reference holding differential pressure and the allowable position holding fluctuation of the non-operating rotary head. The allowable position holding fluctuation can be determined based on the rotary head structure, hydraulic leakage, tool changing accuracy requirements, tool load status, or allowable angle offset. In this way, the preset position holding conditions can be formed based on the actual position holding state of the non-operating rotary head, rather than simply relying on a fixed pressure threshold, thereby improving the adaptability and accuracy of position holding judgment.

[0029] Furthermore, hydraulic isolation includes cutting off the connection between the two working chambers of the non-operating rotary head and the oil supply side and return side of the common oil circuit, respectively, so that the two working chambers of the non-operating rotary head are in a pressure-holding and locked state.

[0030] As a preferred embodiment of the above, hydraulic isolation is used to isolate the non-operating rotary head from pressure disturbances in the common oil circuit during the current tool change operation performed by the operating rotary head; the non-operating rotary head has two working chambers, which are respectively connected to the oil supply side and oil return side of the common oil circuit through corresponding oil circuits. When hydraulic isolation of the non-operating rotary head is required, the controller controls the isolation valve, hydraulic check valve, directional valve or lock-up valve in the corresponding oil circuit of the non-operating rotary head to operate, cut off the connection between the two working chambers and the oil supply side and return side of the common oil circuit respectively, so that the hydraulic oil in the two working chambers is restricted to the corresponding chamber and local oil circuit. After the two working chambers are isolated from the common oil circuit, the non-operating rotary head forms a pressure-holding and locking state. At this time, even if the pressure of the common oil circuit fluctuates during the start-up, operation or stop of the rotary head, the pressure fluctuation will not directly affect the two working chambers of the non-operating rotary head, thereby reducing the possibility of the non-operating rotary head shifting due to hydraulic disturbance.

[0031] Furthermore, the determination of the baseline differential pressure includes: Before the rotating head performs the current tool change action, obtain the first working chamber pressure and the second working chamber pressure when the non-rotating head is in its current position. The initial holding differential pressure of the non-operating rotary head when it is not disturbed by the common oil circuit pressure is calculated based on the pressure of the first working chamber and the pressure of the second working chamber. The initial holding differential pressure is latched as the reference holding differential pressure, and the reference holding differential pressure is used as the target value for differential pressure compensation during the current tool change operation of the rotating head.

[0032] As a preferred embodiment of the above, the reference holding differential pressure is used to represent the actual holding differential pressure state of the non-operating rotary head when it is in its current position and is not disturbed by the common oil circuit pressure before the operating rotary head performs the current tool change action; Before the rotating head performs the current tool change action, the controller acquires the pressure in the first and second working chambers of the non-rotating rotating head. To reduce the impact of instantaneous pressure fluctuations on the reference value, the pressure in the first and second working chambers can be continuously acquired within a reference sampling period, and the instantaneous differential pressure corresponding to each sampling can be calculated. ; in, The instantaneous holding differential pressure obtained from the i-th sampling is expressed in Pa. The pressure in the first working chamber during the i-th sampling is expressed in Pa. The pressure in the second working chamber during the i-th sampling is expressed in Pa; i is the sampling number, which is dimensionless. After completing multiple samplings, the controller calculates the initial holding differential pressure based on each instantaneous holding differential pressure: ; in, The initial differential pressure is expressed in Pa; N is the number of samples taken within the baseline sampling time, which is dimensionless. The number of samples can be determined by the pressure sampling frequency and the reference sampling time: ; in, This refers to the pressure sampling frequency, measured in Hz. The reference sampling time is expressed in seconds. To ensure that the initial holding differential pressure represents the stable position of the non-operating rotating head, the fluctuation of the instantaneous holding differential pressure during the reference sampling time can be calculated: ; in, The fluctuation of differential pressure maintained during the reference sampling time, in Pa; The instantaneous holding differential pressure obtained from the i-th sampling is expressed in Pa. The initial differential pressure is expressed in Pa. When the differential pressure fluctuation during the reference sampling time is within the allowable range, the controller latches the initial differential pressure as the reference differential pressure and uses this reference differential pressure as the target value for subsequent differential pressure compensation during the current tool change action of the rotating head. In this way, the reference differential pressure comes from the actual force state of the non-rotating head before entering the hydraulic isolation, which can provide a reliable reference for subsequent position holding judgment and differential pressure compensation.

[0033] Furthermore, such as Figure 3 As shown, differential pressure compensation for the non-operating rotary head includes: While the non-operating rotary head is in a hydraulically isolated state, acquire the current holding differential pressure of the non-operating rotary head; The compensation deviation is determined based on the difference between the current holding differential pressure and the reference holding differential pressure; Based on the direction of the compensation deviation, the compensation working chamber is determined in the first and second working chambers of the non-operating rotary head. Perform flow-limited oil replenishment or pressure-limited oil unloading on the compensation working chamber to restore the current differential pressure toward the reference differential pressure. When the current differential pressure is within the allowable range for maintaining the position, stop performing flow-limited oil replenishment or pressure-limited oil unloading on the compensation working chamber.

[0034] As a preferred embodiment of the above, differential pressure compensation is used to restore the current holding differential pressure toward the reference holding differential pressure during the period when the non-operating rotary head is in a hydraulically isolated state, thereby maintaining the current position of the non-operating rotary head; While the non-operating rotary head is in hydraulic isolation, the controller acquires the current pressure of the first working chamber and the current pressure of the second working chamber, and calculates the current holding differential pressure: ; in, The current differential pressure is expressed in Pa. The pressure in the first working chamber at the current moment is expressed in Pa. The pressure in the second working chamber at the current moment is expressed in Pa; t is the current sampling time, expressed in seconds. The controller determines the compensation deviation based on the difference between the current holding differential pressure and the reference holding differential pressure: ; in, To compensate for deviations, the unit is Pa; Maintain differential pressure as a reference, in Pa; when When positive, it indicates that the current holding differential pressure is higher than the reference holding differential pressure; when... A negative value indicates that the current holding differential pressure is lower than the reference holding differential pressure; To avoid frequent compensation within the allowable fluctuation range, the controller determines the effective compensation deviation based on the allowable fluctuation amount for position maintenance: ; in, To effectively compensate for deviations, the unit is Pa; To maintain the allowable fluctuation range, the unit is Pa; when When the differential pressure is within the allowable range, no differential pressure compensation is required; when When this occurs, it indicates that the current differential pressure has exceeded the allowable range for maintaining the position, and differential pressure compensation is required. In this embodiment, with As a definition for maintaining differential pressure direction; when When the current differential pressure is below the allowable range, it indicates that the current differential pressure needs to be increased. At this time, the controller determines the first working chamber as the oil replenishment chamber or the second working chamber as the oil unloading chamber. When the current differential pressure is higher than the allowable range, it means that the current differential pressure needs to be reduced. At this time, the controller determines the second working chamber as the oil replenishment working chamber or the first working chamber as the oil unloading working chamber. After determining the compensation working chamber, the controller can estimate the compensation oil quantity based on the effective compensation deviation: ; in, The volume of hydraulic oil that needs to be added to or released to compensate for the working chamber is expressed in cubic meters (m³). 3 ; The equivalent hydraulic volume of the working chamber and its partially connected oil circuits is measured in cubic meters (m³). 3 ; This is the equivalent bulk modulus of elasticity of the hydraulic oil and piping system, expressed in Pa; in this formula, The unit is m 3 / Pa, and After multiplication, we get m 3 The dimensions are consistent; The controller can also generate compensation flow based on the effective compensation deviation: ; in, To compensate for the direction of flow, the unit is m. 3 / s; This is the proportionality constant, with units of m. 3 / (s·Pa); These are the integral coefficients, in units of m. 3 / (Pa·s 2 ); These are the differential coefficients, in units of m. 3 / Pa; t is the time when compensation begins; t is the current time. The variable is the integral variable, and the unit is seconds (s). To prevent surges during the compensation process, the compensation flow can be further limited: ; in, The actual output compensation flow rate is expressed in m³ / s. 3 / s; The maximum allowable compensation flow rate is expressed in m³ / s. 3 / s; To compensate for the direction of flow, the unit is m.3 / s; when When the controller increases the current differential pressure, it performs compensation in the direction of increasing the current differential pressure, that is, it limits the flow of oil in the first working chamber or limits the pressure of oil in the second working chamber; when When the controller reduces the current differential pressure, it performs compensation in the direction of reducing the current differential pressure, that is, limiting the flow of oil to replenish the second working chamber or limiting the pressure of oil to unload the first working chamber. The limiting of oil replenishment can be achieved by a pressure replenishment valve, a proportional flow valve or a throttling oil replenishment branch, and the limiting of oil unloading can be achieved by a pressure relief valve, a proportional pressure relief valve or a controlled return oil branch. During the compensation process, the controller continuously acquires the current holding differential pressure and determines whether the current holding differential pressure has returned to the allowable holding range: ; in, Maintain differential pressure as a reference; To maintain the current differential pressure; To maintain the allowable fluctuation range; when the above relationship is met, the controller stops performing flow-limited oil replenishment or pressure-limited oil unloading on the compensation working chamber; when the above relationship is not met, the controller continues to perform differential pressure compensation according to the direction of the compensation deviation; in this way, differential pressure compensation is no longer a simple one-sided pressure replenishment, but a directional compensation based on the deviation direction of the current holding differential pressure relative to the reference holding differential pressure.

[0035] Furthermore, resolving the hydraulic isolation state of the non-moving rotating head includes: After the rotating head completes the current tool change action, obtain the isolation side pressure of the control oil circuit and the main oil circuit pressure of the common oil circuit corresponding to the non-rotating head; Calculate the differential pressure based on the isolation side pressure and the main oil circuit pressure; When the differential pressure at the input is higher than the preset differential pressure threshold, the control oil circuit corresponding to the non-operating rotary head and the common oil circuit are pressure transitioned through throttling or pulse connection. When the differential pressure decreases to no higher than the preset differential pressure threshold, the hydraulic isolation state of the non-operating rotary head is released.

[0036] As a preferred embodiment of the above, releasing the hydraulic isolation state is used to allow the non-operating rotary head to smoothly reconnect to the common oil circuit after the operating rotary head completes the current tool changing action, so as to avoid hydraulic shock caused by excessive pressure difference between the isolation side and the common oil circuit. After the rotating head completes the current tool change action, the controller acquires the isolation side pressure of the control oil circuit corresponding to the non-rotating head and the main oil circuit pressure of the common oil circuit. When the non-rotating head has a first working chamber and a second working chamber, the controller can acquire the isolation side pressure of the first working chamber, the isolation side pressure of the second working chamber, the oil supply side pressure of the common oil circuit, and the oil return side pressure of the common oil circuit, and calculate the differential pressure according to the following formula: ; in, To connect differential pressure; To relieve the pressure on the isolation side of the first working chamber before hydraulic isolation; To relieve the pressure on the isolation side of the second working chamber before hydraulic isolation; Supply pressure to the public oil circuit on the oil side; The pressure on the return side of the common oil circuit; max(·) is the function to take the maximum value; When the access differential pressure meets When the controller determines that the pressure difference between the control oil circuit corresponding to the non-operating rotary head and the common oil circuit is within the allowable connection range, the hydraulic isolation state can be released; among which, To allow differential pressure input, the unit is Pa. The allowable differential pressure input can be determined based on the allowable impact pressure of the hydraulic rotary head, the pressure resistance of the valve, the pipeline volume, the positioning accuracy requirements of the tool magazine, or the allowable attitude fluctuation. When the access differential pressure meets At this time, the controller does not directly release the hydraulic isolation state, but instead makes the pressure transition between the control oil circuit corresponding to the non-acting rotating head and the common oil circuit through throttling connection or pulse connection. When using a throttling connection method, the transition flow rate can be estimated using the following formula: ; in, The transition flow rate during throttling and connection is expressed in m³. 3 / s; The flow coefficient is dimensionless. The effective opening area of ​​the throttle valve or transition valve; To connect differential pressure; The density of the hydraulic oil; To limit the impact flow during pressure transition, the controller can limit the effective opening area based on the maximum permissible transition flow: ; in, To allow the maximum transition flow rate, the controller can control the opening of the proportional throttle valve according to this formula, or select a transition channel that meets the opening area requirement, so that the pressure on the isolation side gradually approaches the pressure in the common oil circuit. When using pulse connection mode, the controller can determine the pulse connection duty cycle based on the input differential pressure: ; in, The duty cycle of the pulse connection; This is the effective opening area when the pulse-connecting valve is open. To allow the maximum transient flow rate; when the differential pressure is large, the duty cycle is small to limit the transient flow rate per unit time; when the differential pressure gradually decreases, the duty cycle increases to accelerate the pressure equalization process; The valve opening time within each pulse cycle can be determined using the following formula: ; in, The valve opening time within each pulse cycle; The pulse connection period is expressed in seconds (s). During the pressure transition, the controller continuously acquires the pressure on the isolation side and the pressure in the common oil circuit, and updates the access differential pressure. When the access differential pressure drops to no higher than the allowable access differential pressure, the controller controls the isolation valve, lock-up valve, or directional valve to release the isolation state, allowing the non-operating rotary head to reconnect to the common oil circuit. In this way, the non-operating rotary head is not directly connected when the pressure difference between the isolation side and the common oil circuit is large, but is connected after a pressure transition, thereby reducing the hydraulic shock when the hydraulic isolation is released.

[0037] Furthermore, such as Figure 4 and Figure 5 As shown, when the non-operating rotary head does not meet the preset position-holding conditions, interlock protection is applied to the non-operating rotary head. The interlock protection includes: During differential pressure compensation for the non-operating rotary head, record the number of compensations or the duration of compensation. When the number of compensations reaches the preset number of compensations or the compensation duration reaches the preset compensation time and the non-operating rotary head still does not meet the preset position holding condition, the hydraulic isolation state of the non-operating rotary head is maintained. After maintaining the hydraulic isolation state of the non-operating rotary head, the next tool change action corresponding to the tool change command of the tool magazine is prohibited from being executed; After prohibiting the next tool change action, a protection signal corresponding to the differential pressure position maintenance abnormality of the non-operating rotary head is output.

[0038] As a preferred embodiment of the above, the interlock protection is used to prevent the tool magazine from continuing to perform subsequent tool changing actions when the differential pressure compensation cannot restore the non-operating rotary head to a stable position. During differential pressure compensation for the non-operating rotary head, the controller records the number of compensations and the duration of compensation; the number of compensations is incremented by one each time flow-limited oil replenishment or pressure-limited oil unloading is performed; the time from the start of differential pressure compensation to the current time is used as the compensation duration. When the number of compensation attempts reaches the set number of compensation attempts, or the compensation duration reaches the set compensation time, and the non-operating rotary head still does not meet the preset position holding conditions, the controller determines that there is a differential pressure position holding abnormality in the non-operating rotary head. At this time, the controller maintains the hydraulic isolation state of the non-operating rotary head, does not release its isolation state, and prohibits the execution of the next tool change action corresponding to the tool change command of the tool magazine. After entering interlock protection, the controller outputs a protection signal corresponding to the differential pressure position holding abnormality. The protection signal can be used to trigger an alarm, stop the machine, prompt manual inspection, or execute preset safety procedures. In this way, it is possible to avoid the mechanism from becoming unstable when the non-operating rotary head position holding is abnormal and the tool changing continues.

[0039] Example 2; Based on the same inventive concept as the differential pressure positioning method for the non-operating side of a dual rotary head of a tool magazine in the foregoing embodiments, the present invention also provides a differential pressure positioning system for the non-operating side of a dual rotary head of a tool magazine, the system comprising: The tool change timing recognition module determines the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position among the two rotary heads based on the tool magazine tool change command and the timing of the tool change action. The non-operating side isolation module hydraulically isolates the non-operating rotary head during the current tool changing operation of the operating rotary head, thus isolating the non-operating rotary head from pressure disturbances in the common oil circuit. The differential pressure detection module acquires the differential pressure of the non-operating rotating head in the hydraulic isolation state, and determines whether the non-operating rotating head meets the preset position holding conditions based on the differential pressure. The differential pressure position keeping compensation module compensates for the non-operating rotating head by differential pressure when the non-operating rotating head does not meet the preset position keeping conditions, so that the non-operating rotating head remains in the current position. The isolation state release module releases the hydraulic isolation state of the non-moving rotating head after the moving rotating head completes the current tool change action.

[0040] The system described above in this invention can effectively implement a differential pressure positioning method for the non-operating side of a dual rotating head of a tool magazine, and the technical effects it can achieve are as described in the above embodiments, and will not be repeated here.

[0041] Example 3; Based on the same inventive concept as the differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine in the foregoing embodiments, the present invention also provides a differential pressure positioning device for the non-operating side of the dual rotating head of the tool magazine, for implementing the differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine.

[0042] Similarly, the above-mentioned optimization schemes for the system can also achieve the optimization effects corresponding to the methods in Embodiment 1, which will not be repeated here.

[0043] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for maintaining the position of a tool magazine dual rotary heads on the non-operating side using differential pressure, wherein the dual rotary heads obtain hydraulic power through a common oil circuit, characterized in that... The method includes: Based on the tool change command and the timing of the tool change action, the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position are determined among the dual rotary heads. During the current tool change operation performed by the rotating head, the non-rotating head is hydraulically isolated to isolate it from pressure disturbances in the common oil circuit. Obtain the holding differential pressure of the non-operating rotary head in the hydraulic isolation state, and determine whether the non-operating rotary head meets the preset position holding conditions based on the holding differential pressure; When the non-operating rotating head does not meet the preset position-keeping condition, differential pressure compensation is performed on the non-operating rotating head to keep it in the current position. Once the rotating head completes the current tool change action, the hydraulic isolation state of the non-rotating head is released.

2. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 1, characterized in that, The holding differential pressure is the pressure difference between the first working chamber pressure and the second working chamber pressure of the non-operating rotary head, and the direction of the holding differential pressure is used to characterize the hydraulic pressure direction required for the non-operating rotary head to maintain the current position.

3. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 2, characterized in that, The preset position holding condition is that the position holding differential pressure is within the position holding allowable range defined by the position holding allowable fluctuation amount of the non-acting rotary head, based on the reference position holding differential pressure formed before the non-acting rotary head enters the hydraulic isolation state.

4. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 1, characterized in that, The hydraulic isolation includes cutting off the connection between the two working chambers of the non-operating rotary head and the oil supply side and oil return side of the common oil circuit, respectively, so that the two working chambers of the non-operating rotary head are in a pressure-holding and locked state.

5. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 3, characterized in that, The determination of the reference differential pressure includes: Before the rotating head performs the current tool change action, the first working chamber pressure and the second working chamber pressure are obtained when the non-rotating head is in the current position; The initial holding differential pressure of the non-operating rotary head when it is not disturbed by the pressure of the common oil circuit is calculated based on the pressure of the first working chamber and the pressure of the second working chamber. The initial holding differential pressure is latched as the reference holding differential pressure, and the reference holding differential pressure is used as the target value for differential pressure compensation during the current tool change action performed by the rotating head.

6. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 5, characterized in that, Differential pressure compensation for the non-operating rotary head includes: During the period when the non-operating rotary head is in the hydraulically isolated state, the current holding differential pressure of the non-operating rotary head is acquired; The compensation deviation is determined based on the difference between the current holding differential pressure and the reference holding differential pressure; Based on the direction of the compensation deviation, a compensation working chamber is determined in the first and second working chambers of the non-operating rotary head; Perform flow-limited oil replenishment or pressure-limited oil unloading on the compensation working chamber to restore the current holding differential pressure toward the reference holding differential pressure; When the current differential pressure is within the allowable range of the position, stop performing the flow-limiting oil replenishment or the pressure-limiting oil unloading on the compensation working chamber.

7. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 1, characterized in that, Releasing the hydraulic isolation state of the non-operating rotating head includes: After the rotating head completes the current tool change action, the isolation side pressure of the control oil circuit corresponding to the non-rotating head and the main oil circuit pressure of the common oil circuit are obtained. Calculate the differential pressure based on the isolation side pressure and the main oil circuit pressure; When the access differential pressure is higher than the preset access differential pressure threshold, the control oil circuit corresponding to the non-operating rotary head and the common oil circuit are pressure transitioned through throttling or pulse connection. When the access differential pressure decreases to no higher than the preset access differential pressure threshold, the hydraulic isolation state of the non-operating rotating head is released.

8. The differential pressure positioning method for the non-operating side of the dual rotating head of the tool magazine according to claim 1, characterized in that, When the non-operating rotating head does not meet the preset position-keeping condition, the non-operating rotating head is interlocked for protection, and the interlocking protection includes: During the differential pressure compensation process for the non-operating rotary head, the number of compensations or the duration of compensation are recorded. When the number of compensations reaches the preset number of compensations or the compensation duration reaches the preset compensation time and the non-operating rotating head still does not meet the preset position-keeping condition, the hydraulic isolation state of the non-operating rotating head is maintained. After maintaining the hydraulic isolation state of the non-operating rotary head, the execution of the next tool change action corresponding to the tool change command of the tool magazine is prohibited; After prohibiting the next tool change action from being executed, a protection signal corresponding to the differential pressure position maintenance abnormality of the non-operating rotary head is output.

9. A differential pressure position-holding system for the non-operating side of a dual-rotating head tool magazine, characterized in that, The system includes: The tool change timing recognition module determines the active rotary head that performs the current tool change action and the non-active rotary head that maintains the current position among the two rotary heads based on the tool magazine tool change command and the timing of the tool change action. The non-operating side isolation module hydraulically isolates the non-operating rotary head during the current tool changing operation of the operating rotary head, thus isolating the non-operating rotary head from pressure disturbances in the common oil circuit. The differential pressure detection module acquires the differential pressure of the non-operating rotating head in the hydraulic isolation state, and determines whether the non-operating rotating head meets the preset position holding conditions based on the differential pressure. The differential pressure position keeping compensation module compensates for the differential pressure of the non-operating rotating head when the preset position keeping conditions are not met, so that the non-operating rotating head remains in its current position. The isolation state release module releases the hydraulic isolation state of the non-moving rotating head after the rotating head completes the current tool change action.

10. A differential pressure position-holding device for the non-operating side of a dual-rotating head of a tool magazine, characterized in that, The differential pressure holding device on the non-operating side of the dual rotating head of the tool magazine is used to implement the differential pressure holding method on the non-operating side of the dual rotating head of the tool magazine as described in any one of claims 1-8.

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