Mould unlocking and locking control method and system

Abstract

The invention discloses a mold unlocking and locking control method and system. The method comprises the following steps that a first relational expression between the theoretical stroke of a middle plate and a mechanism movement included angle and a second relational expression between the theoretical stroke of an oil cylinder and the mechanism movement included angle are deduced; the actual stroke of the middle plate and the actual stroke of the oil cylinder are monitored in the mold unlocking and locking process; calculating a correction value of a mechanism motion included angle corresponding to a difference value between a theoretical stroke and an actual stroke of the middle plate through a first relational expression; and the corrected value obtained through calculation is substituted into the second relational expression to obtain the corrected value of the oil cylinder stroke through calculation, and correction is conducted. The system is used for implementing the method. The method has the beneficial effects that the stroke of the oil cylinder and the stroke of the middle plate are calculated by adopting the relational expression under the same mechanism motion included angle parameter, so that in the actual mold unlocking and locking control process, the stable and accurate control of the mold unlocking and locking process can be realized only by calculating the correction value of the corresponding mechanism motion included angle according to the deviation; and the mold locking efficiency can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of die-casting machines, and in particular to a die opening and locking control method and system. Background Art

[0002] The die-casting machine is a kind of equipment used to manufacture metal parts, which has been widely used in various fields of industry. Among them, the die opening and locking device occupies an important position in the die-casting machine. It directly determines the precision of the metallographic structure and the good mechanical properties of the parts, and has a great impact on the manufacturing cost and production efficiency of the die-casting machine. At present, traditional die-casting machines at home and abroad mostly use hydraulic mechanical die opening and locking mechanisms, that is, the oil pump sucks oil from the oil tank, and then sends the hydraulic oil into the die opening and locking cylinder through the oil valve. The oil pressure is used to push the cylinder piston rod, and the generated power is amplified by the machine hinge assembly to realize the movement of the die opening and locking of the middle plate.

[0003] In order to improve the product quality and work efficiency of die-casting machines, the position of the middle plate connected to the piston rod needs to be accurately positioned during the opening and locking of the mold. However, there are different stages of speed and acceleration in the opening and locking of the mold. Due to the sudden changes in pressure and flow provided by the oil pump and the inertia of the mechanical equipment, the opening and locking of the mold will cause large shocks and vibrations, making it impossible to accurately position the opening and locking of the middle plate, resulting in unstable movement of the middle plate and vibration of the machine body, which will affect the accuracy of parts processing and the service life of the die-casting machine. Summary of the invention

[0004] One of the purposes of the present application is to provide a mold opening and locking control method that can solve at least one of the defects in the above-mentioned background technology.

[0005] Another object of the present application is to provide a mold opening and locking control system that can solve at least one of the defects in the above-mentioned background technology.

[0006] In order to achieve at least one of the above purposes, the technical solution adopted in the present application is: a mold opening and locking control method, comprising the following steps: S100: Based on the structural dimensions of the clamping mechanism and the positional relationship between the opening and closing of the mold, the theoretical stroke S of the middle plate is derived. m The relationship between the angle of the mechanism movement and the theoretical stroke S of the cylinder is o The relationship between the angle of the mechanism movement and the second equation; S200: The actual stroke S of the center plate and the cylinder during the mold opening and clamping process m ´ and S o ´Monitoring; if the actual travel S m ´ and theoretical travel S m The difference ΔS m If the mold opening and locking accuracy is within the set threshold range, it is determined that the mold opening and locking accuracy meets the requirements, otherwise, step S300 is performed; S300: Calculate the difference ΔS by using equation 1 m The corresponding correction value of the mechanism motion angle; the calculated correction value is substituted into the relationship 2 to calculate the correction value of the cylinder stroke and make corrections.

[0007] Preferably, the mold locking mechanism includes a front connecting rod and a rear connecting rod. In step S100, the rotation angle α of the rear connecting rod during the mold opening and locking process is used as the mechanism movement angle in relational expressions 1 and 2.

[0008] Preferably, the length of the front connecting rod is L2, the length of the rear connecting rod is L1, and the angle between the straight line formed by the front connecting rod and the rear connecting rod when they are straightened in the mold-locking state and the horizontal direction is θ; then the specific expression of the relational expression 1 is: .

[0009] Preferably, the horizontal distance from the middle plate to the hinge point of the rear connecting rod and the tail plate in the clamped state is S m1 The horizontal distance from the middle plate to the hinge point of the rear connecting rod and the tail plate in the mold opening state is S m2 , then the theoretical travel of the middle plate is S m = S m2 -S m1 ; Among them, the horizontal distance S m1 and S m2 The specific calculation formula is: S m1 =(L1+L2)cosθ; .

[0010] Preferably, the clamping mechanism further comprises a small connecting rod respectively hinged to the piston rod of the oil cylinder and the rear connecting rod, the length of the small connecting rod is L4, the distance between the hinge point of the rear connecting rod and the small connecting rod and the hinge point of the rear connecting rod and the tail plate is L5, and the angle between the connecting line from the hinge point of the rear connecting rod and the tail plate to the hinge point of the rear connecting rod and the small connecting rod and the hinge point of the rear connecting rod and the front connecting rod is γ; then the specific expression of the relationship formula 2 is: ; Among them, E d It indicates the vertical distance from the hinge point of the small connecting rod and the cylinder piston rod to the hinge point of the rear connecting rod and the tail plate.

[0011] Preferably, in the clamped state, the horizontal distance from the hinge point between the small connecting rod and the cylinder piston rod to the hinge point between the middle plate and the rear connecting rod is S o1 ; In the mold opening state, the horizontal distance from the hinge point of the small connecting rod and the cylinder piston rod to the hinge point of the middle plate and the rear connecting rod is S o2 ; then the theoretical stroke of the cylinder So = S o1 + S o2; Among them, the horizontal distance S o1 and S o2 The specific calculation formula is: ; .

[0012] Preferably, in step S200, the threshold value is set in the range of 0.1‰ to 0.5‰ of the theoretical stroke.

[0013] A mold opening and locking control system is used to implement the above-mentioned mold opening and locking control method, including a control module and a detection module; the control module is suitable for storing a relationship for calculating the theoretical stroke of the middle plate and the cylinder; the detection module monitors the stroke of the middle plate and the cylinder in the mold opening and locking process in real time and feeds back to the control module, and then the control module calculates the correction value of the cylinder stroke according to the monitoring result of the detection module and outputs a corresponding correction signal.

[0014] Preferably, the control module includes a display terminal and a second controller, the display terminal is used to input the target parameters required for the mold opening and locking process, and the display terminal is equipped with a first controller for storing and calculating the relationship between the center plate and the theoretical stroke of the cylinder; the second controller is used to receive the data sent by the detection module and feed it back to the first controller, and then the first controller feeds back the calculated correction value to the second controller, so that the second controller outputs corresponding correction signals to the servo driver that drives the cylinder to move and the mold opening and locking oil valve.

[0015] Preferably, the detection module includes a displacement sensor and an electronic ruler for opening and locking molds; the displacement sensor is installed on the middle plate to monitor the position of the middle plate, and the electronic ruler for opening and locking molds is installed on the crosshead fixed on the cylinder piston rod in the clamping mechanism to monitor the position of the cylinder piston rod.

[0016] Compared with the prior art, the beneficial effects of this application are: The cylinder stroke and the middle plate stroke are calculated using the relationship under the same mechanism motion angle α parameter. Therefore, in the actual mold opening and locking control process, it is only necessary to calculate the corresponding correction value of the mechanism motion angle α according to the deviation to achieve smooth and precise control of the mold opening and locking process, thereby effectively improving the mold locking efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the workflow of the mold opening and locking control method in this application.

[0018] Figure 2 This is a simplified structural diagram of the mold locking mechanism in this application when performing mold opening and locking movements.

[0019] Figure 3 It is a structural schematic diagram of the mold opening and locking control system in this application.

[0020] In the figure: middle plate 1, clamping mechanism 2, oil cylinder 3, mold opening and clamping oil valve 31, oil pump motor 32, servo driver 33, display terminal 41, first controller 42, second controller 43, displacement sensor 44, mold opening and clamping electronic ruler 45. DETAILED DESCRIPTION

[0021] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0022] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present application.

[0023] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0024] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0027] One aspect of the present application provides a method for controlling a mold opening and locking, such as Figure 1 As shown, one of the preferred embodiments includes the following steps: S100: Based on the structural dimensions of the clamping mechanism 2 and the positional relationship between the opening and closing of the mold, the theoretical stroke S of the middle plate 1 is derived. m The relationship between the angle of the mechanism movement and the theoretical stroke S of the cylinder 3 is: o The second relationship between the angle of movement of the mechanism.

[0028] S200: The actual stroke S of the center plate 1 and the cylinder 3 during the mold opening and clamping process m ´ and S o ´Monitoring; if the actual travel S m ´ and theoretical travel S m The difference ΔS m If it is within the set threshold range, it is determined that the mold opening and locking accuracy meets the requirements, otherwise, step S300 is performed.

[0029] S300: Calculate the difference ΔS by using equation 1 m The corresponding correction value of the mechanism motion angle; the calculated correction value is substituted into the relationship 2 to calculate the correction value of the cylinder 3 stroke and make corrections.

[0030] It should be known that the mold opening and locking compensation of the clamping mechanism 2 is generally carried out in the clamping state, that is, by comparing whether the current clamping position meets the theoretical clamping position, so as to ensure that the mold has sufficient clamping pressure. The traditional mold opening and locking control generally adopts the target curve method, that is, the displacement target curve of the middle plate 1 is set at the beginning of the mold opening and locking. Then, the actual position of the middle plate 1 is detected during the process of mold opening and locking, and the oil cylinder 3 is controlled to make corresponding compensation corrections according to the comparison results between the current actual position and the target curve position when the middle plate 1 is locked. At this time, the compensation signal of the oil cylinder 3 has only the forward direction. During the compensation process of the oil cylinder 3, the actual position of the middle plate 1 after compensation is compared with the target position in real time until the difference between the two is within the set error range. It can be determined that it meets the clamping accuracy. From the above analysis process, it can be seen that the traditional mold opening and locking control method is a progressive compensation control method based on the distance difference, and its compensation correction duration is relatively long, which leads to a decrease in the efficiency of the clamping. In more popular terms, when the traditional mold opening and locking control method performs stroke correction on the oil cylinder 3, the oil cylinder 3 does not have a clear correction value, but only a correction direction, that is, the oil cylinder 3 only performs acceleration and deceleration processes when performing stroke correction.

[0031] In this embodiment, the theoretical travel S of the middle plate 1 can be derived from the structural dimensions of the clamping mechanism 2 and the operating position relationship during the mold opening and clamping process. m , the theoretical stroke S m In fact, it is the formula of the target position curve corresponding to the middle plate 1 in the traditional mold opening and locking control method. It can express the theoretical stroke S m There are many relationship equations. In this embodiment, the theoretical stroke S of the oil cylinder 3 is used. o There is a relationship between common parameters to carry out the theoretical travel S m There are many common parameters that can be used to calculate the theoretical stroke of the middle plate 1 and the theoretical stroke of the oil cylinder 3 at the same time. In this embodiment, the mechanism operation angle of the clamping mechanism 2 during the mold opening and clamping process is preferably used. In the process of mold opening and clamping, the actual strokes of the middle plate 1 and the oil cylinder 3 are monitored. If the actual stroke of the middle plate 1 deviates too much from the theoretical stroke, the deviation value of the common parameter in the relationship between the theoretical stroke of the oil cylinder 3 and the middle plate 1 can be calculated based on the deviation value. The deviation value is the premise for the correction of the oil cylinder 3.

[0032] Specifically, after obtaining the difference between the actual stroke and the theoretical stroke of the middle plate 1, the mechanism movement angle corresponding to the actual stroke and the mechanism operation angle corresponding to the theoretical stroke can be subtracted to obtain a correction value of the mechanism movement angle. At this time, the obtained correction value can be substituted into the theoretical stroke calculation formula of the cylinder 3 to obtain the stroke correction value of the cylinder 3, and then the cylinder 3 only needs to perform a fixed value compensation according to the calculated correction value. Compared with the traditional method, the mold opening and locking control method of the present application can effectively improve the stability and accuracy of the mold opening and locking process. At the same time, the mold opening and locking control method of the present application does not require multiple progressive compensations, which makes the correction compensation process faster, thereby effectively improving the mold locking efficiency.

[0033] For ease of understanding, the specific derivation process of the theoretical stroke relationship between the oil cylinder 3 and the middle plate 1 in step S100 may be described in detail below.

[0034] It should be noted that the specific structure and working principle of the clamping mechanism 2 are well known to those skilled in the art, but in order to facilitate the description of the subsequent derivation process, the following can be combined with Figure 2 The schematic diagram of mold opening and locking operation shown briefly describes the structure of the mold locking mechanism 2 and the mold opening and locking process.

[0035] like Figure 2 As shown, the clamping mechanism 2 includes a front connecting rod, a rear connecting rod and a small connecting rod. One end of the rear connecting rod is hinged to the tail plate, and the hinge point is marked as D; one end of the front connecting rod is hinged to the rear connecting rod, and the other end of the front connecting rod is hinged to the middle plate 1; one end of the small connecting rod is hinged to the rear connecting rod, and the other end of the small connecting rod is hinged to the cross head fixedly installed on the piston rod head of the oil cylinder 3.

[0036] In the clamped state, Figure 2 As shown by the solid line, the hinge position of the front link and the rear link is marked as E, the hinge position of the front link and the middle plate 1 is marked as C, the hinge position of the small link and the rear link is marked as B, and the hinge position of the small link and the crosshead is marked as A. In this state, the front link and the rear link can be straightened to form a straight line to form a dead point, that is, the three points D, E and C are collinear.

[0037] In the mold open state, Figure 2 As shown by the middle dotted line, the hinge position of the front link and the rear link is marked as E', the hinge position of the front link and the middle plate 1 is marked as C', the hinge position of the small link and the rear link is marked as B', and the hinge position of the small link and the crosshead is marked as A'.

[0038] It is understandable that during the whole process of mold opening and locking, the hinge points A and A', as well as the hinge points C and C', move horizontally. Since the position of the tail plate remains unchanged by default during the whole process of mold opening and locking, the theoretical stroke calculation of the middle plate 1 and the oil cylinder 3 during the process of mold opening and locking is based on the hinge point D of the tail plate and the rear connecting rod.

[0039] 1. Theoretical stroke S of middle plate 1 m The derivation process.

[0040] like Figure 2 As shown, the theoretical travel S of the middle plate 1 during the mold opening and clamping process m The horizontal distance from the middle plate 1 to the tail plate in the mold-locked state minus the horizontal distance from the middle plate 1 to the tail plate in the mold-opened state can be obtained. The horizontal distance from the middle plate 1 to the tail plate in the mold-locked state is the horizontal distance S from the hinge point C to the hinge point D. m1 The horizontal distance from the middle plate 1 to the tail plate in the mold opening state is the horizontal distance S from the hinge point C' to the hinge point D m2 ; then S m = S m1 -S m2 .

[0041] Depend on Figure 2 As shown, the horizontal distance S m1 That is, the length of the projection of the straight line CD in the horizontal direction. In this case, we only need to use the straight line CD as the hypotenuse and use the right angle side calculation formula of the right triangle to get the horizontal distance S. m1 The value of .

[0042] Specifically, the angle between the straight line formed by the front and rear connecting rods in the clamped state and the horizontal direction can be θ, that is, the angle between the straight line CD and the horizontal direction; the length of the front connecting rod is L2, and the length of the rear connecting rod is L1. Then the horizontal distance S m1 The calculation formula is: m1 =(L1+L2)cosθ.

[0043] For the horizontal distance S m2 ,like Figure 2 As shown, it can be obtained by subtracting the length X1 of the projection of the straight line C'E' in the horizontal direction from the length X2 of the projection of the straight line DE' in the horizontal direction, that is, S m2 =X1-X2.

[0044] Depend on Figure 2It can be seen that the rotation angle α of the rear connecting rod during the mold opening and locking process, that is, the angle between the straight line DE and the straight line DE' is α; then the angle between the straight line DE' and the vertical direction is α+θ-90°, and then the length X2 of the projection of the straight line DE' in the horizontal direction is: X2=L1sin(α+θ-90°)=- L1cos(α+θ).

[0045] The length X1 of the projection of the straight line C´E´ in the horizontal direction can be used as one of the right-angled sides of the right triangle. The length X3 obtained by subtracting the length of the projection of the straight line DE´ in the vertical direction from the length of the projection of the straight line DC in the vertical direction is used as the other right-angled side, and the straight line C´E´ is used as the hypotenuse of the right triangle. Then, according to the Pythagorean theorem, X1 can be calculated. 2 =L2 2 -X3 2 .

[0046] Among them, the length of the projection of the straight line DE' in the vertical direction is: L1cos(α+θ-90°)= L1sin(α+θ); the length of the projection of the straight line DC in the vertical direction is: (L1+ L2)sinθ; then the length X3= L1sin(α+θ)- (L1+ L2)sinθ. Then the calculation formula of the length X1 is: .

[0047] Then S m2 =X1- X2 is calculated as: .

[0048] Finally, according to the horizontal distance S m1 and S m2 The expression of the middle plate 1 theoretical stroke S can be obtained m The specific expression of the relationship 1 is: .

[0049] 2. Theoretical stroke S of cylinder 3 o The derivation process.

[0050] It should be noted that the theoretical stroke of the oil cylinder 3 is the theoretical stroke of the crosshead fixedly mounted on the piston rod head. Figure 2 As shown, the theoretical stroke S of the oil cylinder 3 during the mold opening and locking process o It can be obtained by adding the horizontal distance from the crosshead of the oil cylinder 3 to the tail plate in the mold-locking state to the horizontal distance from the crosshead of the oil cylinder 3 to the tail plate in the mold-opening state. Among them, the horizontal distance from the crosshead of the oil cylinder 3 to the tail plate in the mold-locking state can be obtained by the horizontal distance S from the hinge point A to the hinge point D. o1The horizontal distance from the crosshead of the oil cylinder 3 to the tail plate in the mold opening state is the horizontal distance S from the hinge point A' to the hinge point D. o2 The theoretical formation S of cylinder 3 is o = S o1 +S o2 .

[0051] like Figure 2 As shown, for the horizontal distance S o1 It can be obtained by subtracting the length of the projection of line AB from the length of the projection of line BD in the horizontal direction. Among them, the length of line AB is the length of the small link, which can be set to L4; the length of line BD is the distance from the hinge point of the rear link and the small link to the hinge point of the rear link and the tail plate, which can be set to L5; the angle between the hinge point of the rear link and the tail plate to the hinge point of the rear link and the small link and the hinge point of the rear link and the front link can also be set to γ, that is, the angle between line BD and line DE.

[0052] Among them, the length of the projection of straight line BD in the horizontal direction is: L5sin(90°-γ-θ)= L5cos(γ+θ).

[0053] The length of the projection of the straight line AB in the horizontal direction can be measured by the vertical distance E from the hinge point A between the small connecting rod and the piston rod of the oil cylinder 3 to the hinge point D between the rear connecting rod and the tail plate. d The result is calculated by subtracting the vertical length of the projection of line BD as the other right-angled side and using line AB as the hypotenuse.

[0054] The length of the projection of straight line BD in the vertical direction is: L5cos(90°-γ-θ)= L5sin(γ+θ).

[0055] Then the square of the horizontal length of the projection of line AB is: L4 2 -[E d - L5sin(γ+θ)] 2 .

[0056] Then the horizontal distance S o1 The calculation formula is: .

[0057] like Figure 2 As shown, for the horizontal distance S o2 It can be obtained by adding the length of the projection of the straight line B´D in the horizontal direction to the length of the projection of the straight line A´B´ in the horizontal direction.

[0058] Among them, the length of the projection of straight line B´D in the horizontal direction is: L5sin(γ+θ+α-90°)= -L5cos(γ+θ+α).

[0059] The horizontal length of the projection of line A´B´ can be calculated by subtracting the vertical distance E from the vertical length of the projection of line B´D. d The calculation is done for a right triangle with the line A´B´ as the other right-angled side and the hypotenuse as the right-angled side.

[0060] The length of the projection of straight line B´D in the vertical direction is: L5cos(γ+θ+α-90°)= L5sin(γ+θ+α).

[0061] Then the square of the horizontal length of the projection of line A´B´ is: L4 2 -[ L5sin(γ+θ+α)-E d ] 2 .

[0062] Then the horizontal distance S o2 The calculation formula is: .

[0063] Finally, according to the horizontal distance S o1 and S o2 The expression of the theoretical stroke S of cylinder 3 can be obtained. o The specific expression of the second relation is: .

[0064] It should be known that, from the specific expressions of the above-mentioned Relationship 1 and Relationship 2, L1, L2, L4 and L5 are the structural dimensions of the specific parts of the clamping mechanism 2, which can be regarded as constant parameters. The value of the angle γ does not change during the mold opening and locking process, and only depends on the connection position of the small connecting rod and the rear connecting rod, so the angle γ can also be regarded as a constant parameter. Then the variable parameters in Relationship 1 and Relationship 2 are angles α and θ, and these two angles can be defined as the mechanism operation angles of the clamping mechanism 2 during the mold opening and locking process. Since the position reference of angle α during the mold opening and locking process is itself, it has a higher calculation accuracy than angle θ; therefore, in this embodiment, angle α is preferably used for the mechanism operation angle for correction and compensation. Of course, the two angles α and θ can also be used as the mechanism operation angles for correction and compensation at the same time.

[0065] In this embodiment, the specific value range of the threshold value set in step S200 can be based on the actual needs of those skilled in the art. Generally speaking, the mold clamping accuracy of the clamping mechanism 2 is required to be a few tenths of a millimeter; and the mold opening and closing stroke of the middle plate 1 during the mold opening and clamping process is generally in the meter level. Therefore, in this embodiment, the threshold range set for error judgment of the middle plate 1 can be preferably 0.1‰~0.5‰ of the theoretical stroke of the middle plate 1. For ease of understanding, a specific example can be taken. Assuming that the theoretical stroke of the middle plate 1 is 1m, the threshold range for error judgment can be set to 0.1mm~0.5mm, and the preferred threshold is 0.1mm; then when the difference between the actual stroke and the theoretical stroke of the middle plate 1 is greater than 0.1mm, the middle plate 1 can be stroke compensated.

[0066] Another aspect of the present application provides a mold opening and locking control system for implementing the above-mentioned mold opening and locking control method. Figure 3 As shown, one of the preferred embodiments includes a control module and a detection module. The relationship derived from the theoretical stroke of the middle plate 1 and the theoretical stroke of the cylinder 3 in the foregoing content can be stored in the control module. The control module can be connected to the detection module for communication, and the control module can also be connected to the cylinder 3 for drive control. The detection module can respectively monitor the stroke of the middle plate 1 and the cylinder 3 in the process of opening and locking the mold in real time and feed it back to the control module, and then the control module can substitute the monitoring result sent by the detection module into the existing relationship to calculate the correction value of the stroke of the cylinder 3 based on the current position of the middle plate 1 and output the corresponding correction signal to the drive module of the cylinder 3.

[0067] It should be known that the oil cylinder 3 is generally driven and controlled by an oil pump motor 32, and the oil pump motor 32 needs to be servo-controlled according to the working condition requirements, so a servo driver 33 needs to be installed on the oil pump motor 32. The control module can be connected to the servo driver 33 for communication, so that the correction signal output by the control module can be sent to the servo driver 33, and then the servo driver 33 can pump a set amount of oil into the oil cylinder 3 to drive the oil cylinder 3 to move a determined distance for stroke correction.

[0068] It should be noted that the control module obtains the stroke increase of the oil cylinder 3 after calculating through the relationship, which is a length value; but the oil pump motor 32 delivers the amount of oil, so after obtaining the stroke increase of the oil cylinder 3, the control module can infer the amount of oil that needs to be replenished corresponding to the stroke increase based on the model of the oil cylinder 3, that is, the rodless cavity size of the oil cylinder 3. The amount of oil is then converted into the servo control amount of the servo driver 33 according to the rated flow of the oil pump motor 32, and the servo control amount is the correction signal output by the control module. Generally speaking, there are many ways for the control module to control the servo driver 33. In this embodiment, PID control is preferably used. The specific implementation of PID control is a well-known technology for those skilled in the art, so it will not be elaborated in detail here.

[0069] At the same time, the oil pump motor 32 supplies oil to the oil cylinder 3 through the pipeline equipped with the mold opening and locking oil valve 31; then during the stroke correction process of the oil cylinder 3, when the oil supply of the oil pump motor 32 changes, the opening of the mold opening and locking oil valve 31 also needs to be adaptively changed, thereby ensuring that the opening of the mold opening and locking oil valve 31 can match the oil supply of the oil pump motor 32, thereby ensuring that the oil delivered to the oil cylinder 3 by the oil pump motor 32 can be delivered in a timely and sufficient manner, ensuring that the correction process is carried out quickly to improve the mold locking efficiency. Therefore, in this embodiment, the mold opening and locking oil valve 31 can adopt an electromagnetic valve, and the specific structure and working principle are well known to those skilled in the art, so they are not elaborated in detail here. The control end of the mold opening and locking oil valve 31 is connected to the control module by signal, so that when the control module sends a correction signal to the servo driver 33, it can also send a corresponding correction signal to the mold opening and locking oil valve 31 for opening control.

[0070] In this embodiment, there are many specific structures of the control module that can realize the above functions. For the sake of easy understanding, one of the structures will be used for detailed description below. Figure 3 As shown, the control module includes a display terminal 41 and a second controller 43. The display terminal 41 can facilitate the user to input the required target parameters during the mold opening and locking process, and can also be conveniently used to observe the state parameters of the die-casting machine during the mold opening and locking process. In order to facilitate the storage of the relationship between the theoretical stroke of the center plate 1 and the cylinder 3, a first controller 42 can be built into the display terminal 41 to store the above relationship. The second controller 43 is communicatively connected to the first controller 42 to receive the data sent by the detection module and feed it back to the first controller 42, and then the first controller 42 feeds back the calculated correction value to the second controller 43, so that the second controller 43 outputs corresponding correction signals to the servo driver 33 that drives the cylinder 3 to act and the mold opening and locking oil valve 31.

[0071] In this embodiment, there are multiple specific structures of the detection module that can realize the above functions. For the sake of easy understanding, the following will be described in detail using one of the structures. Figure 3 As shown, the detection module includes a displacement sensor 44 and an electronic ruler 45 for opening and locking the mold. The specific structure and working principle of the displacement sensor 44 are well-known technologies for those skilled in the art, so they will not be elaborated in detail here; the displacement sensor 44 is installed on the middle plate 1 to monitor the position of the middle plate 1. The specific structure and working principle of the electronic ruler 45 for opening and locking the mold are also well-known to those skilled in the art, so they will not be elaborated in detail here; the electronic ruler 45 for opening and locking the mold is installed on the crosshead fixed on the piston rod of the oil cylinder 3 in the mold locking mechanism 2, so as to monitor the position of the piston rod of the oil cylinder 3.

[0072] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A mold opening and locking control method, characterized in that: The steps include: S100: Based on the structural dimensions of the clamping mechanism and the positional relationship between the opening and closing of the mold, the theoretical stroke S of the middle plate is derived. m The relationship between the angle of the mechanism movement and the theoretical stroke S of the cylinder is o The relationship between the angle of the mechanism movement and the second equation; S200: The actual stroke S of the center plate and the cylinder during the mold opening and clamping process m ´ and S o ´Monitoring; if the actual travel S m ´ and theoretical travel S m The difference ΔS m If the mold opening and locking accuracy is within the set threshold range, it is determined that the mold opening and locking accuracy meets the requirements, otherwise, step S300 is performed; S300: Calculate the difference ΔS by using equation 1 m The correction value of the corresponding mechanism motion angle; the calculated correction value is substituted into the relational expression 2 to calculate the correction value of the cylinder stroke and make correction; The mold locking mechanism includes a front connecting rod and a rear connecting rod. In step S100, the rotation angle α of the rear connecting rod during the mold opening and locking process is used as the mechanism motion angle in relational equations 1 and 2; The length of the front connecting rod is L2, the length of the rear connecting rod is L1, and the angle between the straight line formed by the front connecting rod and the rear connecting rod when the mold is clamped and the horizontal direction is θ; then the specific expression of relational formula 1 is: ； The clamping mechanism also includes a small connecting rod hinged to the piston rod of the oil cylinder and the rear connecting rod respectively. The length of the small connecting rod is L4. The distance from the hinge point of the rear connecting rod and the small connecting rod to the hinge point of the rear connecting rod and the tail plate is L5. The angle between the hinge point of the rear connecting rod and the tail plate and the hinge point of the rear connecting rod and the small connecting rod and the hinge point of the rear connecting rod and the front connecting rod is γ. Then the specific expression of the relationship formula 2 is: ； Among them, E d It indicates the vertical distance from the hinge point of the small connecting rod and the cylinder piston rod to the hinge point of the rear connecting rod and the tail plate.

2. The mold opening and locking control method according to claim 1, characterized in that: The horizontal distance from the middle plate to the hinge point of the rear connecting rod and the tail plate in the clamped state is S m1 The horizontal distance from the middle plate to the hinge point of the rear connecting rod and the tail plate in the mold opening state is S m2 , then the theoretical travel of the middle plate is S m = S m2 -S m1 ; Among them, the horizontal distance S m1 and S m2 The specific calculation formula is: ； 。 3. The mold opening and locking control method according to claim 1, characterized in that: In the clamped state, the horizontal distance from the hinge point between the small connecting rod and the cylinder piston rod to the hinge point between the middle plate and the rear connecting rod is S o1 ; In the mold opening state, the horizontal distance from the hinge point of the small connecting rod and the cylinder piston rod to the hinge point of the middle plate and the rear connecting rod is S o2 ; then the theoretical stroke of the cylinder So = S o1 + S o2 ; Among them, the horizontal distance S o1 and S o2 The specific calculation formula is: ； 。 4. The mold opening and locking control method according to any one of claims 1 to 3, characterized in that: In step S200, the threshold value is set in the range of 0.1‰ to 0.5‰ of the theoretical stroke.

5. A mold opening and locking control system, used to implement the mold opening and locking control method according to any one of claims 1 to 4, characterized in that: include: Control module; The control module is suitable for storing a relational expression for calculating the theoretical stroke of the middle plate and the oil cylinder; as well as Detection module; The detection module monitors the stroke of the middle plate and the cylinder in the process of opening and locking the mold in real time and feeds back to the control module. Then the control module calculates the correction value of the cylinder stroke according to the monitoring result of the detection module and outputs a corresponding correction signal.

6. The mold opening and locking control system according to claim 5, characterized in that: The control module comprises: Display terminal; the display terminal is used to input target parameters required for the mold opening and locking process, and the display terminal is built with a first controller for storing and calculating the relationship between the middle plate and the theoretical stroke of the oil cylinder; and The second controller is used to receive the data sent by the detection module and feed it back to the first controller, and then the first controller feeds back the calculated correction value to the second controller, so that the second controller outputs corresponding correction signals to the servo driver that drives the cylinder to move and the mold opening and locking oil valve.

7. The mold opening and locking control system according to claim 5, characterized in that: The detection module includes: A displacement sensor; the displacement sensor is mounted on the middle plate to monitor the position of the middle plate; and Electronic ruler for opening and locking molds; the electronic ruler for opening and locking molds is installed on the crosshead fixed on the piston rod of the cylinder in the mold locking mechanism to monitor the position of the piston rod of the cylinder.

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